Making informed decisions about incorporating a CAD/CAM system into dental practice.

J Am Dent Assoc. 2006 Sep;137 Suppl:32S-36S

Authors: Trost L, Stines S, Burt L

BACKGROUND: The authors drew from their clinical application and practice management experience to present a guide to incorporating into the dental practice computer-aided design/computer-aided manufacturing (CAD/CAM) technology for creating dental restorations. METHODS: The authors examine various factors in the purchase of CAD/CAM technology: clinical considerations and implications, practice and patient impact, and practical aspects of financial return. They also offer guidelines to and provide questions for dentists who may be considering a purchase of such technology. CONCLUSIONS: CAD/CAM technology is a key component for a technologically current dental office. CLINICAL IMPLICATIONS: Today's dental care consumer is more aware of his or her treatment options, and CAD/CAM technology may help the dentist meet such a patient's needs. With software improvement, attention to user-friendliness and positive clinical performance history, CAD/CAM systems are a significant stride forward into one-appointment esthetic dentistry.

PMID: 16950935 [PubMed - indexed for MEDLINE]

Clinical performance of chairside CAD/CAM restorations.

J Am Dent Assoc. 2006 Sep;137 Suppl:22S-31S

Authors: Fasbinder DJ

BACKGROUND: The CEREC system (Sirona Dental Systems GmbH, Bensheim, Germany) is marking its 20th year of clinical service. The author reviews the literature on the effectiveness of this chairside CAD/CAM system. TYPES OF STUDIES REVIEWED: The author identified and reviewed clinical studies from 1985 through 2006 that included CEREC-generated inlays, onlays or crowns. These studies were conducted in both private practice and university settings. The author summarized the findings as they relate to postoperative sensitivity, restoration fracture, color match, margin adaptation and clinical longevity. RESULTS: Although postoperative sensitivity was reported, it was due to mainly occlusal interferences. Long-term postoperative sensitivity was not a reported problem. Similar to other ceramic restorations, restoration fracture is the primary mode of failure for CEREC-generated restorations. Although margin wear is detected consistently, consequences of the wear leading to restoration failure were reported rarely. The survival probability of CEREC-generated restorations was reported to be approximately 97 percent for five years and 90 percent for 10 years. CLINICAL IMPLICATIONS: The low rate of restoration fracture and long-term clinical survivability document the effectiveness of the CEREC system as a dependable, esthetic restorative option for patients.

PMID: 16950934 [PubMed - indexed for MEDLINE]

Materials for chairside CAD/CAM-produced restorations.

J Am Dent Assoc. 2006 Sep;137 Suppl:14S-21S

Authors: Giordano R

BACKGROUND: and Overview. Although the use of computer-aided design/computer-aided manufacturing (CAD/CAM) seems to be a recent addition to the dental restorative armamentarium, this concept was first investigated more than 35 years ago. CEREC (Sirona Dental Systems GmbH, Bensheim, Germany) was the first and is the only available chairside system, and it has more than 20 years of use in the dental office. The initial concept had three tenets: esthetic ceramic reconstruction, a single patient visit and minimal tooth reduction (inlays and onlays instead of crowns). The author reviews the materials used for CAD/CAM-fabricated restorations. The structure, properties and clinical success of the materials for full-contour chairside restorations, as well as laboratory-based high-strength all-ceramic restorations are presented. RESULTS: CAD/CAM restorations have demonstrated clinical success owing to a combination of improvements in materials with advances in CAD/CAM systems. Full-contour ceramic restorations fabricated chair-side may reinforce the tooth, providing good long-term clinical success. High-strength milled restorations allow for the use of all-ceramic restorations for multiple-unit posterior and anterior bridges. CLINICAL IMPLICATIONS: Examination of the structure, properties and clinical results of CAD/CAM materials supports their use in routine dental practice.

PMID: 16950933 [PubMed - indexed for MEDLINE]

The evolution of the CEREC system.

J Am Dent Assoc. 2006 Sep;137 Suppl:7S-13S

Authors: Mörmann WH

BACKGROUND AND OVERVIEW: Early in 1980, the author anticipated the attraction of restoring posterior teeth with tooth-colored material. He conducted studies and developed the clinical concept of bonded ceramic inlays, at the same time raising the issue of the fast fabrication of the ceramic restorations. The author developed plans for in-office computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication of ceramic restorations specifically to enable the dentist to complete one or multiple ceramic restorations chairside, in a single appointment. The initial concept comprised a small mobile CAD/CAM unit integrating a computer, keyboard, trackball, foot pedal and optoelectronic mouth camera as input devices, a monitor and a machining compartment. CEREC 3 (Sirona Dental Systems GmbH, Bensheim, Germany) divided the system into an acquisition/design unit and a separate machining unit. Three-dimensional software makes the handling illustrative and easy both in the office and in the laboratory. CONCLUSIONS: It appears that the CEREC CAD/CAM concept is becoming a significant part of dentistry. CLINICAL IMPLICATIONS: Sound knowledge of adhesive bonding and diligent planning are essential for the successful integration of CAD/CAM into clinical dental offices.

