Effects of smoking on the outcome of implant treatment: a literature review.

Indian J Dent Res. 2007 Oct-Dec;18(4):190-5

Authors: Baig MR, Rajan M

STATEMENT OF PROBLEM: The use of osseointegrated implants as a foundation for the prosthetic replacement of missing teeth has become widespread in the last decade. Owing to the remarkable success of dental implants, there has been growing interest in identifying the factors associated with implant failure. Given the well-documented deleterious effect of smoking on wound healing after tooth extraction and its association with poor quality bone and periodontal disease, a negative effect of tobacco use on implant success is to be expected. PURPOSE: To establish the relationship between smoking and implant-related surgical procedures (i.e, sinus lift procedures, bone grafts and dental implants), including the incidence of complications related to these procedures and the long-term survival and success rates of dental implants among smokers and nonsmokers based on relevant literature.MATERIALS AND METHODS: Relevant clinical studies published in English between 1990 and 2006 were reviewed. The articles were located through Medline and, manually, through the references of peer-reviewed literature. This was supplemented with a hand search of selected dental journals and text books.RESULTS: The majority of the past and current literature implicates smoking as one of the prominent risk factors affecting the success rate of dental implants with only a handful of studies failing to establish a connection. Most of the studies report the failure rate of implants in smokers as being more than twice that in nonsmokers. These findings are difficult to ignore. There is a statistically significant difference between smokers and nonsmokers in the failure rates of dental implants. Smoking also has a strong influence on the complication rates of implants: it causes significantly more marginal bone loss after implant placement, it increases the incidence of peri-implantitis and affects the success rates of bone grafts. The failure rate of implants placed in grafted maxillary sinuses of smokers is again more than twice that seen in nonsmokers.Conclusion: Smokers have higher failure rates and complications following dental implantation and implant-related surgical procedures. The failure rate of implants placed in grafted maxillary sinuses of smokers is more than twice that seen in nonsmokers.

PMID: 17938497 [PubMed - in process]

A method of gauging dental radiographs during treatment planning for dental implants.

J Contemp Dent Pract. 2007;8(6):82-8

Authors: Anil S, Al-Ghamdi HS

AIM: The goal of pre-surgical dental implant treatment planning is to position the optimum number and size of implant fixtures to achieve the best restorative results. The purpose of this article is to describe the use of radiographic imaging software to calibrate and measure anatomical landmarks to overcome inherent distortions associated with dental radiographs. The procedure along with its potential use as an adjunct to radiographic interpretation in routine clinical implant practice is presented. BACKGROUND: Diagnostic imaging is an essential component of implant treatment planning, and a variety of advanced imaging modalities have been recommended to assist the dentist in assessing potential sites for implants. Although technological advances have resulted in new imaging innovations for implant dentistry, dental radiography remains the most widely used tool for determining the quantity and quality of alveolar bone as it is a non-invasive procedure. However, the unreliable magnification factor associated with conventional radiographs remains a major problem when estimating the amount of bone available at the implant site. SUMMARY: This image measurement technique is capable of assessing the bone quantity by measuring the height and width of the alveolar crest for a specified region in a two dimensional plane in any direction related to the visible landmarks in the oral cavity. These measurements can be used by the clinician to select the type of implant and its position. Since there is no additional equipment or cost involved, the technique can be used as an important adjunct in implant practice.

PMID: 17846675 [PubMed - indexed for MEDLINE]

Augmentation in two stages of atrophic alveolar bone prior to dental rehabilitation: a case report.

J Contemp Dent Pract. 2007;8(6):57-63

Authors: Zahrani AA

AIM: The aim of this report is to describe a significantly deficient case of alveolar bone that was managed by alveolar bone augmentation using a technique of distraction osteogensis and onlay bone grafting prior to dental implant placement. BACKGROUND: Injury to the teeth and alveolar ridge of the maxillary anterior region can cause a severe alveolar ridge deficiency resulting in ridge atrophy and maxillary retrognathism. The loss of these teeth and alveolar bone together with fibrotic scar formation can result in adverse changes of the interarch space, occlusal plane, arch relationship, and arch form which complicates rehabilitation and can compromise the esthetic outcome. While implant dentistry has become a new paradigm in oral reconstruction and replacement of missing teeth, ideal implant positioning can be compromised by inadequate alveolar bone in terms of bone height, width, and quality of the bone itself. Correction of osseous deficiencies with ridge augmentation allows ideal implant placement and creates a more natural soft tissue profile which influences crown anatomy and esthetics. REPORT: A 20-year-old female presented with a complaint of poor esthetics resulting from oral injuries incurred in a traffic accident six years previously. In addition to a mandibular parasymphyseal fracture, five maxillary anterior teeth and the most of the alveolar ridge were lost. Clinical examination revealed severe loss of bone in the maxillary anterior region, an absence of a labial sulcus, loss of upper lip support, and a slight over eruption of the mandibular anterior teeth. In preparation for dental implants a distraction osteogenesis surgical procedure was done to lengthen the height of the alveolar ridge. After a three-month healing period, the width of the residual ridge was found to be insufficient for implant placement. To correct this deficiency, a bone graft of a cortiocancellous block was harvested from the chin and fixed to the labial aspect of the ridge. To facilitate revascularization, small perforations were made in the cortical bone of the alveolar ridge at the recipient site before cancellous bone retrieved from the donor site was gently placed between the bone block and the ridge. The patient was then appropriately medicated and healing was uneventful. After three months, the width of the residual ridge was assessed to be adequate for endosseous implants. SUMMARY: The clinical result reported here has shown several procedures may be necessary for the rehabilitation of a trauma patient. Distraction osteogenesis per se may not always satisfactorily improve the anatomical alveolar anatomy but it has advantages over other methods of augmentation. It can improve the height and also expand the soft tissue for further bone grafting. Augmentation of the alveolar bone with an onlay bone graft often provides the desired gain of bone, allows for the ideal placement of dental implants, and improves any discrepancy between the upper and lower arches.

PMID: 17846672 [PubMed - indexed for MEDLINE]

Pre-operative drilling simulation method for dental implant treatment.

Bull Tokyo Dent Coll. 2007 Feb;48(1):27-35

Authors: Arataki T, Furuya Y, Ito T, Miyashita Y, Shimamura I, Yajima Y

The position, depth and direction of implant placement are often planned based on evaluation of radiographs and study casts. Insertion planned in such a manner may not be adequate for precise and safe surgery in some cases due to inadequate working clearance in the oral cavity. In order to obtain high initial stability and ensure osseointegration at the implant-bone interface, careful and precise drilling must be performed at the implant placement site. Therefore, we propose the necessity of evaluating the operability of implant treatment-devices prior to surgery. The amount of handling space needed during implant placement surgery was determined. The results showed that for implants with a length of 7-18 mm, a vertical distance of as much as 50-60 mm was required, depending on the implant platform. These results suggest the necessity of pre-operative drilling simulation in each individual. Handling space was measured with angled heads and probes fabricated on a trial basis for pre-surgical drilling simulation in the oral cavity. We believe that these instruments may be clinically useful in estimating the amount of handling space required prior to surgery and ensuring precise implant placement. Evaluation of the intra-oral environment for handling of treatment devices should be included in the pre-surgical intra-oral evaluation of dental implant cases to avoid changes in treatment planning due to intra-oral interference during the course of surgery.

PMID: 17721064 [PubMed - indexed for MEDLINE]

Dentin dysplasia type I: a challenge for treatment with dental implants.

Head Face Med. 2007;3:31

Authors: Depprich RA, Ommerborn MA, Handschel JG, Naujoks CD, Meyer U, Kübler NR

ABSTRACT: BACKGROUND: Dentin dysplasia type I is characterized by a defect of dentin development with clinical normal appearance of the permanent teeth but no or only rudimentary root formation. Early loss of all teeth and concomitant underdevelopment of the jaws are challenging for successful treatment with dental implants. METHODS: A combination of sinus lifting and onlay bone augmentation based on treatment planning using stereolithographic templates was used in a patient with dentin dysplasia type I to rehabilitate the masticatory function. RESULTS: (i) a predisposition for an increased and accelerated bone resorption was observed in our patient, (ii) bone augmentation was successful using a mixture of allogenic graft material with autogenous bone preventing fast bone resorption, (iii) surgical planning, based on stereolithographic models and surgical templates, facilitated the accurate placement of dental implants. CONCLUSION: Bony augmentation and elaborate treatment planning is helpful for oral rehabilitation of patients with dentin dysplasia type I.

