This study assessed the shear bond strength (SBS) and failure modes of lithium disilicate ceramic veneering material to different high-performance polymers. Thirty-six square specimens measuring 7 × 7 × 2 ± 0.05 mm were prepared from pure polyetheretherketone (PEEK), Bio-high performance PEEK (BioHPP) and Trilor discs. Polymer specimens were air-borne abraded utilizing aluminum oxide particles, cleaned, and a bonding agent was applied (visio. link). The veneering LDC material (3 × 2 mm) was milled, hydrofluoric acid etched (9.5%) and primed (Clearfil ceramic). The LDC was bonded to the polymer specimens using dual-cured resin cement (Panavia V5) and light polymerized. The bonded specimens were subjected to 5000 cycles of physiological aging by thermocycling, and the SBS test was performed in a universal testing machine at 0.5 mm/min cross-head speed. The debonded specimens were analyzed to determine the primary bond failure sites (adhesive, mixed or cohesive). Data analysis was performed using one-way ANOVA and a post hoc Tukey test (α ≤ 0.05). The BioHPP material demonstrated the highest SBS values (23.94 ± 1.43 MPa), and the Trilor group recorded the lowest SBS values (17.09 ± 1.07 MPa). The PEEK group showed a mean SBS of 21.21 ± 1.51 MPa. The SBS comparison showed significant variations across all material groups (p < 0.001). Regarding failure modes, adhesive failure was observed in 40% of BioHPP and PEEK specimens and 90% of Trilor specimens. The cohesive failure occurred in 50% of PEEK and 30% of BioHPP specimens, while the Trilor specimens showed no cohesive failure. Mixed failures were reported in 30% of BioHPP and 10% of PEEK and Trilor specimens. The BioHPP material demonstrated high SBS followed by PEEK and Trilor. The SBS between the tested materials was statistically significant. However, the SBS of the tested implant framework materials was above the limit stipulated by the ISO 10477 standard (5 MPa) and the clinically acceptable range of 10–12 MPa.

Background: This study evaluated and compared the effects of thermal aging on the color stability and mechanical properties of CAD/CAM polymers utilized for provisional restorations. Material and Methods: Three CAD/CAM polymers in this study: CAD-Temp (CAT), Everest C-Temp (CT), and PEEK (PK). Forty specimens of each material were randomly assigned to two subgroups. Subgroup A was immersed in distilled water for 24 h, whereas Subgroup B was subjected to 5000 thermal cycles. The color stability, flexural strength (FS), survival probability, and microstructures were evaluated following thermal cycling. Data analysis was conducted utilizing two-way ANOVA along with Tukey’s test. Results: The CAT (3.74 ± 0.39) and CT (3.51 ± 0.54) groups exhibited the highest color variations, while PEEK (2.95 ± 0.45) showed the lowest color change. The baseline groups showed that the CT group had the highest flexural strength value (p < 0.05). The flexural strength values of CAT and CT groups significantly decreased (p < 0.05) following thermal cycling. No significant decrease in FS was observed following thermal cycling in the Pk group (p = 0.16). Conclusions: The color measurement and flexural strength outcomes were significantly influenced by CAD/CAM materials and thermal cycling. The CT group demonstrated superior flexural strength compared to the other groups, both before and after thermal cycling. The PK group shows the lowest color change compared to other groups. Regardless of aging condition, C-Temp and PEEK materials recorded the highest survival probability, a 95% significance level compared to CAD-Temp.

Objective: This study aimed to radiographic evaluation of two different bar attachments (bar/locator and bar/ball) for mandibular overdenture supported by 2 implants after 5-year period. Subjects and Methods: For this study, ten completely edentulous participants were selected. Each participants received two dental implants at mandibular canine regions. They were divided into two equal groups: Group I: Each patient received overdentures with bar/locator attachment. Group II: Each patient received overdentures with bar/ball attachment. The vertical marginal bone loss was evaluated using digital peri-apical radiographs over 5-year period. Results: There was a statistically insignificant difference between group I and group II in vertical marginal bone loss after 1 year. However, after five years follow up there was a statistically significant difference between both groups as marginal bone loss was found to be more in group I than that in group II. Conclusion: Bar/ball attachment offers better results in vertical marginal bone loss than bar/locator attachment. bar locator Preferred to be used with four-implants overdenture instead of two-implants to decrease bone loss around implants. It is mandatory to perform monitoring follow-up to avoid any harmful effect on implant and/or residual ridge, maintaining the prosthesis/attachment/ tissue relation to assure proper functional load distribution to avoid further bone resorption.

Background: Edentulous mandible rehabilitation via single implant mandibular overdenture (SIMO) became mundane as a facile therapy averred promising results. SIMO was reported to prone to fracture thus, represented a concern for the clinicians. Objectives: This study targeted at assessing Satisfaction of the Patient and Oral Health–Related Quality of Life OHRQoL referring to (SIMO) reinforced by metal or PEEK frameworks in comparison to conventional complete denture CD.Materials and Methods: Eighteen complete dentures were delivered for the eligible participants (group I). Three months later, they were evaluated for Satisfaction of patient and OHRQoL. Patient satisfaction was performed employing the visual analog scale (VAS). Assessment of OHRQoL by oral health impact profile (OHIP-14) was accomplished. Through pursuing the delayed loading protocol, in the midline region of the mandible, single implant was inserted. Each patient received two overdentures utilizing a crossover design; metal reinforced (Group II) and PEEK reinforced overdentures (Group III). Patient Satisfaction and OHRQoL for groups (II and III) were carried out following three months of using each overdenture. Questions of VAS and OHIP-14 were evaluated for both overdentures. Results: SIMOs revealed statistically significant improvement compared to traditional dentures. Non-significant difference between SIMOs reinforced with metal or PEEK was demonstrated except for denture stability and retention in favor of PEEK reinforced SIMOs. Conclusion: SIMOs ameliorated patient satisfaction together with OHRQoL when compared with CDs no matter the involved reinforcement material was. SIMOs reinforced with PEEK are deemed advantageous over the metal ones in terms of denture stability and retention.