Effectiveness of a silicon-based root canal sealer for filling of simulated lateral canals.

Braz Dent J. 2007;18(1):20-3

Authors: Barbizam JV, Souza M, Cecchin D, Dabbel J

The purpose of this in vitro study was to evaluate the ability of a silicon-based root canal sealer, compared to zinc oxide and eugenol and an epoxy resin-based sealers, for filling of simulated lateral canals. Thirty extracted single-rooted human teeth were selected, conventional access was made and the working length was established 1 mm from the apical foramen. Three simulated lateral canals, one in each root third (coronal, middle and apical) were prepared in both the mesial and distal surfaces of each tooth using a size 15 reamer adapted to a low-speed handpiece. Each root canal was instrumented using ProTaper rotary files up to file F3 at the working length, and then irrigated with 2.5% NaOCl followed by EDTA. The teeth were assigned to 3 groups (n=10), according to the root canal sealer: Roeko Seal (Group 1), Sealer 26 (group 2) and Grossman's sealer (Group 3). Gutta-percha cold lateral condensation technique was performed in all groups. Postoperative radiographs were taken and the images were projected for evaluation of the quality of lateral canal filling. Data were submitted to statistical analysis by Kruskal Wallis test at 5% significance level. The results showed that Grossman's sealer filled a larger number of lateral canals than Roeko Seal (p<0.05) and Sealer 26 (p<0.01). It may be concluded that Roeko Seal silicone-based root canal sealer was not as effective as the Grossman's sealer for filling of simulated lateral canals. The lateral canals localized in the apical third of the root were more difficult to be filled.

PMID: 17639195 [PubMed - indexed for MEDLINE]

Antimicrobial analysis of different root canal filling pastes used in pediatric dentistry by two experimental methods.

Braz Dent J. 2006;17(4):317-22

Authors: Amorim Lde F, Toledo OA, Estrela CR, Decurcio Dde A, Estrela C

The objective of this study was to compare, by two experimental methods, the antimicrobial efficacy of different root canal filling pastes used in pediatric dentistry. The tested materials were: Guedes-Pinto paste (GPP), zinc oxide-eugenol paste (OZEP), calcium hydroxide paste (CHP), chloramphenicol + tetracycline + zinc oxide and eugenol paste (CTZP) and Vitapex. Fiven microbial strains (S. aureus, E. faecalis, P. aeruginosa, B. subtilis and C. albicans) obtained from the American Type Culture Collection were inoculated in Brain Heart Infusion (BHI) and incubated at 37 degrees C for 24 h. For the direct exposure test (DET), 72 paper points were contaminated with the standard microbial suspensions and exposed to the root canal filling pastes for 1, 24, 48 and 72 h. The points were immersed in Letheen Broth (LB), followed by incubation at 37 degrees C for 48 h. An inoculum of 0.1 mL obtained from LB was then transferred to 7 mL of BHI, under identical incubations conditions and the microbial growth was evaluated. The pastes showed activity between 1 and 24 h, depending on the material. For the agar diffusion test (ADT), 30 Petri plates with 20 mL of BHI agar were inoculated with 0.1 mL of the microbial suspension, using sterile swabs that were spread on the medium. Three cavities were made in each agar plate (total = 90) and completely filled with one of the filling root canal pastes. The plates were pre-incubated for 1 h at room temperature and then incubated at 37 degrees C for 24 to 48 h. The inhibition zone around each well was recorded in mm. The complete antimicrobial effect in the direct exposure test was observed after 24 h on all microbial indicators. All root canal filling materials induced the formation of inhibition zones, except for Vitapex (range, 6.0-39.0 mm).

PMID: 17262146 [PubMed - indexed for MEDLINE]

Evaluation of the antimicrobial activity of each component in Grossman's sealer.

Braz Oral Res. 2006 Apr-Jun;20(2):127-31

Authors: Savioli RN, Pecora JD, Mian H, Ito IY

The antimicrobial activity of Grossman's sealer and its components was evaluated on 13 different strains using the double layer well-diffusion method. Results revealed that Grossman's sealer presented antimicrobial activity against all the tested strains. Among the components of the cement, sodium tetraborate presented the greatest antimicrobial activity, both in type and diameter of the halo and ring of inhibition. Sealer powder, rosin, and eugenol presented similar activity, with no effect on P. aeruginosa and C. albicans. Among these, only eugenol had an effect on E. coli. Zinc oxide was only active against S. sobrinus and E. coli. Barium sulfate and bismuth subcarbonate did not show any antimicrobial effect.

PMID: 16878205 [PubMed - indexed for MEDLINE]

Effectiveness of 4 pulpotomy techniques--randomized controlled trial.

J Dent Res. 2005 Dec;84(12):1144-8

Authors: Huth KC, Paschos E, Hajek-Al-Khatar N, Hollweck R, Crispin A, Hickel R, Folwaczny M

Pulpotomy is the accepted therapy for the management of cariously exposed pulps in symptom-free primary molars; however, evidence is lacking about the most appropriate technique. The aim of this study was to compare the relative effectiveness of the Er:YAG laser, calcium hydroxide, and ferric sulfate techniques with that of dilute formocresol in retaining such molars symptom-free. Two hundred primary molars in 107 healthy children were included and randomly allocated to one of the techniques. The treated teeth were blindly re-evaluated after 6, 12, 18, and 24 months. Descriptive data analysis and logistic regression analysis, accounting for each patient's effect by a generalized estimating equation (GEE), were used. After 24 months, the following total and clinical success rates were determined (%): formocresol 85 (96), laser 78 (93), calcium hydroxide 53 (87), and ferric sulfate 86 (100). Only calcium hydroxide performed significantly worse than formocresol (p = 0.001, odds ratio = 5.6, 95% confidence interval 2.0-15.5). In conclusion, calcium hydroxide is less appropriate for pulpotomies than is formocresol.

