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At least 649 records · Page 36Linked to original sources
PubMed2003

Dens evaginatus of anterior teeth (talon cusp): report of five cases.

The talon cusp, or dens evaginatus of anterior teeth, is a relatively rare dental developmental anomaly characterized by the presence of an accessory cusplike structure projecting from the cingulum area or cementoenamel junction. This occurs in either maxillary or mandibular anterior teeth in both the primary and permanent dentition. This article reports five cases of talon cusp, two of them bilateral, affecting permanent maxillary central and lateral incisors and canines that caused clinical problems related to caries or occlusal interferences.

Adult↗
PubMed2003

The microleakage between alloy and polymeric materials in veneer crowns.

OBJECTIVE: This study investigated the cervical microleakage between a cobalt-chromium (Co-Cr) alloy and four indirect polymeric veneering materials using different adhesive systems. METHOD AND MATERIALS: The Co-Cr-based alloy for fixed prosthesis used in this study (Biosil F, Degussa) was veneered with four different polymeric materials: Artglass, Chromasit, Solidex, and Superacryl. RESULTS: Superacryl produced the highest microleakage score (4 +/- 0.0). The least microleakage at the interface was produced by Artglass (1 +/- 0.816), followed by Chromasit (2 +/- 1.414) and Solidex (2.5 +/- 1.0). Only the differences between Artglass and Superacryl were significant. CONCLUSION: Within the limitations of this in vitro study, cervical microleakage between the coping and the veneer depended on the particular polymeric material used for veneering. Leakage was significantly lower when resin materials were used together with a chemical conditioning system (ie, Artglass/Siloc).

Analysis of Variance↗
PubMed2003

Cervical dentin hypersensitivity. Part III: resolution following occlusal equilibration.

OBJECTIVE: This retrospective study was designed to investigate changes of cervical dentin hypersensitivity (CDH) in response to occlusal equilibration. METHOD AND MATERIALS: Written records for 250 active-care patients were randomly selected and analyzed for associations between CDH, and its resolution following occlusal equilibration. Patients in group A (treatment) and B (delayed treatment) received occlusal equilibration following the detection of verified CDH using the air indexing method. Group C patients were not detected with verified CDH during the study period of 17 years. The resolution of CDH was measured by the loss of a positive patient threshold response to air stimulation. RESULTS: Significant associations existed between CDH, hyperfunction, parafunction, and abfractive lesions. Furthermore, it was found that occlusal equilibration resulted in the long-term resolution of CDH. CONCLUSIONS: The resolution of CDH by occlusal equilibration, thus negating the null hypothesis, suggests that further studies are indicated to evaluate the impact of these findings upon restoring and maintaining health of the masticatory system.

Adult↗
PubMed2003

Influence of the number of sections on reliability of in vitro microleakage evaluations.

PURPOSE: To test how the number of sections affects the maximum depth of tracer penetration. MATERIALS AND METHODS: This study was simultaneously performed in three different centers. C-shaped Class V cavities were made on 60 human third molars. The cavities were located across the cementum-enamel junction. One restorative system was used: Scotchbond Multi-Purpose and Z100. After restoration, the samples were thermally cycled 3000 times, between 5 and 55 degrees C with a dwell time immersion of 10 seconds. Silver nitrate was used by two centers and basic fuchsin was used by the third. The teeth were longitudinally sectioned with a diamond saw: 5 sections per tooth provided 10 surfaces for evaluation. The penetration of the tracer was recorded on a scale from 0 to 3. The deepest leakage per restoration was identified for comparison with lesser measured values elsewhere in the tooth. The Spearman test was applied to evaluate the relationship between the reference and data from one, two and three sections (i.e. two, four and six measurements). The Kruskal-Wallis test was applied to compare the three centers. RESULTS: Whatever the study center, the Spearman correlation coefficient (r(s)) increased as a function of the number of sections (S) up to three: Center 1 (1S, 0.47; 2S, 0.68; 3S, 1.0), Center 2 (1S, 0.60; 2S, 0.99; 3S, 0.99), Center 3 (S1, 0.40; 2S, 0.73; 3S, 1.0). No statistically significant difference was found between the three study centers.

Composite Resins↗
PubMed2003

Effect of the cavity configuration factor on the marginal microleakage of esthetic restorative materials.

