Narrow-diameter versus regular-diameter dental implants for mandibular overdentures: A systematic review and meta-analysis

Retrospective study on the clinical and radiographic outcomes of 2.8 mm diameter implants supporting fixed prostheses up to 11 years

OBJECTIVES

This study aimed to report the clinical and radiographic results of 2.8 mm two-piece narrow diameter implant (NDI) supporting fixed restorations.

MATERIALS AND METHODS

Clinical and radiographic data of 54 NDIs in 32 patients were retrospectively assessed after 2 to 11 (mean 8.17) years of follow-up. Clinical and radiographic measurements were taken. Survival rate, implant and prosthesis failure, pink aesthetic scores (PES), white aesthetic scores (WES), bleeding on probing (BOP), probing depth (PD), marginal bone loss (MBL), and mechanical and biological complications were evaluated.

RESULTS

An implant failed during the follow-up period, resulting in a cumulative survival rate of 98.15% at the implant level and 96.88% in the patient. The total mean values of PES and WES for 2.8 mm NDIs were 7.09 ± 1.15 (range: 3.33-9.00) and 7.42 ± 1.03 (range: 3.67-9.33). The prevalence of sites with positive BOP was 38.14 ± 29.77%. The mean PD value was 2.46 ± 0.62 mm. The average MBL was 1.15 ± 0.74 mm (range: 0.25-4.03 mm). No implant or abutment fracture was detected. A veneer chipping was present in one patient, and a loose crown appeared in another patient. Two implants (3.7%) and two patients (6.3%) were diagnosed with peri-implantitis.

CONCLUSION

Within the limitation of the study, the results indicate that the use of two-piece 2.8 mm NDI for the fixed prosthetic rehabilitation of edentulous regions with reduced interdental and/or buccal-lingual width is viable.

The Influence of Patient-, Site-, and Implant-Related Factors on Marginal Bone Levels of Dental Implants in a Rural Population in China: A Retrospective Study

OBJECTIVES

Limited research is available on implant treatment outcomes in rural populations. This may be due to the presence of various barriers, such as access to oral health care, resources, health literacy, and education. The aim of this study was to evaluate the influence of patient-, site-, and implant-related factors on marginal bone levels of dental implants in a rural population in China.

MATERIAL AND METHODS

A retrospective study was conducted using data from a private dental office. Subjects included in this study received dental implants as part of their routine dental treatment. Information on age, gender, smoking status, diabetes, heart disease, jaw location, restorative type, loading protocol, survival rate, implant length, and diameter was collected. Marginal bone loss was recorded as the largest value at either the mesial or distal aspect on peri-apical radiographs. Descriptive and inferential statistics were performed along with linear regression analysis.

RESULTS

Overall, 428 implants were placed in 90 subjects over an average follow-up period of 453 days. No implant failures were recorded. The average marginal bone loss was 0.10 mm, with 80.6% of implants showing no marginal bone loss. The extent of marginal bone loss was greater in the mandible (0.13 ± 0.25) than in the maxilla (0.08 ± 0.19). An increase in implant diameter by 1 mm resulted in 0.08 mm of marginal bone loss, indicating wider diameter implants are associated with more bone loss. Age was also positively correlated with marginal bone loss, increasing by 0.002 mm per year. No differences were found for gender, smoking, diabetes, heart disease, restoration type, and immediate loading.

CONCLUSIONS

Dental implant therapy in a rural Chinese population demonstrated high survival rates and minimal marginal bone loss. Factors such as age, implant location, and diameter influenced bone loss. This study fills a critical gap in understanding implant outcomes specifically within rural settings, highlighting the need for tailored approaches to enhance patient access and care in these communities. Further research is needed to explore these relationships and assess implant outcomes in rural populations.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of select 2023 dental literature to briefly touch on several topics of interest to modern restorative dentistry. Each committee member brings discipline-specific expertize in their subject areas that include (in order of appearance here): prosthodontics; periodontics, alveolar bone, and peri-implant tissues; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine, oral and maxillofacial surgery, and oral radiology; and dental caries and cariology. The authors have focused their efforts on presenting information likely to influence the daily dental treatment decisions of the reader with an emphasis on current innovations, new materials and processes, emerging technology, and future trends in dentistry. With the overwhelming volume of literature published daily in dentistry and related disciplines, this review cannot be comprehensive. Instead, its purpose is to inform and update interested readers and provide valuable resource material for those willing to subsequently pursue greater detail on their own. Our intent remains to assist colleagues in navigating the tremendous volume of newly minted information produced annually. Finally, we hope readers find this work helpful in providing evidence-based care to patients seeking healthier and happier lives.