PMID: 17714586 [PubMed - in process]

Infections in implantology: from prophylaxis to treatment.

Med Oral Patol Oral Cir Bucal. 2007 Aug;12(4):E323-30

Authors: Bowen Antolín A, Pascua García MT, Nasimi A

Since the introduction of osseointegrated implant treatment, odontology, and in particular the area of prosthodontic replacement of lost teeth, has evolved in an unimaginable way, to the extent that the age-old idea of "restitutio ad integrum" has almost become possible. Implant treatment has a high success rate that has been rated as high as 95 to 99%, according to different casuists, but there is another group of cases in which implants fail, and in fact it is hard to know the causes of such failures. The microbiological component plays an important role in encouraging and facilitating implant infection during implant placement, and also later when the implant is in function in the mouth, which is a septic medium. In this paper we will study infections in implantology, classified according to the treatment phase: Infection prior to the implant; Peri-surgical infection; Severe post-surgical infection; Peri-implant disease.

PMID: 17664920 [PubMed - indexed for MEDLINE]

Recurrent central giant cell granuloma in the mandible: surgical treatment and dental implant restoration.

Med Oral Patol Oral Cir Bucal. 2007 May;12(3):E229-32

Authors: Infante Cossío P, Martínez de Fuentes R, Carranza Carranza A, Torres Lagares D, Gutiérrez Pérez JL

Central giant cell granuloma is an uncommon benign intraosseus lesion of jaws. Traditional treatment has been local curettage, although aggressive sub-types have a high tendency to recur. This patient report describes a recurrent central giant cell granuloma involving the body of the mandible in a 48-year-old-woman. Initial treatment of lesion consisted of curettage and peripheral ostectomy. When recurrence was detected one year later, an en bloc resection and defect regeneration with a composite bone graft of autogenous bone, xenograft, and autologous platelet-rich plasma was carried out. Adequate new bone formation was observed during follow-up of 24 months. Two dental implants were placed, and implant-supported prosthesis was constructed, providing a satisfactory dental restoration.

PMID: 17468721 [PubMed - indexed for MEDLINE]

Rehabilitation of severely resorbed maxillae with zygomatic implants: an update.

Med Oral Patol Oral Cir Bucal. 2007 May;12(3):E216-20

Authors: Galán Gil S, Peñarrocha Diago M, Balaguer Martínez J, Marti Bowen E

Studies highlight the zygomatic bone as a suitable anatomical structure for implant placements since they cross four corticals. Zygomatic implants were described by Branemark in 1988, since then zygomatic implants are indicated in maxillae with atrophy of the posterior area. They have been used in systemic diseases associated with bone loss in this area, and in patients who have suffered radical surgery for maxillofacial tumors. Computed tomography is recommended before placement in order to discount any pathology of the maxillary sinus. The surgical technique has been slightly modified since its description with procedures such as the sinus slot technique. The success rate obtained by different authors varies between 82% and 100%, indicating this technique as a valid treatment option. The objective of this study was to revise the literature with the aim of updating the subject.

PMID: 17468718 [PubMed - indexed for MEDLINE]

Histological comparison of bone to implant contact in two types of dental implant surfaces: a single case study.

J Contemp Dent Pract. 2007;8(3):29-36

Authors: Shibli JA, Feres M, de Figueiredo LC, Iezzi G, Piattelli A

AIM: The purpose of this single case study was to evaluate the influence of different implant surfaces on human bone and osseointegration. METHODS AND MATERIALS: A 47-year-old partially edentulous woman received two experimental implants along with conventional implant therapy. Experimental implants placed in the mandibular ramus consisted of machined and anodized surfaces, respectively. After three months of healing, the experimental implants were removed and prepared for ground sectioning and histological analysis. RESULTS: The data demonstrate anodized implant surfaces present a higher percentage of osseointegration when compared to a machined surface in cortical human bone after a healing period of three months. CONCLUSION: This single case study suggests an anodized implant surface results in a higher percentage of bone to implant contact when compared to machined surfaced implants when placed in dense bone tissue. However, further investigations should be conducted.

PMID: 17351679 [PubMed - indexed for MEDLINE]

[Evaluation of peri-implant augmentation with collected bone]

Shanghai Kou Qiang Yi Xue. 2006 Oct;15(5):473-7

Authors: Wang KT, Wang JH, Zhao HQ, Zhang D, Wang L, Wei FC

PURPOSE: To determine the amount of bone harvested from dental implant osteotomies with aspeo 12000 bone collector, to characterize the nature of the debris, and to evaluate the histological viability and clinical effect of peri-implant augmentation with immediate implantation of collected bone. METHODS: From May 2004 to Oct 2005, 15 recruited patients without peri-implant imperfections underwent 18 ITI implants installation. During the implant bed preparation, 18 samples of bone were collected using the instrument and an analysis of variance was used to determine if there were statistical differences between female versus male, maxilla versus mandible, anterior versus posterior alveolar bone. After decalcification, the material from each sample was fixed in paraffin wax and stained with haematoxylin and eosin, all sections were examined by optical microscope and the proportion of bone was established histomorphometrically. During the time, 12 defects occurred in 11 patients when 16 dental implants were installed, and all the defects were augmented with collected bone debris simultaneously. RESULTS: About 93% volume of 'wet' bone could be obtained from one dental implant osteotomy, and there were no statistical differences between female and male, maxilla and mandible, anterior and posterior alveolar bone. Histological observation showed that all samples contained bone and coagulum, the mean bone proportion was 94.2%. 3 to 6 months after surgery, the defects were successfully augmented, and during the secondary operation, bone growth was found over the defects. CONCLUSION: The use of bone collectors is a good method for obtaining material to fill small bone imperfections in dental implantation.

PMID: 17348217 [PubMed - in process]

Cone-beam CT (CB Throne) applied to dentomaxillofacial region.

Bull Tokyo Dent Coll. 2006 Aug;47(3):133-41

Authors: Yajima A, Otonari-Yamamoto M, Sano T, Hayakawa Y, Otonari T, Tanabe K, Wakoh M, Mizuta S, Yonezu H, Nakagawa K, Yajima Y

Cone-beam CT (CBCT) systems specifically designed for hard-tissue imaging of the maxillofacial region have recently become commercially available. The newly-developed CBCT system, CB Throne (Hitachi Medical Corp., Tokyo), is characterized by a number of features such as low dose, sub-millimeter spatial resolution, and a small footprint. This system has been clinically applied at Chiba Hospital, Tokyo Dental College, since April 2005. This article reports the characteristics of this system, and its diagnostic power for maxillofacial lesions and the pre-operative planning dental implants.

PMID: 17344621 [PubMed - indexed for MEDLINE]

Reliability of linear distance measurement for dental implant length with standardized periapical radiographs.

Bull Tokyo Dent Coll. 2006 Aug;47(3):105-15

Authors: Wakoh M, Harada T, Otonari T, Otonari-Yamamoto M, Ohkubo M, Kousuge Y, Kobayashi N, Mizuta S, Kitagawa H, Sano T

The purpose of this study was to investigate the accuracy of distance measurements of implant length based on periapical radiographs compared with that of other modalities. We carried out an experimental trial to compare precision in distance measurement. Dental implant fixtures were buried in the canine and first molar regions. These were then subjected to periapical (PE) radiography, panoramic (PA) radiography, conventional (CV) and medical computed (CT) tomography. The length of the implant fixture on each film was measured by nine observers and degree of precision was statistically analyzed. The precision of both PE radiographs and CT tomograms was closest at the highest level. Standardized PE radiography, in particular, was superior to CT tomography in the first molar region. This suggests that standardized PE radiographs should be utilized as a reliable modality for longitudinal and linear distance measurement, depending on implant length at local implantation site.

