Multicentre prospective evaluation of implant-assisted mandibular bilateral distal extension removable partial dentures: patient satisfaction

Effect of surgical and prosthodontic protocols of distal extension implant-supported removable partial dentures on clinical and patient-reported outcomes: A systematic review

STATEMENT OF PROBLEM

Standard surgical and prosthodontic protocols for managing partially dentate patients with implant-supported removable partial dentures (ISRPDs) are lacking.

PURPOSE

The purpose of this systematic review was to determine clinical and patient-reported outcome measures (PROMs) in patients provided with ISRPDs in distal edentulous arches based on different surgical and prosthodontic protocols.

MATERIAL AND METHODS

An electronic and manual literature search was conducted in 3 databases, PubMed/MEDLINE, SCOPUS, and Cochrane Library, for clinical studies on distal extension ISRPDs related to clinical and patient-reported outcomes. Kennedy Class I and II arches described in articles published from January 2000 to December 2023 were included. Clinical parameters regarding implant type, location, loading protocols, and implant survival rate and PROMs including masticatory performance, esthetics, and overall satisfaction were compared. The risk of bias was determined by using the Cochrane Risk of Bias Tool 2.0 (RoB 2.0).

RESULTS

An initial total of 103 studies were identified, but only 11 articles were selected after implementing the inclusion and exclusion criteria. Ten studies evaluated PROMs, and 6 studies evaluated clinical outcomes (5 studies evaluated both). The implant survival rate ranged from 91.7% to 100%, with no clear differentiation among the studies with immediate or delayed loading protocols. Most studies described implants positioned in the molar region. In general, patient satisfaction and oral health-related quality of life (OHRQoL) improved significantly with ISRPDs compared with conventional removable partial dentures (RPDs) or RPDs with healing abutments. Posttreatment clinical outcomes revealed stable peri-implant health with no significant bone loss or prosthetic complications. No specific implant configuration, including implant type and location or attachment system, appeared to be better than another. Ball attachments were the commonly used attachments. Two studies were of high risk and 3 studies of low risk. The remaining 6 studies were judged to have some concerns based on the RoB 2.0 analysis.

CONCLUSIONS

Providing an ISRPD improved patient satisfaction, OHRQoL, and the clinical outcomes in distal extension situations, with most studies positioning the implants in the molar region. The type of attachment did not significantly affect the outcomes, although ball attachments were the most used attachment in ISRPDs.

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.

A Systematic Review of Patient Satisfaction With Removable Partial Dentures (RPDs)

Removable partial dentures (RPDs) offer a broad range of aesthetics and restorative functions for partially edentulous patients. This systematic review examines patients' satisfaction rates and the factors that influence RPD satisfaction. This systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and the Cochrane Handbook for Systematic Reviews. A systematic literature search was done on PubMed, Scopus, and Google Scholar using preset inclusion criteria. A total of 923 non-duplicate articles were screened, and 35 were included in this review. Among the included studies, RPDs generally exhibited high satisfaction rates, with reported rates ranging between 50% and 81%. Several factors influenced satisfaction. Age played a major role, with older adults expressing higher satisfaction. Gender differences were also noted, especially in appearance satisfaction where women were more satisfied with RPDs than men. Prior experience with RPDs correlated positively with overall satisfaction. The number and location of missing teeth, as well as the type of RPD (metal vs. flexible), significantly influenced satisfaction levels. Flexible dentures were more satisfactory than metal RPDs. Attachments, such as magnetic attachments and implants, increased satisfaction. Patient complaints, encompassing pain, aesthetics, and cleanliness, were identified as common sources of dissatisfaction. The results underscore the significance of customizing RPD treatment to individual needs, considering factors that influence RPD satisfaction. Recognizing the importance of influential factors such as age, gender RPD experience, etc., for clinicians seeking to optimize patient outcomes in RPD therapy is crucial.

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.

Mandibular 3-implant overdenture: A clinical report of a novel design

OBJECTIVE

To report on the use of a mandibular 3-implant overdenture with a novel implant distribution opposing a maxillary complete denture for the rehabilitation of an older edentulous patient.

BACKGROUND

The use of oral implants with attachment systems of various numbers and designs to support removable partial and complete dentures is well documented with success and predictability.

MATERIALS AND METHODS

An older edentulous patient with a mandibular implant-assisted removable partial denture was presented with failing remaining dentition. Teeth were extracted and a single midsymphyseal implant was placed. A mandibular overdenture on three implants with ball attachments in a tripod distribution was constructed to oppose a new maxillary complete denture made using a modified impression technique.

RESULTS

Over 2 years of follow-up, no significant biological or mechanical complications were reported, and denture retention and stability remained optimum.

CONCLUSION

Mandibular overdentures on three implants with ball attachments in a tripod distribution, opposing a maxillary complete denture, could be an alternative treatment option for the older edentulous patients.

