The relationship of hydrogen peroxide exposure protocol to bleaching efficacy.

The purpose of this study was to compare two in-office bleaching methods with respect to tooth color change and level of hydrogen peroxide penetration into the pulp cavity and to evaluate relationships between penetration level and color change. Eighty extracted canines were exposed to two different bleaching regimens (conventional vs sealed bleaching technique). After exposure to 38% hydrogen peroxide gel for one hour, hydrogen peroxide amount was estimated spectrophotometrically. Color change was measured per Commission Internationale de l'Eclairage methodology. Linear regression was used to evaluate factors affecting color change, including bleaching technique. The conventional and sealed bleaching groups showed no difference for any color change parameters (ΔL, Δa, Δb, ΔE); however, there was significantly greater hydrogen peroxide penetration in the conventional bleaching group (p<0.05). Linear modeling of the change in lightness (ΔL) showed that the increase in lightness tended to be greater for teeth with lower initial L* values (r=-0.32, p<0.05). After adjustment for initial L*, there was no evidence that ΔL differed with hydrogen peroxide penetration levels (p>0.05) or bleaching technique (mean group difference in ΔL=0.36; p>0.05).

Cavity preparation devices: effect on microleakage of Class V resin-based composite restorations.

PURPOSE: To evaluate the effect of cavity preparation device (i.e. carbide bur, diamond bur, air abrasive, Sonicsys, and Er:YAG laser) on microleakage of Class V resin-based composite (RBC) restorations, the tooth restoration interface and dentin ultrastructure. MATERIALS AND METHODS: Eight groups (n=18) of 9 human molars each were prepared on the buccal and lingual surfaces for Class V RBC restorations using five preparation devices: Group 1: carbide bur #8 round; Group 2: diamond bur #801; Group 3: KCP 1000 air abrasion unit; Group 4: Sonicsys Approx.; Group 5: Er:YAG laser; Group 6: carbide bur plus air abrasive; Group 7: carbide bur plus laser, and Group 8: laser without etching. Circular cavity preparations, 3 mm diameter and 1.5 mm deep, were cut at the CEJ on the buccal and lingual surfaces of each tooth. A bevel was placed on the enamel margin. All cavities were restored using Single Bond adhesive system and Silux Plus according to manufacturer's directions, with the exception that no etchant was used with Group 8. After thermocycling, specimens were tested for microleakage using silver nitrate methodology. Dye penetration data was collected and subjected to non-parametric statistical analysis. SEM analysis of the dentin-RBC interface, as well as the effect of each cavity preparation device on the surface of dentin was performed. RESULTS: Microleakage did not occur in enamel for any method of cavity preparation when the enamel was etched prior to adhesive application. Kruskal-Wallis One-way ANOVA revealed differences in dentin microleakage among the tested groups at alpha=0.05. Mann-Whitney Test for Paired Comparisons at alpha=0.01 demonstrated significantly greater dentin microleakage in Groups 5 and 7 compared to all groups except Group 3 (air abrasive). Although Group 8 had the least microleakage in dentin, this was not significantly different from Groups 1, 2, 4 and 6. SEM observation revealed hybridization at the dentin-resin interface for all groups except for Group 8 (laser prepared, non-etched). Surface analysis showed differences related to the operating mode of each preparation device. CLINICAL SIGNIFICANCE: The method of cavity preparation did not affect microleakage in etched enamel. When using a laser for cavity preparation, enamel should be etched although not etching dentin may help to improve marginal seal.

Restoration of enamel and dentin erosion due to gastroesophageal reflux disease: a case report.

Gastroesophageal reflux disease (GERD) is a condition where acid contents of the stomach are regurgitated into the oral cavity, which results in continual exposure of the teeth to these acids. Knowledge of the relationship between GERD and dental erosion enables the appropriate diagnosis and treatment of the underlying medical condition as well as the affected teeth. This article details a case report where severe dental erosion was present due to GERD. After management of the disease, treatment (i.e., diagnosis, treatment planning, and restoration) of the eroded dentition is described.

