Prosthesis, Volume 8, Issue 5 (May 2026) – 7 articles

Objectives. This study evaluated the performance of three intraoral scanners with different acquisition technologies in detecting early signs of tooth wear, using micro-computed tomography (micro-CT) as the reference standard. Methods and Materials. Three IOS were examined, including an active triangulation scanner, a structured-light triangulation scanner, and a parallel confocal technology scanner. Ten extracted unrestored and caries-free premolars were placed in the maxillary left second premolar position of a dental mannequin and scanned at baseline, generating quadrant digital models. Micro-CT scans were also obtained at baseline. Wear was simulated by immersion in a 1% citric acid solution followed by brushing of the buccal surfaces. All specimens were rescanned with IOS and micro-CT. Micro-CT datasets were reconstructed into stereolithography models and compared with IOS models using mesh analysis software. Statistical analysis was performed in R using linear mixed-effects models to account for repeated measurements across teeth. RMS values and absolute errors relative to the micro-CT reference were analysed with device as a fixed effect and tooth as a random effect, with Tukey-adjusted pairwise comparisons. Repeatability was additionally assessed from the repeated scans using within-tooth variability. Results. Significant differences were observed among the evaluated systems in the detection of changes related to tooth wear (p < 0.001). The micro-CT reference showed the lowest RMS value, followed by Trios 3, Primescan, and Omnicam. Model-based analyses confirmed significant differences among the evaluated systems, while the magnitude and statistical support of pairwise contrasts depended on the specific outcome considered. Repeatability analysis showed that Trios 3 had the lowest within-tooth standard deviation and repeatability coefficient (0.0215 mm and 0.0595 mm, respectively), followed by Primescan (0.0290 mm and 0.0802 mm), whereas Omnicam showed the highest within-tooth variability and repeatability coefficient (0.0624 mm and 0.173 mm). Conclusions. The parallel confocal and structured-light triangulation intraoral scanners produced RMS values numerically closer to the micro-CT reference than the active triangulation scanner. However, none of the evaluated intraoral scanners demonstrated quantitative agreement sufficient to be considered interchangeable with the reference standard. Full article

Background/Objectives: The development of high-performance biocompatible polymers such as zirconium-reinforced polyether ether ketone (BioHPP^®) has expanded the range of materials available for implant-supported prostheses, traditionally limited to metal alloys and zirconia. Due to its favorable mechanical properties and elastic modulus similar to cortical bone, BioHPP^® has been proposed as a potential alternative in implant prosthodontics. This systematic review aimed to analyze the biomechanical behavior of zirconium-reinforced PEEK and assess its advantages and limitations in implant prosthetic applications. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines, including studies published between 2011 and 2025 that evaluated the performance of BioHPP in implant prosthetic applications. Results: The search strategy identified 34 studies that met the inclusion criteria. The included studies evaluated mechanical properties such as fracture resistance, elastic modulus, stress distribution, and peri-implant tissue response. Zirconium-reinforced PEEK demonstrated fracture resistance values reaching up to 1623.31 N and an elastic modulus of approximately 4 GPa, comparable to cortical bone. Several studies also reported favorable stress distribution patterns and reduced mechanical complications when compared with conventional metallic materials. Conclusions: Zirconium-reinforced PEEK exhibits promising biomechanical characteristics for use in implant-supported prostheses, particularly due to its fracture resistance and bone-like elastic modulus. However, the available evidence is predominantly based on in vitro and finite element studies. Long-term clinical trials are required to confirm its clinical performance and establish definitive recommendations for routine use. Full article

Background: Rehabilitation of edentulous mandibles in a post-oncologic setting remains a major clinical challenge. In such situations, placement of conventional endosseous implants may be compromised by severe bone deficiency, a history of peri-implant infection, and constraints related to reconstructive soft tissues. Customized titanium subperiosteal implants, made possible by three-dimensional imaging, computer-aided design, and additive manufacturing, represent a potential alternative when conventional options are unfavorable. This case report describes a full-arch fixed rehabilitation of an edentulous mandible in a patient previously treated for squamous cell carcinoma of the floor of the mouth. Methods: A patient-specific titanium additively manufactured subperiosteal jaw implant (AMSJI) made of biocompatible titanium was designed using a digital planning workflow. Implant placement was performed in a single surgical session under general anesthesia, with fixation using osteosynthesis screws. A screw-retained full-arch provisional prosthesis was delivered intraoperatively, allowing immediate loading with adjustments aimed at avoiding compression of the healing soft tissues. Results: The patient achieved satisfactory functional and esthetic rehabilitation. Postoperative follow-up showed overall favorable mucosal tolerance; an early, limited peri-abutment mucosal dehiscence was observed and managed with suturing under local anesthesia, without compromising implant stability. Conclusions: This case highlights the clinical interest of patient-specific titanium subperiosteal implants as a fixed rehabilitation option in post-oncologic patients with major osseous and mucosal constraints and a history of reconstructive procedures. The combination of accurate digital planning and custom-made manufacturing may avoid the need for extensive bone grafting. However, these findings should be interpreted with caution due to the short-term follow-up and the inherent limitations of a single-case report, which limit the level of evidence and generalizability. Full article

