Background and Aim: Several methods are available for intraoral repair of chipped porcelain restorations by composite resin. Also, there is still controversy regarding the best method of porcelain repair in terms of bond strength and cost effectiveness. This study aimed to compare three methods of porcelain surface treatment on shear bond strength (SBS) of composite to porcelain. Materials and Methods: This in vitro, experimental study was conducted on 30 porcelain blocks with a metal base in three groups. In group 1, porcelain surface was etched with hydrofluoric (HF) acid and silanized. After the application of bonding agent, several composite increments with 2mm thickness were applied on the porcelain surface. In group 2, porcelain surface was sandblasted with 50µaluminum oxide particles, etched and silanized. In group 3, grooves with 2mm length and 0.5 mm depth were created on the porcelain surface. The surface was then etched and silanized. Bonding agent and composite were then applied. The samples were then mounted in acrylic resin, stored in water for one week and subjected to thermocycling. The SBS was then measured using a universal testing machine. The SBS data were compared among the three groups using one-way ANOVA. Results: The mean SBS was 9.13±6.09, 12.71±9.82 and 11.44±7.37 MPa in groups 1-3, respectively. No significant difference in bond strength was noted among the three groups (P>0.05). Conclusion:No significant difference exists among the three surface treatment methods evaluated in this study in terms of SBS of composite to porcelain.

Aim: This study investigated the effects of implant angulation and cyclic dislodgment on retention of Locator and Dalbo Plus attachments.Materials and methods: Fifty pairs of acrylic blocks for five implant angulations (0, 10, 20, 30 and 40 degrees) and two attachment systems (locator and Dalbo Plus®; n = 5) were fabricated. In each pair, one block contained two implant analogs connected to their attachments, and the other block contained matrix parts of the attachments. 1440 cycles of insertion and removal were implicated on specimens after mounting the blocks in the universal testing machine. The retention was registered at cycle numbers 1, 120, 360, 720, and 1440. Data were analyzed using one-way analysis of variance (ANOVA) and Duncan's multiple range test (p ≤ 0.05).Results: Data analysis showed that implant angulation had significant effects on retention of both attachments at all different angles (p ≤ 0.05). Dalbo Plus showed no significant differences between 30 and 40 degrees (p ≥ 0.05), but between 0 and 30 degrees, differences were significant (p ≤ 0.05). Moreover, cyclic loading had significant effects on retention of both attachments at all different loading cycles (p ≤ 0.05). On evaluating combined effects of cyclic loading and implant angulation on retention, a significant decrease in retention was noted for both Locator and Dalbo Plus attachments at angulations of 0, 10, 20 degrees after 1440 cycles (1 year of clinical use; p ≤ 0.05). Conclusion:Both angulation and cyclic loading have negative effects on implant-supported overdentures and decrease retention over time. Furthermore, as the angle between implants increases, decrement of retention becomes more significant.

Aim:The aim of this study is to evaluate the anticandidal effects of essential oils derived from fennel (Foeniculum vulgare) and cumin (Cuminum cyminum) on Candida strains isolated from edentulous patients. Materials and methods: Candida samples were isolated from 30 edentulous patients and the strains were identified using the CHROMagar method. Using the macro-broth dilution method and punched-hole tests, the effectiveness of fennel and cumin essential oils (prepared through distillation by water) was clarified. Nystatin was used as a positive control. Results: Nystatin (44 µg/mL) had the strongest antifungal effect, followed by cumin [minimum inhibitory concentration (MIC) = 662 μg/mL; minimum fungicidal concentration (MFC) = 630 μg/mL] and fennel (MIC = 1,074 μg/mL; MFC = 1,227 μg/mL). The average diameter of the fungal growth inhibition zone was 23 mm for Nystatin, 14 mm for cumin essential oil, and 5 mm for fennel essential oil. Conclusion:The anti-Candida effects of fennel and cumin show promise as alternatives to conventional drugs for the treatment of Candida infections.