A conservative aesthetic solution for a single anterior edentulous space: case report and one-year follow-up.

Conservative solutions for the restoration of a single edentulous space in the anterior maxilla present an aesthetic challenge to the clinician. Treatment options for tooth replacement include implant placement, a classical fixed partial denture, or a resin-bonded appliance with a metal substructure or fiber-reinforced resin. The resin-bonded Encore Bridge (daVinci Studios, Woodland Hills, CA) offers a restorative solution that is conservative and aesthetic when compared to the required full-tooth preparation in a conventional three-unit fixed partial denture. This case report addresses the indications, preparation guidelines, and restorative procedures for an Encore Bridge.

The physical properties of packable and conventional posterior resin-based composites: a comparison.

BACKGROUND: The authors compared the physical properties of three packable hybrid resin-based composites with those of a conventional hybrid and a microfill composite material advocated for use as posterior restorative materials. They evaluated diametral tensile strength, or DTS; compressive strength, or CS; flexural strength, or FS; and depth of cure, or DC. METHODS: The authors studied the following resin-based restorative materials: three packable composites, Alert Condensable Composite (Jeneric Pentron), SureFil High Density Posterior Restorative (Dentsply Caulk) and Solitaire (Heraeus Kulzer); one conventional hybrid composite, TPH Spectrum (Dentsply Caulk); and one microfill, Heliomolar Radiopaque (Ivoclar-Vivadent). The authors evaluated DTS, CS, FS and DC, according to American National Standards Institute criteria. They made scanning electron micrographs of the packable resin-based composites. RESULTS: Results demonstrated that the conventional hybrid, TPH Spectrum, had significantly greater DTS and FS than other resin-based composites. Alert and SureFil had comparable DTS and FS, which were significantly greater than Heliomolar's DTS and FS. Solitaire had significantly lower DTS and FS than all other resin-based composites. SureFil had the highest CS, followed by TPH Spectrum, Solitaire and Alert, which were comparable and had significantly greater CS than Heliomolar. TPH Spectrum and Alert had significantly greater DC than all other resin-based composites, followed in decreasing order by SureFil, Solitaire and Heliomolar. CONCLUSION: While the packable composites tested in this study had physical properties superior to those of the microfill composite, they were no better suited for use as a posterior restorative material than was the conventional hybrid resin-based composite. CLINICAL IMPLICATIONS: Packable composites may be easier for clinicians to handle than conventional resin-based composites; however, their physical properties were not superior to those of the conventional small-particle hybrid resin-based composite. In addition, these materials may have the clinical drawback of increased wear and surface roughness that was seen with early, large-particle composite restorative materials.

A direct approach to restore anterior teeth.

When selecting the correct treatment for a patient with anterior esthetic problems, the dentist must choose between direct and indirect procedures. With situations allowing conservative treatment, direct resin restoration should be given strong consideration. Advances in materials and techniques that can positively affect this choice include pre-restorative bleaching procedures, new bonding agents, and new highly esthetic direct resin systems. A procedure is described to maximize esthetics and minimize finishing time during direct resin placement.

Amalgam shear bond strength to dentin using single-bottle primer/adhesive systems.