PMID: 16950932 [PubMed - indexed for MEDLINE]

Dental CAD/CAM systems: a 20-year success story.

J Am Dent Assoc. 2006 Sep;137 Suppl:5S-6S

Authors: Rekow ED

PMID: 16950931 [PubMed - indexed for MEDLINE]

Computer-aided design and fabrication of dental restorations: current systems and future possibilities.

J Am Dent Assoc. 2006 Sep;137(9):1289-96

Authors: Strub JR, Rekow ED, Witkowski S

BACKGROUND: For more than 20 years, researchers have been trying to automate conventional manual processes in dental technology with the hope of producing higher- and more uniform-quality materials, standardizing manufacturing processes and reducing production costs. METHODS: The authors review existing computer-aided design (CAD)/computer-aided manufacturing (CAM) systems, describing the components of CAD/CAM technologies and addressing the limitations of current systems, and suggest possibilities for future systems. CONCLUSIONS: Existing dental CAD/CAM systems vary dramatically in their capabilities; each has distinct advantages and limitations. None can yet acquire data directly in the mouth and produce the full spectrum of restoration types (with the breadth of material choices) that can be created by traditional techniques. Emerging technologies may expand dramatically the capabilities of future systems, but they also may require a different type of training to use them to their full effectiveness. CLINICAL IMPLICATIONS: In the future, automatically fabricated, fully esthetic restorations might be produced more quickly and have longer lifetimes than restorations currently produced with CAD/CAM systems.

PMID: 16946436 [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]

[Design of geometric models of the removable partial denture framework]

Shanghai Kou Qiang Yi Xue. 2006 Apr;15(2):213-7

Authors: Wu L, Ai HJ, Lv PJ, Wang YP

PURPOSE: The aim of this study was to introduce a method on computer aided design (CAD) of removable partial denture(RPD) framework based on domestic CAD/CAM software system, which contributes to the further research to develop the domestic software system applied in restorative dentistry. METHODS: Point cloud data of a partially edentulous cast, a mandibular Kennedy Class II modification 2 arch, was captured by an optical scanning system with projective grating and high-resolution digital camera. Using domestic CAD/CAM software system, the above point cloud data was reduced, digital surveying line and inserting path were determined. In terms of the principle of clinical design, the tissue surfaces and polishing surfaces of every component of RPD were built such as clasp, rest, lingual bar, and mesh construction, et al. As well as the characteristic structures of the framework, including the half-pear shaped cross section of lingual bar, the internal and external finish lines, the tissue stop at the tissue surface of mesh construction and so on, were fabricated on the base of reduced data model. 3-D surface model of the RPD framework was created. RESULTS: Geometric model of the RPD framework was fabricated successfully, which took on good fitting, high visibility and editing conveniently. And the data converted to STL file format that could be read by any other CAD/CAM software system and was in preparation for subsequent computer aided manufacture (CAM) of RPD framework. CONCLUSIONS: It is suggested that this method based on domestic software in CAD of RPD framework be feasible.

PMID: 16685370 [PubMed - in process]

Is now the time to purchase an in-office CAD/CAM device?

J Am Dent Assoc. 2006 Feb;137(2):235-6, 238

Authors: Christensen GJ

In-office CAD/CAM is a reality. It allows fabrication of tooth-colored inlays and onlays, crowns and veneers in one appointment. It is especially well-suited to dentists who accomplish many single-tooth or single-quadrant restorations. As with any new technology, its cost is high, but using it can be financially feasible. Clinical and basic science investigations have resulted in positive findings on the concept. There are some significant advantages and several disadvantages. In-office CAD/CAM works well for many dentists, but practitioners should evaluate it carefully before accepting it, as it is not for everybody.

PMID: 16521390 [PubMed - indexed for MEDLINE]

The clinical performance of CAD/CAM-generated composite inlays.