PMID: 17344618 [PubMed - indexed for MEDLINE]

Animal models for implant biomaterial research in bone: a review.

Eur Cell Mater. 2007;13:1-10

Authors: Pearce AI, Richards RG, Milz S, Schneider E, Pearce SG

Development of an optimal interface between bone and orthopaedic and dental implants has taken place for many years. In order to determine whether a newly developed implant material conforms to the requirements of biocompatibility, mechanical stability and safety, it must undergo rigorous testing both in vitro and in vivo. Results from in vitro studies can be difficult to extrapolate to the in vivo situation. For this reason the use of animal models is often an essential step in the testing of orthopaedic and dental implants prior to clinical use in humans. This review discusses some of the more commonly available and frequently used animal models such as the dog, sheep, goat, pig and rabbit models for the evaluation of bone-implant interactions. Factors for consideration when choosing an animal model and implant design are discussed. Various bone specific features are discussed including the usage of the species, bone macrostructure and microstructure and bone composition and remodelling, with emphasis being placed on the similarity between the animal model and the human clinical situation. While the rabbit was the most commonly used of the species discussed in this review, it is clear that this species showed the least similarities to human bone. There were only minor differences in bone composition between the various species and humans. The pig demonstrated a good likeness with human bone however difficulties may be encountered in relation to their size and ease of handling. In this respect the dog and sheep/goat show more promise as animal models for the testing of bone implant materials. While no species fulfils all of the requirements of an ideal model, an understanding of the differences in bone architecture and remodelling between the species is likely to assist in the selection of a suitable species for a defined research question.

PMID: 17334975 [PubMed - indexed for MEDLINE]

Retrieval of blade implants with piezosurgery: two clinical cases.

Minerva Stomatol. 2007 Jan-Feb;56(1-2):53-61

Authors: Sivolella S, Berengo M, Fiorot M, Mazzuchin M

In this work an ultrasound device was used to perform an ostectomy for the removal of blade implants in order to save as much bone tissue as possible, so that root form implants might later be inserted. Two patients underwent surgery for the removal of two blade implants (one maxillary, the other mandibular) that were no longer functional. The peri-implant ostectomy was carried out with a piezoelectric surgery device. The instrument demonstrated to be effective and precise during ostectomy, providing an extremely thin cutting line. During the course of the operation and at controls after 7 and 30 days, patients did not show any relevant complications and both still had sufficient alveolar bone to be treated with root form implants. The piezosurgery device proved to be an effective instrument in interventions requiring a significant saving of bone tissue, extreme precision in cutting, and respect of soft tissues.

PMID: 17287707 [PubMed - indexed for MEDLINE]

Esthetics and implantology: medico-legal aspects.

Minerva Stomatol. 2007 Jan-Feb;56(1-2):45-51

Authors: Santoro V, De Donno A, Dell'Erba A, Introna F

In recent years the high number of malpractice lawsuits in dentistry has attracted closer attention of dental practitioners to its medico-legal aspects. Implantology, in particular, presents many points of medico-legal concern connected with the difficulties inherent to dental procedures and objectives (both functional and esthetic), as well as full patient collaboration as an essential part of successful treatment. An accurate assessment of each case by the clinician is fundamental, especially in circumstances where esthetic considerations are preponderant as, for instance, in the frontal sectors. In such cases, the options of implantology or of a traditional fixed prosthesis need to be carefully weighed in light of the patient's anatomic condition. The patient should therefore receive complete information and be made fully aware of the risk of treatment failure, as well as possible complications, limits to the procedures, and the fact that successful outcome will also depend on her/his scrupulous observance of the practitioner's instructions. In short, the aim is to make the patient an active ''accomplice'' in treatment. To this end, the use of an extremely detailed information leaflet is strongly advised; after careful clarification of any doubts the patient may have, the patient's written informed consent should be obtained. Nevertheless, there is the risk that excessive intrusion of bureaucracy into medical procedures in defence of the practitioner against malpractice suits may hinder the principal aim of traditional medicine, i.e. to provide the best care for the patient through mutual trust fostered within the doctor-patient relationship.

PMID: 17287706 [PubMed - indexed for MEDLINE]

Densitometric analysis of the autogenous demineralized dentin matrix on the dental socket wound healing process in humans.

Braz Oral Res. 2006 Oct-Dec;20(4):324-30

Authors: Gomes MF, Abreu PP, Morosolli AR, Araújo MM, Goulart MG

The aim of this study was to evaluate the effects of the autogenous demineralized dentin matrix (ADDM) on the third molar socket wound healing process in humans, using the guided bone regeneration technique and a polytetrafluoroethylene barrier (PTFE). Twenty-seven dental sockets were divided into three groups: dental socket (Control), dental socket with PTFE barrier (PTFE), and dental socket with ADDM slices associated to PTFE barrier (ADDM + PTFE). The dental sockets were submitted to radiographic bone densitometry analysis and statistical analysis on the 15th, 30th, 60th and 90th days using analysis of variance (ANOVA) and Tukey's test (p < or = 0.05). The radiographic analysis of the ADDM + PTFE group showed greater homogeneity of bone radiopacity than the Control group and the PTFE group, during all the observation times. The dentin matrix gradually disappeared from the dental socket during the course of the repair process, suggesting its resorption during the bone remodeling process. It was concluded that the radiographic bone density of the dental sockets treated with ADDM was similar to that of the surrounding normal bone on the 90th day. The ADDM was biocompatible with the bone tissue of the surgical wounds of human dental sockets. The radiographic analysis revealed that the repair process was discreetly faster in the ADDM + PTFE group than in the Control and PTFE groups, although the difference was not statistically significant. In addition, the radiographic image of the ADDM + PTFE group suggested that its bone architecture was better than that of the Control and PFTE groups.

PMID: 17242793 [PubMed - indexed for MEDLINE]

Short-term success of osseointegrated dental implants in HIV-positive individuals: a prospective study.

J Contemp Dent Pract. 2007 Jan 1;8(1):1-10

Authors: Stevenson GC, Riano PC, Moretti AJ, Nichols CM, Engelmeier RL, Flaitz CM

PURPOSE: Except for the occasional case report, there are no studies evaluating the success rate of osseointegrated dental implants in individuals infected with the human immunodeficiency virus (HIV). This study investigated the short-term clinical outcome of implant placement in a group of HIV-positive and HIV-negative individuals who required complete dentures. METHODS AND MATERIALS: Edentulous subjects were recruited from an HIV-dedicated clinic and a dental school clinic. Two BioHorizons dental implants were placed in the anterior mandible to support an overdenture opposing a maxillary denture. Outcome measurements obtained six months after activation of implants were presence of pain, mobility, soft tissue status, and radiographic bone level. Descriptive statistics were used. RESULTS: Twenty-nine edentulous adults, including 20 HIV-positive subjects (test) and nine HIV-negative subjects (control), participated. The test group had six females, 14 males; 13 Whites, four African-Americans, and three Hispanics with a mean age of 48.9 years (range: 35-59). The mean CD4 count was 467 cells/mm3 (range: 132-948). The control group had six females, three males; seven Whites, and two Hispanics with a mean age of 65.3 years (range: 50-82). Short-term success rate was 100% for both groups. No difference in clinical outcome was found between the groups. CONCLUSION: This study demonstrated dental implants are well tolerated and have predictable outcomes for HIV-infected individuals for the duration of the study and probably over an even longer term.

PMID: 17211499 [PubMed - indexed for MEDLINE]

Effects of diabetes on the osseointegration of dental implants.

