Development and Assessment of Discrimination Exercises for Faculty Calibration in Preclinical Operative Dentistry.

The aims of this study were to identify the level of interexaminer agreement among preclinical operative dentistry faculty members when grading Class II preparations performed by first-year dental students; to develop discrimination exercises for specific preparation components where interexaminer agreement was poor; and to evaluate if the discrimination exercises were able to improve inter- and intraexaminer agreement. In the preliminary phase of this study, 13 components of 32 Class II cavity preparations were assessed by eight course faculty members at one U.S. dental school. Analysis of average interexaminer agreement on these components revealed that six were below 60%. These were proximal contact clearance, retention groove placement, retention groove depth, preparation walls, preparation margins, and preparation toilet/debris. A 30-minute calibration session was subsequently developed to provide discrimination exercises utilizing 3-D models and digital images of various levels of student performance for five of the six components. Immediately following calibration, the course faculty assessed the same 32 preparations (Phase I) followed by a delayed assessment without calibration (Phase II) approximately six months later. The results showed that overall interexaminer reliability improved after calibration. Although there was a decline in interexaminer reliability after an interval of six months (Phase II), the degree of variation among examiners was lower than in the preliminary assessment. These findings support the use of discrimination exercises for preclinical operative dentistry course faculty to increase interexaminer agreement and thereby improve the consistency of faculty-student communication.

Six-year clinical performance of etch-and-rinse and self-etch adhesives.

OBJECTIVE: To evaluate the 6-year clinical performance of Xeno IV, Xeno III, and XP Bond adhesives in the restoration of non-carious cervical lesions (NCCLs). METHODS: This was a randomized controlled clinical trial where 39 participants met the inclusion/exclusion criteria and were enrolled. Lesions restored were notch-shaped NCCLs. Prior to adhesive procedures, NCCLs were roughened. No enamel bevel was placed and no mechanical retention was created. Adhesive systems were applied following manufacturer's instructions and the NCCLs were restored with composite resin (TPH(3)). Restorations were finished immediately after placement and scored with regard to retention, marginal discoloration, marginal adaptation, sensitivity, and secondary caries using modified USPHS criteria. Descriptive statistics were performed. Logistic regression models were performed for each outcome separately with compound symmetry correlation structure where teeth were clustered by participants. All analyses were conducted using SAS 9.2. RESULTS: The 6-year recall rate was 77.5% of the restorations (76.9% of the participants). No statistical differences were found between adhesives for retention, marginal discoloration, and marginal adaptation. Restorations failed by loss of retention (16.7%, 27.6%, and 11.8% of Xeno IV, Xeno III, and XP Bond restorations, respectively) and marginal discoloration (7.4% of Xeno IV restorations). For every unit increase in restoration volume it was 1.31 (95%C.I. 1.05, 1.63, P=0.01) times more likely that the restoration retention would be maintained. SIGNIFICANCE: The tested adhesive systems presented similar clinical performance after six years of service, with annual failure rates of 2.8%, 4.6%, and 2.0% for Xeno IV, Xeno III, and XP Bond, respectively.

Three-year clinical evaluation of a silorane composite resin.

STATEMENT OF PROBLEM: Composite resins are still outperformed by amalgams in the clinical practice with secondary caries and fractures being their most common failures. A material that suffers less polymerization shrinkage might improve the clinical performance of composite resins. PURPOSE: To evaluate the clinical performance of a low-shrink silorane-based composite resin (Filtek LS Low Shrink Posterior Restorative, 3M ESPE, St. Paul, MN, USA) in comparison with a methacrylate-based composite resin (Tetric EvoCeram, Ivoclar Vivadent, Schaan, Principality of Liechtenstein) over time. MATERIALS AND METHODS: Candidates in need of Class II composite resin restorations participated in this randomized controlled clinical trial. Those were 25 female and six male subjects with average age of 44.3 ± 12.7 years. Participants received 82 restorations, being 54 in premolars and 28 in molars. Procedures, which included the restoration of primary caries lesions or replacement of failing restorations, were done using modified preparations with no bevels or additional retention. Restorations were placed using Filtek LS (and dedicated self-etch adhesive) or Tetric EvoCeram (with AdheSE, Ivoclar Vivadent), following manufacturers' instructions. Incremental placement technique was applied and the restorations were immediately finished. Follow-up evaluations occurred at six, 12, 24, and 36 months and were done using the Fédération Dentaire Internationale criteria. Statistical analysis was performed using generalized estimating equations. RESULTS: The recall rate at 36 months was 89%. All interaction terms were not significant. CONCLUSIONS: Filtek LS performs as well as Tetric EvoCeram performs in the clinical setting at 36 months. CLINICAL SIGNIFICANCE: The silorane-based composite resin Filtek LS and the conventional methacrylate-based composite resin Tetric EvoCeram performed similarly well in posterior restorations over at least 36 months of clinical service.