PMID: 16304444 [PubMed - indexed for MEDLINE]

In vitro activity of zinc oxide-eugenol and glass ionomer cements on Candida albicans.

Braz Oral Res. 2005 Apr-Jun;19(2):134-8

Authors: Cassanho AC, Fernandes AM, Oliveira LD, Carvalho CA, Jorge AO, Koga-Ito CY

The aim of this study was to evaluate in vitro the antimicrobial activity of glass ionomer (GIC) and zinc oxide-eugenol (ZOE) cements against Candida albicans. Standardized GIC and ZOE specimens were maintained in contact with C. albicans suspension (1 x 10(6) cells/ml) at 37 degrees C for 24 h, 48 h or 7 days. A control group without any testing cement was included. After the incubation period, aliquots of 0.1 ml were plated on Sabouraud's agar, and then the number of colonies was counted. The results were expressed as values of logarithms of colony-forming units per milliliter (log CFU/mL) and were analyzed statistically by Kruskal-Wallis ANOVA. After 48 h of incubation, the ZOE group presented no growth of C. albicans. GIC and control groups presented similar mean values at all tested periods. According to the results obtained, it could be concluded that, under the experimental conditions, ZOE cement was more effective in vitro against C. albicans than GIC.

PMID: 16292447 [PubMed - indexed for MEDLINE]

Effect of different dye solutions on the evaluation of the sealing ability of Mineral Trioxide Aggregate.

Braz Oral Res. 2005 Apr-Jun;19(2):119-22

Authors: Tanomaru Filho M, Figueiredo FA, Tanomaru JM

Alkaline materials have shown incompatibility with methylene blue dye in leakage experiments. The goal of the present study was to analyze the effect of different dyes on the evaluation of the apical sealing ability of Mineral Trioxide Aggregate root-end fillings. Fifty-six extracted human canines were submitted to root canal instrumentation and obturation. After apical resection, retrograde cavities were prepared and teeth were randomly divided into four experimental (n = 13) and two control groups (n = 2). The following root-end filling materials were used: groups 1 and 2--Pro Root MTA (Dentsply), groups 3 and 4--zinc oxide-eugenol cement (ZOE). Teeth in groups 1 and 3 were immersed in 2% methylene blue solution, while teeth in groups 2 and 4 were immersed in 0.2% rhodamine B in a reduced pressure environment for 48 hours. Teeth were then longitudinally sectioned and leakage was evaluated. Results were submitted to statistical analysis (ANOVA and Tukey's test). Group 1 presented the least leakage (p < 0.05). It was concluded that the evaluation of the sealing ability of MTA is influenced by the dye used, since this material presented better sealing ability when evaluated with Methylene Blue, but was similar to ZOE when evaluated with rhodamine B.

PMID: 16292444 [PubMed - indexed for MEDLINE]

Microbial leakage of Cavit, IRM, and Temp Bond in post-prepared root canals using two methods of gutta-percha removal: an in vitro study.

J Contemp Dent Pract. 2005 Aug 15;6(3):53-61

Authors: Balto H, Al-Nazhan S, Al-Mansour K, Al-Otaibi M, Siddiqu Y

The aim of this study was to evaluate the integrity of the coronal seal of Temp-Bond and compare it to Cavit and IRM after post space preparation using S. faecalis as a microbial tracer. In addition, the affect of two methods of gutta percha removal on the apical seal of root canal fillings was also evaluated. Forty extracted human single rooted teeth were prepared chemomechanically and obturated with gutta percha and AH26 sealer cement using the lateral cold condensation technique to a standardized working length of 15 mm. About 10 mm of the coronal gutta-percha was removed with either Peeso-reamer or a hot plugger. The roots were divided into three experimental groups of 10 roots and a control group. Each experimental group was subdivided equally into two groups of 15 each according to the method of post space preparation. Cavit, IRM, and Temp-Bond were used to seal the access opening. Each root was fixed in a cuvette containing Tryptic Soya Broth which, covered 2 mm of the root apex. Bacterial suspension was introduced through pipette. Fresh bacterial suspension was added every week, and the system was monitored daily for the growth of microorganisms for a period of one month. The results showed there was no significant difference in terms of coronal leakage between the three coronal materials used (P=0.478), but the methods of gutta-percha removal did have an impact on the apical leakage (P=0.047). The mean value showed the Peeso-reamer provided less leakage compared to using a hot plugger during the 30-day experimental time period. It was concluded the temporary type of coronal seal of endodontically treated teeth will not prevent coronal leakage if left for a long period of time. In addition, permanent cementation of the post with the coronal restoration should be carried out as soon as possible to prevent recontamination of the root canal.

PMID: 16127472 [PubMed - indexed for MEDLINE]

Influence of zinc-oxide eugenol, formocresol, and ferric sulfate on bond strength of dentin adhesives to primary teeth.

J Contemp Dent Pract. 2005 Aug 15;6(3):14-21

Authors: Salama FS

This study evaluated in vitro the influence of a temporary filling {zinc oxide-eugenol (ZOE)} and two pulpotomy agents {formocresol (FC) and ferric sulfate (FS)} on shear bond strength (SBS) of two dentin adhesives to the dentin of primary molars. A total of 80 dentin surfaces were prepared and randomly allocated into 10 groups of 8 specimens each. Groups were subjected to different treatments, which included covering with a paste of ZOE mixed at different powder:liquid (P:L) ratios, placement on a gauze soaked in FC or FS, or they received no pretreatment and served as a control. XRV Herculite composite cylinders were bonded to dentin surfaces using Prime and Bond NT adhesive resin or Opti Bond Solo Plus adhesive resin. SBSs were determined using the lnstron testing machine running at a crosshead speed of 0.5 mm/min. The use of ZOE mixed at the lower P:L ratio of 10g:2g significantly decreased the values of SBS of the two adhesives. The use of two pulpotomy agents (FC and FS) significantly decreased the SBS of the two adhesives. The bond strength to dentin of primary teeth was influenced by the pulpotomy agents used and the ZOE P:L ratio but not by the adhesive system used.

