Strategies to Avoid Underdiagnosing Pit-and-Fissure Caries.

Traditionally, testing for whether pit-and-fissure caries should be restored involved probing with a sharp explorer and evaluating resistance to withdrawal (ie, "stick"). Alternative visual methods of evaluation and classification have been proposed, validated, and accepted formally in the core curriculum on caries management in both Europe and North America. This article examines the resistance to occlusal breakdown of fluoridehardened enamel despite progression of underlying dentin caries with accompanying difficulty in diagnosis. Traditional methods of pit-and-fissure caries diagnosis, including radiographs or fissure probing with an explorer, have been shown to be inaccurate and potentially destructive. The clinical process of using the visual/tactile International Caries Detection and Assessment System (ICDAS) and/or the Caries Classification System (CCS) is described and illustrated through case examples.

Uninfiltrated Collagen in Hybrid Layers produced after Reduced Acid-etching Time on Primary and Permanent Dentin.

AIM: This study evaluated the influence of acid-etching time on collagen exposure in adhesive interfaces established on primary and permanent dentin. MATERIALS AND METHODS: Flat dentin surfaces were produced on sound primary molars and premolars (n = 8). The surfaces were divided into mesial and distal halves, and each half was etched with phosphoric acid for 5 or 15 seconds. The teeth were randomly allocated into two groups according to the adhesive system applied: Prime & Bond NT or Prime & Bond 2.1. After the adhesive application, the specimens were processed for Goldner's trichrome staining. The thickness of the uninfiltrated collagen zone (UCZ) in the hybrid layer was measured under optical microscopy. Data were analyzed by analysis of variance and Tukey tests (α = 0.05). RESULTS: The thickness of UCZ was adhesive dependent. Within the same substrate, the specimens treated with Prime & Bond 2.1 presented thicker UCZ when etched for 15 seconds. Collagen exposure was significantly higher for the primary teeth etched for 5 seconds and treated with Prime & Bond 2.1. CONCLUSION: The thickness of UCZ in hybrid layers is directly affected by acid-etching time and by the adhesive system applied. Primary dentin seems to be more susceptible to collagen exposure than is permanent dentin. CLINICAL SIGNIFICANCE: Both acid-etching time and adhesive system can influence the amount of exposed collagen interfering on resin-dentin bond quality, especially on primary dentin.

Quaternary ammonium silane-functionalized, methacrylate resin composition with antimicrobial activities and self-repair potential.

The design of antimicrobial polymers to address healthcare issues and minimize environmental problems is an important endeavor with both fundamental and practical implications. Quaternary ammonium silane-functionalized methacrylate (QAMS) represents an example of antimicrobial macromonomers synthesized by a sol-gel chemical route; these compounds possess flexible Si-O-Si bonds. In present work, a partially hydrolyzed QAMS co-polymerized with 2,2-[4(2-hydroxy 3-methacryloxypropoxy)-phenyl]propane is introduced. This methacrylate resin was shown to possess desirable mechanical properties with both a high degree of conversion and minimal polymerization shrinkage. The kill-on-contact microbiocidal activities of this resin were demonstrated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC 12104) and Candida albicans (ATCC 90028). Improved mechanical properties after hydration provided the proof-of-concept that QAMS-incorporated resin exhibits self-repair potential via water-induced condensation of organic modified silicate (ormosil) phases within the polymerized resin matrix.

In vitro osteogenic potential of an experimental calcium silicate-based root canal sealer.

