To Evaluate and Compare the Effect of Various Surface Treatment Modalities on Shear Bond Strength of Composite to Polyetherketoneketone and SEM Analysis: An In vitro Study.

Context: It is a challenge to bond resin materials with polyetherketoneketone (PEKK). To increase the bond strength, surface treatments using chemical adhesion, mechanical adhesion, or a combination of both can be used. Aims: The objective of the present study was to evaluate and compare the shear bond strength of PEKK to the composite resin after various surface treatments and to evaluate the fracture mode analyses. Materials and Methods: One hundred and twenty PEKK specimens were randomly divided into four groups (n = 30) after three different surface treatments (95% sulfuric acid etching, airborne abrasion with 110 µm aluminum-oxide, and 99% acetone). With the help of polytetrafluorethylene tube, resin composite (3M ESPE) was bonded on all the specimens, thermocycled, and subjected to shear bond strength testing. Thereafter, 15 samples from each group were assessed for fracture mode analyses using a scanning electron microscope. Statistical Analysis Used: Mean, Standard deviation, one-way analysis of variance (ANOVA) f-test, post hoc Tukey's test. Results: Statistical analysis using one-way ANOVA f-test revealed that the results were significant with a P < 0.05 with the maximum value obtained in the case of air abraded group and the minimum value obtained in the case of the untreated group. Adhesive failure mode was the most common among the air-abraded group. Conclusions: The mechanical surface treatment group (air abrasion) showed higher shear bond strength than the chemical surface treatment groups (sulfuric acid and acetone). The mixed-type fracture mode was most commonly noted in the air-abraded group.

Comparative evaluation of biological, mechanical, and patient-reported outcomes of angulated screw channel abutments versus multi-unit abutment-retained single-unit implant restorations in the anterior esthetic zone: An-in vivo study.

Aims: The study aimed to evaluate biological, mechanical, and patient reported parameters associated with ASC abutments and MU abutments for the fabrication of screw retained implant crowns in the anterior esthetic zone. Setting and Design: For the study, 20 patients were selected and implants were placed within the constraints of prosthetic envelope. Later, the screw retained crown was fabricated. Materials and Methods: Biological parameters (including implant survival rate, marginal bone levels using cone beam computed tomography, and soft tissue assessment using periodontal indices) were measured at the time of crown placement and 1 year follow up. Mechanical parameter (screw loosening) was calculated using removal torque loss (RTL) values obtained at the time of crown placement and 1 year follow up. Patient reported parameters were evaluated using a questionnaire at 1 year follow up. Statistical Analysis Used: All data were tabulated, statistically analyzed, and compared using SPSS version 23 IBM Corporation, Armonk, NY, USA. Results: Implant survival was found 100% in both the groups. The marginal bone level reduced considerably in both the groups from baseline to 1 year follow up. The MU abutment group had slightly less marginal bone loss than the ASC abutment group. Additionally, there was no statistically significant difference between the two groups' periodontal indices at baseline and 1-year follow-up values. At baseline, the RTL value was substantially lower (P <0.003) in the ASC abutment group than in the MU abutment group, however at the 1-year follow-up, there was no statistically significant difference in RTL or screw loosening between the two groups. Patient-reported data showed no statistically significant difference. Conclusion: Within the constraints of this study, it was suggested that both ASC and MU abutments provide equally promising results in terms of biological, mechanical, and patient-reported parameters in the anterior esthetic region for single screw-retained crowns.

A review of techniques of iris replication and a novel method of fabrication of ocular prosthesis using two different iris location methods.

Anophthalmic patients suffer from social, functional, and emotional agony. The role of a maxillofacial prosthodontist is to restore this loss and to restore the self-esteem of such patients. Fabrication of a prosthesis for the anophthalmic cavity can be successful with the judicious use of the materials, the vision, and the skill of the prosthodontist. This article describes various techniques used for iris replication and a novel method to locate the iris, which is the most crucial step to fabricate a natural gaze.