Converting Bilateral Free-End Removable Partial Dentures to Implant-Assisted Removable Partial Dentures Using 6 mm Short Implants: Patient-Reported Outcomes of a Prospective Clinical Study

The study assessed oral health-related quality of life (OHRQoL) of patients who received two 6 mm short implants in mandibular molar sites, converting existing bilateral free-end removable partial dentures (RPDs) to implant-assisted RPDs (IARPDs). After a postsurgical healing period of 4 months, the participants received a non-retentive dome abutment for 8 weeks, and then a retentive ball abutment for another 8 weeks. Afterwards, the participants made their final choice on which abutment to keep. The final follow-up was 1 year after implant placement. OHRQoL was evaluated with the 49-items version of the Oral Health Impact Profile (OHIP-49) at the abutment exchanges and the final follow-up. Furthermore, numerical rating scales were used to analyze patient satisfaction after 1 year. Questionnaire data of 13 participants were evaluated. Overall, OHRQoL increased with both the dome (p = 0.02) and the ball abutments (p < 0.001), without a significant difference between the abutments (p = 0.953). The questionnaires revealed an improvement in terms of oral situation, quality of life, and masticatory capacity (all p < 0.01). Patients showed a significant preference for the ball abutments (p < 0.001). Converting RPDs to IARPDs resulted in significant improvement of OHRQoL. Patients seem to prefer retentive over non-retentive abutments, although no differences in terms of OHRQoL were observed.

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.

Treatment outcomes of implant-assisted removable partial denture with distal extension based on the Kennedy classification and attachment type: a systematic review

BACKGROUND

Implant-assisted removable partial dentures (IARPDs) have recently become popular, but little information is available on the treatment outcomes based on the Kennedy classification and attachment types.

OBJECTIVE

The objective of this review was to evaluate the treatment outcomes of IARPD delivered for distal extension edentulous areas based on the differences in the Kennedy classification and attachment type.

MATERIALS AND METHODS

English-language clinical studies on IARPD published between January 1980 and February 2020 were collected from MEDLINE (via PubMed), the Cochrane Library (via the Cochrane Central Register of Controlled Trials), Scopus online database, and manual searching. Two reviewers selected the articles based on pre-determined inclusion and exclusion criteria, followed by data extraction and analysis.

RESULTS

Eighty-one studies were selected after evaluating the titles and abstracts of 2410 papers. Nineteen studies were finally included after the perusal of the full text. Fourteen studies focused on Class I, 4 studies investigated both Class I and II, and only 1 study was conducted on Kennedy's class II. Eight types of attachments were reported. The ball attachment was the most frequently used attachment, which was employed in 8 of the included studies. The implant survival rate ranged from 91 to 100%. The reported marginal bone loss ranged from 0.3 mm to 2.30 mm. The patient satisfaction was higher with IARPD than with conventional RPDs or that before treatment. The results of prosthetic complications were heterogeneous and inconclusive.

CONCLUSION

IARPD exhibited favorable clinical outcomes when used as a replacement for distal extension edentulous areas. The comparison between the clinical outcomes of Kennedy's class I and II was inconclusive owing to the lack of studies focusing on Kennedy Class II alone. The stud attachment was the most commonly used type in IARPDs. Overall, the different attachment systems did not influence the implant survival rate and patient satisfaction. Further high-quality studies are needed to investigate the attachment systems used in IARPD.

Stress Analysis of Implant-Supported Removable Partial Denture with Anterior Fixed Prostheses and Conventional Implant-Supported Overdentures in the Edentulous Mandible

Aim:

To compare new design implant-supported removable partial dentures retained with anterior fixed prosthesis with a conventional locater and bar attached implant overdenture prostheses retained by two or four implants via photoelastic stress analysis.

Materials and Methods:

Seven edentulous mandibuler acryclic models prepared and divided into two main groups; two to four implant models, subgroup separation as stated; for two implant models overdenture with locator attachment, crown design retained removable prosthesis with clasp retention, bridge design retained removable prosthesis with clasp retention, bridge design retained removable prosthesis with precision attachment retention; and for four implant models prosthesis with bar attachment overdenture, fixed bridge design retained removable prosthesis with clasp retention, fixed retained removable prosthesis with precision attachment retention. A 300 N load was applied to the first premolars. Photoelastic stress analysis method that is a specific method concerning stress visualization, and does not require statistical analysis, was used. The stress distributions were seen in optically using a poloriscope.

Results:

In the models with two implant-retained removable partial dentures, the stress distribution was found to be lower than that with the four implant-retained removable partial dentures. Nonsplinted implants caused high stress around the distal implant on the loading side.

Conclusion:

The stress loads were transmitted to other implants by splinting. Implant-supported removable partial dentures with an anterior fixed prosthetic design show lower stress distributions compared with bar retained prosthesis. These dentures appear to be advantageous in terms of stress transmission.

