Distal extension mandibular removable partial denture with implant support

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.

Implant-supported removable partial dentures compared to conventional dentures: A systematic review and meta-analysis of quality of life, patient satisfaction, and biomechanical complications

Objectives

The purpose of this systematic review and meta‐analysis was to compare implant‐supported removable partial dentures (ISRPDs) with distal extension removable partial dentures (DERPDs) in terms of patient‐reported outcome measures (PROMs: patients' quality of life and satisfaction) and to determine mechanical and biological complications associated with ISRPDs.

Material and Methods

An electronic search was performed on four databases to identify studies treating Kennedy class I or II edentulous patients and which compared ISRPDs with DERPDs in terms of PROMS and studies, which evaluated mechanical and biological complications associated ISRPDs. Two authors independently extracted data on quality of life, patient satisfaction, and biomechanical complications from these studies. The risk of bias was assessed for each study, and for PROMs, the authors performed a meta‐analysis by using a random‐effects model.

Results

Thirteen articles were included based on the selection criteria. The difference in mean scores for quality of life (30.5 ± 1.8; 95% confidence interval [CI], 24.9–36.1) and patient satisfaction (−20.8 ± 0.2; 95% CI, −23.7 to −17.8) between treatments with conventional and implant‐supported removable dentures was statistically significant (p < .05). Implant‐supported removable dentures improved patients' overall quality of life and satisfaction. Some mechanical and biological complications, such as clasp adjustment, abutment or implant loosening, marginal bone resorption, and peri‐implant mucositis, were noted in ISRPDs during patient follow‐up. Studies assessing PROMs were very heterogeneous (I² = 65%, p = .85; I² = 75%, p = .88).

Conclusions

ISRPDs significantly improved quality of life and patient satisfaction. Some mechanical and biological complications have been associated with ISRPDs treatment, requiring regular monitoring of patients to avoid the occurrence of these complications.

Clinical and radiographic evaluations of implants as surveyed crowns for Class I removable partial dentures: A retrospective study

PURPOSE

The purpose of this study was to evaluate survival rates and marginal bone loss (MBL) of implants in IC-RPDs.

MATERIALS AND METHODS

Seventy implants were placed and used as surveyed crowns in 30 RPDs. The survival rates and MBL around implants based on multiple variables, e.g., position, sex, age, opposing dentitions, splinting, type of used retainer, and first year bone loss, were analyzed. Patient reported outcome measures (PROMs) regarding functional/esthetic improvement after IC-RPD treatment, and complications were also inspected.

RESULTS

The 100% implant survival rates were observed, and 60 of those implants showed MBL levels less than 1.5 mm. No significant differences in MBL of implants were observed between implant positions (maxilla vs. mandible; P = .341) and type of used retainers (P = .630). The implant MBL of greater than 0.5 mm at 1 year showed significantly higher MBL after that (P < .001). Splinted implant surveyed crowns showed lower MBL in the maxilla (splinted vs. non-splinted; P = .037). There were significant esthetic/functional improvements observed after treatment, but there were no significant differences in esthetic results based on implant position (maxilla vs. mandible). Implants in mandible showed significantly greater improvement in function than implants in the maxilla (P = .002). Prosthetic complication of IC-RPD was not observed frequently. However, 2 abutment teeth among 60 were failed. The bone loss of abutment teeth was lower than MBL of implants in IC-RPDs (P = .001).

CONCLUSION

Class I RPD connected to residual teeth and strategically positioned implants as surveyed crowns can be a viable treatment modality.

Clinical Performance of Implant Crown Retained Removable Partial Dentures for Mandibular Edentulism-A Retrospective Study

The studies on implant-crown-retained removable partial dentures (IC-RPDs) for edentulism are scarce. The purpose of this study was to evaluate survival rates and marginal bone loss (MBL) of IC-RPDs compared to implant overdentures (IODs) in mandibular edentulism. Variables that influenced survival and marginal bone loss (MBL) of implants in both treatment modalities were analyzed and the functional/esthetic satisfaction of patients as well as prosthetic complications were also observed. Eighteen IC-RPDs with a total of 60 implant-supported survey crowns and 24 IODs with a total 94 implants retained with magnet attachments were observed. After a median observation period of 46.6 months (up to 149 months), we observed 98.3% implant survival rates for IC-RPDs and 92.5% for IODs. Kaplan–Meier survival curves based on the treatment modality showed that, at 96 months, cumulative survival rates were 98.3% in IC-RPD and 83.1% in IOD. For implant survival rates, no statistical differences were observed according to age, sex, opposing dentition, or implant positions (p = 0.515, 0.666, 0.201, 0.749, respectively). The implant MBL measurements for IC-RPD and IOD groups at the final recall check were 0.93 ± 1.22 mm and 2.12 ± 2.09 mm, respectively. Additionally, there were no significant differences between groups (p = 0.554). The implants with peri-implantitis at year 1 showed significantly higher MBL at final check-up (p < 0.001). The MBL of implants showed significant differences based on age (p = 0.008) and opposing dentition (p = 0.003). No significant differences of implant MBL were observed for the position of placed implants (p = 0.621) or sex (p = 0.666). Patient-reported outcome measures (PROMs) on functional and esthetic satisfaction were significantly improved after IC-RPD or IOD treatment (p < 0.001). The most frequent prosthetic complication of IC-RPD was clasp loosening, while for IOD group, it was attachment dislodgement. Within the limitations of this retrospective study, we concluded that IC-RPDs could be considered as a viable treatment option for edentulous patients who need few fixed abutments for satisfaction.