PMID: 16127468 [PubMed - indexed for MEDLINE]

Endodontics.

J Am Dent Assoc. 2005 May;136(5):581-2; author reply 582

Authors: Piacine MJ

PMID: 15966645 [PubMed - indexed for MEDLINE]

Success of an alternative for interim management of irreversible pulpitis.

J Am Dent Assoc. 2004 Dec;135(12):1707-12

Authors: McDougal RA, Delano EO, Caplan D, Sigurdsson A, Trope M

BACKGROUND: Extraction and endodontic therapy are treatment options for irreversible pulpitis. Extraction often is chosen for financial reasons. The authors conducted a study to investigate an alternative interim therapy. METHODS: The authors recruited patients (N = 73) with irreversible pulpitis and whose teeth were restorable but who opted for extraction owing to financial reasons. After undergoing pulpotomy, the teeth were restored by random assignment with one of two intermediate restorative materials: Caulk IRM (Dentsply Caulk, Milford, Del.) (Group I, n = 38) or an IRM base with glass ionomer core (Fuji IX GP, GC America, Alsip, Ill.) (Group II, n = 35). The authors monitored the teeth over six and 12 months for pain, integrity of restoration and radiographic periapical status by densitometric analysis. RESULTS: By six months, 10 percent of subjects remaining in the study (Group I, n = 27; Group II, n = 25) reported pain; by 12 months, 22 percent (Group I, n = 22; Group II, n = 18) reported pain. A two-tailed Fisher exact test showed no significant difference (P > or = .05) between groups at either time interval. No apical radiographic change was noted in 49 percent of teeth at six months (Group I, n = 18; Group II, n = 19) and 42 percent at 12 months (Group I, n = 16; Group II, n = 15). Chi2 analysis demonstrated no significant differences (P > or = .05) between groups. Seven of 22 restorations in Group I and four of 18 in Group II required repair at 12 months with no statistical difference (chi2 analysis, P > or = .05). CONCLUSIONS: The interim treatment of eugenol pulpotomy using either restorative material reliably prevented pain for six months. For longer periods, both restorations may require repair. CLINICAL IMPLICATIONS: This option should preserve the integrity of the arch and extend the use of the tooth while the patient finds the means to finance complete endodontic treatment.

PMID: 15646604 [PubMed - indexed for MEDLINE]

The pH changes of four different root canal sealers after mixing at various time intervals in vitro.

J Contemp Dent Pract. 2004 Nov 15;5(4):71-8

Authors: Evcil MS, Colak M

The purpose of this study was to compare the surface pH level of four different type sealers after mixing at various time intervals in vitro. After cleaning and shaping root canals in 50 recently extracted, single-rooted human teeth, they were divided into six groups. Each of four groups was obturated with Apexit, N2, Sealapex, and Grossman sealers. The remaining groups served as controls. In group 1 nothing was added to the vial of saline solution. In group 2 canals had been instrumented but not obturated with sealer. The pH level of saline solutions was determined at intervals of 1 hour, 4 hours, 1 day, 2 days, 3 days, 1 week, and 4 weeks after teeth were placed in them. The pH levels of the five solutions were compared to each other and to that of saline solution only.

PMID: 15558092 [PubMed - indexed for MEDLINE]

Making provisional restorations easy, predictable and economical.

J Am Dent Assoc. 2004 May;135(5):625-7

Authors: Christensen GJ

PMID: 15202755 [PubMed - indexed for MEDLINE]

Root-end filling materials alter fibroblast differentiation.

J Dent Res. 2004 May;83(5):408-13

Authors: Bonson S, Jeansonne BG, Lallier TE

Root-end filling materials are commonly used following endodontic surgical procedures; however, their effect on adjacent soft tissues is poorly understood. We predict that, due to the differences in their chemical composition, these materials will have profoundly different effects on the survival and differentiation of fibroblasts. Many of the root-end filling materials examined were initially cytotoxic to both PDL and gingival fibroblasts in co-culture experiments; however, this was reduced after the materials were washed in either mineral trioxide aggregate (MTA) or hybrid ionomere composite resin (HICR) for 2 wks. Additionally, PDL fibroblasts displayed enhanced proliferation on MTA and survival on amalgam when compared with gingival fibroblasts. MTA preferentially induced alkaline phosphatase expression and activity in both PDL and gingival fibroblasts. In contrast, HICR inhibited alkaline phosphatase expression and activity. In addition, MTA and HICR repressed pleiotrophin in PDL fibroblasts, while HICR repressed periostin in both fibroblasts. Thus, root-end filling materials differentially affect periodontal fibroblast differentiation. Abbreviations: mineral trioxide aggregate (MTA), zinc-oxide eugenol cement (ZOEC), hybrid ionomer composite resin (HICR), reverse-transcriptase polymerase chain-reaction (RT-PCR).

PMID: 15111634 [PubMed - indexed for MEDLINE]

Effects of oral environment stabilization procedures on counts of Candida spp. in children.

Pesqui Odontol Bras. 2003 Oct-Dec;17(4):332-6

Authors: do Rego MA, Koga-Ito CY, Jorge AO

The effects of oral environment stabilization procedures on counts of Candida spp. have rarely been discussed, and no conclusive results are found in the literature. The aim of this study was thus to ascertain the effects of oral environment stabilization procedures with glass ionomer and zinc oxide-eugenol cements on counts of Candida spp. in the oral cavity of children. For this purpose, oral rinses of sterile phosphate-buffered saline were initially collected from 30 boys and 30 girls, positive for Candida in the saliva and aged from 4 to 10 years. Data on the initial quantity of CFU/ml of Candida were obtained. Then, the children were randomly divided into two groups and oral environment stabilization procedures were performed using zinc oxide-eugenol cement or glass ionomer cement. One week after the procedures were performed, oral rinses were collected again and final Candida counts were obtained. An expressive reduction in Candida counts was observed in both groups. The zinc oxide-eugenol and glass ionomer cements were efficient in the reduction of Candida counts and statistically significant differences were observed between initial and final counts in both groups. Considering the percentage of reduction, the zinc oxide-eugenol cement presented more favorable results, with a reduction of 70%. A reduction of 46% was observed with the use of the glass ionomer cement. According to the obtained results, we concluded that oral environment stabilization procedures were efficient in reducing Candida spp. counts, especially when the zinc oxide-eugenol cement was employed.

