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Objectives: This study aims to evaluate the color‐matching ability of OMNICHROMA composite, a single‐shade composite, using the CIE L∗a∗b∗ system and determining ΔE values. Materials and Methods: In this in vitro study, 30 intact premolar teeth were collected, cleaned, and disinfected with 0.5% thymol solution. The teeth were stored in distilled water at 37°C. A putty index calibrated the color assessment sites on buccal and lingual surfaces. Two cavities were prepared, one with 1.25 mm depth (enamel) and another with 2.25 mm depth (dentin), and restored using OMNICHROMA composite resin. The putty index measured the color of the cured composite, and ΔE between the composite and original tooth color was calculated. Statistical analysis: Data analysis included t‐tests, correlation coefficients, and Fisher's exact test (α = 0.05). Results: The mean ΔE was 2.39 in enamel cavities and 2.32 in dentin cavities, both within the clinically acceptable range (<3.3). In enamel cavities, the composite color was darker than the tooth, shifting toward green and blue shades. In dentin cavities, the composite color was lighter than the tooth, with shifts toward green and yellow shades. Color matching was slightly better in dentin cavities, but the difference was not statistically significant (p = 0.719). Conclusion: OMNICHROMA composite resin's color matching falls within the clinically acceptable range, unaffected by cavity depth. [ABSTRACT FROM AUTHOR]

Background: Porcelain fracture or chipping is one of the limitations of all ceramic restorations. This study investigated the shear bond strength (SBS) of composite resins to lithium disilicate ceramics using universal bondings and different methods of surface preparation. Materials and Methods: In this experimental study, 72 specimens of e.max computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic blocks were divided into six groups of 12 according to surface treatment: Group I-Hydrofluoric (HF) acid etching + All-Bond Universal bonding (ABU), Group II-Bur roughening (BR) + HF + ABU, Group III-BR + HF + Bis-Silane (Si) + ABU, Group IV-Sandblasting (SB) + ABU, Group V-SB + HF + ABU, Group VI-SB + HF + Si + ABU. After bonding of composite resin to the prepared ceramic surface and storage of samples in distilled water for 24 h, SBS test was done using the universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed using the analysis of variance and Tukey's post hoc test (α = 0.05). Results: The mean values of SBS in six studied groups were 6.65 ± 2.78 MPa, 8.56 ± 2.69 MPa, 8.49 ± 2.14 MPa, 3.13 ± 1.66 MPa, 7.94 ± 2.4 MPa, and 10.04 ± 2.47 MPa, respectively. The mean values of SBS were significantly different (P < 0.001). The highest value of SBS was observed in Group VI and the lowest in Group IV. Conclusion: Ceramic sandblasting followed by HF etching, Bis Si, and ABU resulted in a higher SBS of composite resins to lithium disilicate ceramics. [ABSTRACT FROM AUTHOR]

Background: The goal of this study is to determine the effect of different sandblasting particles and dental adhesive systems on the repair strength of dimethacrylate-based composite resins. Materials and Methods: In this in-vitro study, 96 specimens of X-trafil composite blocks were prepared and divided into eight groups (n = 12). Four groups were sandblasted with Aluminum Oxide (AL) and four other groups with Bio-Active Glass particles (BAG). A two-component silane was applied on the surface of all the samples after phosphoric acid etching and rinsing. Two groups of the sandblasted specimens were treated with Clearfil SE Bond (CSB) and the other two groups were treated with Single Bond Universal (SBU) and new composite was bonded to the prepared surfaces. Half of the specimens in each group were thermocycled. Shear force was applied to the bonded composite using a universal testing machine with a crosshead speed of 0.5 mm/min and mean shear bond strength (MSBS) was calculated (MPa). The data was analyzed using Kruskal--Wallis and Man--Whitney U-tests with the significance level of 0.05. Results: Significant differences were observed between different groups (P < 0.001). The highest and the lowest MSBS of the thermocycled samples were reported 18.88 MPa with application of AL and SBU and 11.46 MPa with the application of AL and CSB, respectively. No significant difference was observed with application of BAG particles after thermocycling. Conclusion: Effect of AL on repair shear bond strength of composite resins is affected by bonding type. Bonding type did not affect repair shear bond strength of BAG. Thermocycling reduced bond strength in all groups. [ABSTRACT FROM AUTHOR]