PURPOSE: To evaluate the effect of the cavity configuration factor (CF) on the marginal microleakage of cervical restorations with four aesthetic restorative materials. MATERIALS AND METHODS: Conventional cavities, 2.9 mm in diameter and 1.5 mm deep, with CF=2.7 and "saucer"-shaped ones with CF=2 were created in 60 extracted premolars. The following groups were established: G1: Z100/Single Bond, G2: Freedom/Stae, G3: Vitremer/Primer and G4: Durafill/Durafill Bond, following each manufacturer's directions. Thermocycling of the specimens was performed in an aqueous solution of 2% buffered methylene blue, with the temperature varying between 5 to 55 degrees C, for a total of cycles of 60 minutes per day, for 7 days. The specimens were then sectioned and evaluated by two observers using photographs acquired from a stereomicroscope. The values were subjected to Kruskal-Wallis analysis and the Dunn and Wilcoxon test. RESULTS: The averages of the microleakage scores observed in the conventional and "saucer"-shaped cavities were respectively: G1: 0.66/0.46; G2: 0.92/0.69; G3: 1.8/1.86; G4: 3.54/2.3.

Bisphenol A-Glycidyl Methacrylate↗
PubMed2003

Effect of low-viscosity resin-based composite on the microleakage of cervical restorations.

PURPOSE: To investigate the effect of a low-viscosity resin-based composite (LVC) liner on the microleakage of cervical resin-based composites bonded with new adhesive systems. METHODS: 180 wedge-shaped cervical cavities on bovine incisors were treated with AQ Bond (all-in-one), ABF (experimental two-step self-etching primer containing antibacterial monomer) or Clearfil SE Bond (two-step self-etching primer) systems according to the manufacturers' instructions. Half of the treated cavities in each adhesive system were lined with an LVC (Protect Liner F) and filled with a hybrid resin-based composite (Clearfil AP-X). Ten specimens from each group were immersed in 0.5% basic fuchsin solution immediately after finishing the restorations. The specimens to be subjected to thermocycling (5-60 degrees C, 15 seconds dwell time, 5,000 cycles) or to flexural load cycling (approximately 0.5 mm labio-lingual displacement at the incisal edge, 10,000 cycles, 1 Hz) prior to immersion in the dye solution were also prepared. The teeth were sectioned through the center of the restorations and the degrees of dye penetration were scored. The data were analyzed with the Mann-Whitney U-test or the Kruskal-Wallis test (P < 0.05). RESULTS: The use of the LVC liner significantly improved marginal sealing of AQ Bond. However, the LVC liner could not prevent the deterioration in the marginal integrity caused by thermocycling or flexural load cycling. In the case of ABF, the use of the LVC liner showed a trend toward less microleakage. For Clearfil SE Bond, the LVC liner prevented the deterioration in the marginal seal caused by thermocycling.

Animals↗
PubMed2003

Implication of cervical enamel projection to furcation involvement in molars. A pilot clinical study.

The aim of this study was to investigate the correlation of cervical enamel projection (CEP) with furcation involvement (FI) and compare the healing response of molars with or without CEP after surgery. A total of 30 patients contributing 78 maxillary and mandibular first or second molars were included. Plaque Index (PII), Gingival Index (GI), probing pocket depth (PPD) and probing attachment level (PAL) were measured before surgery and 1 and 3 or 6 months postoperatively. During surgery, CEPs were identified and classified with a modified grading system from Masters & Hoskins (24). FI was measured horizontally from the buccal aspect into the furcation with a graduated probe to the nearest mm. Any measurement > or = 1 mm was considered as FI. CEPs were found in 33 molars (42%). Grade III CEPs were found in 14 teeth, Grade IIIb in 4 teeth, Grade II in 1 tooth and Grade I in 14 teeth. The results showed no significant correlation of CEP with FI. Nor was CEP significantly affecting the PPD and PAL 3 or 6 months after surgery. However, FI was a significant factor in the further loss of PAL after surgery. Further studies, involving larger sample size may be necessary in order to give more conclusive results.

Adult↗
PubMed2003

Sealing ability of packable resin composites in class II restorations.