PMID: 15107915 [PubMed - indexed for MEDLINE]

[Clinical evaluation of zinc oxide eugenol and Vitapex as root canal filling materials in primary teeth]

Shanghai Kou Qiang Yi Xue. 2003 Oct;12(5):377-9

Authors: Zhang XF, Xu XB

PMID: 14966617 [PubMed - indexed for MEDLINE]

Tissue reactions after intraosseous implantation of three retrofilling materials.

Bull Tokyo Dent Coll. 2003 Feb;44(1):1-7

Authors: Morinaga K, Nakagawa K, Carr GB

Bone tissue reactions to EBA, IRM, and cyanoacrylate cement (Base Liner) were studied in the rat mandible using an intraosseous implant method. Osseous cavities (1.4 mm in diameter) were surgically created in the mandibles, and materials were implanted in 60 male Wistar rats. Each specimen was evaluated histologically after 4 and 8 weeks. The development of fibrous connective tissue in direct apposition to the material was observed in the EBA and IRM groups at 4 weeks. A slight degree of macrophage infiltration was seen in the EBA group. After the 8-week observation period, IRM and EBA were frequently separated from the bone cavity by a fibrous connective tissue layer (p < 0.01). The Base Liner appeared to be in direct apposition to the osseous tissue in several areas (p < 0.01). These findings indicate that Base Liner reacts favorably with osseous tissue, compared with the EBA and IRM materials tested and seems to be a biocompatible material.

PMID: 12772580 [PubMed - indexed for MEDLINE]

Pulp-capping with recombinant human insulin-like growth factor I (rhIGF-I) in rat molars.

Adv Dent Res. 2001 Aug;15:108-12

Authors: Lovschall H, Fejerskov O, Flyvbjerg A

The aim of this study was to explore pulp healing and reparative dentinogenesis following pulp-capping by using recombinant human insulin-like growth factor I (rhIGF-I). Exposures were made through the mesial pulp horn in first upper molars in two-month-old Wistar rats. The pulp was covered with one dose of sterile 4% methylcellulose gel containing either 400 ng rhIGF-I or saline in contralateral controls. The exposure site was closed with sterile Teflon membrane, and the cavity was filled with IRM cement. Additional molars were capped with Dycal as controls. After 3, 7, or 28 days, animals were anesthetized and fixed by intravascular glutaraldehyde perfusion. Molars were decalcified and processed for histological analysis and cut with membrane and residual methacrylate from IRM in situ. Only specimens with acceptable pulp sealing according to blinded microscopy control were included. On day 3, identical inflammatory responses in the upper pulp were observed in molars with rhIGF-I gel or control gel. On day 7, granulation tissue ingrowth had partly replaced inflammatory infiltration in both groups. After 28 days, complete dentin bridging and tubular dentin formation were observed more frequently and closer to the test substance containing rhIGF-I. The reparative dentin response to capping with rhIGF-I was similar to that after the use of Dycal. In conclusion, microscopic control of membrane sealing in situ gives valid information on the more subtle pulp effects of growth factors. The observations suggest that pulp-capping of rat molars by means of rhIGF-I enhances reparative dentinogenesis in comparison with vehicle controls.

PMID: 12640754 [PubMed - indexed for MEDLINE]

Adverse reactions associated with the use of eugenol in dentistry.

Br Dent J. 2002 Sep 14;193(5):257-9

Authors: Sarrami N, Pemberton MN, Thornhill MH, Theaker ED

Eugenol is a material commonly used in dentistry with few reported side effects. It is not however, a bio-friendly material when in contact with oral soft tissues. It can produce both local irritative and cytotoxic effects, as well as hypersensitivity reactions. Here we report on two cases of adverse local reaction to eugenol, contained within a temporary restorative material and a temporary cementation material respectively, which illustrate these problems.

PMID: 12353045 [PubMed - indexed for MEDLINE]

Influence of the spatulation of two zinc oxide-eugenol-based sealers on the obturation of lateral canals.

Pesqui Odontol Bras. 2002 Apr-Jun;16(2):127-30

Authors: Pecora JD, Ribeiro RG, Guerisoli DM, Barbizam JV, Marchesan MA

The objective of this research was to evaluate, in vitro, the importance of the correct manipulation of endodontic sealers, correlating it with flow rate and with the consequent obturation of root canals. Twenty-four human canines were prepared, 1 mm from the apex, with K-files up to size 50, by means of the step-back technique. Six lateral canals were then drilled in each tooth, with size 10 file fixed to a low-speed handpiece. The teeth were randomly divided into 4 groups, and root canals were obturated either with the Endom&#xE9;thasoneregister mark or target sealer or Grossman sealer, prepared at ideal or incorrect clinical consistency. After obturation by means of the lateral condensation technique, the teeth were radiographed and evaluated as to the number of sealed lateral canals. Statistical analysis revealed significant differences (p < 0.001) between the tested sealers, and indicated the higher capacity of the well-manipulated Grossman sealer to fill lateral canals. It can be concluded that the flow rate of a sealer and its correct manipulation are very important for the satisfactory obturation of lateral canals.

PMID: 12131985 [PubMed - indexed for MEDLINE]

Restorative pulpal and repair responses.