J Am Dent Assoc. 2005 Dec;136(12):1714-23

Authors: Fasbinder DJ, Dennison JB, Heys DR, Lampe K

BACKGROUND: The authors conducted a study to evaluate the longitudinal clinical performance of a resin-based composite (Paradigm, 3M ESPE, St. Paul, Minn.) for computer-aided design/computer-aided manufacturing (CAD/CAM)-generated adhesive inlays. METHODS: The researchers used a CAD/CAM unit (CEREC 2, Sirona Dental Systems, Bensheim Germany) to fabricate 40 porcelain (Vita Mark II, Vita Zahnfabrik, Bad Säckingen, Germany) and 40 resin-based composite (Paradigm, 3M ESPE) inlays. Both restorative materials were cemented with a total-etch technique using Single Bond dental adhesive (3M ESPE) and a dual-cured resin cement (RelyX ARC Adhesive Resin Cement, 3M ESPE). Two examiners evaluated the inlays using modified U.S. Public Health Service (PHS) criteria at six months, one year, two years and three years. RESULTS: No sensitivity was reported for either material at any recall period. There was no significant difference between the two materials relative to margin adaptation at three years. Margin adaptation initially was very good for both materials, with an increase in margin detection due to apparent wear of the resin-based composite luting agent. There was a significant difference in color match between the two materials at three years, with 91.4 percent of the resin-based composite inlays and 58.8 percent of the porcelain inlays rated Alfa. CONCLUSIONS AND CLINICAL IMPLICATIONS: The resin-based composite inlays had a significantly better color match at three years than did the porcelain inlays. Resin-based composite CAD/CAM inlays performed as well as porcelain CAD/CAM inlays after three years of clinical service.

PMID: 16383055 [PubMed - indexed for MEDLINE]

Clinical performance of large, all-ceramic CAD/CAM-generated restorations after three years: a pilot study.

J Am Dent Assoc. 2004 May;135(5):605-12

Authors: Reich SM, Wichmann M, Rinne H, Shortall A

BACKGROUND: Adhesively luted all-ceramic restorations preserve and stabilize weakened tooth structure, but there is little published information about the clinical performance of large, all-ceramic restorations. METHODS: In this pilot study, the authors placed 58 large, single-tooth, all-ceramic restorations in 26 patients using a computer-aided design/computer-aided manufacturing, or CAD/CAM, system (CEREC 2, Sirona Dental Systems GmbH, Bensheim, Germany). They documented the maximum height of the restoration and remaining cementoenamel junction, or CEJ. In 21 cases, rubber dam isolation was not possible during adhesive luting. They re-evaluated the restorations after three years according to the U.S. Public Health Service criteria. RESULTS: After three years, the authors rated 56 (97 percent) of the 58 restorations as Bravo or better in regard to marginal integrity, secondary caries (four could not be rated), discoloration and anatomical form. One restoration was rated as Charlie because of poor marginal integrity, and one restoration had to be replaced owing to a bulk fracture. The authors rated the adequacy of proximal contact and occlusal relationships as acceptable-to-good for all restorations. Neither the extent of the remaining enamel at the cavity margin nor application of a rubber dam had any statistically significant influence (chi2 test, P > .05) on the clinical performance of the restorations after three years. CONCLUSIONS: At the three-year recall appointment, the authors found that the adhesively luted all-ceramic restorations had successfully repaired large coronal defects, irrespective of the cavity margin location (that is, coronal or apical to the CEJ). CLINICAL IMPLICATIONS: Tooth-colored, all-ceramic CAD/CAM-generated restorations are an alternative to conventional restorations if large coronal defects need to be treated.

PMID: 15202752 [PubMed - indexed for MEDLINE]

[3D geometric simulation of mandible with dental arch from CT data]

Shanghai Kou Qiang Yi Xue. 2000 Dec;9(4):235-6

Authors: Li L, Zhang R, Yu LN, Zhang FQ, Wang CT, Xu XY

OBJECTIVE: A 3D geometric simulation of mandible with dental arch from CT has been obtained in this study. METHODS: This process uses automatic system assisted with interactive action to get 2D contour data from CT images,then 3D wireframe model and solid model were obtained by using CAD/CAM software Pro-E(USA) and DELCAM(UK). RESULTS: 3D solid model of mandible with dental arch were presented which can be fully edited. CONCLUSION: This model can be applied to further educational and clinical researches such as RP,biomechanics simulation in prosthetic dentistry.The processes of simulation has wide applications in clinical practice of dentistry and dental education.

PMID: 15014771 [PubMed]

Reliability and properties of ground Y-TZP-zirconia ceramics.

J Dent Res. 2002 Jul;81(7):487-91

Authors: Luthardt RG, Holzhüter M, Sandkuhl O, Herold V, Schnapp JD, Kuhlisch E, Walter M

Yttria-stabilized zirconia ceramics is a high-performance material with excellent biocompatibility and mechanical properties, which suggest its suitability for posterior fixed partial dentures. The hypothesis under examination is that the strength and reliability of Y-TZP zirconia ceramics are affected by the inner surface grinding of crowns, and vary with the grinding parameter. Flexural strength, surface roughness, and fracture toughness were determined on samples machined by face and peripheral grinding with varied feed velocities and cutting depths. Results have been compared with those on lapped samples. Analysis of variance and Weibull parameter were used for statistical analysis. It was found that inner surface grinding significantly reduces the strength and reliability of Y-TZP zirconia compared with the lapped control sample. Co-analysis of flexural strength, Weibull parameter, and fracture toughness showed counteracting effects of surface compressive stress and grinding-introduced surface flaws. In conclusion, grinding of Y-TZP needs to be optimized to achieve the CAD/CAM manufacture of all-ceramic restorations with improved strength and reliability.

PMID: 12161462 [PubMed - indexed for MEDLINE]