Background: The current study evaluated the micro‑shear bond strengths of a new low‑shrinkage composite resin to dentin. Materials and Methods: In this in‑vitro study, 70 extracted premolars were assigned to one of seven groups (n = 10): Group 1: OptiBond Solo Plus (Opt; Kerr); Group 2: SE Bond (SE; Kuraray); Group 3: Silorane System Adhesive (SSA; 3M ESPE); Group 4: OptiBond Solo Plus + LS Bond (Opt LS); Group 5: SE Bond + LS Bond (SE LS); Group 6: OptiBond Solo Plus (Opt Po); and Group 7: SE Bond (SE Po). Occlusal dentin was exposed and restored with Filtek LS (3M ESPE) in groups 1 to 5 and Point 4 (Kerr) in groups 6 and 7. After thermocycling (1000 cycles at 5/55°C), micro‑shear bond test was carried out to measure the bond strengths. The results were submitted to analysis of variance and post hoc Tukeytests (P < 0.05). Results: Two‑way ANOVA showed no significant differences between the two types of composite resin (P = 0.187), between bonding agents (P = 0.06) and between composite resin and bonding agents (P = 0.894). Because P value of bonding agents was near the significance level, one‑way ANOVA was used separately between the two composite groups. This analysis showed significant differences between silorane composite resin groups (P = 0.045) and Tukey test showed a significant difference between Groups 4 and 5 (P = 0.03). Conclusion: The application of total‑etch and self‑etch methacrylate‑based adhesives with and without use of a hydrophobic resin coating resulted in acceptable bond strengths. [ABSTRACT FROM AUTHOR]

Mandibular canal is the most important anatomical landmark in the body of mandible which always must be considered for implant surgery in posterior mandibular region. Damage to vessels and inferior alveolar nerve that passes through the mandibular canal can cause problems such as hemorrhage and neurosensory disturbances. Damage to the mandibular canal can occur during implant surgery. Depending on the severity of injuries, it would result in temporary or permanent neurosensory disturbances. We have reported a case that mandibular canal narrowing occurred following implant surgery and resulted in anesthetic and hypoesthetic areas in the lower lip. Patient had a history of implant surgery in the region of teeth numbered 30 and numbered 31. The inserted implant failed after 6 years, and reimplantation was done in this area, but due to lower lip numbness in the right side, the second implant was removed, and another implant was inserted in the region of the tooth numbered 32. After 2 years, right lower lip numbness was reported again by the patient. Cone beam computed tomography images showed canal narrowing in the region of the tooth numbered 31 where the second implant was inserted. It seems that the main cause for anesthesia and hypoesthesia in this patient is canal narrowing due to damage during implant replacement and removal. [ABSTRACT FROM AUTHOR]

Introduction: Trichloroacetic acid (TCA) is a soft tissue cauterizing agent applied to gingival margins prior to cervical tooth-colored restorations. The present in vitro study evaluated the effects of two different concentrations of TCA hydrogel as a hemostatic/preconditioning agent on the shear bond strength (SBS) of a self-etch adhesive to tooth structures., Materials and Methods: Thirty-six flat enamel and 36 flat dentin surfaces were prepared using human molars; each group was subdivided into three subgroups (n = 12). The groups were made ready as follows: In groups 1 (E1 and D1), the enamel (E) and dentin (D) surfaces were designated as control groups and remained intact. In groups 2 (E2 and D2), 35% TCA gel was applied to enamel and dentin surfaces for 30 seconds. In groups 3 (E3 and D3), 50% TCA gel was applied to enamel and dentin surfaces for 30 seconds. Clearfil SE Bond and Z100 composite resin were applied to the surfaces according to manufacturers' instructions. After 24 hours of incubation and thermocycling, the composite cylinders underwent an SBS test in a DARTEC test machine. Data were analyzed using the ANOVA and Scheffe's test (α=0.05)., Results: The mean SBS±SD in the study groups were 34.73±5.66, 35.32±7.3, 23.75±9.67, 20.94±9.84, 19.32±6.20, 23.50±6.63 MPa in the E1, E2, E3, D1, D2 and D3 groups, respectively. ANOVA revealed significant differences between the SBS values of enamel groups (p=0.001). There were no significant differences between the dentin groups (p=0.425)., Conclusion: Application of 35 and 50% concentrations of TCA to dentin had no detrimental effect on the bond produced by two-step self-etch adhesive under study; however, application of only 35% TCA to enamel did not result in a detrimental effect on the same adhesive.