PURPOSE: To evaluate in Class II restorations the marginal adaptation of ten packable composite resins in combination with the proprietary adhesive system. MATERIALS AND METHODS: Standard Class II cavities were prepared in 100 extracted molars. The sample was randomly divided into ten groups. In each group, one specific packable composite was tested in association with its own adhesive: Groups: 1) Scotchbond1/FiltekP60; 2) Etch & Prime3.0/Definit; 3) Prime & Bond 2.1/SureFil; 4) Excite/Tetric Condensable; 5) Gluma/Solitaire; 6) Kerr Bonding/Prodigy Condensable; 7) One-step/Pyramid; 8) Tenure/Virtuoso; 9) Syntac/Cavex Packable; 10) Excite/Tetric flow/Tetric Ceram. The restored teeth were sectioned at three levels in the mesiodistal direction and processed for the microleakage test. On each section, the degree of dye penetration along the margins of the restoration was assessed, and the differences in the leakage given by the ten materials at either the occlusal or the cervical margin were evaluated for statistical significance. A statistical analysis was also conducted to assess the significance of the differences between the scores recorded at the occlusal margin and those measured at the cervical margin of the restoration. RESULTS: In general, the scores recorded at the cervical margin were significantly higher than those measured at the occlusal margin (p < 0.05). When all of the groups were compared for microleakage at the occlusal margin, the only significant difference revealed by the statistical analysis was that the specimens treated with Etch&Prime 3.0 and Definit (group 2) exhibited a marginal adaptation significantly worse than that seen in groups 1, 3, 4, 6, 8, 10. CONCLUSION: The application of a thin layer of a flowable composite at the cervical margin as a liner underneath the packable composite enhanced the marginal adaptation of the restoration. The use of a self-etching primer to condition the dental substrate resulted at the occlusal margin in greater microleakage than when phosphoric acid was applied.

Analysis of Variance↗
PubMedDate not supplied

Thermal and mechanical load cycling on microleakage and shear bond strength to dentin.

This study evaluated the influence of mechanical and thermal cycling on microleakage at the cervical margins of proximal slot restorations and shear bond strength on flat dentin surfaces. Microleakage Evaluation: One hundred and twenty slot cavity restorations were performed on bovine incisors. The restorations were randomly divided into four groups (n = 30): control (no thermal and mechanical load cycling), thermal cycling (2,000 cycles, 5 degrees C-55 degrees C), mechanical load cycling (50,000-80N) and thermal and load cycling (2,000 5 degrees C-55 degrees C/50,000-80N). The specimens were sealed with acid resistant varnish, leaving a 1-mm window around the cervical margin interface. To detect marginal leakage, a 2% methylene blue buffered solution was used for four hours. The specimens were sectioned longitudinally and qualitatively evaluated by stereomicroscopy (45x) following a ranked score for the dentin cervical margin. The data were analyzed by Kruskal-Wallis test (alpha = 0.05). Shear Bond Strength Evaluation (SBS): Eighty bovine incisors were embedded and polished to obtain a flat standard surface on dentin. The surfaces were restored with Single Bond adhesive system and a resin composite subsequently inserted in a bipartite Teflon matrix. The specimens were randomly divided into the four groups (n = 20) described above for microleakage. Shear bond strengths were measured in a universal testing machine with a crosshead speed of 0.5 mm/minute. The data were analyzed by one way ANOVA test (alpha = 0.05). No statistically significant influence of thermocycling, mechanical load cycling or the combination was observed for both microleakage and shear bond strength.

Analysis of Variance↗
PubMedDate not supplied

Effect of different application and polymerization techniques on the microleakage of proximal resin composite restorations in vitro.

This in vitro study investigated cervical microleakage of proximal resin composite restorations placed with three application and polymerization techniques. Uniform mesio-occlusal-distal (MOD) preparations featuring cervical margins above (mesial) and below (distal) the CEJ suitable for restoration with resin composite were copy milled into 33 recently extracted permanent molars. The teeth were divided randomly into three groups of 11 teeth and restored using a conventional incremental technique (Group A) and two novel curing devices (Groups B and C). After 24 hours, a dye penetration test was used to assess microleakage. Conventional placement in preparations with cervical margins in enamel had significantly lower interfacial leakage scores than those recorded for placement in preparations with margins in cementum regardless of the technique used to place the restorative material. Use of the two novel curing devices conferred no advantage in reducing microleakage irrespective of where preparation margins were placed.

Acid Etching, Dental↗
PubMed2004

Transurgical restoration in the absence of attached gingiva. A case report.

A 45-year-old woman needing a Class V restoration in a mandibular molar without attached gingiva is presented. In an interdisciplinary intervention, transurgical restoration was accomplished, including flap surgery with a slight ostectomy and restoration with a bonding system and a resin composite. A 1-year clinical evaluation showed satisfactory marginal adaptation and restoration contour associated to gingival tissue health.

Alveolectomy↗
PubMed2004

Modeling and characterization of the CEJ for optimization of esthetic implant design.