Comparison between Integrated and Parallel Interlock Designs of an Extracoronal Attachment-retained Distal Extension Removable Partial Dentures: A Clinical Trial

Objective

Precision attachments may exert unfavorable stresses on abutments in distal extension bases. This study compared between two reciprocation designs in attachment removable partial dentures (RPDs).

Materials and Methods

Fourteen patients were allocated into two groups. Each patient received an attachment-retained RPD with one of the two types of attachments being studied. Group I received the integrated interlock type of reciprocation and group II received the parallel interlock type. Abutments were examined for modified plaque index, modified bleeding index, periodontal probing pocket depth, clinical attachment level, and modified papillary bleeding Index.

Results

Comparisons of periodontal parameters between mesial and distal abutments within each group revealed no statistically significant difference. Means of these parameters were used for the comparisons. There was a significant difference at P < 0.05 in all parameters between the two groups at time of insertion and at 3, 6, and 9 months of follow-up with values of group (II) higher than group (I).

Conclusion

RPDs of both designs showed an increase in periodontal parameters. Integrated interlock design showed better scores. It is preferable to use the attachment-retained RPD with integrated interlock instead of parallel interlock design.

In vitro assessment of a novel additive manufactured titanium implant abutment

Background

Dental implant temporization remains a clinical challenge. A novel abutment simplifying the procedure was developed, but conventional fabrication was costly and unpredictable. A workflow was developed to fabricate the novel abutment using additive manufacturing. This in vitro investigation assessed the additive manufactured (AM) novel abutments to conventionally manufactured (CM) abutments.

Material and Methods

The AM abutments were fabricated in dental-grade titanium (Ti-6Al-4V) using Selective Laser Melting and were post-processed. The CM abutments were milled and subsequently laser welded manually. Pin strength of the abutments was assessed using a universal loading machine. Torque was measured by tightening the AM and CM abutments into dental implants within artificial bone.

Results

Average pin strength was 364.4 N for the AM abutments and 62.5 N for the CM abutments. Average torque was 49.9 Ncm for the AM abutments and 62.9 Ncm for the CM abutments. AM abutment's pin strength was higher than the CM abutments. CM abutments measured a higher torque than the AM abutments.

Conclusions

Additive manufacturing with titanium using SLM provided an alternative fabrication pathway of a novel implant abutment. The AM approach was cost-effective, predictable, efficient and demonstrated pin strength and torque suitable for temporization procedures in implant dentistry. Key words:Abutment, dental implant, temporization, medical device, prototype design, additive manufacturing, 3D printing, titanium.

Mechanical analysis of the effects of implant position and abutment height on implant-assisted removable partial dentures

PURPOSE

An increasing number of clinical reports describe the use of dental implants as abutments in implant-assisted removable partial dentures (IARPD). We used three-dimensional finite element analysis to evaluate IARPD as a unilateral mandibular distal extension denture. Specifically, the mechanical effects of implant position and abutment height on the abutment tooth, denture, and denture-supporting tissue were assessed.

METHODS

The models analyzed were defects of the left mandibular second premolar and first and second molars prosthetically treated with an IARPD using one implant for each tooth position. There were two abutment heights: one equal to that of the mucosa and another that was elevated 2 mm above the mucosa. Six models were constructed.

RESULTS

For mucosal-level abutments, movement of the abutment tooth was lower for implants positioned distal to the abutment tooth than for those positioned medial to the abutment tooth. For elevated abutments, movement of the abutment tooth was lower for implants positioned medial to the abutment tooth than for those positioned distal to the abutment tooth.

CONCLUSIONS

The mechanical effects on abutment teeth at the same implant position differed in relation to implant abutment height.

Implant overdentures retained by self-aligning stud-type attachments: A clinical report

The functionality of a new overdenture attachment (LOCATOR R-Tx) was described for different clinical situations: a conventional mandibular implant overdenture (IOD) retained by 2 implants, a straightforward chairside maintenance procedure for replacing a worn LOCATOR (Legacy) attachment with the new LOCATOR R-Tx, and a complex clinical situation with nonideal implant positions with compromised parallelism. The LOCATOR R-Tx is an advance on the existing LOCATOR Legacy attachment and has an improved abutment head design with a more durable surface coating to prevent attachment wear and thereby reduce frequency of maintenance.

Influence of Oral Morphology on Speech Production in Subjects Wearing Maxillary Removable Partial Dentures with Major Connectors

BACKGROUND/AIMS

Speech impairment during the initial phase of removable partial denture (RPD) treatment can prevent patient adaptation to RPDs. This study was undertaken to investigate the influence of oral morphology on speech production in subjects wearing RPDs with major connectors.

METHODS

Two types of connectors were fabricated for 17 subjects with normal dentitions: covering the middle palate (M-bar) and the anterior/posterior palate (AP-bar). Four target sounds ([∫i], [t∫i], [çi], and [ki]) were evaluated under 3 recording conditions: no connector, M-bar, and AP-bar. The mean appearance ratios of correct labels (MARCs) were calculated as parameters representing speech production accuracy with the speech evaluation system. Subgroup analysis was conducted based on palate height, dental arch width, and front space volume of the oral cavity.

RESULTS

Based on the multiple linear regression test, a significant association was found between the MARCs of [∫i] with M-bar and front space (p = 0.036). In the subgroup analysis, the AP-bar had a significant effect on the MARCs of [∫i] among subjects with high palate (p = 0.026), narrow arch (p = 0.004), and small front space (p = 0.014).

CONCLUSION

RPDs with major connectors could disturb speech production among patients with high palates, narrow arches, and small front spaces.