OBJECTIVE: This in vitro study compared the cytotoxicity and osteogenic potential of an experimental calcium silicate-based sealer with an epoxy resin-based sealer (AH Plus; Dentsply Caulk, Milford, DE) and a zinc oxide-eugenol-based sealer (Pulp Canal Sealer; SybronEndo, Orange, CA). METHODS: Disks prepared from the respective sealer and from Teflon (negative control) were placed in direct contact with a MC3T3-E1 osteogenic cell line at 6 weekly intervals after immersion in a culture medium. Succinic dehydrogenase activities were evaluated using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Extracts from these sealers after the 6-week immersion period were investigated also by MTT assay. Aged sealers were then switched to an osteogenic medium for examination of the alkaline phosphatase activity and mineralization of extracellular matrices produced by the differentiated cells. RESULTS: All sealers exhibited severe toxicity after 24 hours, after which toxicity decreased gradually over the experimental period except for Pulp Canal Sealer, which remained severely toxic. Toxicity of the extracts derived from the sealers was concentration dependent, with those derived from the experimental sealer being the least cytotoxic at a 1:10 dilution. Minimal alkaline phosphatase activity and no bone formation were seen with Pulp Canal Sealer. The production of alkaline phosphatase was less intense for the experimental sealer at 7 days. However, both AH Plus and the experimental sealer did not inhibit mineralization of the extracellular matrix after 28 days. CONCLUSION: The experimental calcium silicate-based sealer may be regarded as minimally tissue irritating and does not interfere with bone regeneration even when it is inadvertently extruded through the apical constriction.

Color differences: polymerized composite and corresponding Vitapan Classical shade tab.

OBJECTIVES: This study compared newer composite resin restorative materials to the Vitapan Classical tabs they purported to represent. METHODS: Five Vitapan Classical tabs were studied: A3.5, B2, C1, C3, and D2 (n=3). These tabs created a variety of levels of lightness, chroma and hue. Each of these five shade tabs was removed from three different shade guides, and an intraoral spectrophotometer was used to capture CIELAB color coordinates. Three separate readings were made and all nine were averaged. The inter-tab color differences were also calculated. Five specimens approximately 4.0mm thick were fabricated for each of the shades studied using five different composite resin materials. Composite specimens were of the same size and shape as target shade tabs, and three separate recordings were made for each of them. This average was compared to five Vitapan Classical shade tabs to calculate the color differences using both CIELAB and CIEDE2000 color difference formulas. Color differences were compared to thresholds for perceptibility and acceptability reported in other studies. RESULTS: CIELAB and CIEDE2000 color differences ranged from 3.9 to 22.8 and from 2.1 to 13.8, respectively. None of the materials proved, an acceptable CIELAB color match to any of the shades tested. CONCLUSION: When various shade tabs of Vitapan Classical shade guides were compared with correspondent tabs made of direct restorative composites, no material/shade combination resulted in an acceptable mismatch relative to the used standard of acceptability. Therefore, evaluated resin composites exhibited poor match compared to target Vitapan Classical tabs.

A comparison of human raters and an intra-oral spectrophotometer.

Consistently choosing an accurate shade match is far more difficult than it appears. Recently, several electronic shade-matching devices have been marketed. One device is an intraoral spectrophotometer, Easyshade. The current study compared the accuracy and consistency of the Easyshade (ES) device to three clinicians experienced in tooth whitening trials and trained in the use of the Vitapan 3D Master shade. The maxillary anteriors of 16 participants were matched on three separate occasions one month apart. At each appointment, the three clinicians (R1, R2 & R3) and ES independently chose a single 3D Master tab. A trained research assistant used the Easyshade device to record CIE L*, C* and H* and a shade tab. In addition, color differences between shade tabs were calculated using the Delta E 2000 (delta e 00) formula. The CIE L*C*H* data were also used to establish standards for the five lightness groups of the 3D Master. An intrarater agreement was evaluated using an intraclass correlation statistic, and an inter-rater agreement was evaluated using a weighted Kappa statistic. The percentages of exact matches were: ES = 41%; R1 = 27%; R2 = 22% and R3 = 17%. Matches within a half-shade were also calculated. This represents a mismatch that is perceptible but acceptable. The percentages of matches within a half-tab were: ES = 91%; R1 = 69%; R2 = 85% and R3 = 79%. In terms of lightness, the intra-rater agreement was considered to be very good for ES and R2 and good for R1 and R3. For chroma, agreement for ES was considered good, and for the three clinicians, it was considered moderate. The mean color difference for the L*, C*, H* data recorded at each evaluation was 1.5, or only slightly greater than the color difference between the same tab on different guides (1.2). The delta e 00 data were the most accurate data collected, and they were used to establish a standard to which the tab choices of the four raters were compared. A weighted Kappa statistic was performed and, in terms of lightness, agreement was found to be good for all raters. For chroma, agreement was very good for ES and it was good for the clinicians. In terms of the number of exact matches and matches within a half-shade, the performance of ES was at least comparable to, if not better than, the dentists. Statistically, the same was true in terms of consistency and accuracy when making repeated matches of lightness and chroma using the 3D Master shade guide.

