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Purpose: Zygomatic implants are considered one of the last options for the rehabilitation of severe maxillary atrophy when standard implants cannot be placed. They offer several advantages but can also present complications. This study aimed to investigate the long-term clinical and radiographic outcomes of zygomatic implant placement., Materials and Methods: A retrospective chart review was conducted, and the inclusion criteria consisted of patients previously treated with zygomatic implants who had Class V or VI maxillary bone atrophy according to Cawood and Howell, and with a minimum follow-up period of 2 years after prosthetic loading. Outcome measures included implant and prosthesis survival rate, biological and biomechanical complications, and Lund-Mackay staging score before and after implant placement., Results: The study included 78 patients who received a total of 274 zygomatic implants. The mean follow-up period was 90.4 ± 26.0 months. Seventeen implant failures occurred, resulting in a survival rate of 93.8%, with a statistically significant negative correlation with smoking habits (P = 0.049), anchorage to the two zygomatic bone cortices (bicorticality) (P 0.001) and soft tissue complications (P 0.001). The prosthetic success rate was 92.3%. A statistically significant increase in maxillary sinus radiopacity was recorded when comparing the situation before and after surgery (P 0.001), and the intrasinus pathway had a statistically significant influence on that increase (P = 0.003)., Conclusions: Zygomatic implants utilised for rehabilitating patients with severe maxillary atrophy have shown favourable outcomes. Nonetheless, owing to potential complications, strict case selection is necessary, combined with regular recall visits and proper oral hygiene maintenance. Furthermore, this type of surgery necessitates specialised training and expertise on the part of the practitioner.

Purpose: To compare the clinical effectiveness of three different devices used in guided bone regeneration procedures for partially atrophic arches., Materials and Methods: A randomised controlled trial with three parallel arms was conducted. The study evaluated titanium-reinforced polytetrafluoroethylene membrane (PTFE group), semi-occlusive CAD/CAM titanium mesh (mesh group) and occlusive CAD/CAM titanium foil (foil group) in terms of surgical outcomes and complications as well as surgical times and surgeon satisfaction in 27 guided bone regeneration procedures, presenting results from 1 year post-implant placement., Results: Complications occurred in seven patients. No significant difference was found between the groups in terms of the occurrence of complications (P = 0.51), device exposure (P = 0.12) and implant failure (P = 0.650). Surgeon satisfaction varied significantly, with the PTFE group differing from the mesh (P = 0.003) and foil groups (P 0.001), but not between meshes and foils (P = 0.172). Surgical times also differed significantly, with longer times for PTFE membranes compared to meshes (P 0.001) and foils (P = 0.006), but with no difference between meshes and foils (P = 0.308). The mean reconstructed bone volume was 1269.55 ± 561.08 mm3, with no significant difference observed between the three groups (P = 0.815). There was also no significant difference for mean maximum height (6.72 mm, P = 0.867) and width (7.69 mm, P = 0.998). The mean marginal bone loss at 1 year after implant placement was 0.59 ± 0.27 mm., Conclusions: Although this study provides valuable insights into the potential benefits of using different types of CAD/CAM devices, further research with larger sample sizes and longer follow-up periods is warranted to validate these findings., Conflict-Of-Interest Statement: The authors declare there are no conflicts of interest relating to this study.

Purpose: The reverse guided bone regeneration protocol is a digital workflow that has been introduced to reduce the complexity of guided bone regeneration and promote prosthetically guided bone reconstruction with a view to achieving optimal implant placement and prosthetic finalisation. The aim of the present study was to investigate the accuracy of this digital protocol., Materials and Methods: Sixteen patients with partial edentulism in the maxilla or mandible and with vertical or horizontal bone defects were treated using the reverse guided bone regeneration protocol to achieve fixed implant rehabilitations. For each patient, a digital wax-up of the future rehabilitation was created and implant planning was carried out, then the necessary bone reconstruction was simulated virtually and the CAD/CAM titanium mesh was designed and used to perform guided bone regeneration. The computed tomography datasets from before and after guided bone regeneration were converted into 3D models and aligned digitally. The actual position of the mesh was compared to the virtual position to assess the accuracy of the digital project. Surgical and healing complications were also recorded. A descriptive analysis was conducted and a one-sample t test and Wilcoxon test were utilised to assess the statistical significance of the accuracy. The level of significance was set at 0.05., Results: A total of 16 patients with 16 treated sites were enrolled. Comparing the virtually planned mesh position with the actual position, an overall mean discrepancy between the two of 0.487 ± 0.218 mm was achieved. No statistically significant difference was observed when comparing this to a predefined minimum tolerance (P = 0.06). No surgical complications occurred, but two healing complications were recorded (12.5%)., Conclusion: Within the limitations of the present study, the reverse guided bone regeneration digital protocol seems to be able to achieve good accuracy in reproducing the content of the virtual plan. Nevertheless, further clinical comparative studies are required to confirm these results.