Background/Objectives: Despite growing evidence of benefit, microprocessor-controlled knees (MPKs) are not routinely integrated into standard rehabilitation pathways for low-mobility (K-Level 1–2) transfemoral amputees. This exploratory analysis aimed to characterize functional trajectories of low-mobility amputees associated with early versus delayed or no MPK provision in routine inpatient rehabilitation. Methods: This prospective observational multicenter study evaluated 24-week functional trajectories in low-mobility transfemoral amputees receiving standard inpatient rehabilitation at seven non-specialized centers in Germany. Participants were grouped post hoc into two groups: (1) early MPK provision (initial Kenevo use) and (2) delayed or no MPK provision (initial non-microprocessor knees with or without later transition). Patient-reported mobility (PLUS-M K2), health-related quality of life (EQ-5D-5L), and social reintegration (RNLI) were assessed across multiple time points during inpatient rehabilitation and follow-up. Analyses were descriptive and exploratory due to small sample size. Results: Nineteen participants were included. Across outcomes, the early MPK group showed more consistent improvements over time, whereas the delayed/no MPK group demonstrated more variable trajectories with less sustained gains. Conclusions: In this exploratory real-world cohort, early provision of a K2-specific MPK (Kenevo) was associated with more favorable functional trajectories compared with delayed or no MPK provision. Given the small sample size, post hoc group allocation, and potential confounding by indication, these findings should be considered hypothesis-generating. Larger prospective studies are required to evaluate the timing and role of MPK provision in low-mobility populations. Full article

This case report describes a digital workflow for the aesthetic rehabilitation of a 30-year-old male patient with unaesthetic anterior teeth. The treatment incorporated AI-assisted smile design software (SmileCloud Biometrics) for 2D/3D digital planning and patient communication. Six lithium disilicate veneers (IPS e.max CAD) were fabricated using CAD/CAM technology following mock-up-guided minimally invasive preparation (0.2–0.9 mm reduction). The restorations were adhesively cemented under rubber dam isolation. One-week follow-up confirmed aesthetic integration, occlusal harmony, and patient satisfaction. This case illustrates how digital workflows with AI-assisted tools can support veneer rehabilitation through data-informed planning and conservative preparation while maintaining aesthetic outcomes. Full article

In this study, a fully digital workflow enabling the alignment of pre- and postoperative mandibular intraoral scans in complete-arch implant rehabilitation using intraosseous fiducial reference markers is presented. A prosthetically driven digital workflow was implemented for mandibular complete-arch rehabilitation in which two cylindrical intraosseous pins were placed in a median or paramedian mandibular region and used as fiducial reference markers to align pre- and postoperative intraoral scans. Pin osteotomies were prepared using a calibrated drilling protocol and preserved throughout surgery to allow for the exact repositioning of the pins. Implant positions were recorded using photogrammetry, while postoperative intraoral scans were acquired after suturing with the pins reinserted. Scan alignment was performed using a best-fit algorithm based exclusively on the fiducial pin geometry. Standardized convergent scanbodies without undercuts were used for intraoral scanning. The proposed workflow allowed for the alignment of pre- and postoperative mandibular scans without additional radiographic acquisitions and was compatible with both guided and free-hand implant placement, regardless of the degree of mandibular atrophy. Within the limitations of a proof-of-concept report, the use of intraosseous fiducial reference markers represents a minimally invasive and clinically applicable solution to a critical limitation of fully digital mandibular rehabilitation workflows, without the quantitative validation of accuracy, trueness, or reproducibility. Full article

Objectives: Endodontic complications are among the most frequently reported biological complications in tooth-supported fixed dental prostheses (FDPs). The aim of this study was to evaluate the prevalence of periapical complications in FDPs placed on vital and non-vital abutments and to identify risk factors for these lesions. Methods: This retrospective clinical trial was conducted on participants who had attended routine follow-up visits at the dental hospital at Qassim University, Saudi Arabia. Participants were examined clinically and radiographically for the presence of periapical lesions. Information was recorded on the design, material, location of the prostheses, and oral hygiene. The survival and lesion-free survival rates were determined using the Kaplan–Meier method. Life-table analysis was performed to assess the mean time to event. Univariate Cox proportional hazards regression analysis was used to assess potential risk factors for the development of periapical lesions (α = 0.05). Results: A total of 495 FDPs were placed in 302 participants, with a mean age of 45.7 ± 13.4 years and a mean follow-up period of 7.5 ± 6.5 years. Lesions were detected in 32.3% of FDPs during follow-up. There were no significant differences in the prevalence of lesions in vital compared with non-vital abutments or between males and females (p > 0.05). Poor oral hygiene was the most significant risk factor for the development of periapical lesions (p < 0.05). Univariate Cox regression analysis showed that anterior–posterior FDPs had a higher risk of lesions (p = 0.035). No significant associations were found between lesions and the material used or the design of the abutment (p > 0.05). Conclusions: Periapical complications in FDPs are mainly influenced by oral hygiene and the location of the FDPs, whereas abutment vitality and material type appear to have limited impact. Full article