Minimally retentive gold onlays: a six-year case report.

Partial veneer gold restorations, such as gold onlays, have changed little in preparation design over the past 40 years, as evidenced by textbooks that have long been in print. Such designs must have been based on the assumption that restorations would be luted with zinc phosphate cement but have not altered, despite the introduction of stronger luting cement classes, such as resin composite and resin-modified glass ionomer cements. It is well-established that both porcelain and base metal materials, which have been etched on the intaglio surface, can be combined with resin composite luting cements to produce restorations retained largely through adhesion. However, neither of these materials can equal the combination of minimal tooth reduction and margin adaptation that is possible with high noble gold restorative materials. Although high noble gold alloys cannot be etched, air abrasion of the intaglio surface of restorations likely improves micromechanical retention, but it is unknown whether this, along with a strong luting cement, is sufficient to stabilize high noble gold alloys in preparations with considerably less retention and resistance form than traditional designs.

In vitro cytotoxicity evaluation of a self-adhesive, methacrylate resin-based root canal sealer.

This study compared the cytotoxicity of MetaSEAL (Parkell Inc, Farmington, NY), a methacrylate resin-based sealer with an epoxy resin-based (AH Plus Jet; Dentsply Caulk, Milford, DE) and a zinc oxide-eugenol-based sealer (Pulp Canal Sealer; SybronEndo, Orange, CA). Five-millimeter diameter disks prepared from the respective sealer and disks prepared from Teflon (negative control) and polymethyl methacrylate (positive control) were placed in direct contact with a rat osteosarcoma (ROS) 17/2.8 rat osteoblast-like cell line at six intervals after setting completely at 72 hours and for 5 succeeding weeks after the disks were immersed in simulated body fluid. Succinate dehydrogenase activity was evaluated by using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide assay. All sealers exhibited severe toxicity at 72 hours, after which toxicity decreased gradually over the experimental period except for Pulp Canal Sealer, which remained severely toxic. MetaSEAL was more toxic than AH Plus Jet during the first week. Both were similar to the toxicity profile of the positive control after the first week, which was probably diffusion controlled.

Comparison of traditional and low sensitivity whiteners.

This placebo-controlled, double-blind randomized clinical trial compared five 10% carbamide peroxide tooth whitening formulations. Three products contained varying concentrations of potassium nitrate as desensitizers. One contained no desensitizers and one was a placebo. During the two weeks of active bleaching, participants used a daily diary to record the number of days of sensitivity from hot, cold, gums, tongue and/or throat. The total number of days of sensitivity experienced by the participants in each group was compared. Participants using the agent with no desensitizers did not experience any more sensitivity than those using the agent containing 3% potassium nitrate. The products that included 0.5% potassium nitrate and 0.5% potassium nitrate and 0.25% sodium fluoride were not associated with any more sensitivity than the placebo group. In addition, the shade tab change from baseline to 11 weeks following cessation of bleaching was compared. Using an active bleaching agent, no difference in color change was noted among the four groups. All four groups were associated with significantly higher color change than the placebo. The addition of a small percentage of potassium nitrate to a 10% carbamide peroxide tooth whitener was shown to significantly reduce postoperative sensitivity without reducing efficacy.

Comparison of two low sensitivity whiteners.

