Survival of conventional dental implants in the edentulous atrophic maxilla in combination with zygomatic implants: a 20-year retrospective study

How far can we go? A 20-year meta-analysis of dental implant survival rates

OBJECTIVE

This meta-analysis aims to investigate the long-term survival rates of dental implants over a 20-year period, providing a practical guide for clinicians while identifying potential areas for future research.

MATERIALS AND METHODS

Data were sourced from recent publications, focusing exclusively on screw-shaped titanium implants with a rough surface. Both retrospective and prospective studies were included to ensure an adequate sample size. A systematic electronic literature search was conducted in the databases: MEDLINE (PubMed), Cochrane, and Web of Science. The risk of bias for all studies was analyzed using a tool by Hoy et al. RESULTS: Three prospective studies (n = 237 implants) revealed a mean implant survival rate of 92% (95% CI: 82% to 97%), decreasing to 78% (95% CI: 74%-82%) after imputation (n = 422 implants). A total of five retrospective studies (n = 1440 implants) showed a survival rate of 88% (95% CI: 78%-94%). Implant failure causes were multifactorial.

CONCLUSION

This review consolidates 20-year dental implant survival data, reflecting a remarkable 4 out of 5 implants success rate. It emphasizes the need for long-term follow-up care, addressing multifactorial implant failure. Prioritizing quality standards is crucial to prevent overestimating treatment effectiveness due to potential statistical errors. While dental implantology boasts reliable therapies, there is still room for improvement, and additional high-quality studies are needed, particularly to evaluate implant success.

CLINICAL RELEVANCE

Never before have the implant survival over 20 years been systematically analyzed in a meta-analysis. Although a long-term survival can be expected, follow-up is essential and shouldn't end after insertion or even after 10 years.

20 Years of Clinical Evolution in Zygomatic Implant Rehabilitation: Long-Term Outcomes and Current States

Zygoma implants are an alternative for rehabilitating severe maxillary atrophy. Since 2004, when Prof. Branemark first reported the long-term findings on zygomatic implants using the original intra-sinus approach, various surgical techniques have been introduced. In 2006, an anatomy-guided approach was developed, applying different implant trajectories based on alveolar atrophy levels and sinus concavity. The purpose of this review is to clarify the existing techniques and long-term outcomes of ZI rehabilitation over the past 20 years. Additionally, it aims to enhance the quality of current practices and identify gaps in the understanding of ZI treatment for future studies.

Implant and implant restoration trends among adults 50 years and older in the United States, National Health and Nutrition Examination Survey 1999-2020

BACKGROUND

Dental implants are an important treatment option in contemporary clinical dentistry. The objective of this study was to determine trends in the prevalence of dental implants and implant-supported restorations in adults 50 years and older across demographic groups over a 20-year period.

METHODS

The authors used data from the National Health and Nutrition Examination Survey collected during 1999-2004, 2009-2014, and 2015-2020 for analyses. The authors used data from 2011 through 2020 to analyze implant-supported restoration trends. Participants 50 years or older were included in the study analytic sample. The primary outcome was the presence of dental implants and implant-supported restorations. Covariates assessed included dentition status, age, sex, race and ethnicity, education, poverty status, and smoking status. The authors used population estimates, weighted percentages, SEs, and logistic regression models for study analyses.

RESULTS

There was a total of 17,114 adults from 1999 through 2020 and 11,292 adults from 2011 through 2020 meeting the inclusion criteria. The prevalence (SE) of at least 1 dental implant increased over time, from 1.3% (0.22%) in 1999-2004 to 8.4% (0.68%) in 2015-2020. In general, those who were non-Hispanic Black, experiencing poverty, and had less than a college education were less likely to have implants than their counterparts.

CONCLUSIONS

Although the overall prevalence of implants has increased over time, disparities in prevalence were observed among certain demographic groups.

PRACTICAL IMPLICATIONS

The use of dental implants in clinical dentistry has increased over time. Future research and policy initiatives could help address disparities in implant prevalence.