Med Oral Patol Oral Cir Bucal. 2007 Jan;12(1):E38-43

Authors: Mellado-Valero A, Ferrer Garc&#xED;a JC, Herrera Ballester A, Labaig Rueda C

The increased prevalence of diabetes mellitus has become a public health problem. Hyperglycaemia entails a rise in the morbidity and mortality of these patients. Although a direct relationship with periodontal disease has already been shown, little is known about the results of dental implants in diabetics. The present paper reviews the bibliography linking the effect of diabetes on the osseointegration of implants and the healing of soft tissue. In experimental models of diabetes, a reduced level of bone-implant contact has been shown, and this can be reversed by means of treatment with insulin. Compared with the general population, a higher failure rate is seen in diabetic patients. Most of these occur during the first year of functional loading, seemingly pointing to the microvascular complications of this condition as a possible causal factor. These complications also compromise the healing of soft tissues. It is necessary to take certain special considerations into account for the placement of implants in diabetic patient. A good control of plasma glycaemia, together with other measures, has been shown to improve the percentages of implant survival in these patients.

PMID: 17195826 [PubMed - indexed for MEDLINE]

Digital subtraction technique for evaluation of peri-implant bone change in digital dental imaging.

Bull Tokyo Dent Coll. 2006 May;47(2):57-64

Authors: Wakoh M, Nishikawa K, Otonari T, Yamamoto M, Harada T, Sano T, Yajima Y, Ooguro T

The purpose of this study was to investigate digital subtraction technique in digital dental imaging for implant performance, used to quantitatively evaluate bone change around dental implants. For longitudinal assessment of peri-implant bone change, we applied subtraction technique to digital peri-apical radiographs using a digital dental imaging system in two cases at the upper canine and premolar regions. In both cases, we found two peaks of bone change at the crestal region; we also quantitatively demonstrated a marked change over the first one-month period and approximately three-month period spanning the fourth month to the end of the sixth month following implantation. Digital peri-apical radiography accommodating the digital subtraction program should be re-acknowledged as a reliable modality for assessing amount of bone change at local implantation sites.

PMID: 17167221 [PubMed - indexed for MEDLINE]

Current products and practice: bone anchorage devices in orthodontics.

J Orthod. 2006 Dec;33(4):288-307

Authors: Prabhu J, Cousley RR

Bone anchorage is a promising new field in orthodontics and already a wide variety of bone anchorage devices (BADs) are available commercially. This review aims to assist clinicians by outlining the principles of bone anchorage and the salient features of the available systems, especially those that may influence the choice of a specific BAD for anchorage reinforcement.

PMID: 17142335 [PubMed - indexed for MEDLINE]

Role of mast cells in wound healing process after glass-fiber composite implant in rats.

J Cell Mol Med. 2006 Oct-Dec;10(4):946-54

Authors: Rodella LF, Rezzani R, Buffoli B, Bonomini F, Tengattini S, Laffranchi L, Paganelli C, Sapelli PL, Bianchi R

Glass-fiber composites are frequently used in dentistry. In order to evaluate their biocompatibility we tested, in an experimental model "in vivo", their tissue response pointing our attention on presence of mast cells (MCs) and fibrotic process. Sprague Dawley rats were used for the experimental design. The fibers were introduced in a subcutaneous pocket along the middle dorsal line between the two scapulas for 7, 14 or 21 days. At the end of the treatments the skins were excised and then processed for Toluidine Blue, to determine the presence of MCs, and Picrosirius Red staining, to evaluate the presence of fibrotic tissue. Our preliminary results showed and increase of both MC number and deposition of collagen type I, which characterized the fibrotic tissue. So, subsequent aims of our study were to evaluate the role played by MCs in tissue fibrosis and to give a possible explanation regarding the mechanisms that were responsible of biological response observed, through the analyses of some proteins, such as metalloproteinase-2 (MMP-2), its inhibitor (TIMP-2) and transforming growth factor-beta (TGF-beta). Our data confirmed the involvement of TGF-beta, released by MCs, in the disruption of the equilibrium between MMP-2 and TIMP-2 that were implicated in the enhancement of fibrosis. In summary, this study demonstrate that this type of materials induced an inflammatory response at the site of implant and help to clarify what type of mechanism and which proteins are involved in this biological response. Nevertheless, more extensive investigations are in progress to better evaluate the inflammatory process.

PMID: 17125597 [PubMed - indexed for MEDLINE]

Predicting clustered dental implant survival using frailty methods.

J Dent Res. 2006 Dec;85(12):1147-51

Authors: Chuang SK, Cai T

The purpose of this study was to predict future implant survival using information on risk factors and on the survival status of an individual's existing implant(s). We considered a retrospective cohort study with 677 individuals having 2349 implants placed. We proposed to predict the survival probabilities using the Cox proportional hazards frailty model, with three important risk factors: smoking status, timing of placement, and implant staging. For a non-smoking individual with 2 implants placed, an immediate implant and in one stage, the marginal probability that 1 implant would survive 12 months was 85.8% (95%CI: 77%, 91.7%), and the predicted joint probability of surviving for 12 months was 75.1% (95%CI: 62.1%, 84.7%). If 1 implant was placed earlier and had survived for 12 months, then the second implant had an 87.5% (95%CI: 80.3%, 92.4%) chance of surviving 12 months. Such conditional and joint predictions can assist in clinical decision-making for individuals.

PMID: 17122171 [PubMed - indexed for MEDLINE]

Implant therapy versus endodontic therapy.

J Am Dent Assoc. 2006 Oct;137(10):1440-3

Authors: Christensen GJ

PMID: 17012725 [PubMed - indexed for MEDLINE]

[Establishment of a three-dimensional finite element model of mandible with dental implants for immediate loading]

Shanghai Kou Qiang Yi Xue. 2006 Aug;15(4):391-4

Authors: Ding X, Zhu XH, Liao SH, Tong RF, Fang YM, Zhang L

PURPOSE: To establish a three-dimensional finite element model of mandible with dental implants for immediate loading, which will provide a basis for study of the biomechanical characteristics of the immediate loading implant-bone interface. METHODS: A female edentulous mandible was adopted for CT scanning, the scanned data were saved with the form of DICOM, and then input into compute. Universal Surgical Integration System which was developed by ourselves and ANSYS 10.0 were used to divide mesh and establish finite element model. Three dental implants simulating the real shape of ITI thread implant were embedded in the anterior region of the mandible, of which implant-bone interface was granted with situation of smooth friction simulating the case of immediate loading. RESULTS: The accurate finite element model of mandible with dental implants for immediate loading was established, which included 127811 tetrahedron elements with 182252 nodes. A single dental implant model comprised 13924 elements with 21420 nodes, the thread of it was continuous and smooth. CONCLUSION: The biomechanical similarity, the geometrical analogy and clinical indication of the model were quite good. The three-dimensional finite element model developed by this method can apply for precise analysis of the rule of biomechanics on the implant-bone interface for immediate loading.

PMID: 16955165 [PubMed - in process]

Neurosensory disturbances after immediate loading of implants in the anterior mandible: an initial questionnaire approach followed by a psychophysical assessment.

Clin Oral Investig. 2006 Dec;10(4):269-77

Authors: Abarca M, van Steenberghe D, Malevez C, De Ridder J, Jacobs R

The aim of the study was to assess past and present neurosensory disturbances using a questionnaire and a psychophysical approach in patients treated with immediate loaded implants in the edentulous anterior mandible. A group of 65 patients (age range 30-84 years, mean 58 years, 30 women) was enrolled. All were treated by means of three immediately loaded implants (Branemark Novum System). A self-designed questionnaire was used for data collection. The response rate was 89%. Of the 58 responders, 33% (n=19) reported neurosensory disturbances after implant surgery. Nine of these patients (mean age 56 years, seven women) participated in an objective evaluation and were subjected to a psychological and several psychophysical tests. At the moment of the evaluation none of the nine patients still had clinical complaints. Psychological testing revealed no statistical differences between the patients, who had previously experienced subjective complaints, and the control group. Two-point discrimination and thermal sensation tests revealed no sensory lesions. The light touch sensation test at the lower lip indicated a more frequent reduction of tactility for the test group (p<or=0.03). Neurosensory disturbances can occur in the anterior region of the mandible after implant surgery.

PMID: 16937108 [PubMed - indexed for MEDLINE]

Update in dental implant periapical surgery.