This study evaluated the dimensions and characteristics of the cementoenamel junction (CEJ) of maxillary anterior teeth; the natural CEJ was compared to current implant design and used for design optimization. Standardized digital images of 137 extracted human teeth (45 central incisors, 46 lateral incisors, and 46 canines) were used to measure cervical dimensions, CEJ curvature, and distance from zenith of CEJ to interdental contact on proximal views. The x- and y-coordinates of the CEJ contour were digitized before mathematic processing to allow the representation of a single average curve for buccal, palatal, mesial, and distal surfaces for each tooth type. These measurements were combined to existing data related to dentogingival and "implantomucosal" junction to extrapolate specific biologic landmarks around teeth and implants. Mean cervical dimensions, distance from zenith of CEJ to interdental contact, and CEJ curvature were compared. Cervical dimensions significantly differed, with a more symmetric cervical cross-section for central incisors, slightly more rectangular shape for lateral incisors, and distinctly rectangular shape for canines. CEJ curvature was statistically different between all tooth groups (centrals > laterals > canines); within groups, curvature value was always superior at the mesial aspect compared to distally (3.46 mm vs 3.13 mm for centrals, 2.97 mm vs 2.38 mm for laterals, and 2.55 mm vs 1.60 mm for canines). Tooth-implant biologic width discrepancies ranged from 4.10 to 5.96 mm and were different between all groups of teeth (centrals > laterals > canines); within groups, the discrepancy was always superior at the mesial aspect compared to distally. Current implant design featuring a flat, rotation-symmetric shoulder should be reconsidered in view of natural CEJ contour to improve biologic considerations and related esthetics.

Analysis of Variance↗
PubMedDate not supplied

Scanning electron microscope evaluation of CEREC II and CEREC III inlays.

In response to an increased public demand for esthetic restorations, dentists are using computer-aided design/computer-aided manufacture (CAD/CAM) technology to fabricate inlay/onlay, crown, and laminate veneers. This study evaluated the fit at the gingival margin of surface inlay restorations milled by the CEREC II as well as the more recently developed CEREC III. The marginal fit of inlays milled by the CEREC III was more accurate than the fit of those milled by the CEREC II, although both were within the ADA specifications of 50 micro.

Acetone↗
PubMedDate not supplied

Effect of thermal and mechanical load cycling on microtensile bond strength of a total-etch adhesive system.

To evaluate the effect of thermal and mechanical cycles on dentin bond strength to cervical margins of Class II restorations, 80 box-type Class II cavities were prepared on the surfaces of bovine incisors. The cavities were restored with Single Bond (3M-ESPE) and Z-250 composite (3M-ESPE) according to manufacturer's instructions. The incisors were divided into four groups: G1-Control, G2- Thermal cycling (2,000 cycles, 5 degrees C-55 degrees C), G3- Mechanical cycling (100,000 cycles; 50N) and G4- Thermal and mechanical cycling (2,000 cycles 5 degrees C-55 degrees C/100,000 cycles; 50N). The restorations were sectioned perpendicular to the cervical bonded interface into 0.7 +/- 0.2 mm-thick slabs. The slabs were further trimmed at the interface to 1.4 +/- 0.2 mm with a fine diamond bur to produce a cross-sectional surface area of 1 mm2. All specimens were then subjected to microtensile bond testing. Means and standard deviations were expressed in MPa. The bond strength data were analyzed by one-way ANOVA and Fisher's PLSD test (p<0.05). Fracture mode analysis was performed using SEM. Bond strengths were significantly lower when thermal and mechanical cycling were performed [G4-2.41 (8.57)] when compared to the other groups [G1-28.15 (14.03); G2-27.60 (10.14); G3-27.59 (8.67)]. No differences were observed among Groups 1, 2 and 3. Interfacial fracture of the control (G1) and thermocycling (G2) groups mainly occurred between the deepest portion of the adhesive resin and the top layer of the demineralized dentin (Interphase). Mixed failure was predominant and increased when mechanical cycling was applied (G3 and G4).

Acid Etching, Dental↗
PubMedDate not supplied

Integrating dental anatomy and biomaterials: an innovative use of composite resin.

As part of the new integrated curriculum at the New York University College of Dentistry, a pilot program uses composite resins to teach dental anatomy. The Department of Biomaterials and Biomimetics, in conjunction with the Department of Cariology and Operative Dentistry, has created a teaching module to replicate the morphology of a central incisor through the manipulation and placement of a composite resin.

Biocompatible Materials↗