J Am Dent Assoc. 2001 Apr;132(4):482-91

Authors: Murray PE, About I, Franquin JC, Remusat M, Smith AJ

BACKGROUND: Each year, about 90 million new restorations are placed in the United States and 200 million are replaced. Controversy surrounds the pulpal reactions and frequency of bacterial microleakage associated with common restorative materials. The authors investigated and compared pulpal reactions to different types of restorative materials. METHODS: Two hundred seventy-two teeth with standardized rectangular Class V unexposed cavities were restored with resin-based composite bonded to dentin; resin-based composite bonded to enamel; resin-modified glass ionomers, or RMGI; amalgam lined with zinc polycarboxylate, or ZnPC; amalgam lined with calcium hydroxide, or Ca(OH)2; or zinc oxide-eugenol, or ZnOE. Teeth were extracted for orthodontic reasons between 20 and 381 days later. The authors categorized pulpal responses according to standards set by the Federation Dentaire Internationale and the International Organization for Standardization. Bacteria were detected using Brown-Brenn-stained sections. Pulpal responses were evaluated using histomorphometric analysis and analysis of variance statistics. RESULTS: The results showed that RMGI was the best material for preventing bacterial microleakage, and resin-based composite bonded to enamel was the worst. In regard to minimizing pulpal inflammatory activity, ZnOE was the best material and resin-based composite bonded to enamel was the worst. In terms of maximizing odontoblast survival beneath deep cavity preparations, Ca(OH)2, was the best material and RMGI was the worst. CONCLUSIONS: The results show that bacterial microleakage, pulpal injury and repair responses varied widely with different restorative materials. CLINICAL IMPLICATIONS: The authors recommend that RMGI be used to restore teeth with cavities that are shallow to moderate in depth, with the floor of deep cavities being lined with Ca(OH)2 before the teeth are restored with RMGI.

PMID: 11315379 [PubMed - indexed for MEDLINE]

Mineral trioxide aggregate: a new material for endodontics.

J Am Dent Assoc. 1999 Jul;130(7):967-75

Authors: Schwartz RS, Mauger M, Clement DJ, Walker WA

BACKGROUND: Mineral trioxide aggregate, or MTA, is a new material developed for endodontics that appears to be a significant improvement over other materials for procedures in bone. It is the first restorative material that consistently allows for the overgrowth of cementum, and it may facilitate the regeneration of the periodontal ligament. CASE DESCRIPTION: The authors present five cases in which MTA was used to manage clinical problems. These included vertical root fracture, apexification, perforation repair and repair of a resorptive defect. In each case, MTA allowed bone healing and elimination of clinical symptoms. CLINICAL IMPLICATIONS: Materials such as zinc oxide-eugenol cement and resin composite have been used in the past to repair root defects, but their use resulted in the formation of fibrous connective tissue adjacent to the bone. Because it allows the overgrowth of cementum and periodontal ligament, MTA may be an ideal material for certain endodontic procedures.

PMID: 10422400 [PubMed - indexed for MEDLINE]

Pulpal response to cavity preparation by an erbium, chromium:YSGG laser-powered hydrokinetic system.

J Am Dent Assoc. 1997 Aug;128(8):1099-106

Authors: Eversole LR, Rizoiu I, Kimmel AI

The near red-pulsed erbium, chromium:yttrium-scandium-gallium-garnet laser hydrokinetic system, or Er,Cr:YSGG laser HKS, is effective in cutting dental hard tissues. In this longitudinal study, the authors studied the continuously erupting open-apex incisors of New Zealand albino rabbits and the constricted apex teeth of beagles to determine the effects of HKS-produced lesions at various energy levels and of preparations produced by a tapered fissure bur on dental pulp. No pulpal inflammatory responses could be identified either immediately or 30 days after surgery in HKS preparations that removed enamel and dentin without pulp exposure.

PMID: 9260419 [PubMed - indexed for MEDLINE]

Microleakage of three cement bases.

J Dent Res. 1991 Jan;70(1):55-8

Authors: Heys RJ, Fitzgerald M

The purpose of this study was to evaluate the ability of a glass-ionomer cement-base material to prevent bacterial penetration along the dentin interface and to compare it with two conventional cement-base materials. A total of 107 Class 5 restorations was placed in Rhesus monkey teeth by means of three test materials [zinc oxide-eugenol (ZOE), copalite varnish + zinc phosphate cement base (V + ZP), and a glass-ionomer lining cement (GI)], with unetched and unbonded resin composite used alone as a control material and as a final restoration over the test base materials. Following disinfection, Class 5 cavities were prepared on the buccal surfaces of the teeth to the inner one-half of dentin. A sterile filter-paper disk was then placed on the axial wall and covered with a Teflon disk. Next, the cavities were based to the dento-enamel junction with one of the test base materials and finally restored with unetched and unbonded resin composite. After five and 16 weeks, the filter-paper disks were retrieved and cultivated for the presence and type of bacteria. The five-week results showed positive growth in two groups: the composite-only controls and the V + ZP group. The 16-week results showed growth in all of the test groups, but only one of nine teeth showed growth in the zinc oxide-eugenol group and one of 16 teeth in the glass-ionomer group. The results of this study indicate that under the conditions tested, a glass-ionomer base was capable of minimizing bacterial penetration along the material-tooth interface.

PMID: 1991861 [PubMed - indexed for MEDLINE]

In vivo and in vitro effects of zinc oxide-eugenol (ZOE) on biosynthesis of cyclo-oxygenase products in rat dental pulp.