PURPOSE: To evaluate two commercially available doctor-supplied, patient-applied, bleaching systems for their ability to whiten the maxillary anterior teeth while at the same time not causing sensitivity. METHODS: 46 participants were randomly assigned to one of two groups: One group received Rembrandt Xtra-Comfort and the other group Nite White Excel 2Z. Bleaching stents were fabricated and the bleaching systems were used following manufacturers' instructions. Participants recorded tray use and any sensitivity on a daily basis. Participants bleached for 2 weeks followed by 2 weeks of no bleaching. Color was evaluated at the first, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. RESULTS: As a group, participants in the NW2Z group bleached for 302 days with a total of 48 days (16%) of sensitivity recorded. The Rembrandt Xtra Comfort group bleached for 313 total days with 97 days (31%) of sensitivity recorded. The difference in sensitivity between the two products proved to be statistically significant (Chi-square analysis, P < or = 0.0001). The median shade change for both products following 2 weeks of active treatment was six tabs. At the 4-week evaluation, the median shade change was 5.5 and 6.0 tabs respectively for Rembrandt and Nite White. There was no statistical difference between the products in respect to shade change.

Effect of restoration size on the clinical performance of posterior "packable" resin composites over 18 months.

Fifty predominantly moderate or large Class II or multiple-surface Class I resin composite restorations were placed in molars under rubber dam isolation. The restorative systems used were: Alert Condensable (Jeneric/Pentron) and SureFil (Dentsply/Caulk). The restorations were classified according to size, with 7 small, 25 moderate and 18 large, of which 8 were cusp replacement restorations. Baseline, 6, 12 and 18-month double-blinded clinical evaluations were carried out using modified USPHS criteria. The independent variables: restorative material, restoration size and three other clinical factors, were tested using a Multiple Logistic Regression procedure to determine if any were predictive of failure. Of the 50 restorations, four failed by the 18-month recall, three failed due to fracture of the restoration and one due to secondary caries. Both restorative systems demonstrated a 92% success rate. No association between restoration size (p = 0.99) or restorative material (p = 0.65) and failure was found. Similarly, the additional variables, occlusal contact type, presence of occlusal wear facets and first or second molar, were not predictive of failure.

Comparison of seal after obturation techniques using a polydimethylsiloxane-based root canal sealer.

A polydimethylsiloxane-based sealer (GuttaFlow) was used for filling single-rooted teeth with four obturation techniques. Prefitted gutta-percha master-cones were employed in groups 1 to 3 with backfilling of the sealer. Apical third of the roots were first filled with GuttaFlow, and sealer-coated master cones were seated with up-and-down motion (group 1) or rotated to place (group 2). Master-cones were used as carriers for introducing GuttaFlow into the canals (group 3). Canals were filled with GuttaFlow without master-cones (group 4). Canals were filled with AH Plus/gutta-percha using warm vertical compaction (control group 5). All obturated canals were tested for leakage after 1, 6, and 12 weeks using the fluid filtration technique. All groups exhibited equivalent seal regardless of time except for more extensive leakage in group 3. The use of GuttaFlow with a single gutta-percha master cone creates an apical seal that is equivalent to that produced with gutta-percha/AH Plus sealer using warm vertical compaction.

Initial in vitro biological response to contemporary endodontic sealers.

The objective of this study was to evaluate the cytotoxicity of three endodontic sealers (AH Plus/Maillefer-Dentsply, Epiphany/Pentron, GuttaFlow, Coltene-Whaledent). Materials were mixed according to the manufacturer instructions and packed into Teflon molds (10 x 1 mm). For cytotoxicity testing (MTT method), the specimens were placed in contact with cultured cells, then evaluated at two subsequent time points (24 or 72 h). In addition to testing the mixed materials, 5 microl of primer liquid (GuttaFlow and Epiphany) and resin solvents (HEMA, ethanol, sterile water, or acetone) were added directly in culture for 24 and 72 h. The results showed that most materials pose significant cytotoxic risks and that cytotoxicity generally increased with time. At 72 h, GuttaFlow became significantly less toxic than AH Plus, Epiphany sealer, and Resilon. The current results support the need to continue to develop better endodontic sealers that combine the excellent sealing and bonding properties of resins with acceptable biological properties for endodontic applications.

Microleakage of Class V resin composites placed using self-etching resins: effect of prior enamel etching.