Med Oral Patol Oral Cir Bucal. 2006 Aug;11(5):E429-32

Authors: Pe&#xF1;arrocha Diago M, Boronat López A, Lamas Pelayo J

Implant periapical lesions are infectious-inflammatory alterations surrounding an implant apex, and can be caused by a number of situations--including contamination at instrumentation, overheating of bone, and the prior existence of bone pathology. The diagnosis is based on the clinical manifestations and radiological findings, where a radiotransparency can be seen at periapical level. The lesions are classified according to their evolutive stage as either acute (non-suppurated and suppurated) or chronic (or periapical abscess). The management of implant periapical lesions comprises periapical surgery with curettage and irrigation in the acute phase, or implant extraction when the bone surface is affected and/or primary fixation is lost (chronic phase).

PMID: 16878068 [PubMed - indexed for MEDLINE]

A cost-effectiveness analysis of implant overdentures.

J Dent Res. 2006 Aug;85(8):717-21

Authors: Zitzmann NU, Marinello CP, Sendi P

Placement of dental implants may improve the retention and stability of complete dentures in edentulous patients. Treatment costs, however, substantially increase with implant treatment. We therefore performed a stochastic cost-effectiveness analysis, comparing implant-supported over-denture prostheses (4 implants), implant-retained overdentures (2 implants), and complete dentures, from the patient's perspective in Switzerland, to assess whether implant treatment in the mandible represents value for money spent. Twenty patients were included in each treatment group and were followed up for three years. Health outcomes were expressed in Quality-adjusted Prosthesis Years, and dental health care costs and time costs were recorded in year 2000 Swiss Francs (CHF 100 = US dollars 61). The cost per Quality-adjusted Prosthesis Year gained for implant treatment was CHF 9100 (2 implants) and CHF 19,800 (4 implants) over 3 years. Over a ten-year period, these threshold ratios were reduced to CHF 3800 (2 implants) and CHF 7100 (4 implants) per Quality-adjusted Prosthesis Year gained.

PMID: 16861288 [PubMed - indexed for MEDLINE]

Stress and inflammation as a detrimental combination for peri-implant bone loss.

J Dent Res. 2006 Aug;85(8):711-6

Authors: Heckmann SM, Linke JJ, Graef F, Foitzik Ch, Wichmann MG, Weber HP

The causes of peri-implant bone loss continue to be controversial. To determine the impact of biomechanical stress and inflammation, we investigated a total of 80 interforaminal implants in situ for more than 10 years. Two stress groups, with 14 patients each, were established: a low-stress situation with single-standing implants, and an increased-stress situation with splinted implants. To categorize inflammation, we introduced a Composite Inflammation Score using 4 inflammatory parameters. Peri-implant bone loss was calculated from digital panoramic radiographs. To differentiate between the effects of stress and inflammation, we compared bone loss in both stress groups at equivalent levels of inflammation. With greater Composite Inflammation Score values, a clear discrepancy between single-standing and splinted implants was evident (p = 0.117/0.000, regression analysis; p = 0.135/0.000, analysis of variance; p = 0.002, t tests). While stress and inflammation alone may not necessarily be detrimental factors, the presence of stress heightens peri-implant bone loss significantly as inflammation increases.

PMID: 16861287 [PubMed - indexed for MEDLINE]

Endodontic or dental implant therapy: the factors affecting treatment planning.

J Am Dent Assoc. 2006 Jul;137(7):973-7; quiz 1027-8

Authors: Torabinejad M, Goodacre CJ

BACKGROUND: Clinicians are confronted with difficult choices regarding whether a tooth with pulpal and/or periapical disease should be saved through endodontic treatment or be extracted and replaced with an implant. METHODS: The authors examined publications (research, literature reviews and systematic reviews) related to the factors affecting decision making for patients who have oral diseases or traumatic injuries. RESULTS: The factors to be considered included patient-related issues (systemic and oral health, as well as comfort and treatment perceptions), tooth- and periodontium-related factors (pulpal and periodontal conditions, color characteristics of the teeth, quantity and quality of bone, and soft-tissue anatomy) and treatment-related factors (the potential for procedural complications, required adjunctive procedures and treatment outcomes). CONCLUSIONS: On the basis of survival rates, it appears that more than 95 percent of dental implants and teeth that have undergone endodontic treatment remain functional over time. CLINICAL IMPLICATIONS: Clinicians need to consider carefully several factors before choosing whether to perform endodontic therapy or extract a tooth and place an implant. The result should be high levels of comfort, function, longevity and esthetics for patients.

PMID: 16803823 [PubMed - indexed for MEDLINE]

Two new clinical/laboratory protocols for CAD/CAM implant restorations.

J Am Dent Assoc. 2006 Jun;137(6):794-800

Authors: Drago CJ

BACKGROUND: Conventional casting technology has some disadvantages for dental laboratory technicians and restorative dentists, including porosity of restorations, miscasting and inaccuracy. It also is labor-intensive. Computer-aided design/computer-aided manufacturing (CAD/CAM) technology was developed in the late 1980s for dentistry, and it significantly reduced and/or eliminated problems associated with dental castings. The purpose of this article is to give readers an overview of the use of CAD/CAM technology for dental implants and illustrate two clinical protocols for that use. CLINICAL IMPLICATIONS: The CAD/CAM technology described in this article can reduce restorative dentists' chairside time associated with implant treatment in both edentulous and partially edentulous patients, can decrease costs without sacrificing accuracy or biocompatibility for both clinicians and dental laboratory technicians, and is available to dental laboratories without the capital expenses associated with purchasing new technology.

PMID: 16803809 [PubMed - indexed for MEDLINE]

Genes differentially expressed in titanium implant healing.

J Dent Res. 2006 Jun;85(6):566-70

Authors: Ogawa T, Nishimura I

Bone generation occurs around titanium implants; however, its underlying mechanisms are unknown. We hypothesized that molecular determinants distinct from those undertaking normal bone healing regulate osseointegration. Using differential display-polymerase chain-reaction in the male rat model, we isolated 3 genes that are differentially expressed in bone healing with implants, but not in osteotomy healing. A homology search indicated that these 3 genes are apolipoprotein E, prolyl 4-hydroxylase alpha-subunit, and an unknown transcript. Differential expression of these genes was remarkable during early healing stages up to week 2, and accelerated with rough acid-etched surfaces compared with machined surfaces. The differential expression was confirmed in the female rats, with enhanced expression for the acid-etched surfaces. The osseointegration-unfavorable condition created by gonadal estrogen deficiency reduced the level of differential expression. This study provides evidence that selected gene transcripts are induced by titanium implants under regulatory control strongly associated with the nature of osseointegration.

PMID: 16723657 [PubMed - indexed for MEDLINE]

Harder and stiffer bone osseointegrated to roughened titanium.

J Dent Res. 2006 Jun;85(6):560-5

Authors: Butz F, Aita H, Wang CJ, Ogawa T

Mechanisms underlying the beneficial anchorage of roughened titanium implants have not been identified. We hypothesized that the implant surface roughness alters intrinsic biomechanical properties of bone integrated to titanium. Nano-indentation performed on two- and four-week post-implantation bone specimens of rats revealed that bone integrated to acid-etched titanium was approximately 3 times harder than that integrated to the machined titanium, both at the osseointegration interface and at the inner area of the peri-implant bone. The hardness of the acid-etched surface-associated bone was equivalent to that of untreated cortical bone at week 4, while the bone hardness around the machined surface was equivalent to that of the untreated trabecular bone. The elastic modulus of the integrated bone was 1.5 to 2.5 times greater around the acid-etched surface than around the machined surface. Analysis of the data suggests that the implant surface roughness affects the biomechanical quality of osseo-integrated bone, and that the bone integrated to the acid-etched surface is harder and stiffer than the bone integrated to the machined surface.

PMID: 16723656 [PubMed - indexed for MEDLINE]

A randomized controlled trial of implant-retained mandibular overdentures.