J Dent Res. 1988 Aug;67(8):1092-6

Authors: Hashimoto S, Uchiyama K, Maeda M, Ishitsuka K, Furumoto K, Nakamura Y

To determine the in vivo effects of a zinc oxide-eugenol mixture (ZOE) on the cyclo-oxygenase system in dental pulp, we used radioimmunoassay to measure the levels of prostaglandin E2 (PGE2), 13,14-dihydro-15-keto-PG (DHK-PG), thromboxane B2 (TXB2), and 6-keto-PGF1 alpha in the dental pulp of rats. When the dental pulp was irritated by a hole made in the dentin of the mandibular incisors without use of any coolants, the levels of these cyclo-oxygenase products in the pulp were increased to, respectively, 2.8, 1.7, 10.0, and 2.6 times those in the normal pulp at six hr after treatment. In contrast, these increases in cyclo-oxygenase products disappeared immediately when the artificial cavity in the dentin was filled with ZOE (P/L; 1 g/0.25 mL), but were not altered when the cavity was filled with zinc oxidewater (ZOW, 1 g/1.5 mL). Most of the eugenol portion of ZOE was released into the pulp within two hr after the cavity was filled with ZOE. The maximal eugenol content was 35 pmol per mg of pulp. Furthermore, when the cavity was filled either with ZOE or by the addition of 10 mumol/L eugenol to the pulp homogenate, biosynthesis of 14C-6-keto-PGF1 alpha, PGF2 alpha, and PGE2 from 14C-arachidonic acid in the homogenate was inhibited. These results suggest that eugenol released from ZOE in the cavity prepared in the dentin inhibited the biosynthesis of cyclo-oxygenase products during pulp irritation.

PMID: 3165402 [PubMed - indexed for MEDLINE]

The influence of restorative dental materials on heat transmission in human teeth.

J Dent Res. 1984 Aug;63(8):1096-100

Authors: Spierings TA, de Vree JH, Peters MC, Plasschaert AJ

Using the finite element method, we analyzed the temperature distribution and heat flow patterns in an axisymmetric tooth model. The models of an unrestored tooth and three teeth restored with different restorative materials were evaluated comparatively. The insulating ability of a calcium hydroxide cement base (Ca(OH)2) is low, which is inherent in its insufficient thermal and poor mechanical properties. In the given conditions, the Ca(OH)2 base reduces the temperature increase at the cement-dentin interface by 12.5% with respect to a restoration of amalgam only. By using a double base (Ca(OH)2 + polymer-modified zinc oxide-eugenol), the reduction is 21.9%. With respect to a sound tooth model, the presence of a double base in the restored tooth caused a temperature increase of only 0.1 degree C at the pulpo-dentinal junction. The thermal conductivity coefficient (lambda) of amalgam does not have any influence on the results of the calculations. The heat transfer coefficient (alpha) turned out to be an essential parameter in this mathematical model.

PMID: 6589271 [PubMed - indexed for MEDLINE]

An analysis of the release and the diffusion through dentin of eugenol from zinc oxide-eugenol mixtures.

J Dent Res. 1984 Jun;63(6):881-4

Authors: Hume WR

Tritium-labeled eugenol was released from mixtures of zinc oxide eugenol (ZOE) into aqueous solution at rates which declined exponentially with time, and which were directly proportional to the liquid-powder ratio. The release pattern was consistent with a model of progressive hydrolysis of zinc eugenolate in a limited-thickness ZOE surface layer. Intervening dentin had a profound effect on this pattern of release. In human teeth in vitro containing ZOE as a base or temporary filling, peak eugenol release at the pulpal surface of dentin was of the order of a thousand-fold less than that at the salivary surface. In such teeth, eugenol reached concentrations in excess of 10(-2) M in dentin just beneath ZOE, and 10(-4) M or less adjacent to the pulp space. Both pulpal outflow and dentin concentrations of eugenol remained relatively constant for more than a week, unlike release into aqueous solution. While these data were derived from studies on human teeth in vitro, they give a strong indication of probable events in vivo, and appear to provide a basis for the explanation of the paradox of the therapeutic and toxic actions of ZOE.

PMID: 6588071 [PubMed - indexed for MEDLINE]

Degradation of luting cements measured in vitro.

J Dent Res. 1982 May;61(5):665-72

Authors: Mesu FP

The described method of measuring degradation of luting cements in vitro, by which various media, including bacteriological, can be used, gives results indicating that degradation is a more complex process than could previously be measured. Degradation appears to be a process following a sequence of absorption, disintegration, and solution. Factors, such as cement, thickness of the cement layer, molarity, and pH of the medium, affect, mostly by interaction, the degradation speed. Though the clinical predictability of this test method is not yet determined, it gives the opportunity to measure the various stages of degradation and to appoint the different factors affecting this process. Clinical tests based on the same principle are in progress.

PMID: 6953094 [PubMed - indexed for MEDLINE]

A comparison of the inflammatory response produced by commercial eugenol and purified eugenol.

J Dent Res. 1981 Sep;60(9):1724-8

Authors: Webb JG, Bussell NE

Eugenol "purified" by HPLC20 was compared to commercial USP eugenol to determine if any difference exists between the inflammatory response caused by each. Mixtures of each eugenol with zinc oxide were also compared. Each material was injected subcutaneously beneath the abdominal skin of 40 Walter Reed white rats. Ten animals were sacrificed at four different dates, and the degree of necrosis and inflammation was compared. The purified eugenol caused less necrosis and inflammation at all times than did the commercial eugenol. The purified ZOE mixture produced less necrosis and inflammation than the commercial ZOE mixture at each sacrifice date. The two mixtures of ZOE and the two samples of eugenol produced roughly parallel amounts of inflammation, suggesting that the degree of inflammation of ZOE mixtures is strongly influenced by the amounts of free eugenol in the mixtures. This study suggests that the impurities in commercial eugenol do cause an increase in the inflammatory response in the rat system studied. This increase is most evident at day two and after day ten.

PMID: 6943167 [PubMed - indexed for MEDLINE]

Zinc oxide eugenol cements. V. Instrumental studies of the catalysis and acceleration of the setting reaction.

J Dent Res. 1980 Jan;59(1):44-54

Authors: Crisp S, Ambersley M, Wilson AD

Zinc oxide eugenol (ZOE) cements were prepared by mixing powders of widely differing reactivity with a variety of liquid formulations. The course of the setting reaction was followed by penetrometer, rheological and electrical techniques. Small amounts of water, organic acids, and the reactivity of water, organic acids, and the reactivity of the zinc oxide all have a profound influence on the setting characteristics of cement pastes.