OBJECTIVE: The purpose of this study was to compare the seal along dentin and enamel margins produced by 3 self-etching resin bonding systems to that of an etch-and-rinse adhesive system. Potential improvement in adaptation along enamel margins through the experimental use of conventional enamel etching prior to application of the self-etching adhesives was also evaluated. METHOD AND MATERIALS: Class V resin composite restorations were placed in prepared cavities in extracted third molars using 3 self-etching dentin adhesive systems: Adper Prompt L-Pop (3M Espe), iBond GI (Heraeus Kulzer), and Tyrian SPE (Bisco), and an etch-and rinse adhesive, Adper ScotchBond Multi-Purpose (3M Espe). A group of teeth also underwent conventional enamel etching prior to use of the self-etching products. The restored teeth were thermocycled, subjected to a dye challenge, and sectioned. The sections were scored using an ordinal leakage scale (n = 20). Ranked data were analyzed using a 2-way analysis of variance and Tukey multiple comparison. RESULTS: When used as directed, there were no significant differences along dentin margins for any of the adhesives, but Adper Prompt and iBond demonstrated significantly greater leakage than the etch-and-rinse product along enamel margins. The incidence of enamel margin leakage decreased significantly for the same 2 products when enamel etching preceded use of the resin. Enamel etching increased the leakage along dentin margins for all 3 self-etching products, but not significantly. CONCLUSION: Considerable improvement of all classes of dentin-adhesive resin systems is still needed. Practitioners should await further clinical trials before adopting use of self-etching resins, especially for large occlusal restorations.

Number of in-office light-activated bleaching treatments needed to achieve patient satisfaction.

OBJECTIVE: In-office bleaching has become very popular for patients desiring immediate results. This report discusses the efficacy of in-office bleaching using high-intensity xenon halogen tungsten light on 73 patients in a private practice over 6 months. METHOD AND MATERIALS: Thirty-five percent hydrogen peroxide gel was applied to the tooth surfaces, and then both arches were illuminated with the LumaArch unit light for 8 minutes. The entire procedure was completed 3 times for a total application time of 24 minutes. Thereafter, patients returned every 2 weeks for another 24-minute in-office treatment until the patient was satisfied or did not want additional treatment. After completion of bleaching, patients were classified into groups according to the number of treatments they received. When requested, home bleaching was used as a follow-up treatment. The degree of color change and color relapse were evaluated at baseline and immediately, 2 weeks, and 6 months after bleaching. Also evaluated was the number of patients that requested home bleaching. RESULTS: Of the 73 patients who received 1 to 4 in-office bleaching procedures, 58 were satisfied. Twenty-seven patients requested home bleaching. The average color change per appointment was 2.1 to 3.7 units on a 16-scale Vita Classic shade guide. Color relapse was more noticeable at the 2-week interval than at the 6-month postbleaching evaluation. CONCLUSION: In-office bleaching may be an alternative for patients who do not like home bleaching. In-office treatment may achieve satisfactory results, but often more than 1 visit is necessary to achieve patient satisfaction.

Microleakage of Class V resin composite restorations placed with self-etching adhesives.

STATEMENT OF PROBLEM: Although they are widely available, there is insufficient information about the capability of self-etching adhesives in sealing the margins of resin composite restorations. PURPOSE: The purpose of this study was to compare the in vitro microleakage of Class V resin composite restorations placed using a strong pH self-etching adhesive, an intermediate pH self-etching adhesive, and an adhesive with a separate etchant and primer. MATERIAL AND METHODS: Class V resin composite restorations (n = 8) were placed in prepared cavities in extracted human third molars using 2 self-etching dentin adhesives, Prompt L-Pop (Strong pH) or One-Up Bond F (Intermediate pH), and an adhesive with a separate etchant and primer, ScotchBond Multi-Purpose. The restored teeth received 1000 thermal cycles between 5 degrees C and 55 degrees C water baths with a 1-minute dwell time and were subsequently subjected to a methylene blue dye challenge and sectioned. The sectioned specimens were scored as demonstrating none, slight, or severe leakage (n=16). Ranked data were analyzed using a 1-way analysis of variance at a 5% confidence level. RESULTS: The only leakage observed was along gingival margins, with an incidence of 31% for Prompt L-Pop and One-Up Bond F, and 50% for ScotchBond Multi-Purpose. CONCLUSION: No significant differences in marginal leakage were found among the adhesives tested.