PURPOSE: To evaluate the in vitro shear bond strengths (SBS) of a spherical amalgam alloy (Tytin) to dentin using several single-bottle primer/adhesive systems both alone: Single Bond (SB), OptiBond Solo (Sol), Prime & Bond 2.1 (PB), One-Step (OS) and in combination with the manufacturer's supplemental amalgam bonding agent: Single Bond w/3M RelyX ARC (SBX) and Prime & Bond 2.1 w/Amalgam Bonding Accessory Kit (PBA). Two, three-component adhesive systems, Scotchbond Multi-Purpose (SBMP) and Scotchbond Multi-Purpose Plus w/light curing (S + V) and w/o light curing (S+) were used for comparison. MATERIALS AND METHODS: One hundred eight extracted human third molars were mounted lengthwise in phenolic rings with acrylic resin. The proximal surfaces were ground to expose a flat dentin surface, then polished to 600 grit silicon carbide paper. The teeth were randomly assigned to 9 groups (n = 12), and dentin surfaces in each group were treated with an adhesive system according to the manufacturer's instructions, except for S + V specimens, where the adhesive was light cured for 10 s before placing the amalgam. Specimens were then secured in a split Teflon mold, having a 3 mm diameter opening and amalgam was triturated and condensed onto the treated dentin surfaces. Twenty minutes after condensation, the split mold was separated. Specimens were placed in distilled water for 24 hrs, then thermocycled (300 cycles, between 5 degrees C and 55 degrees C, with 12 s dwell time). All specimens were stored in 37 degrees C distilled water for 7 days, prior to shear strength testing using a Zwick Universal Testing Machine at a cross-head speed of 0.5 mm/min. RESULTS: The highest to the lowest mean dentin shear bond strength values (MPa) for the adhesive systems tested were: S + V (10.3 +/- 2.3), SBX (10.2 +/- 3.5), PBA, (6.4 +/- 3.6), SOL (5.8 +/- 2.5), SBMP (5.7 +/- 1.8), S+ (4.8 +/- 2.3), PB (2.7 +/- 2.6), SB (2.7 +/- 1.1) and OS (2.5 +/- 1.8). One-way ANOVA and Duncan's Multiple Range Test indicated significant differences among groups. SBX and S + V produced significantly higher amalgam to dentin shear bond strengths than all other adhesive systems. Bond strengths of amalgam to dentin for the single-bottle adhesives, SOL and PBA were comparable to the three-component systems, SBMP and S+ and were significantly greater than OS, SB and PB (P < 0.05).

Evaluation of acidic primers in microleakage of Class 5 composite resin restorations.

The purpose of this in vitro study was to evaluate the marginal seal of two adhesive systems on class 5 composite resin restorations. Two adhesive systems that use acidic primers were used in this study: Clearfil Liner Bond 2 and Denthesive II. Scotchbond Multi-Purpose was used as a control. Class 5 cavity preparations were made at the CEJ (half of the preparation was in enamel and half in dentin/cementum) of 60 extracted human molars. Both systems were used with and without etching. The control group was used with etching only. Composite resin restorations were placed, light cured for 40 seconds, and polished. All specimens were thermocycled 500 times. The specimens were immersed in erythrosin B, tetra-iodo-fluorescent 2% solution, then sectioned to obtain 600 mm-thick sections. These were examined under X13.2 magnification, and the degree of dye penetration was measured in microns. A chi-square test demonstrated no significant differences in microleakage among groups for either dentin (P = 0.54) or enamel (P = 0.35).

Interfacial ultrastructure of the resin-enamel region of three adhesive systems.

PURPOSE: To observe the resin/enamel interface produced by different adhesive systems. MATERIALS AND METHODS: A conventional three-step smear layer removing adhesive system (Scotchbond Multi-Purpose), a two-step smear layer removing adhesive system (Prime & Bond), and a two-step smear layer dissolving adhesive system containing a self-etching primer (Panavia 21) were evaluated. Flat enamel surfaces were obtained from approximal surfaces of 18 extracted human molars. A total of 36 surfaces were collected and divided into three groups of 12 samples. One-half of each specimen in each group was etched with 35% phosphoric acid prior to the application of each adhesive system, with the second half being kept unetched. Subsequently, resin composite was placed and polymerized for 40 seconds. The samples were fractured and immersed into HCl and NaOCl solutions, followed by critical point drying and sputter coating for examination with a field emission scanning electron microscope. RESULTS: In the etched samples, Panavia 21 and Scotchbond Multi-Purpose showed more consistent resin tag penetration than did Prime & Bond. Unetched Prime & Bond and Scotchbond Multi-Purpose samples showed minimal or no adhesive penetration in enamel surfaces.

Adhesive composite inlays for the restoration of cracked posterior teeth associated with a tongue bar.

