Adhesive Class VI Resin Composite Restorations of Worn Mandibular Incisal Edges: A Two-year Case Report.

Many authors have advocated retentive tooth preparations for resin composite restorations intended to halt progression of incisal edge attrition with worn concave dentin, probably due to frustration with adhesive restorations being lost from these defects. Unfortunately, this technique further removes the dentin these restorations are intended to preserve. The purpose of this article is to demonstrate a purely adhesive, less invasive technique for restoration of worn concave incisal edges, which includes air particle abrasion and increased etching time for the sclerotic dentin and unprepared enamel. Favorable two-year results for mandibular anterior teeth opposed by natural teeth are reported.

In vivo chlorhexidine stabilization of hybrid layers of an acetone-based dentin adhesive.

The current in vivo study evaluated the degradation of dentin hybrid layers in deep occlusal-surface resin composite restorations using TEM. Caries-free premolars scheduled for extraction as part of orthodontic treatment were prepared and restored, then extracted after 12 months. The adhesive used was a single-bottle etch-and-rinse acetone-based product (Prime & Bond NT, Dentsply/Caulk). Control group restorations (n=8) were placed according to the manufacturer's instructions, while the experimental group received application of a 2% solution of chlorhexidine digluconate after etching and rinsing and prior to application of the adhesive. Extensive degradation was observed in all of the teeth in the control group after 12 months, while no degradation was observed in the experimental group. In vitro testing showed no significant difference in immediate microtensile bond strength between the control and experimental adhesive protocols.

Replacement of a Missing Maxillary Central Incisor Using a Direct Fiber-Reinforced Fixed Dental Prosthesis: A Case Report.

The use of the direct fiber-reinforced fixed dental prosthesis (FDP) restorative technique presented in this article will result in an ideal restoration considering both esthetics and function in a single appointment. Although indirect techniques are available and may be used, they are time-consuming, resulting in higher cost; therefore, a simplified approach combining a prebonded fiber-reinforced mesh with a sculptable micro-hybrid composite will deliver an acceptable esthetic result with proper function.

Diagnosis of Pit-and-fissure Caries Using Three-dimensional Scanned Images.

Diagnosis of the extent of pit-and-fissure caries has been subjective and thus difficult to teach and categorize for treatment planning. This in vitro study compares occlusal caries diagnosis of extracted posterior teeth (n=49) using three-dimensional (3D) scanned images vs visual examination, according to the International Caries Detection and Assessment System (ICDAS). The surfaces chosen for study represent all ICDAS classifications. Five experienced restorative faculty members examined scanned images for 60 seconds from a standardized series of views of each surface and scored them independently. One month later, the same teeth were examined visually by the same five raters with magnification and LED headlamps, with compressed air available. Intrarater and interrater agreement and validity were assessed using intraclass correlation coefficients (ICCs). The ICCs, ranging from 0.90 to 0.93, indicated excellent agreement between and within raters and between the raters and the gold standard ICDAS determination. This suggests that both photographs and 3D scans of pits and fissures are equally effective in diagnosing caries.

Use of a Modified Matrix Band Technique to Restore Subgingival Root Caries.

Given the increasing incidence of root caries in the elderly population, clinicians frequently must isolate and restore subgingival preparations. This article demonstrates a technique utilizing a modified Tofflemire matrix band that creates a preparation free of crevicular fluid and blood for restoration with resin-modified glass ionomer cement.

Postoperative sensitivity: a comparison of two bonding agents.

Historically, postoperative pain associated with temperature was considered a thermal conduction problem. More recently, pulpal hydrodynamics has been used to explain this sensitivity. Relative to restorations placed with dentin bonding agents that require a separate etching step, agents that include an acidic primer are believed to result in a better seal of the dentinal tubules. This study compared pain associated with a standardized cold stimulus in two groups of restorations. One group was placed with a self-priming resin that required a separate etch step, the other with a self-etching, self-priming dentin bonding agent. This was a community-based, randomized, double-blind clinical trial. Two hundred and nine restorations were placed for 76 participants. All teeth were asymptomatic at the start of the trial. Immediately following application of a standardized cold stimulus, participants rated the pain for each restored tooth using a Visual Analog Scale (VAS). For each group of restorations, VAS scores at 13 weeks were compared to preoperative scores. In addition, the preoperative score was subtracted from the 13-week score, and the two groups of restorations were compared. For both groups of restorations, the median scores were significantly reduced at 13 weeks. This decrease in the VAS score reflects a reduction in sensitivity below that which existed preoperatively. There was no significant difference between the two groups of restorations in terms of change in sensitivity at 13 weeks.

Restorative Technique Selection in Class IV Direct Composite Restorations: A Simplified Method.