Zygomatic implant-supported rehabilitation has grown in popularity for use in clinical practice. Although many studies have been carried out into the surgical procedure, the prosthetic workflow is not clearly defined and standard techniques are not readily applied; thus, a digital approach may ultimately streamline the procedure. In the present study, the authors examined a digital workflow for immediately loaded prostheses supported by zygomatic implants. The novel technique proposed by the present authors, involving use of an impression reference, achieved promising results in terms of accuracy and procedural simplification.

Purpose: Guided bone regeneration is a widely used technique for the treatment of atrophic arches. A broad range of devices have been employed to achieve bone regeneration. The present study aimed to investigate the clinical and histological findings for a new titanium CAD/CAM device for guided bone regeneration, namely semi-occlusive titanium mesh., Materials and Methods: Nine partially edentulous patients with vertical and/or horizontal bone defects underwent a guided bone regeneration procedure to enable implant placement. The device used as a barrier was a semi-occlusive CAD/CAM titanium mesh with a laser sintered microperforated scaffold with a pore size of 0.3 mm, grafted with autogenous and xenogeneic bone in a ratio of 80:20. Eight months after guided bone regeneration, surgical and healing complications were evaluated and histological analyses of the regenerated bone were performed., Results: A total of 9 patients with 11 treated sites were enrolled. Two healing complications were recorded: one late exposure of the device and one early infection (18.18%). At 8 months, well-structured new regenerated trabecular bone with marrow spaces was mostly present. The percentage of newly formed bone was 30.37% ± 4.64%, that of marrow spaces was 56.43% ± 4.62%, that of residual xenogeneic material was 12.16% ± 0.49% and that of residual autogenous bone chips was 1.02% ± 0.14%., Conclusion: Within the limitations of the present study, the results show that semi-occlusive titanium mesh could be used for vertical and horizontal ridge augmentation. Nevertheless, further follow-ups and clinical and histological studies are required.

Purpose: To explore whether extra-short (4-mm) implants could be used to rehabilitate sites where regenerative procedures had failed in order to avoid additional bone grafting., Materials and Methods: A retrospective study was conducted among patients who had received extra-short implants after failed regenerative procedures in the posterior atrophic mandible. The research outcomes were complications, implant failure and peri-implant marginal bone loss., Results: The study population was composed of 35 patients with 103 extra-short implants placed after the failure of different reconstructive approaches. The mean follow-up duration was 41.3 ± 21.4 months post-loading. Two implants failed, leading to a failure rate of 1.94% (95% confidence interval 0.24%-6.84%) and an implant survival rate of 98.06%. The mean amount of marginal bone loss at 5 years post-loading was 0.32 ± 0.32 mm. It was significantly lower in extra-short implants placed in regenerative sites that had previously received a loaded long implant (P = 0.004). Failure of guided bone regeneration before placement of short implants tended to lead to the highest annual rate of marginal bone loss (P = 0.089). The overall rate of biological and prosthetic complications was 6.79% (95% confidence interval 1.94%-11.70%) and 3.88% (95% confidence interval 1.07%-9.65%), respectively. The success rate was 86.4% (95% confidence interval 65.10%-97.10%) after 5 years of loading., Conclusions: Within the limitations of this study, extra-short implants seem to be a good clinical option to manage reconstructive surgical failures, reducing surgical invasiveness and rehabilitation time.