PMID: 6927984 [PubMed - indexed for MEDLINE]

Biological evaluation on glass ionomer cement.

J Dent Res. 1979 Mar;58(3):1080-6

Authors: Kawahara H, Imanishi Y, Oshima H

Biological properties of a new dental cement of glass ionomer cement were compared with other types of conventional cement. The biological test was carried out by tissue culture method and animal examination. The culture cells showed weaker reaction to the glass ionomer cement than zinc oxide-eugenol or polycarboxylate cement. Pulp tissue reaction showed no significant difference between glass ionomer and zinc oxide-eugenol cement from in vivo experiments using monkeys.

PMID: 106077 [PubMed - indexed for MEDLINE]

The metal oxide/eugenol cements. II. A diffuse reflectance spectrophotometric study of the setting of zinc oxide and magnesium oxide cements.

J Dent Res. 1978 Jul-Aug;57(7-8):805-9

Authors: Douglas WH

In a continuing study, spectrophotometry has been used to study the diffuse reflectance of the setting of ZnO and MgO cements.

PMID: 281353 [PubMed - indexed for MEDLINE]

Clinical study of dental cements. VII. A study of bridge retainers luted with three different dental cements.

J Dent Res. 1978 May-Jun;57(5-6):703-7

Authors: Silvey RG, Myers GE

In a clinical study of three luting cements, 547 bridges and 162 crowns were permanently cemented. Patients were recalled at 6-month intervals and the restorations were examined for looseness. A pattern of retainer type, cement type and retainer success was demonstrable.

PMID: 279587 [PubMed - indexed for MEDLINE]

SEM identification of zinc eugenolate crystals in postoperatively collected ZOE cements.

J Dent Res. 1977 Oct;56(10):1264

Authors: Bayne SC, Pfaffenbach HE, Marshall GW

PMID: 272393 [PubMed - indexed for MEDLINE]

Clinical study of dental cements. VI. A study of zinc phosphate, EBA-reinforced zinc oxide eugenol and polyacrylic acid cements as luting agents in fixed prostheses.

J Dent Res. 1977 Oct;56(10):1215-8

Authors: Silvey RG, Myers GE

A clinical trial for the final cementation of crowns and bridges with a reinforced zinc oxide and eugenol cement, a polyacrylic acid cement and a zinc phosphate cement was made over a 3-year period. The study involved 441 patients for whom 547 bridges and 162 single restorations were cemented. The patients were recalled at 6-month intervals for the duration of the study and the restorations were examined for looseness. Of the 547 bridges 520 remained firmly cemented to the abutment teeth. Of 1,082 bridge retainers, 1,049 remained in position; success and failure by types of retainer will be the subject of a subsequent paper. Of the 162 single restorations 159 remained in place.

PMID: 272385 [PubMed - indexed for MEDLINE]

Primate pulpal response to ultraviolet light-polymerized direct-bonding material systems.

J Dent Res. 1976 Nov-Dec;55(6):1118-24

Authors: Myers CL, Stanley HR, Heyde JB, Chamberlain J

The results of this study, plus those of a previous study, show that a layer of CaOH lining the floor of the tooth cavity will protect the dental pulp against toxic irritants inherent to an UV light-polymerized cavity liner and a UV light-polymerized composite restorative resin. This study also showed that a layer of CaOH lining the floor of the cavity will protect the dental pulp against acid irritants inherent in the enamel etching solution. It is recommended to restorative dentistry that all primary dentin within clinically accessible areas of the cavity preparation be covered with a layer of CaOH before the enamel is etched with the acid-conditioning solution. Precautionary protection of primary dentin in this manner affords a margin of safety should the conditioning solution inadvertently spill onto the primary dentin during the enamel-etching procedure. Second, if the conditioning solution does accidentally spill onto the previously placed protective layer of CaOH during the enamel-etching procedure, then it logically follows that this acid-contaminated layer of CaOH should be mechanically removed and a new layer of CaOH that completely lines at least the floor of the tooth cavity should be placed before the resins are applied.

PMID: 826551 [PubMed - indexed for MEDLINE]

Specification test for the solubility and disintegration of dental cements: a critical evaluation of its meaning.

J Dent Res. 1976 Sep-Oct;55(5):721-9

Authors: Wilson AD

The specification test for solubility and disintegration is an essential screening test for the quality control of certain cement types. No cement fails it can be considered for use; however, the test has only a limited clinical significance because it does not give an indication of the stability of the fully hardened cement matrix either in oral fluids or water. Instead, it gives a measure of the content of the soluble reaction intermediate present in cements that are still hardening and where the matrix has not fully formed. The test relates, therefore, to early vulnerability to aqueous attack and hardening rate. The period of test is, in fact, an atypical one and the true extent of the erosion of the cement matrix is obscured by the presence of soluble reaction intermediates. Long-term extrapolations cannot be made and so test results for broadly satisfactory cements within a category cannot be used for valid comparisons of clinical excellence, and they can be used even less to compare different cement types with different setting reactions. For example, in general, the dental silicate cement has a higher solubility and distinegration figure than the zinc phosphate cement because it contains soluble sodium salt and hardens more slowly. However, it is more stable under oral conditiont an indication of the vulnerability of the forming matrix to attack. The test is not valid when applied to zinc oxide-eugenol cements because the products of decomposition are either virtually water-insoluble or volatile and therefore not measured under the conditions of the test. A method is suggested for overcoming this deficiency. The test needs to be supplemented by other tests done on fully hardened cements for longer periods of time and in mediums that can represent oral conditions. One example would be to stimulate acid conditions developed in stagnation areas. A total estimation of decomposition products, both soluble and insoluble, is called for rather than the determination of soluble materials only.

PMID: 1067288 [PubMed - indexed for MEDLINE]

Thermal diffusion through amalgam and cement base: comparison of in vitro and in vivo measurements.