Use of the techniques presented here will yield highly esthetic resin composite restorations in minimal time. Although more elaborate composite layering techniques exist and may be used in complex esthetic scenarios, a simplified approach combining two body shades and implementing basic dental anatomy concepts often will deliver highly acceptable esthetic results.

Relative microhardness of glass ionomer restorative materials as an indicator of finishing time.

Microhardness was evaluated as an indicator of appropriate finishing intervals for glass ionomer restorative materials. The hardness of several materials was determined after the first hour of mixing. A material clinically documented to be satisfactorily finished after a delay of 15 minutes attained 29% of its 24-hour hardness during that interval. Samples of the other materials finished on reaching this relative hardness, which differed from the manufacturers' suggested finishing delays, showed no differences in surface characteristics, appearance, or surface roughness compared with specimens finished at the recommended times.

The influence of mixing speed on the setting rate of high-copper amalgams.

This study was undertaken to assess the effect of mixing speed on the setting rate of high-copper dental amalgam. The surface hardness during setting of two representative brands of dental amalgam was related to working and carving times determined by clinicians. From this information, a means of evaluating setting rate of amalgam based on surface hardness was developed.

The retention of titanium pins in high-copper amalgam and their influence on its fracture resistance.

The influence of titanium pins on the fracture resistance of amalgam and the retention of amalgam by titanium pins were compared to that of stainless-steel pins. The retention of stainless-steel pins embedded in amalgam to various depths was also evaluated. None of the pins had a significant influence on the compressive fracture resistance of amalgam. All pins embedded to standard depth in amalgam failed in tension, with titanium pins demonstrating the lowest resistance to tensile forces. Stainless-steel pins embedded 1.75 or 1.5 mm and loaded in tension caused failure in the amalgam, but at forces comparable to the retention of such pins in dentin.

The antimicrobial action of chlorhexidine-containing zinc-phosphate cement.

In this study chlorhexidine dihydrochloride and diacetate salts were incorporated at a low level into a zinc-phosphate luting cement. Inhibition of three cariogenic organisms by cement specimens aged up to 8 weeks was significantly greater than the bacterial inhibition of unaltered zinc-phosphate cement. The addition of chlorhexidine caused no significant degradation in strength, film thickness, or solubility of the cement.

Resistance to condensation of 'condensable' resin composites as evaluated by a mechanical test.

This study compared the resistance-to-condensation forces of recently introduced condensable resin composites to that of amalgams and conventional resin composites. Using the flat platens of a servohydraulic testing machine, cylindrical specimens of each material 2.8 mm in diameter and 5.5 mm in length were compressed diametrally over two seconds to a thickness of 0.75 mm. Peak forces generated during compression were recorded. This method ranked the various classes of restorative material for resistance to condensation in the same order as most clinicians subjectively reported, with the highest forces observed with admixed dental amalgams, followed in order by spherical amalgams, condensable resin composites and conventional resin composites. Although peak forces observed with the condensable resin composites were generally higher than those observed with conventional resin composites, these were significantly lower than the peak forces observed with amalgams.

The retention of amalgam and composite resin by a smooth, reverse-tapered pin.

In this study, the retention of composite resin and amalgam by a smooth, reverse-tapered pin was compared to that of threaded pins. The smooth pin was significantly lower in retention than the threaded pins for each material, and caused a greater frequency of failure of the restorative material than the threaded pins. The newer smooth pin is probably not an improvement over the conventional threaded design.

Retention of microfilled and hybrid resin-based composite in noncarious Class 5 lesions: a double-blind, randomized clinical trial.

This double-blind clinical trial was undertaken to compare the retention rate of restorative materials with contrasting stiffness in noncarious class 5 lesions. All restorations were placed using retraction cord and cotton roll isolation to more closely mimic the general practice setting. Thirty subjects with at least two lesions were recruited to participate in the study. Each subject received one restoration using Silux Plus and one using Z100. The assignment of material was randomized, and the subjects were unaware of which tooth had received which material. All restorations were placed with a fourth-generation adhesive liner, Scotchbond Multi-Purpose. Evaluations were performed at baseline, 6, and 12 months by two independent examiners unaware of the restoration's group identity. The restorations were evaluated using criteria developed by Cvar and Ryge in a forced-consensus model. Despite the fact that the two materials have widely different elastic modulus values, after 12 months no difference between the retention rates for the two groups was found, and both groups of restorations performed very well.

Two-year clinical comparison of a microfilled and a hybrid resin-based composite in non-carious Class V lesions.

