Survival and success rates of soft-milled cobalt-chromium-ceramic full-arch screw-retained implant-supported prostheses: a 2- to 7-year follow-up retrospective study

Clinical performance of polymer frameworks in dental prostheses: A systematic review

STATEMENT OF PROBLEM

High-performance polymers including polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) have been used as substitutes for metal frameworks in dental prostheses. However, the clinical performance of polymer-based frameworks is still uncertain.

PURPOSE

The purpose of this systematic review was to compare the clinical performance of PEEK and PEKK with that of metal frameworks for different dental prostheses.

MATERIAL AND METHODS

This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six databases and non-peer-reviewed literature (without language or follow-up restrictions) were searched for studies conducted before February 2022. Only clinical studies, either randomized clinical trials (RCTs) or nonrandomized clinical trials (N-RCTs), comparing the clinical performance of polymer and metal frameworks were included. The risk of bias and certainty of the evidence were assessed with the RoB 2.0, ROBINS-I, and GRADE. Biologic (plaque and gingival indices, probing depth, bleeding scores, implant stability quotient, marginal bone loss) and mechanical outcomes (ridge base relation, prosthetic marginal gap, and fracture) were assessed.

RESULTS

Only 9 studies (7 RCTs and 2 N-RCTs) were included, all with moderate to serious risk of bias and low to very low certainty of evidence. No meta-analysis was possible, but qualitative analysis revealed lower plaque and gingival indices, probing depth, and marginal bone loss, with higher survival rates for implant-supported fixed prostheses and overdentures fabricated with PEEK than for metal frameworks. No significant differences were found between groups for removable partial dentures. The marginal fit of PEEK frameworks was also better for single crowns. Three fractures were reported in the 3 PEKK fixed dental prostheses with cantilevers.

CONCLUSIONS

PEEK and PEKK seem to be promising materials for dental prostheses, with acceptable response from the periodontal tissue. However, further well-designed studies are necessary to better understand their clinical and long-term limitations.

Maxillary Full Arch Restorations - Biological Complications: A Narrative Review Outlining Criteria for Long Term Success

PURPOSE

Patients receiving full arch implant borne maxillary prostheses require functional, esthetic, and long term success. The importance of this review is to document the difficulty with implant maintenance, the prevalence of peri-implant disease, and the improvement in biologic health when using a prosthesis that can be maintained to minimize plaque. The objective is to provide surgeons with a reference to optimize surgical procedures that can result in improved hygiene and long term maintenance, as well as acceptable functional and esthetic goals.

METHODS

Pubmed.gov was the information source. Years reviewed included 1990-2022. Inclusion criteria included only articles in journals referenced in pubmed.gov. The reports excluded were case reports, reports that only included implant survival, and articles without a statistical analysis to generate meaningful conclusions. Biological complications included bone loss, hygiene difficulty, mucositis and recession, the incidence of peri-implantitis, and how complications related to patient co-morbidities. Data collected included outcomes of the study including statistical significance.

RESULTS

The search identified articles for review using terms which included full arch maxillary restorations (n = 736), long term success with full arch maxillary prostheses (n = 22), ceramic full arch restorations (n = 102), and complications with full arch restorations (n = 231). From this search, 53 articles were collated that satisfied the inclusion criteria. Factors found to be significant contributors to biological complications included bone loss and peri-implant disease, difficulty with daily hygiene access, plaque and biofilm coverage, and the need for continued maintenance for long term implant health.

CONCLUSION

The surgeon needs to place implants to allow a full arch maxillary prosthesis to be fabricated with full access to the implants for maintenance, which should decrease the incidence of biological complications. With excellent maintenance full arch implant restorations can have limited peri-implant disease.

Outcomes and Complications of 33 Soft-Milled Cobalt-Chromium-Ceramic Full-Arch Screw-Retained Implant-Supported Prostheses: A Retrospective Study with up to 10-Year Follow-up

This retrospective study assessed outcomes and complications related to implants and prostheses in edentulous patients treated with soft-milled cobalt-chromium-ceramic full-arch screw-retained implant-supported prostheses (SCCSIPs). After the final prosthesis was delivered, patients participated in an annual dental check-up program, including clinical and radiographic assessments. Outcomes of implants and prostheses were evaluated, and biological and technical complications were categorized as major or minor. Implant and prosthesis cumulative survival rates were assessed using the life table analysis. A total of twenty-five participants (mean age 63.6 ± 7.3 years) with 33 SCCSIPs were observed for a mean of 68.9 ± 27.9 months (range 1–10 years). A total of 7 out of 245 implants were lost, with no effect on prosthesis survival, leading to cumulative survival rates of 97.1% for implants and 100% for prostheses. The most recurrent minor and major biological complications were soft tissue recession (9%) and late implant failure (2.8%). Among 25 technical complications, porcelain fracture was the only major technical complication, requiring prosthesis removal (1%). Porcelain chipping was the most frequent minor technical complication, affecting 21 crowns (5.4%), which required polishing only. At the end of the follow-up, 69.7% of the prostheses were free of technical complications. Within the limitations of this study, SCCSIP showed promising clinical performance after 1–10 years.

Polyetheretherketone CAD-CAM framework for all-on-4 mandibular full arch prosthesis: Three years' retrospective study of periimplant soft tissue changes and ridge base relationship

PURPOSE

This study was conducted to evaluate the clinical peri-implant soft tissue changes during first year after occlusal loading and the ridge base relation after three years for mandibular CAD-CAM manufactured screw-retained implant-supported hybrid prosthesis of polyetheretherketone (PEEK) framework utilized with All-on-Four treatment concept.

MATERIAL AND METHODS

Sixteen completely edentulous patients were rehabilitated by 4 implants following the All-On-Four protocol. After 3 months, the definitive prosthesis was constructed to be a screw retained CAD-CAM milled framework from the modified PEEK (BioHPP), bonded to polymethylmethacrylate (PMMA) teeth and a pink shaded indirect light-polymerized nanofilled composite resin imitating the soft tissues. Peri-implant soft tissue changes regarding plaque, bleeding, gingival scores, and probing depth were evaluated at prosthesis insertion (T0), six months (T1) and 12 months (T2) after insertion. Also, monitoring of the ridge base relation was performed using cone beam computed tomography after one year (T0), two years (T1), and three years (T2) after mandibular fixed detachable All-on-Four framework insertion. Using Shapiro Wilk tests using SPSS^® software version 22 (SPSS Inc.), all clinical data were non- parametric while the ridge base relation data was parametric.

RESULTS

There were statistically significant differences regarding plaque, gingival, and bleeding scores for all implants with advancement of time. However, there was a statistically insignificant difference regarding probing depth in the posterior implants (p = .581). Regarding ridge base relation, there was a significant difference between observation times only in the anterior ridge area in between the two anterior implants (p = .011).

CONCLUSION

Within limitations of the study, the full arch PEEK framework of fixed-detachable, hybrid prosthesis used with All-on-Four concept for rehabilitation of mandibular edentulous arches is an acceptable treatment approach. Based on the stable ridge base relation posteriorly found in this study, less stress is distributed to the underlining bone due to the shock absorbing ability of PEEK. Special considerations for frequent soft tissue follow up and regular maintenance of oral hygiene measures are recommended. This article is protected by copyright. All rights reserved.