J Dent Res. 2006 Jun;85(6):547-51

Authors: Allen PF, Thomason JM, Jepson NJ, Nohl F, Smith DG, Ellis J

Evidence from randomized clinical trials of implant-retained overdentures is very limited at the present time. The aim of this study was to compare implant-retained mandibular overdentures and conventional complete dentures in a randomized controlled trial (RCT). Our a priori hypothesis was that implant-retained mandibular overdentures would be significantly better than conventional complete dentures. Edentulous patients (n = 118) were randomly allocated to either an Implant Group (n = 62) or a Denture Group (n = 56). Patients completed the Oral Health Impact Profile (OHIP) and a denture satisfaction scale pre-treatment and three months post-treatment. Upon completion of treatment, both groups reported improvement (p < 0.001, Wilcoxon Ranks Sum test) in oral-health-related quality of life and denture satisfaction. There were no significant post-treatment differences between the groups, but a treatment effect may be masked by application of "intention to treat" analysis. The OHIP change scores were significantly greater for patients receiving implants than for those who refused them.

PMID: 16723653 [PubMed - indexed for MEDLINE]

Implant surface roughness and bone healing: a systematic review.

J Dent Res. 2006 Jun;85(6):496-500

Authors: Shalabi MM, Gortemaker A, Van't Hof MA, Jansen JA, Creugers NH

A systematic review was performed on studies investigating the effects of implant surface roughness on bone response and implant fixation. We searched the literature using MEDLINE from 1953 to 2003. Inclusion criteria were: (1) abstracts of animal studies investigating implant surface roughness and bone healing; (2) observations of three-month bone healing, surface topography measurements, and biomechanical tests; (3) provision of data on surface roughness, bone-to-implant contact, and biomechanical test values. The literature search revealed 5966 abstracts. There were 470, 23, and 14 articles included in the first, second, and third selection steps, respectively. Almost all papers showed an enhanced bone-to-implant contact with increasing surface roughness. Six comparisons were significantly positive for the relationship of bone-to-implant contact and surface roughness. Also, a significant relation was found between push-out strength and surface roughness. Unfortunately, the eventually selected studies were too heterogeneous for inference of data. Nevertheless, the statistical analysis on the available data provided supportive evidence for a positive relationship between bone-to-implant contact and surface roughness.

PMID: 16723643 [PubMed - indexed for MEDLINE]

Teaching implant dentistry in the predoctoral curriculum: a report from the ADEA Implant Workshop's survey of deans.

J Dent Educ. 2006 May;70(5):580-8

Authors: Petropoulos VC, Arbree NS, Tarnow D, Rethman M, Malmquist J, Valachovic R, Brunson WD, Alfano MC

In 2004, a survey of the deans of U.S. and Canadian dental schools was conducted to determine the implant dentistry curriculum structure and the extent of incorporating implant dentistry clinical treatment into predoctoral programs. The questionnaire was mailed to the deans of the fifty-six dental schools in advance of the ADEA Implant Workshop conference held in Arizona in November 2004. Out of the fifty-six, thirty-nine responded, yielding a response rate of 70 percent. Thirty-eight schools (97 percent) reported that their students received didactic instruction in dental implants, while one school (3 percent) said that its students did not. Thirty schools (86 percent) reported that their students received clinical experience, while five schools (14 percent) reported that theirs did not. Four schools (10 percent) did not respond to this question. Fifty-one percent of the students actually receive the clinical experience in restoring implants, with the range of 5-100 percent. Of those schools that provide clinical experience in restoring implants, four schools (13 percent) reported that it is a requirement for them, while twenty-eight schools (88 percent) reported that it is not a requirement for them. Three schools (9 percent) did not respond. The fee for implants is 45 percent higher than a crown or a denture, with a range of 0-100 percent. Twenty-nine schools (85 percent) indicated that they did receive free components from implant companies, while five schools (15 percent) did not. The conclusions of this report are as follows: 1) most schools have advanced dental education programs; 2) single-tooth implant restorations are performed at the predoctoral level in most schools; 3) implant-retained overdenture prostheses are performed at the predoctoral level in most schools; 4) there is no predoctoral clinical competency requirement for surgical implant placement in all schools that responded to the survey; 5) there is no predoctoral clinical competency requirement for implant prosthodontics in most schools that responded to the survey; 6) prosthodontic specialty faculty are often responsible for teaching implant prosthodontics at the predoctoral level; 7) periodontics and oral and maxillofacial faculty are commonly responsible for teaching implant surgery at the predoctoral level; 8) support from implant companies is common for dental schools, with most providing for implant components at discounted costs; and 9) there is a lack of adequately trained faculty in implant dentistry, which is a significant challenge in providing predoctoral students with clinical experience with dental implants.

PMID: 16687644 [PubMed - indexed for MEDLINE]

Bone apposition to titanium implants biocoated with recombinant human bone morphogenetic protein-2 (rhBMP-2). A pilot study in dogs.

Clin Oral Investig. 2006 Sep;10(3):217-24

Authors: Becker J, Kirsch A, Schwarz F, Chatzinikolaidou M, Rothamel D, Lekovic V, Laub M, Jennissen HP

The aim of the present study was to investigate bone formation to recombinant human bone morphogenetic protein-2 (rhBMP-2)-biocoated and rhBMP-2-nonbiocoated titanium implants after implantation in dogs. Implantation of sand-blasted and acid-etched (C), chromosulfuric acid surface-enhanced (CSA), and rhBMP-2-biocoated CSA [BMP-A: noncovalently immobilized rhBMP-2 (596 ng/cm(2)), BMP-B: covalently immobilized rhBMP-2 (819 ng/cm(2))] implants was performed in both the mandible and tibia of dogs. After 4 weeks of healing, the percentage of direct bone to implant contact (BIC) and the induced bone density (BD) at a distance of less than and greater than 1 mm adjacent to each implant was assessed. Histomorphometric analysis of implants inserted in the mandible and tibia revealed that BIC values appeared to be highest in the BMP-B group, followed by BMP-A, CSA, and C. BD as measured at a distance of <1 mm revealed obvious differences between groups: BMP-B>BMP-A>CSA>C. However, no differences between groups were observed at a distance of >1 mm. Within the limits of the present study, it may be concluded that rhBMP-2 immobilized by covalent and noncovalent methods on CSA-treated implant surfaces seemed to be stable and promoted direct bone apposition in a concentration-dependent manner.

PMID: 16683108 [PubMed - indexed for MEDLINE]

Removal torque and physico-chemical characteristics of dental implants etched with hydrofluoric and nitric acid. An experimental study in Beagle dogs.

Med Oral Patol Oral Cir Bucal. 2006 May;11(3):E281-5

Authors: Mart&#xED;nez-González JM, García-Sabán F, Ferrándiz-Bernal J, Gonzalo-Lafuente JC, Cano-Sánchez J, Barona-Dorado C

OBJECTIVE: To study the composition, surface characteristics and response to removal torque of an implant surface subjected to hydrofluoric acid etching and posterior passivating with hydrofluoric and nitric acid. STUDY DESIGN: Twelve implants were initially selected and their physico-chemical characteristics were evaluated by means of energy-dispersive X-rays (EDS), scanning electron microscopy (SEM) and photoelectron spectroscopy (XPS). In addition, 24 implants - 12 measuring 8 mm and 12 measuring 10 mm in length - were implanted in 6 Beagle dogs. Twelve implants were removed after a recovery period of 6 weeks, followed by removal of the remaining 12 implants after 12 weeks, using a torque calibrator (Gauge Tonichi model BGT150CN-S) with a force registry range of 0-150 Ncm. RESULTS: EDS analysis of the surface chemical composition only revealed the presence of titanium in the etched surfaces. In the same way as with the surfaces of other dental implants, XPS analysis revealed traces of other elements present in the surface, fundamentally carbon. Following dual acid etching, the surface showed the roughness resulting from acid action, with a morphology that proved to be quite homogeneous. The roughness values obtained exceeded 1 mm. The mean removal torque values after 6 weeks were 79.7 Ncm for the 8 mm implants and 115 Ncm for the 10 mm implants. After 12 weeks, these values increased to 101.2 Ncm and 139.7 Ncm, respectively. CONCLUSIONS: Hydrofluoric and nitric acid etching affords optimum surface characteristics comparable to those of other surfaces. The recorded removal torque values raise the possibility of human clinical application for early or immediate loading procedures.