A 12-year clinical evaluation of a three-step dentin adhesive in noncarious cervical lesions.

BACKGROUND: The authors conducted a study to evaluate the clinical performance of a dual-cured, three-step dentin adhesive (OptiBond Dual Cure, Kerr, a subsidiary of Sybron Dental Specialties, Orange, Calif.; no longer on the market) at 12 years. METHODS: The authors restored 100 noncarious cervical lesions without use of macromechanical retention or enamel bevels. In one-half of the lesions (group A), the authors etched only the enamel; in the other half (group B), they etched both enamel and dentin. After etching, they applied a light-cured primer and dual-cured adhesive to enamel and dentin in both groups. They restored the preparations with a resin-based composite. They performed direct evaluations by using modified U.S. Public Health Service criteria at insertion (baseline) and at one year and 12 years after insertion. RESULTS: The 12-year retention rates were 93 percent in group A and 84 percent in group B, for an overall retention rate of 89 percent. Except for marginal discoloration in both groups and retention in group B, the restorations in both groups had Alfa ratings of 88 percent or greater in all of the direct clinical evaluation categories. CONCLUSIONS: The 12-year clinical performance, including retention rate, of a dual-cured dental adhesive was excellent and was not affected by dentin acid-etching. CLINICAL IMPLICATIONS: This clinical study provides additional evidence for the long-term durability of a three-step etch-and-rinse adhesive in non-carious cervical lesions.

An eight-year clinical evaluation of filled and unfilled one-bottle dental adhesives.

BACKGROUND: The strategies for accomplishing resin adhesion to dentin involve surface conditioning, priming and bonding. One-bottle adhesives combine the priming and bonding functions in a single solution. In this study, the authors compared the eight-year clinical performance of two one-bottle adhesives made by different manufacturers. METHODS: The authors placed a total of 99 Class V restorations using either a filled, ethanol-based adhesive (OptiBond Solo [OS], SDS Kerr, Orange, Calif.) or an unfilled, acetone-based adhesive (Prime & Bond 2.1 [PB] Dentsply Caulk, Milford, Del.) and a hybrid resin-based composite in 33 subjects with noncarious cervical lesions. The authors did not bevel the enamel margins and used no mechanical retention. They evaluated the restorations at baseline and for as long as eight years after placement using modified U.S. Public Health Service criteria. They analyzed differences between groups using appropriate statistical tests. RESULTS: The authors examined 56 restorations after eight years and found retention rates of 69 percent for OS and 59 percent for PB. These rates did not differ statistically (P = .449) and were not significantly affected by subject or lesion characteristics. The authors noted marginal discoloration on 55 percent of the retained OS restorations and on 31 percent of the retained PB restorations, but they detected no secondary caries around any restoration. They noted poor anatomical form and poor marginal adaptation in 15 percent and 40 percent of the retained OS restorations, respectively. CONCLUSIONS: The performance of both adhesives was good during this eight-year clinical trial. The filled, ethanol-based adhesive OS demonstrated slightly better bond durability than did the unfilled, acetone-based adhesive PB, but the difference between the two materials was not statistically significant. CLINICAL IMPLICATIONS: Despite a high incidence of marginal discoloration, the one-bottle adhesives evaluated in this study provided good clinical retention of Class V restorations without mechanical retention. When the materials are used properly, restorations are retained at an acceptable rate through at least eight years of clinical service.

Clinical evaluation of an all-in-one adhesive in non-carious cervical lesions with different degrees of dentin sclerosis.