While body piercing has become fashionable in contemporary society, numerous health risks are directly related to this trend. Tongue piercing in particular presents several concomitant complications for the attending clinician, including the possibility of soft tissue infection or damage to the natural dentition or existing restorations. Clinicians must be proficient in the selection of the proper materials and techniques utilized to treat affected patients. This article details a comprehensive clinical protocol for the use of adhesive composite inlay restorations for cracked posterior teeth.

Protocol for predictable restoration of anterior teeth with composite resins.

The composite resins have reached a high degree of excellence and are now used with predictable results in restoring the anterior dentition. This article discusses the development of these resins and the histologic and optical considerations (polychromatic characteristics, hue translucency and opacity, chroma, value, strength and polishability). In restorative materials, the use of universal or all-purpose restorative resins is considered: i.e. materials that combine the junctional strength necessary for the posterior regions and the high gloss polishability necessary to emulate enamel in the anterior. The restorative sequence of cervical, middle, and incisal thirds describes the materials best suited for each third, along with aids to create the intricate refinement of hue, chroma, and value. The learning objective of this article is to review the principles involved in these restorations and to provide a protocol for their clinical implementation.

Intraoral repair of cosmetic restorations.

The longevity of porcelain and composite resin restorations can often be prolonged by using sound principles, up-to-date materials, and judicious attention to repair when fracture problems arise. Careful case selection and correct usage of surface treatment agents, followed by the use of a quality bonding system and restorative materials, can result in a repair that exhibits excellent retention and natural color blending. This article outlines procedures and materials to repair both resin composite and porcelain intraorally.

Dentin desensitizing agents: SEM and X-ray microanalysis assessment.

PURPOSE: To evaluate the effect of four proprietary dentin desensitizing agents on dentin tubular occlusion, chemical composition changes on the dentin surface, and the effect of saliva and toothbrushing on these agents. MATERIALS AND METHODS: Fifty dentin discs, obtained from 50 freshly extracted human premolar and molar teeth were used in this study. These were divided into five groups of 10 discs each. Five discs from each group were treated with the desensitizing agents, viewed under the SEM and subjected to energy dispersive X-ray analysis. The other five discs were treated with the desensitizing agents, immersed in artificial saliva, subjected to simulated toothbrushing equivalent to 3 weeks of normal brushing and viewed under the SEM. The agents studied were Sensodyne Dentin Desensitizer, Therma-Trol Desensitizer Gel, Gluma Desensitizer and All-Bond DS. RESULTS: The Kruskal-Wallis test followed by the Wilcoxon signed-rank test showed that Sensodyne Dentin Desensitizer exhibited the greatest amount of tubular occlusion among the unbrushed samples, followed by Therma-Trol Desensitizer Gel, Gluma Desensitizer and All-Bond DS (P < 0.05) in that order. Toothbrushing increased tubular occlusion in all cases except the Sensodyne Dentin Desensitizer treated samples.

An in vitro comparison of three fluoride regimens on enamel remineralization.

The purpose of this study was to compare the enamel remineralization effectiveness of a fluoride rinse, fluoridated dentifrice, and fluoride-releasing restorative material. Forty extracted molars had 1 x 5 mm artificial carious lesions formed at the interproximal contact point. One-hundred-micrometer sections were obtained at the caries sites, and polarized light photomicrographs were obtained. The sections had varnish placed, leaving only the external section site exposed, and were situated back into the original tooth. Forty other molars were obtained; 10 had Class-II glass ionomer cement restorations placed. These 40 teeth were mounted to have interproximal contact with the adjacent teeth containing artificial carious lesions. Specimens were placed in closed environments of artificial saliva for 1 month, with saliva being changed every 48 h. Ten specimen pairs were brushed with a fluoridated dentifrice for 2 min, twice per day, 10 specimen pairs were rinsed with a 0.05% sodium fluoride rinse for 1 min twice per day, 10 specimen pairs had Class-II glass ionomer cement restorations positioned adjacent to 10 teeth with artificial carious lesions, and 10 specimen pairs acted as controls. After 30 days, the same sections were photographed again under polarized light, and areas of the lesions were digitized quantitatively. Results demonstrated the mean (+/- SD) remineralization (mu m2) in Thoulet's 1.41 imbibition media to be: lesions adjacent to glass ionomer cement restorations, 2.45 +/- 170; lesions exposed to a fluoridated dentifrice, 223 +/- 102; lesions exposed to 0.05% sodium fluoride rinse, 374 +/- 120, and control lesions only exposed to artificial saliva, 101 +/- 69. Duncan's analysis indicated the fluoridated rinse to have significantly greater remineralization effects on adjacent caries than the other groups (p < or = 0.05). The glass ionomer restorative material and fluoridated dentifrice also had significantly greater remineralization effects on adjacent caries than the control, yet significantly less than the fluoridated rinse (p < or = 0.05).