PMID: 16648769 [PubMed - indexed for MEDLINE]

Resonance frequency analysis after the placement of 133 dental implants.

Med Oral Patol Oral Cir Bucal. 2006 May;11(3):E272-6

Authors: Boronat-López A, Peñarrocha-Diago M, Martínez-Cortissoz O, Mínguez-Martínez I

INTRODUCTION: The primary stability of dental implants is related to the bone in contact with the latter, and can be evaluated by resonance frequency analysis. MATERIAL AND METHODS: Measurements were made in 133 implants (62 in the upper jaw and 71 in the mandible) of resonance frequency and insertion force to determine implant stability on the day of surgery, with an evaluation of its relationship to different variables. RESULTS: The stability quotient of the implants on the day of surgery was 62.1, with an insertion force of 35.7 N. The insertion force was proportional to the resonance frequency, with an increasing stability quotient with growing insertion force. The stability quotient was greater in the larger diameter implants, shorter implants, in mandibular placement and in areas of more compact bone. CONCLUSIONS: The stability quotient on the day of implant placement is greater in higher bone density areas.

PMID: 16648767 [PubMed - indexed for MEDLINE]

Peri-implant inflammation defined by the implant-abutment interface.

J Dent Res. 2006 May;85(5):473-8

Authors: Broggini N, McManus LM, Hermann JS, Medina R, Schenk RK, Buser D, Cochran DL

An implant-abutment interface at the alveolar bone crest is associated with sustained peri-implant inflammation; however, whether magnitude of inflammation is proportionally dependent upon interface position remains unknown. This study compared the distribution and density of inflammatory cells surrounding implants with a supracrestal, crestal, or subcrestal implant-abutment interface. All implants developed a similar pattern of peri-implant inflammation: neutrophilic polymorphonuclear leukocytes (neutrophils) maximally accumulated at or immediately coronal to the interface. However, peri-implant neutrophil accrual increased progressively as the implant-abutment interface depth increased, i.e., subcrestal interfaces promoted a significantly greater maximum density of neutrophils than did supracrestal interfaces (10,512 +/- 691 vs. 2398 +/- 1077 neutrophils/mm(2)). Moreover, inflammatory cell accumulation below the original bone crest was significantly correlated with bone loss. Thus, the implant-abutment interface dictates the intensity and location of peri-implant inflammatory cell accumulation, a potential contributing component in the extent of implant-associated alveolar bone loss.

PMID: 16632764 [PubMed - indexed for MEDLINE]

The 'mini'-implant has arrived.

J Am Dent Assoc. 2006 Mar;137(3):387-90

Authors: Christensen GJ

There is no question that dental implants have been the most influential change in dentistry during the last half-century. In general, they are well-proven and highly useful. However, the diameter of standard implants (approximately 3.75 mm), along with the frequent need to graft bone to allow for their placement, have limited their use for those who most need implants. The introduction, approval and continuing observation of success of smaller-diameter mini-implants have stimulated use of implants in situations in which standard-sized implants could not have been used without grafting. The result has been more patients who have been served successfully at reduced cost with minimized pain and trauma--patients who could not have been treated with implants otherwise. Continuing research is needed for further verification of the acceptability of mini-implants.

PMID: 16570473 [PubMed - indexed for MEDLINE]

Oxygen plasma surface modification enhances immobilization of simvastatin acid.

Biomed Res. 2006 Feb;27(1):29-36

Authors: Yoshinari M, Hayakawa T, Matsuzaka K, Inoue T, Oda Y, Shimono M, Ide T, Tanaka T

Simvastatin acid (SVA) has been reported to stimulate bone formation with increased expression of BMP-2. Therefore, immobilization of SVA onto dental implants is expected to promote osteogenesis at the bone tissue/implant interface. The aim of this study was to evaluate the immobilization behavior of SVA onto titanium (Ti), O(2)-plasma treated titanium (Ti + O(2)), thin-film coatings of hexamethyldisiloxane (HMDSO), and O(2)-plasma treated HMDSO (HMDSO + O(2)) by using the quartz crystal microbalance-dissipation (QCM-D) technique. HMDSO surfaces were activated by the introduction of an OH group and/or O(2)-functional groups by O(2)-plasma treatment. In contrast, titanium surfaces showed no appreciable compositional changes by O(2)-plasma treatment. The QCM-D technique enabled evaluation even at the adsorption behavior of a substance with a low molecular weight such as simvastatin. The largest amount of SVA was adsorbed on O(2)-plasma treated HMDSO surfaces compared to untreated titanium, HMDSO-coated titanium, and O(2)-plasma treated titanium. These findings suggested that the adsorption of SVA was enhanced on more hydrophilic surfaces concomitant with the presence of an OH group and/or O(2)-functional group resulting from the O(2)-plasma treatment, and that an organic film of HMDSO followed by O(2)-plasma treatment is a promising method for the adsorption of SVA in dental implant systems.

PMID: 16543663 [PubMed - indexed for MEDLINE]

Evaluation of 80 implants subjected to immediate loading in edentulous mandibles after two years of follow-up.

Med Oral Patol Oral Cir Bucal. 2006 Mar;11(2):E165-70

Authors: Mart&#xED;nez-González JM, Barona-Dorado C, Cano-Sánchez J, Fernández-Cáliz F, Sánchez-Turrión A

AIM: An analysis is made of the clinical and radiological behavior of 80 implants with a new surface subjected to etching with a sulfuric and hydrofluoric acid solution followed by thermal treatment, and subjected to immediate loading in patients with lower overdentures. STUDY DESIGN: A prospective observational study was made of 20 patients with lower overdentures supported by four implants measuring 13 mm in length. All patients were included after the obtainment of informed consent, anamnesis, clinical examination and radiological study, with prior clinical elaboration of the lower dentures. RESULTS: Over two years of follow-up, no important plaque or tartar accumulation was observed (with Silness and Loe indexes of 0-1). Periodontal probing proved favorable, with no pocket depths of over 2 mm in any case. The radiological controls showed no implant failures during follow-up. No cervical bone loss was recorded in the first year in a large proportion of cases (65%), while reabsorption of the cervical half was observed in 10%, and of three-quarters of the cervical portion in the remaining 35%. Performance in the second year was compatible with the standard references--with losses of between 0.5-1.5 mm. CONCLUSIONS: Rehabilitation with lower overdentures should be regarded as a priority indication, and implantological treatment substitution by conventional and/or early resting periods should be considered.

PMID: 16505797 [PubMed - indexed for MEDLINE]

Prosthetically driven implant placement. How to achieve the appropriate implant site development.

Keio J Med. 2005 Dec;54(4):172-8

Authors: Brugnami F, Caleffi C

Dental implants are established alternatives for replacing missing teeth. Tooth loss for different reasons may leads to alveolar resorption. Shortage of bone can prevent proper positioning of dental implants according to prosthetic needs and treatment planning, unless the volume of hard and soft tissues is increased before implantation. In the esthetic area it is essential not only to achieve well-anchored implants but also sufficient soft and hard tissue in order to obtain natural looking result. This article will present several treatment modalities to augment the soft and hard tissues in order to obtain proper insertion of implants according to prosthetic needs and patient satisfaction.

PMID: 16452826 [PubMed - indexed for MEDLINE]

Characterization of the peri-implant epithelium in hamster palatine mucosa: behavior of Merkel cells and nerve endings.

