The Effect of Connective Tissue Graft Compared to Concentrated Growth Factor Graft on Buccal Peri-Implant Gingival Thickness: A 12-month Randomized Controlled Clinical Trial.

BACKGROUND: Attached gingival phenotype has a crucial impact on the implant's durability and its future success. PURPOSE: This study aims to measure and compare buccal peri-implant gingival thickness following grafting with connective tissue graft (CTG) and the concentrated growth factor (CGF) graft. STUDY DESIGN, SETTING, SAMPLE: This is a split-mouth designed randomized controlled clinical study in which a total of 20 aged 18 to 55 have bilateral missing teeth in the maxillary premolar region with less than 2 mm of healthy peri-implant gingival thickness. Patients were excluded if they were smokers, had poor oral hygiene, had uncontrolled widespread periodontal disease, or had a history of radiation treatment. The same surgical protocol was followed for each study participant, where an independent blinded medical practitioner assigned the first stage side to be treated with CTG, while the second stage side with CGF 2 weeks later. EXPOSURE VARIABLE: The primary exposure variable of this study was the gingival grafting technique; CTG or CGF. OUTCOME VARIABLE: The primary outcome variable was the buccal peri-implant gingival thickness. Gingival thickness was measured at six different times; immediately before the procedure (T0), after 30 days (T1), after 45 days (T2), after 3 months (T3), after 6 months (T4), and after 12 months (T5). COVARIATES: The covariates were age, sex general health, and periodontal status. ANALYSIS: The statistical analysis; repeated measures analysis of variance test was used to compare the gingival thickness between the studied follow-up times within each group. The level of significance was set at ≤ 0.05. RESULTS: The sample was composed of 40 treatment sites of 20 patients. The mean age of the sample was 32 years and 45% were male. The mean gingival thickness value of the CTG group was 1.62 mm with a (standard deviation = 0.18) compared to 1.28 mm for the CGF group with (standard deviation = 0.20) and an overall P value (0.001) at T5. CONCLUSIONS AND RELEVANCE: CTG showed to have better gingival thickness than CGF in managing peri-implant buccal gingival thickness deficiency.

The effect of repeated baking of porcelain on its bonding strength to a Co-Cr alloy 3D-printed by selective laser melting.

Objectives: This study aimed to evaluate the effect of multiple baking cycles of porcelain on its shear bond strength to a cobalt-chromium (Co-Cr) alloy that is three-dimensionally printed using Selective Laser Melting (SLM) technique. Materials and methods: The research sample comprised forty-eight discs measuring 5 mm × 3 mm, divided into four groups according to: the manufacturing method (SLM, casting) and the number of porcelain baking cycles (1, 3) as follows: Group A: Co-Cr alloy by SLM with one baking cycle; Group B: Co-Cr alloy by SLM with three baking cycles; Group C: Ni-Cr alloy by casting with one baking cycle; Group D: Ni-Cr alloy by casting with three baking cycles. Then, porcelain was melted on disks, shear testing was performed and the values of the Shear Bond Strength (SBS) in MegaPascals (MPa) were calculated. Results: The mean SBS values for each group were (A: 25.69 - B: 19.51 - C: 35.72 - D: 28.67 MPa). Statistical analysis showed that the manufacturing method and the number of porcelain baking cycles had a significant influence on shear bond durability (P > 0.05): the strength of this bond decreased when baking cycles increased. The Co-Cr samples manufactured by SLM also showed a decrease in binding strength compared to the Ni-Cr samples made by casting. Conclusion: Repeated baking of porcelain reduces the strength of the porcelain bond with the Co-Cr alloy made by Selective Laser Melting (SLM) technique.

Retention force of Molloplast-B with ball attachment in implant-supported overdentures: An in vitro study.

Aim: The purpose of this study is to evaluate the retention effectiveness of Molloplast B as a female attachment compared to O rings' in implant supported overdentures. Settings and Design: This systematic review and meta-analysis was evaluated using the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Materials and Methods: Sixteen female part models were divided into two groups: eight female parts made with O ring (Group A) and eight female parts made with Molloplast B (Group B). All of the models were soaked in artificial saliva for 24 h, then, their retention force was measured in Newton using a Universal mechanical testing machine, initially, after 500, after 1000, and after 1500 of loading and dislodging cycles. Statistical Analysis Used: : The statistical analysis was conducted by using one way ANOVA test and Bonferroni test. SPSS Software (SPSS, Version 27, IBM Co., Chicago, IL, USA). Results: After 1500 loading and dislodging cycles, Group B has the highest mean retention force (4.09), followed by Group A, which has a mean retention force of 3.73. Conclusion: Molloplast B with a 2.7 mm diameter ball attachment lost the least amount of retention force after 1500 loading and dislodging cycles.