Effect of Number and Location on Stress Distribution of Mini Dental Implant-Assisted Mandibular Kennedy Class I Removable Partial Denture: Three-Dimensional Finite Element Analysis

Implant-assisted removable partial dentures: Part II. a systematic review of the effects of implant position on the biomechanical behavior

PURPOSE

This systematic review aimed to evaluate the effects of implant placement sites on the biomechanical behavior of implant-assisted removable partial dentures (IARPDs) using finite element analysis (FEA).

STUDY SELECTION

Two reviewers independently conducted manual searches of the PubMed, Scopus, and ProQuest databases for articles investigating implant location in IARPDs using FEA, according to the 2020 Systematic Reviews and Meta-analyses statement. Studies published in English up to August 1, 2022, were included in the analysis based on the critical question.

RESULTS

Seven articles meeting the inclusion criteria were systematically reviewed. Six studies investigated mandibular Kennedy Class I and one study investigated mandibular Kennedy Class II. Implant placement reduced the displacement and stress distribution of the IARPD components, including dental implants and abutment teeth, regardless of the Kennedy Class type and dental implant placement site. Most of the included studies showed that, based on the biomechanical behavior, the molar region, rather than the premolar region, is the preferred implant placement site. None of the selected studies investigated the maxillary Kennedy Class I and II.

CONCLUSIONS

Based on the FEA regarding mandibular IARPDs, we concluded that implant placement in both the premolar and molar regions improves the biomechanical behaviors of IARPD components, regardless of the Kennedy Class. Implant placement in the molar region results in more suitable biomechanical behaviors compared with implant placement in the premolar region in Kennedy Class I. No conclusion was reached for Kennedy Class II due to the lack of relevant studies.

Implant-assisted removable partial dentures: Part I. a scoping review of clinical applications

PURPOSE

This scoping review aimed to systematically map research regarding implant-assisted removable partial dentures (IARPDs), and identify existing gaps in knowledge.

STUDY SELECTION

Two reviewers independently conducted a search of the MEDLINE-PubMed and Scopus databases according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) extension for Scoping Review and included articles published in English up to August 31, 2022, including human studies, reviews, and in vitro studies. Expert opinions, animal studies, and clinical studies involving complete overdentures were excluded, and ten aspects for establishing the treatment strategy for IARPDs were examined.

RESULTS

One hundred and twelve articles were chosen. There were two treatment modalities: IARPDs retained by implant- and tooth-supported surveyed single crowns (SCs) or fixed partial dentures (FPDs). In IARPDs retained by tooth-supported surveyed SCs or FPDs, the survival rate of dental implants for IARPDs was relatively higher with a wide range of marginal bone loss and many complications, but with improved functional performance, oral health-related quality of life, and patient satisfaction. There were limited data on survival or success rates and designs of IARPDs, attachment selections, length and diameter, inclination, placement sites, and loading protocols of implants, regardless of prosthetic types. There was limited information on maxillary IARPDs except for survival rates of implants.

CONCLUSIONS

Although IARPDs could become a useful treatment strategy, there is limited scientific consensus with gaps in knowledge about their use. Additional well-designed clinical and in vitro studies are necessary to scientifically establish IARPDs as definitive prostheses in implant dentistry.

An in vitro assessment of optimizing implant positions in bilateral distal extension implant-assisted removable partial dentures: A microstress analysis

AIM

The aim of this study was to analyze and compare the stress distribution on dental implants in various positions when used with implant-assisted removable partial dentures.

SETTINGS AND DESIGN

This was an in vitro study.

MATERIALS AND METHODS

A model representing a mandibular bilateral partially edentulous condition, with missing premolars and molars, was fabricated using epoxy resin. Two implants of similar diameter measuring 4.0 mm × 10 mm (Dentium, Korea) were inserted in the second molar and the second premolar region on either side of the model for comparing the biomechanical effect of various implant locations. Two types of loads 100N and 125N were applied vertically using universal testing machines in the premolar and molar regions. The loads on the implants beneath the cast partial denture were measured by physical stress analysis using a microstrain gauge.

STATISTICAL ANALYSIS USED

A comparison of maximum stress observed at the premolar versus molar regions due to the application of the 100N and 125N loads was done using the Mann-Whitney U-test.

RESULTS

In physical stress analysis, obtained results were statistically analyzed, and the result was statistically not significant (P = 0.435 at 100N and P = 0.718 at 125N) in positional changes of implant.

CONCLUSION

In the current study, the statistical analysis of physical stress revealed no significant differences in stress values between the loadings at the premolar and molar regions. This suggests that the implant can be placed in either the premolar or molar region based on the availability of bone without affecting stress distribution.

Impact of implant location on load distribution of implant-assisted removable partial dentures: a review of in vitro model and finite-element analysis studies

BACKGROUND

Appropriate load distribution among the supporting elements is essential for the long-term success of implant-assisted removable partial dentures; however, there is little information available on load distribution.

PURPOSE

This study aimed to evaluate the effect of implant location on load distribution in implant-assisted removable partial dentures by reviewing in vitro models and finite-element analysis studies.

MATERIALS AND METHODS

English-language studies which examined the load distribution of implant-assisted removable partial dentures and were published between January 2001 and October 2022 were extracted from PubMed, ScienceDirect, and Scopus online databases, and manual searching. Two reviewers selected the articles based on the predetermined inclusion and exclusion criteria, followed by data extraction and analysis.

RESULTS

Forty-seven studies were selected after evaluating the titles and abstracts of 264 articles; two were identified manually. After screening the text, 12 studies were included: six in vitro model experiments and six finite-element analysis studies. All included studies used a mandibular free-end missing model (Kennedy Class I or II). The influence of implant location on load distribution to the abutment tooth, implant, and mucosa under the denture base was summarized in three cases: implant at the premolar, first molar, and second molar region. Due to differences in the measurement method of load distribution and loading condition to the denture, the results differed among the studies.

CONCLUSIONS

The implant location in implant-assisted removable partial dentures can affect load distribution to the supporting elements, such as the abutment tooth, implant, and mucosa under the denture base.