The purpose of this double-blind clinical trial was to compare the retention rate in noncarious Class V lesions of two resin-based composite restorative materials with contrasting stiffness. Isolation with retraction cord, pressed paper triangles, and cotton rolls was used to closely mimic the procedures generally used in a practice setting. Thirty pairs of restorations were placed, one using Silux Plus and one using Z100. The assignment of material was randomized, and the subjects were unaware of the material used. All restorations were placed with a fourth-generation adhesive liner, Scotchbond Multi-Purpose. Evaluations were performed at baseline, 6, 12, 18, and 24 months by two independent examiners using criteria developed by Cvar and Ryge in a forced consensus model. Examiners were unaware of the restoration's group identity. No difference between the retention rates for the two groups was found after 24 months, bringing into question the role that a material's stiffness plays in determining retention in a noncarious Class V lesion.

Two-year clinical performance of a resin-modified glass-ionomer restorative material.

This study was a 2-year clinical evaluation of a conventional and a resin-modified glass-ionomer restorative material. Thirty-four restorations each of Ketac-Fil and Photac-Fil were placed without tooth preparation in cervical abrasion/abfraction lesions, primarily in premolar teeth. Patients ranged in age from 30 to 73 years, with a median age of 45 years. Isolation for the restorations was accomplished with cotton rolls. Restorations of both materials were retained at the rate of 93%, and both were comparable in appearance, receiving Alfa ratings for more than 85% of the restorations. One occurrence of secondary caries was observed for each material. No significant difference between the materials was observed for any evaluation category (exact binomial test, P > 0.05).

One-year clinical performance of a resin-modified glass ionomer and a resin composite restorative material in unprepared Class V restorations.

This study evaluated the clinical performance and appearance of a resin-modified glass ionomer and a resin composite over one year. Thirty-seven pairs of restorations of Fuji II LC and Z250/Single Bond were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline and 6 and 12 months, using modified Ryge/USPHS criteria. No significant difference (p>0.05) was observed in performance of both materials, although retention of the Z250 restorations was below the minimum specified in the ADA Acceptance Program for Dentin and Enamel Adhesives. Little difference in the restorations' appearance was observed.

Two-year clinical performance of a polyacid-modified resin composite and a resin-modified glass-ionomer restorative material.

This study compared the clinical performance of a polyacid-modified resin composite and a resin-modified glass-ionomer restorative material over two years. Thirty-four pairs of restorations of Compoglass and Fuji II LC were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline, 6, 12, 18 and 24 months using modified Ryge/USPHS criteria. A significantly higher incidence of failed restorations was found with the polyacid-modified resin composite (p < 0.05).

Effect of plasma arc curing on the microleakage of Class V resin-based composite restorations.

PURPOSE: To evaluate the effect of plasma arc light-curing on the microleakage of Class V resin-based composite (RBC). MATERIALS AND METHODS: Facial and lingual Class V cavities were prepared at the cemento-enamel junction of extracted third molars. Restorations of the two materials (Z250; Amelogen) were placed, using the supplied dentin adhesives (Single Bond; PQ 1, respectively), and light-cured by either a halogen light curing unit (H) or a plasma arc curing unit (P). After thermal cycling, the teeth were immersed in methylene blue dye, then sections of the restored teeth were visually assessed for leakage. RESULTS: No leakage was observed at the interface between enamel and RBC in any restoration in this study. At gingival margins, the incidence of leakage (slight/severe) was: Z250 H = 2/4, P = 6/6; Amelogen H = 3/4, P = 1/12, where n = 16. The greatest incidence of leakage was observed in restorations cured by the plasma arc method. A two-way ANOVA of leakage data rankings showed curing method to be a significant factor (P = 0.002), restorative material not to be a significant factor (P = 0.24), and no significant interaction between material and curing method (P = 0.38).

Effect of finishing method on the microleakage of Class V resin composite restorations.

PURPOSE: To evaluate the effect of three finishing methods on the microleakage of Class V hybrid resin composite. MATERIALS AND METHODS: Facial and lingual Class V cavities were prepared at the cemento-enamel junction of bovine incisors. Restorations of the two materials (Z100; Prodigy) were placed, using the supplied dentin-adhesives (Scotchbond Multipurpose; OptiBond FL, respectively). Finishing methods were carbide (C) and diamond (D) finishing instruments operated at high-speed, and finishing disks (S). After thermal cycling, the teeth were immersed in methylene blue dye, then sections of the restored teeth (n = 12) were visually assessed for leakage. RESULTS: No leakage was observed at the resin-enamel interface in any restoration. At gingival margins, the incidence of leakage (slight/severe) was: Z100 D = 4/3, C = 5/3, S = 2/0; Prodigy D = 3/0, C = 2/4, S = 3/2. The greatest incidence of leakage was observed in restorations finished with carbide finishing burs. A two-way ANOVA of leakage data rankings showed no significant difference among the three methods (P = 0.07) or between the two materials (P = 0.55), and no significant interaction of material and finishing method (P = 0.07).