Interfacial micromorphology and shear bond strength of single-bottle primer/adhesives.

OBJECTIVES: This study was conducted 1) to characterize through SEM analysis the resin-dentin interface produced by single-bottle primer/adhesives and a three-component system [Scotchbond Multi-Purpose (3M Dental)] and 2) to evaluate the shear bond strength to dentin of these adhesive systems. METHODS: Single-bottle primer/adhesives [Bond 1 (Jeneric/Pentron), Single Bond, (3M Dental Products); One Step (Bisco Inc.), OptiBond Solo (Kerr Corp.), Prime & Bond 2.1 (L.D. Caulk-Dentsply), Syntac Single-Component (Ivoclar-Vivadent), Tenure Quilk with Fluoride (Den-Mat)] were used according to manufacturers' instructions to bond resin composite to flat dentinal surfaces of extracted human third molars (n = 15). All samples were thermocycled 300x. Twelve specimens per group were used to measure shear bond strength and three specimens were used to evaluate the interfacial morphology under SEM. A one-way ANOVA and Turkey's test were used to assess the results. RESULTS: Mean shear bond strengths in MPa +/- SD for the groups ranged from 22.27 +/- 4.5 MPa for Single Bond to 7.6 +/- 3.9 MPa for Syntac Single-Component. The statistical analysis indicated that Single Bond produced significantly higher (p < 0.001) bond strengths than Syntac Single-Component, Prime & Bond 2.1, Bond 1 and Tenure Quik With Fluoride. Bond strengths for Syntac Single-Component were significantly lower than One-Step, OptiBond Solo, Scotchbond Multi-Purpose Plus and Single Bond. SEM examination clearly revealed the formation of a distinct hybrid layer for all adhesive systems; however, minor variations in ultrastructure existed among products. SIGNIFICANCE: Some single-bottle primer/adhesive present in vitro bond strengths and hybrid layer formation similar to those found for the conventional three-component adhesive system tested.

Evaluation of adhesive systems using acidic primers.

PURPOSE: To evaluate in vitro the dentin and enamel shear bond strength of two adhesive systems that contain acidic primers. MATERIALS AND METHODS: Clearfil Liner Bond 2 (CLB2) and Denthesive II (DTII), containing acid primers were used with (ETCH) and without (NOET) etching. Scotchbond Multi-Purpose (SBMP) was utilized as a control. Sixty flat enamel and dentin bonding sites were prepared to 600 grit on extracted human molars. Both acidic primer systems were used with (ETCH) and without etching (NOET) for both enamel and dentin surfaces. The control group used etching only. After applying primer and adhesive, a microfill composite (Silux Plus) was placed in a 2.5 mm diameter matrix on the tooth surface, and polymerized for 40 seconds. All specimens were thermocycled 500 times. Shear bond strengths were determined using a Zwick testing machine. RESULTS: One-way ANOVA revealed significant differences among groups for enamel (P = 0.0001) and dentin (P = 0.0002). Duncan's multiple range test (alpha = 0.05) revealed that enamel shear bond strength of DTII-ETCH was equal to that of CLB2-NOET and these were significantly greater than CLB2-ETCH, SBMP and DTII-NOET. For dentin, bond strengths for CLB2-ETCH and CLB2-NOET were significantly greater than DTII-NOET.

