Prosthesis

Background/Objectives: Implant-supported rehabilitations using the All-on-4 concept represent a viable treatment option for completely edentulous patients. The guided surgery software allows for the performance of a flapless computer-guided surgery with similar results to those achieved through a flap surgery. This study aimed to evaluate the long-term outcomes of complete edentulous implant-supported rehabilitations using an All-on-4 arrangement, following a computer-guided protocol. Methods: A total of 111 patients (68 females, 43 males) with an average age of 60.9 years ± 9.67 years were treated. The primary outcome measures were implant and prosthetic survival. Secondary outcome measures were marginal bone loss (MBL) and the incidence of mechanical and biological complications. Results: Thirty-nine patients were lost to follow-up. Thirty-seven implants and five prostheses failed, rendering a 92.5% implant cumulative survival rate and a 96.2% prosthetic survival rate at 12 years. The average MBL per implant was 1.19 ± 1.16 mm, with 1.26 ± 1.33 mm for axial implants and 1.12 ± 0.95 mm for tilted implants at 10 years. The incidence rate of mechanical complications at the patient level was 90.1% for provisional prostheses and 55.9% for definitive prostheses. The rate of biological complications was 14.3% at the implant level. Conclusions: Full-arch rehabilitations following an All-on-4 implant arrangement and assisted by a computer-guided protocol may be a viable alternative for patients with edentulism/hopeless teeth in the long term.

Objectives: This study investigated the effects of three over-the-counter (OTC) whitening products, whitening pen (WP, Dazzling White Instant Whitening Pen, Dazzling White, Grand Rapids, MI, USA), whitening mouthwash (MW, Colgate Optic White, Colgate-Palmolive, New York, NY, USA), and whitening toothpaste (TP, Crest 3D White, Procter & Gamble, Cincinnati, OH, USA), on the microhardness, gloss retention, and surface roughness of a nanofilled resin composite (Filtek Z350 XT Universal Restorative, 3M ESPE). Methods: Composite resin specimens were prepared and subjected to treatment with WP, MW, or TP. Microhardness, gloss retention, and surface roughness were measured before and after treatment. Data were subjected to statistical analysis, with normality assessed by Shapiro–Wilk testing. Parametric data were summarized as mean ± SD, and differences were evaluated using paired t-tests and one-way ANOVA with a significance level of p ≤ 0. 05. Results: All whitening products significantly altered the tested surface properties. Microhardness decreased in all groups (MD [95% CI]: 2.28 [1.84–2.71] for WP, 5.05 [4.22–5.88] for MW, and 3.09 [2.35–3.83] for TP; p < 0.001), with the greatest reduction observed in the MW group. Gloss retention also declined significantly (MD [95% CI]: 9.52 [6.28–12.76] for WP, 17.97 [14.92–21.01] for MW, and 18.92 [15.64–22.21] for TP; p < 0.001), with TP and MW showing greater loss compared to WP. Surface roughness increased significantly within each group (MD [95% CI]: −0.07 [–0.10 to −0.04] for WP, −0.23 [–0.30 to −0.16] for MW, and −0.25 [–0.38 to −0.13] for TP; p < 0.001), although no significant differences were found among groups in post-treatment values. Conclusions: OTC whitening products adversely affected the optical and mechanical properties of Z350 XT universal composite resin. Whitening MW caused the most pronounced microhardness reduction, while MW and TP induced greater gloss loss than WP. Clinicians should consider the potential impact of whitening products on resin composite restorations when advising patients on their use.

Background/Objectives: The use of zirconia implants is gaining traction as a potential alternative to titanium. Although having excellent properties, the zirconia surface has limited osteogenic potential. The purpose of this study was to produce, for the first time, mechanically stable, thick micron-scale hydroxyapatite coatings on zirconia implant material using radiofrequency (RF) magnetron sputtering. Methods: Zirconia samples were coated with HA using an RF magnetron sputtering device at a temperature of 125 °C for 20 h with 155 W of power. The procedure included rotating the substrate at a speed of 10 rpm while an argon gas flow was maintained continuously. Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) analysis, atomic force microscopy, and Vickers hardness measurements were used to evaluate the coat’s characteristics. Results: A smooth hydroxyapatite coating layer that was consistent and free of cracks was observed in all FESEM pictures. The EDX study revealed that the substrate surface contains HA particles, and the ratio of calcium (Ca) to phosphorus (P) was 16.58 to 11.31, which is very close to the ratio in original HA. FESEM cross-section pictures showed good adhesion between the coating and substrate without any gaps, and the coating thickness was 5 µm on average. A statistically significant difference was found in the roughness analysis between the samples of uncoated Zr and HA-coated Zr (p-value < 0.05). Conclusions: Zirconia implant material can be coated with a uniform layer of HA, displaying good adhesion and a thickness of a few micrometers when using magnetron sputtering for an extended period of time.