J Dent Res. 1976 May-Jun;55(3):441-51

Authors: Tibbetts VR, Schnell RJ, Swartz ML, Phillips RW

Thermal diffusion was measured in vitro and in vivo through amalgam and amalgam underlaid with bases of zinc phosphate, zinc oxide-eugenol, and calcium hydroxide cements. Although the magnitudes differed, there generally was good agreement between in vitro and in vivo data with respect to the relative rates of thermal diffusivity through amalgam restorations underlaid with bases of each of the three materials. In all tests, both in vitro and in vivo, the zinc oxide-eugenol base proved to be the best thermal insulator. Calcium hydroxide was the next best thermal barrier and was followed by zinc phosphate cement. In vitro tests indicated dentin to be a better thermal insulator than zinc phosphate cement but inferior to the zinc oxide-eugenol and calcium hydroxide base materials used here. Although a method has been presented here for the in vivo assessment of the efficacy of thermal insulating bases and a number of in vivo experiments were conducted, much research remains to be done in this area. Additional investigation is needed to better define the parameters of thermal change beneath various types of restoratives and also to establish more exactly the role of base thickness in providing thermal protection beneath clinical metallic restorations.

PMID: 1063755 [PubMed - indexed for MEDLINE]

Clinical studies of dental cements: V. Recall evaluation and a zinc phosphate cement.

J Dent Res. 1976 Mar-Apr;55(2):289-91

Authors: Silvey RG, Myers GE

Patients with restorations cemented with a reinforced zinc oxide-eugenol cement and a zinc phosphate cement were recalled after a four- to seven-year interval. No significant differences in clinical success were observed between restoration luted with the two cements. No significant difference in the incidence of caries at the restoration margins was noted between the cements.

PMID: 1062430 [PubMed - indexed for MEDLINE]

Examination of the test for compressive strength applied to zinc oxide eugenol cements.

J Dent Res. 1976 Jan-Feb;55(1):142-7

Authors: Wilson AD

The distribution of compressive strength results for a zinc oxide eugenol cement is negatively skewed. However, removal of a small number of outlying low results converts the distribution to a normal one. Crosshead speed and friction at the anvil have no significant effect on results, but compressive strength is a function of the diameter-length ratio of the cylinder and increases with this ratio.

PMID: 1060649 [PubMed - indexed for MEDLINE]

In vivo tetracycline labeling of experimentally induced reparative dentin in human teeth.

J Dent Res. 1975 May-Jun;54(3):444-8

Authors: Tagger M, Perlmutter S, Galon H, Helft M

Tetracycline hydrocholoride was administered to label reparative dentin in teeth indicated for extraction. Deep cavities or pulp capping performed on the teeth one of four months before extraction served as a stimulus for new dentin formation. Examination of undemineralized sections under ultraviolet light revealed fluorescent bands in the reparative dentin of most teeth. The technique can be safely used in studies of the effects of clinical procedures on the dentin and pulp of human teeth.

PMID: 1056349 [PubMed - indexed for MEDLINE]

Effects of cement bases on the stresses in amalgam restorations.

J Dent Res. 1975 Jan-Feb;54(1):10-5

Authors: Farah JW, Hood JA, Craig RG

A computerized dental model was used to study the stress induced in a Class 1 amalgam restoration when supported by bases of varying materials and thickness. Under the same load, the maximum tensile stresses and deflections in the amalgam restoration increased at least threefold with a zinc oxide-eugenol base as compared with a ZnPO4 cement base.

PMID: 1053748 [PubMed - indexed for MEDLINE]

Temperature in the pulp chamber during polishing of amalgam restorations.

J Dent Res. 1974 Sep-Oct;53(5):1189-95

Authors: Grajower R, Kaufman E, Rajstein J

PMID: 4529128 [PubMed - indexed for MEDLINE]

Dielectric properties of zinc oxide-eugenol type cements.

J Dent Res. 1974 Sep-Oct;53(5):1263-7

Authors: Braden M, Clarke RL

PMID: 4529083 [PubMed - indexed for MEDLINE]

Chemical nature of cementing matrixes of cements formed from zinc oxide and 2-ethoxybenzoic acid-eugenol liquids.

J Dent Res. 1974 Jan-Feb;53(1):146

Authors: Wilson AD, Mesley RJ

PMID: 4520438 [PubMed - indexed for MEDLINE]

Pulp reaction to a resin-bonded quartz composite material.

J Dent Res. 1973 Nov-Dec;52(6):1281-6

Authors: Tobias M, Cataldo E, Shiere FR, Clark RE

PMID: 4357227 [PubMed - indexed for MEDLINE]

Effect of zinc oxide-eugenol cement containing monofluorophosphate on fluoride uptake and solubility of enamel.

J Dent Res. 1973 Sep-Oct;52(5):1065-9

Authors: Wei SH, Bitner TJ

PMID: 4517745 [PubMed - indexed for MEDLINE]

Effect of addition of Cafpo3 to a zinc oxide-eugenol base liner on the michrohardeness and fluoride content of dentin.

J Dent Res. 1973 May-Jun;52(3):467-71

Authors: Wolf O, Gedalia I, Reinsstein I, Goldman H, Stieglitz H

PMID: 4521638 [PubMed - indexed for MEDLINE]

Zinc oxide-eugenol cements. IV. Microstructure and hydrolysis.

J Dent Res. 1973 Mar-Apr;52(2):253-60

Authors: Wilson AD, Clinton DJ, Miller RP

PMID: 4511306 [PubMed - indexed for MEDLINE]

Histopathological study of a quartz-filled composite dental restorative material.

J Dent Res. 1973 Mar-Apr;52(2):362-5

Authors: Adams RJ, Lord GH

PMID: 4347830 [PubMed - indexed for MEDLINE]

Further studies of resin-modified temporary restorative materials.

J Dent Res. 1973 Jan-Feb;52(1):59-64

Authors: Civjan S, Huget EF, De Simon LB, Rapheld TV

PMID: 4509506 [PubMed - indexed for MEDLINE]