Can narrow-diameter implants enhance patient-reported outcomes for mandibular implant-retained overdentures?

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVE

To evaluate and compare stability and functionality between narrow and standard implant-retained mandibular overdentures in edentulous patients from multiple perspectives. Assessments included clinical parameters [survival rate (SR) and marginal bone loss (MBL)], along with patient-reported outcome measures (PROMs) including patient satisfaction and oral health-related quality of life (OHRQoL).

METHODS

The study protocol followed PRISMA criteria for reporting reviews and meta-analyses. Using appropriate keywords, electronic search was conducted in each of the following databases: Medline, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus, up to July 22, 2022. There were no restrictions based on language, publication type, or publication date. Additionally, ongoing studies were explored in ClinicalTrials.gov and WHO ICTRP, while cross-references in each selected study were manually examined. The eligible studies were randomized controlled trials (RCTs) or controlled clinical trials (CCTs) comparing narrow implants (diameter ≤ 3.5 mm) to standard implants (diameter > 3.5-4.5 mm) retaining mandibular overdentures in edentulous patients. Excluded were studies with unclear implant diameter information, fewer than 5 patients per group, observational studies, reviews, and laboratory studies. Two authors independently conducted study selection, data collection, and analysis, resolving any discrepancies through discussion with a third author. Methodological quality was assessed using RoB-2 and ROBINS-I tools. Implant SR and MBL measurements at final follow-up were recorded, while patient satisfaction and OHRQoL were evaluated using visual analogue scale (VAS-100) and oral health impact profile (OHIP) questionnaire, respectively.

RESULTS

After duplicate removal, 782 publications and 83 registered clinical trials were identified, of which 26 were eligible for full-text assessment. Ultimately, the quantitative evaluation included 12 publications from 8 independent studies: 4 parallel design RCTs and 4 CCTs. Risk of bias assessment revealed variations among the studies, with only one study being rated as having low risk. The follow-up periods ranged from 1 to 3 years. Meta-analysis showed no significant difference in SR and MBL between narrow and standard implant groups (p = 0.29 and p = 0.93, respectively), with considerable heterogeneity (I2 = 100% and I2 = 78%, respectively). Regarding PROMs, the narrow implant group showed significantly higher levels of patient satisfaction (mean difference (MD): 8.18; 95% CI: 5.83 to 10.53; p < 0.00001; I2 = 36%) and exhibited a significant improvement in OHRQoL (MD: -4.36; 95% CI: -6.83 to -1.89; p < 0.001; I2 = 55%) compared to the standard implant group.

CONCLUSION

For implant-retained mandibular overdentures, the use of narrow implants is associated with comparable SR and MBL, along with higher patient satisfaction and better OHRQoL improvement as compared to standard implants, offering a viable alternative option for patients with diminished alveolar bone width.

Clinical outcomes of narrow- and regular-diameter implants with bone augmentation in the anterior maxilla: a systematic review and meta-analysis

OBJECTIVES

To evaluate the clinical outcomes of narrow-diameter implants (NDIs) and regular-diameter implants (RDIs) with bone augmentation in the anterior maxilla, with implant survival rate (ISR) as the primary outcome. Additionally, secondary outcomes such as peri-implant marginal bone loss (MBL), pocket probing depth (PPD), mechanical complications, and biological complications were also considered.

MATERIALS AND METHODS

A thorough literature search was performed to identify randomized controlled trials and cohort studies comparing outcomes of NDIs and RDIs with bone augmentation in the anterior maxilla published up to February 2024. Only studies with a minimum follow-up period of 12 months were selected for analysis. Meta-analysis was performed if at least two articles with similar characteristics were available.

RESULTS

Of the 288 articles initially considered, 5 were included in the analysis, involving 282 NDIs and 100 RDIs. At the 36-month follow-up, no statistically significant differences in ISR, which ranged 93.8-100% for NDIs and were 100% for RDIs, were observed between the two groups (relative risk, 0.989; 95% confidence interval, 0.839-1.165; p = 0.896). Similarly, MBL and PPD did not differ significantly between the two groups. Soft tissue dehiscence was the most common complication found in RDIs.

CONCLUSION

The results indicate that NDIs yield clinical outcomes similar to those of RDIs with bone augmentation in the anterior maxilla over a 36-month follow-up period.

CLINICAL RELEVANCE

Considering the similar clinical outcomes, the shortened treatment duration and more rapid esthetic improvement associated with NDIs may render them preferrable to RDIs with bone augmentation, particularly in this esthetic zone.