Biomed Res. 2005 Dec;26(6):257-69

Authors: Suzuki Y, Matsuzaka K, Ishizaki K, Tazaki M, Sato T, Inoue T

The purpose of this study was to investigate the relationship between Merkel cells and nerve elements during tissue regeneration after receiving dental implants. Golden hamsters were divided into 3 groups and titanium alloy implants were fixed in their left-side maxilla through the third palatine rug. Animals were sacrificed at 1, 2, 3, 4, 5, 6, and 7 days after the implantation and tissues were characterized at the immunohistochemical and morphological levels. CK 20 and PGP 9.5 antibodies which react with Merkel cells and nerve fibers were used. Immunohistochemically, no CK 20-positive Merkel cells were seen in the peri-implant epithelium throughout the 7 days. However, starting at day 4, PGP 9.5-positive nerve fibers appeared in the connective tissue, and by day 7, nerve fibers had invaded the more superficial layer of the peri-implant epithelium compared to the mucosa removal control group. At the electron microscopic level, the intercellular spaces of the regenerating epithelium in the mucosa removal control group were small. In contrast, intercellular spaces of the peri-implant epithelium tended to be wide and regenerating nerve fibers invaded those intercellular spaces. In both the mucosa removal control group and the implantation group, the basal lamina and connective tissues regenerated completely. However, clear Merkel cells containing neurosecretory granules were not observed. Taken together, our results indicate that Merkel cells in the hamster palatine mucosa do not regenerate in the peri-implant epithelium. However, regenerative nerve fibers seem to play essential roles as part of the defense and sensory systems around the peri-implant epithelium to compensate for the weakened defense mechanism.

PMID: 16415507 [PubMed - indexed for MEDLINE]

Compressive osteotomes for expansion and maxilla sinus floor lifting.

Med Oral Patol Oral Cir Bucal. 2006 Jan;11(1):E52-5

Authors: Calvo-Guirado JL, Saez-Yuguero R, Pardo-Zamora G

AIM: The aim of this article is to assess the efficiency of the technique for the posterior alveolar expansion and elevation of the upper maxillary alveolar ridge through the use of compressive osteotomes (Quirurgical Bontempi, Espa&#xF1;a) which have been specifically designed for Osseotite NT and Osseotite NT Certain of 3i implants (Implants Innovations, USA). MATERIALS AND METHODS: 24 adult patients (16 female and 12 male), who were selected according to Albrektsson's inclusion and exclusion criteria, took part in the study. All the patients presented bone deficiency in the width and height of the upper maxilla. 48 Osseotite implants were performed (four Osseotite Standard; six Osseotite NT; 38 NT Certain (3i, Implants Innovations, CA, USA)). Implant diameters were 4 mm in 44 cases and 5 mm in 4 cases with lengths varying between 11.5 (n = 4) and 13 mm (n = 44). The alveolar ridges of the 24 patients had initial widths from 1.5 mm to 5 mm and heights between 5 and 13 mm. Results: The data obtained were analysed using the SPSS 11.0 program. In the 48 areas treated with immediate implants, an increase in bone height of 6.75 mm -/+ 1.25 mm was achieved. In the case of the alveolar expansion for the 48 implants, the average was 3.2 mm -/+ 0.15 mm. CONCLUSIONS: The technique for alveolar expansion and elevation of the upper maxilla with compressive osseotomes can lead to a 100% success rate after a 9-month follow-up of the implants and insertion of prostheses. It is a highly predictable surgical procedure which allows implants to be performed at the same time as surgery, thus reducing the number of such interventions while recovering aesthetic and functional losses in the patient.

PMID: 16388295 [PubMed - indexed for MEDLINE]

The advantages of minimally invasive dentistry.

J Am Dent Assoc. 2005 Nov;136(11):1563-5

Authors: Christensen GJ

Minimally invasive dentistry, in cases in which it is appropriate, is a concept that preserves dentitions and supporting structures. In this column, I have discussed several examples of minimally invasive dental techniques. This type of dentistry is gratifying for dentists and appreciated by patients. If more dentists would practice it, the dental profession could enhance the public's perception of its honesty and increase its professionalism as well.

PMID: 16329421 [PubMed - indexed for MEDLINE]

Oral implants.

J Am Dent Assoc. 2005 Nov;136(11):1514; author reply 1514

Authors: Weaver MM

PMID: 16329412 [PubMed - indexed for MEDLINE]

Characterization of titanium surfaces for dental implants with inorganic contaminant.

Braz Oral Res. 2005 Apr-Jun;19(2):106-11

Authors: Diniz MG, Pinheiro MA, Andrade Junior AC, Fischer RG

The aim of this research was to characterize titanium surfaces blasted with aluminum oxide (Al2O3) particles using the KS 400 digital image processing program. Samples of grade II titanium plates were submitted to blasting processes using particles of Al2O3, and treated with a hydrofluoric acid-based solution. Three digital images from each sample surface were obtained using Scanning Electron Microscopy, and half-quantitative chemical analyses were subsequently performed using Electron Dispersive Spectroscopy (EDS). In addition, parameters related to the alumina phase, such as the concentration level, the area and perimeter of the particles and their circular form factor were measured using KS 400. The mechanical/chemical treatment caused depressions up to 10 microm on homogeneous surfaces. Although the chemical attack significantly removed the alumina phase, residual particles could still be identified by the EDS. The average area occupied by the alumina phase on the samples surfaces was 469.32 (+/- 284.98) microm2, the particle average perimeter was 81.61 (+/- 27.68) microm, and the mean circular form factor was 0.60 (+/- 0.05). Characterizing the titanium surface is essential in the evaluation of the material manufacturing process because the presence of residual aluminum particles may have deleterious effects on the formation of the osseous/implant tissue.

PMID: 16292442 [PubMed - indexed for MEDLINE]

Strain driven fast osseointegration of implants.

Head Face Med. 2005 Sep 1;1:6

Authors: Joos U, B&#xFC;chter A, Wiesmann HP, Meyer U

BACKGROUND: Although the bone's capability of dental implant osseointegration has clinically been utilised as early as in the Gallo-Roman population, the specific mechanisms for the emergence and maintenance of peri-implant bone under functional load have not been identified. Here we show that under immediate loading of specially designed dental implants with masticatory loads, osseointegration is rapidly achieved. METHODS: We examined the bone reaction around non- and immediately loaded dental implants inserted in the mandible of mature minipigs during the presently assumed time for osseointegration. We used threaded conical titanium implants containing a titanium2+ oxide surface, allowing direct bone contact after insertion. The external geometry was designed according to finite element analysis: the calculation showed that physiological amplitudes of strain (500-3,000 ustrain) generated through mastication were homogenously distributed in peri-implant bone. The strain-energy density (SED) rate under assessment of a 1 Hz loading cycle was 150 Jm-3 s-1, peak dislocations were lower then nm. RESULTS: Bone was in direct contact to the implant surface (bone/implant contact rate 90%) from day one of implant insertion, as quantified by undecalcified histological sections. This effect was substantiated by ultrastructural analysis of intimate osteoblast attachment and mature collagen mineralisation at the titanium surface. We detected no loss in the intimate bone/implant bond during the experimental period of either control or experimental animals, indicating that immediate load had no adverse effect on bone structure in peri-implant bone. CONCLUSION: In terms of clinical relevance, the load related bone reaction at the implant interface may in combination with substrate effects be responsible for an immediate osseointegration state.

PMID: 16270927 [PubMed]

Bone grafting simultaneous to implant placement. Presentation of a case.

Med Oral Patol Oral Cir Bucal. 2005 Nov-Dec;10(5):444-7

Authors: Pe&#xF1;arrocha-Diago M, Gómez-Adrián MD, García-Mira B, Ivorra-Sais M

Bone defects at mandibular alveolar crest level complicate the placement of dental implants in the ideal location. Surgical reconstruction using autologous bone grafts allows implant fixation in an esthetic and functional manner. We describe a patient with large mandibular bone loss secondary to periodontal inflammatory processes. Reconstruction of the mandibular alveolar process was carried out using onlay block bone grafts harvested from the mandible. The grafts were stabilized by positioning the dental implants through them--a procedure that moreover afforded good primary implant fixation. After two years of follow-up the clinical and radiological outcome is good. In the lower jaw, where bone regeneration is complicated, we were able to achieve good results in this patient--minimizing the corresponding waiting time by grafting and placing the implants in the same surgical step.

PMID: 16264379 [PubMed - indexed for MEDLINE]