Effect of condensation techniques on amalgam bond strengths to dentin.

This in vitro study determined the shear bond strengths of Tytin amalgam to dentin using All-Bond 2, Amalgambond Plus, Amalgambond Plus with HPA powder, and OptiBond with hand and mechanical (Condensaire) condensation. The occlusal enamel surfaces were ground flat to expose the dentin surfaces, and polished with 600-grit SiC paper. The dentin surfaces were treated with one of the combinations of a dentin bonding agent and a condensation technique. All specimens were thermocycled 300 cycles in water between 5-55 degrees C, and shear bond strengths were determined with a Zwick Universal Testing Machine. Two-way ANOVA and Duncan's tests showed no significant differences (P > 0.05) in shear bond strength between hand and mechanical condensation of the paired groups, with the exception of Amalgambond Plus, where hand condensation was shown to be significantly better. For both condensation techniques, shear bond strength of Amalgambond Plus with HPA powder was significantly higher than the other materials. For mechanical condensation, OptiBond was significantly higher than either Amalgambond Plus or All-Bond 2, and no significant difference was found between Amalgambond Plus and All-Bond 2. For hand condensation, OptiBond was only significantly higher than All-Bond 2, while there was no significant difference between OptiBond and Amalgambond Plus or between Amalgambond Plus and All-Bond 2. In conclusion, for both condensation techniques, Amalgambond Plus with HPA powder performed the best in bonding amalgam to dentin. The two different condensation techniques did not significantly affect shear bond strength, except with Amalgambond Plus.

Effect of desiccation on microleakage of five Class 5 restorative materials.

Resin-modified glass ionomers, combinations of resin and glass-ionomer chemistry, have resulted in materials with longer working times and command set by visible light activation. These materials are easier to use and more resistant to early moisture contamination and fracture. A glass-ionomer or resin-modified glass-ionomer restoration may be inadvertently desiccated by isolation of the same quadrant for subsequent restorative procedures. The present study is an assessment of the effects of desiccation on microleakage of three resin-modified glass-ionomers: Vitremer, Photac-Fil, Fuji II LC; a glass-ionomer, Ketac-Fil; and a microfill resin, Silux Plus. Fifty extracted molars were prepared with class 5 preparations buccal and lingual and randomly assigned to 10 groups (n = 10). Restorations were placed according to the manufacturers' specifications and finished wet after the manufacturers' specified setting interval. All samples were thermocycled 300 cycles between 50 and 500 degrees C. Samples were stored in water at all times until the five groups to be desiccated were air dried and stored dry for 45 minutes. Desiccated groups were then rehydrated for 24 hours prior to AgNO3 staining. Teeth were sectioned mesiodistally and four buccolingual sections (0.6 mm thick) through each class 5 restoration were obtained with a Silverstone-Taylor hard tissue microtome. Each section was scored on a scale of 0-4 for microleakage, and the highest score for dye penetration was used as the score for that restoration. An increase in microleakage was observed in all desiccated groups. Three materials showed a statistically significant increase in microleakage (P < 0.05) following desiccation. Microleakage increases following a brief period of desiccation corresponding to typical treatment times indicate that clinicians need to protect previously placed restorations from undue drying during subsequent dental treatment.

Class V restorations utilizing a new compomer material: a case presentation.

Restorative materials used in the anterior cervical region should be able to restore the affected area in an aesthetic manner, require only a minimal amount of tooth structure removal, and provide protection from further cervical decalcification. The latest generation of restorative materials have combined the qualities of composite resins and glass-ionomers. Some of these materials incorporate resin components into glass-ionomer systems and are termed resin-modified glass-ionomers; others add glass-ionomer particles to acidic polymerizable monomers in a resin matrix and are commonly called "compomers." The learning objective of this case report is to present a step-by-step clinical procedure for restoration of a Class V defect in the maxillary anterior region, using a recently introduced "compomer."