All-on-4 Hybrid with Extra-Long Transnasal Implants: Descriptions of the Technique and Short-Term Outcomes in Three Cases

Background/Objectives: There is a need for alternative approaches to full-arch rehabilitation of atrophic maxillae. The aim of this short case series was to describe the technique and assess the short term-outcomes of atrophic maxillae rehabilitation using transnasal implants in conjunction with zygomatic implants. Methods: Three female patients (average age: 62 years) presenting comorbidities and atrophic maxillae preventing the insertion of standard maxillary anchored implants received a full-arch fixed prosthesis supported by transnasal implants together with zygomatic implants, using the ad modum all-on-4 concept. Patients were followed during the functional osseointegration period. Primary outcome measures were prosthetic and implant survival based on function. Secondary outcome measures were complication parameters (biological and mechanical), plaque and bleeding levels, and probing pocket depths > 4 mm. Results: No implant failures were registered, and all prostheses remained in function. The only complication was a fracture of a provisional crown that was resolved. Plaque and bleeding scores were mild during the follow-up period. Conclusions: The present manuscript describes the use of extra-long transnasal implants in combination with zygomatic implants in immediate function for full-arch fixed prosthetic rehabilitation of atrophic maxillae, with the objective of promoting more research into this relatively recent technique. More studies are needed to validate the technique.

Zygomatic Implant Length Measurement Without Excessive Flap Release: A Human Cadaver Study

One of the most important steps in zygomatic implant surgery is to determine the implant length. This cadaver study aims to identify an alternative technique for determining the length of the implant in zygoma surgery without excessive elevation of the flap. A total of 30 cadavers were included in this study. Measurements were made with a probe by seeing the exit point of the drills from the lateral aspect of the zygomatic bone. Secondly, without excessive flap release, the distance that the depth probe first raises the skin over the lateral border of the zygoma is measured. The average difference between the measurements made without excessive elevation of the flap and with a retractor placed on the zygomaticofrontal notch was found to be 5.41 ± 0.94 mm (range: 5-7.5 mm). According to the results of this study, the zygomatic implant should be placed at least 5 mm shorter than the length at which the depth probe first raises the skin over the lateral border of the zygomatic bone.

Bruxism and dental implants: A systematic review and meta-analysis

BACKGROUND

Overload from bruxism may affect survival of dental implants.

OBJECTIVES

To evaluate implant failure and marginal bone loss (MBL) in patients presenting with probable bruxism compared to non-bruxers. The study was registered in PROSPERO (CRD42021238397).

METHODS

An electronic search September 2022 in PubMed/Medline, Web of Science and Science Direct was combined with a hand search. Two independent reviewers carried out abstract screening, full-text assessment, quality assessment (National Institutes of Health tool) and data extraction. Only studies that provided information on self-report and clinical examination needed for the diagnosis of at least 'probable' bruxism were included. A pairwise random-effect meta-analysis was carried out.

RESULTS

In total 1338 studies were identified, and after screening and full-text assessment 27 studies that presented data on 2105 implants in probable bruxers and 10 264 implants in non-bruxers were included, with 138 and 352 implant failures in respective groups. the meta-analysis showed that implants placed in probable bruxers had a higher risk of failure than in non-bruxers (OR 2.189; 95% CI 1.337, 3.583, p = .002). A meta-regression showed that follow-up time did not affect this OR. Eighteen studies provided general data on MBL but did not report results separated between bruxers and non-bruxers. Therefore, an analysis of MBL was not possible.

CONCLUSION

The results of the present systematic review show that implants placed in probable bruxers present a significantly higher risk of failure than implants placed in non-bruxers. This should be considered in treatment planning and management of implant patients.

Indications for zygomatic implants: a systematic review

PURPOSE

The purpose of this systematic review was to assess the evidence regarding the indications for placement of zygomatic implants to rehabilitate edentulous maxillae.

MATERIAL AND METHODS

A focused question using the PIO format was developed, questioning "in patients in need of an implant-supported rehabilitation of the edentulous maxillae, what are the indications for the use of zygomatic implants''. The primary information analyzed and collected was a clear description of the indication for the use of zygomatic implants.

RESULTS

A total of 1266 records were identified through database searching. The full-text review was conducted for 117 papers, and 10 were selected to be included in this review. Zygomatic implant indications were extreme bone atrophy or deficiency secondary to different factors. The quad zygoma concept (two zygomatic implants bilaterally placed and splinted) was applied to 107 patients, the classic zygoma concept (one zygomatic implant bilaterally placed and splinted to standard anterior implants) was used in 88 patients, and the unilateral concept (one zygomatic implant on one side, splinted with one or more conventional implants) was employed in 14 patients.

CONCLUSIONS

The main indication for the use of zygomatic implants was considered extreme maxillary bone atrophy, resulting from many factors. The clear definition of what was considered "extreme bone atrophy" is not uniquely defined in each paper. Further studies are needed to develop clear indications for zygomatic implants.