Objectives:This in vitro study evaluated the fracture resistance of weakened human premolars (MOD cavity preparation and pulp chamber roof removal) restored with condensable resin composite with and without cusp coverage.Material and Methods:Thirty human maxillary premolars were divided into three groups: Group A (control), sound teeth; Group B, wide MOD cavities prepared and the pulp chamber roof removed and restored with resin composite without cusp coverage; Group C, same as Group B with 2.0 mm of buccal and palatal cusps reduced and restored with the same resin. The teeth were included in metal rings with self-curing acrylic resin, stored in water for 24 h and thereafter subjected to a compressive axial load in a universal testing machine at 0.5 mm/min.Results:The mean fracture resistance values ± standart deviation (kgf) were: group A: 151.40 ± 55.32, group B: 60.54 ± 12.61, group C: 141.90 ± 30.82. Statistically significant differences were found only between Group B and the other groups (p<0.05). The condensable resin restoration of weakened human premolars with cusp coverage significantly increased the fracture resistance of the teeth as compared to teeth restored without cusp coverage.Conclusion:The results showed that cusp coverage with condensable resin might be a safe option for restoring weakened endodontically treated teeth.

Overal, packable resin composites are unlikely to show superior wear resistance with regard to weight loss and surface roughness compared with current resin composites also indicated for posterior restorations.

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Objective:Tooth bleaching tends to increase enamel roughness and porosity, in addition to reducing surface microhardness. The aim of this in vitro study was to evaluate the effects of bleaching treatments using different hydrogen peroxide (HP) concentrations, with and without light activation on bovine enamel microhardness.Materials and Methods:The buccal surfaces of sixty bovine incisors were flattened and polished and the enamel specimens were divided into six groups: G1 : c0 ontrol, exposed to artificial saliva; G2: 35% HP applied in two sessions (45’ each); G3: 35% HP applied in two sessions (3 × 15’ each); G4: 35% HP applied in one session (3 × 7’30”) plus hybrid light (HL); G5: 25% HP applied in one session (3 × 7’30”) plus HL; and G6: 15% HP applied in one session (3 × 7’30”) plus HL. After the treatment, the enamel specimens were stored in artificial saliva. The surface microhardness (Knoop) was measured at the baseline, 24 h and 7 days after bleaching. The data was analyzed using the ANOVA test, followed by the Tukey–Krummer test (P < 0.05).Results:All bleaching procedures lead to a decrease in surface microhardness when compared with the control group after 24 h. The lowest change in surface microhardness was found in the specimens treated with 15% HP plus HL. However, 35% HP plus HL induced the highest decrease in surface microhardness. After 7 days of remineralization, the surface microhardness returned to normal levels for all bleached specimens.Conclusion:Therefore, it can be concluded that the bleaching protocols caused a slight enamel surface alteration. However, the remineralization process minimized these effects.

Unluted specimens presented significantly lower fracture resistance than luted specimens. Higher cement film thickness resulted in increased fracture resistance for the 1-mm ceramic plates. Film thickness did not influence the fracture resistance of 2-mm porcelain plates.

This study aimed at analyzing the compomers wear by an "in vitro" toothbrushing abrasion test. The null hypotheses tested were that there would be no differences in weight loss and no significant changes in surface roughness of the compomers after this test. The utilized commercial brands were Dyract (Dentsply), Dyract AP (Dentsply), Compoglass F (Vivadent), Freedom (SDI), F2000 (3M ESPE), which were compared to the two resin composites Z100 (3M ESPE) and Silux Plus (3M ESPE). Ten cylindrical specimens for each commercial brand were prepared with 5mm diameter and 3mm thickness. An appropriate machine with soft bristle tips containing dentifrice solution and deionized water was used. A total of 100,000 brushing cycles were performed. The amount of weight loss was measured by the percentage alteration between the initial (before toothbrushing) and final weight (after toothbrushing), measured by a Sartorius analytical balance. The surface roughness change was determined by the percentage difference between initial and final means after 5 tracings by a T 1000 Hommel Tester roughness meter on the specimen's surfaces before and after toothbrushing abrasion test. The statistical analysis (Students paired t-test, ANOVA and Tukey, á=0.05) showed that all materials presented statistically significant weight loss and roughness increase after abrasion test. All compomers presented higher weight loss than resin composites. Freedom and Dyract AP presented the lowest weight loss among compomers. F2000 presented the worst abrasion resistance, without statistical differences with Dyract. For roughness changes, Dyract, Dyract AP, Z100, Compoglass F and Silux Plus showed the lowest surface roughness alteration, in increasing order, without statistical differences between them. Freedom was the statistically roughest material of the study.

Atraumatic Restorative Treatment (ART) has been adopted around the world to avoid unnecessary extractions, especially in non-industrialized countries. The development of specific glass ionomer cements marketed for the ART technique has contributed to the technical success rate. In this study, Ketac-Molar (3M ESPE, Dental Medzin, Germany) was used to restore 150 Class I cavities in 118 Brazilian public school children, aged from 7-12 years. At baseline and at subsequent recalls, CPI probes with a ball-end of 0.5 millimeters (mm) were used to assess loss of restorative material, and photographic color transparencies of restorations were made. After six months, 83 patients returned for follow-up examinations, with 71.8% of their restorations designated as acceptable. After three years, 49 patients with 57 ART-restorations were evaluated, with 21.0% of these restorations graded as acceptable. Another 29.8% of their restorations had been replaced by more permanent materials. The main objective of the ART technique is tooth retention; this was achieved for 94.7% of the restored teeth in a high caries risk population who returned for recalls.

<p><strong>ABSTRACT</strong></p><p><strong> </strong></p><p>The purpose of this clinical case description article was to present the planning sequence, indication, treatment and performance to obtain a crown of the Endocrown type. This clinical case description article illustrates a therapeutic option for functional and esthetic rehabilitation of a devitalized mandibular molar, presenting a small amount of remaining coronal tooth structure, by means of cementing a pure porcelain crown of the Endocrown type (Adhesive Endodontic Crown). A 39-year-old woman presented to the Graduate clinic of the Bauru Dental School (FOB), University of São Paulo (USP), with the complaint that tooth #36 had an extensive and unsatisfactory composite resin restoration. The lithium disilicate-based system of monolithic porcelain was used with the lost wax technique. This therapy promoted the stability and retention of the indirect restoration, without the need for performing reconstruction of the above mentioned tooth, either by means of a cast metal core or reconstruction with intracanal post, thereby reducing the treatment time. After the tooth preparation, the provisional restoration was done with acrylic resin to determine if the retention and stability of the remaining tooth was adequate to receive the indirect Endocrown restoration. The characteristics of the internal and external walls of the dental remnants, cervical termination, impression-taking, laboratory stages and adhesive cementation will be discussed. The major advantage of indicating an endocrown is the use of the dental remnants itself, particularly the pulp chamber, to promote retention and stability in cases without adequate height for performing complete dental and crown reconstruction.<strong></strong></p><p><strong>Keywords</strong></p><p>Adhesive endodontic crown; Devitalized tooth; Lithium dissilicate.</p>