This randomized clinical trial compared the performance of an all-in-one adhesive (iBond) applied in sclerotic and non-sclerotic non-carious cervical lesions with that of a three-step etch-prime-bond adhesive (Gluma Solid Bond, SB). One-hundred and five lesions were randomly assigned to four groups according to adhesive, sclerosis scale and technique: 1) SB applied to lesions with sclerosis scale 1 and 2 (n=26); 2) iBond applied to lesions with sclerosis scale 1 and 2 (n=28); 3) iBond applied to lesions with sclerosis scale 3 and 4 (n=25) and 4) iBond applied with prior acid-etching to lesions with sclerosis scale 3 and 4 (n=26). A microfilled composite (Durafill VS) was used as the restorative material. The restorations were evaluated for retention, color match, marginal adaptation, anatomic form, cavosurface margin discoloration, secondary caries, pre- and post-operative sensitivity, surface texture and fracture at insertion (baseline), 6, 18 months and at 3 years using modified USPHS evaluation criteria (Alfa=excellent; Bravo=clinically acceptable; Charlie=clinically unacceptable). There was a high percentage of Bravo scores for marginal adaptation (4%-32%) and marginal discoloration (18%-60%) in Groups 2, 3 and 4, but all groups had <5% Charlie scores at 6 months and <10% Charlie scores at 18 months for retention and marginal discoloration, respectively. However, it should be noted that 13% of the restorations in Group 4 were not retained at three years.

36-month clinical evaluation of two adhesives and microhybrid resin composites in Class I restorations.

PURPOSE: To compare the clinical performance of a self-etching adhesive with that of a popular etch-and-rinse adhesive in Class I posterior composite restorations. METHODS: 60 Class I resin composite restorations (30 per group) were placed in matched pairs using either the self-etch adhesive Xeno III and the microhybrid resin composite Esthet-X or the etch-and-rinse adhesive OptiBond Solo Plus and Point 4 microhybrid resin composite. Subjects were interviewed via telephone 1 week after restoration placement to assess early post-operative sensitivity. In addition, the restorations were evaluated clinically for post-operative sensitivity, marginal quality, wear, and other characteristics immediately after placement and at 6, 12, 18, and 36 months from baseline. RESULTS: During the first week after placement, subjects reported that 23% of restorations in each group had post-operative sensitivity. Sensitivity decreased greatly with time, and differences between the two groups were never statistically significant. Marginal integrity and discoloration were similar for each group at each recall evaluation. Wear of both resin composites increased over time, but mean wear remained at less than 100 microm for each resin composite at 3 years.

Consequences of posterior cusp fracture.

Although posterior cusp fracture occurs frequently, its consequences are not well-delineated. This study recorded short-term outcomes (distribution of fractured teeth and cusps, fracture severity, and treatment received up to two years postfracture) for 517 fractured teeth from 498 subjects at a large group practice. Maxillary and mandibular tooth fractures occurred with similar frequency. In the maxillary arch, first and second molars and premolars fractured with roughly the same frequency; premolar fractures were more severe. In the mandible, first molars accounted for approximately 50% of all fractures and were most likely to be severe fractures. Nonholding cusps were more likely to fracture in both arches. Proportions of fractured teeth receiving "catastrophic" treatment were low (3% extraction; 4% endodontic treatment) and the large majority of fractured teeth were treated in a single visit using direct restorative materials. A knowledge of the relatively small proportions of fractured teeth that suffer serious consequences and the tooth-specific distributions of cusp fracture should help dentists and patients to make informed decisions regarding preventive restorative intervention prior to fracture.

Fracture resistance of prepared teeth restored with bonded inlay restorations.

STATEMENT OF PROBLEM: intact, prepared, and restored human maxillary premolars. MATERIAL AND METHODS: Fifty intact, noncarious human maxillary premolars were divided into 5 groups of 10 and were mounted with their roots imbedded in autopolymerized acrylic. In the first group, the teeth were intact with no preparation. In the other 4 groups, Class II MOD preparations were made with a water-cooled high-speed hand piece. In 1 group, the cavity preparations were restored with bonded CAD/CAM ceramic inlays. In 2 groups, the preparations were restored with bonded CAD/CAM composite inlays (acid etched or air particle abraded). In the final group, the teeth were prepared but unrestored. Specimens were tested individually in a universal testing machine, in which a 4.82-mm-diameter steel sphere plunger was mounted in the crosshead moving at 0.5 mm/min. The plunger contacted the facial and lingual triangular ridges beyond the margins of the restorations. Peak load to fracture (N) was measured for each specimen. Means were calculated and analyzed with analysis of variance (P