Are implant-supported removable partial dentures a suitable treatment for partially edentulous patients? A systematic review and meta-analysis

STATEMENT OF PROBLEM

A consensus on the clinical performance of implant-supported removable partial dentures (ISRPDs) is lacking.

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the clinical performance of ISRPDs in terms of the implant survival rates, marginal bone loss, and patient-reported outcome measures (PROMs).

MATERIAL AND METHODS

Four electronic databases (MEDLINE/PubMed, EMBASE, Web of Science, and Cochrane Library) were independently searched by 2 reviewers for articles published up to December 2020. A single-arm meta-analysis was performed to evaluate the implant survival rates and marginal bone loss by using the R program. The Cochrane collaboration tool was used to evaluate the risk of bias of randomized controlled trials (RCTs), and the Newcastle-Ottawa scale for non-RCT studies.

RESULTS

Sixteen studies were included, with a total of 334 participants and a mean age of 58 years. The participants received a total of 581 dental implants, 475 conventional and 106 mini-implants. All included studies reported implant survival rate above 90% (range: 92% to 100%). Meta-analysis indicated a high proportion of implant survival rates of 3% (95% confidence interval [CI]: 2% to 5%) and a low mean raw score of marginal bone loss 0.98 mm (CI: 0.61 to 1.36 mm). Compared with conventional RPDs, improved patient quality of life and satisfaction were reported by studies that evaluated ISRPDs. RCT studies exhibited a low risk of bias for most domains, while most non-RCT studies were classified as good quality.

CONCLUSIONS

ISRPDs exhibited high implant survival rates and acceptable bone loss with improvement in the quality of life and satisfaction of patients when compared with conventional RPDs. Therefore, they can be considered suitable for the rehabilitation of partially edentulous patients.

Effect of the attachments on clinical outcomes of mandibular distal extension implant-supported removable partial dentures: A systematic review

STATEMENT OF PROBLEM

Healing abutments and attachments have been used for implant-supported removable partial dentures (ISRPDs). However, the effects of these abutments and attachments on the clinical outcomes of the implants and prostheses are elusive because of the lack of standardized research protocols.

PURPOSE

The purpose of this systematic review was to determine the clinical outcomes of mandibular distal extension ISRPDs with healing abutments and attachments by analyzing qualified studies.

MATERIAL AND METHODS

An electronic and manual literature search was conducted on PubMed, Web of Science, Scopus, Embase, and Cochrane Library databases including articles published in English from 1980 to 2020. Publications of clinical outcome studies on the mandibular distal extension ISRPDs with healing abutments or attachments were screened by inclusion and exclusion criteria. Clinical outcomes of removable partial dentures (RPDs) and ISRPDs with different types of abutments or attachments were compared by using patient-reported outcome measures, implant survival rate, masticatory performance, and implant- or prosthesis-related complications. Study designs and clinical outcome data were extracted and analyzed. The evidence of the selected studies and degree of recommendation were made according to the Oxford Centre for Evidence-based Medicine, and the risk of bias of the studies was assessed based on Newcastle-Ottawa criteria.

RESULTS

Of 541 articles initially identified after removing duplicate records, 11 articles were selected by applying the inclusion and exclusion criteria, by inter-viewer agreement, and by hand searching. Nine prospective cohort studies, 1 retrospective cohort study, and 1 randomized controlled trial were included with evidence levels assessed at 1b, 2b, and 2c. The risk of bias varied from 5 to 8 out of 9. Patient overall satisfaction, oral health-related quality of life (OHRQoL) scores, and masticatory ability were significantly improved for ISRPDs with either healing abutments, ball, or LOCATOR attachments when compared with RPDs. The implant survival rate varied from 92% to 97% at 2 to 10 years for ball attachment and was 100% at 1 year for LOCATOR attachment-supported ISRPDs. Marginal bone loss (MBL) varied from 0 to 1 mm in all studies, although LOCATOR attachments had significantly less MBL compared with ball attachments. The maximal pocket depth and bleeding on probing index around implants at 1 year were 1.7 to 1.8 mm and 0.1 to 0.3. Loose healing caps were the main mechanical complication of implants. There were more prosthetic complications in ISRPDs with ball attachments than RPDs at 10-year follow-up, including gold matrix loosening, loss of retention, and denture base fractures. No direct comparisons were made of patient-reported outcomes or prosthetic complications between ball and LOCATOR attachment-supported ISRPDs.

CONCLUSIONS

Healing abutments and attachments (ball or LOCATOR) improved patient-reported outcomes and the masticatory function of mandibular distal extension ISRPDs. However, insufficient evidence was found to determine the relative effectiveness of different attachment systems on the clinical outcomes of mandibular distal extension ISRPDs. Abutment loosening was the most frequent mechanical complication for healing abutments. More prosthetic complications were associated with ball attachment-supported ISRPDs than RPDs. The major weaknesses of this systematic review were the relatively moderate level of evidence and the publication language, since implant attachments are used in many non-English speaking countries.

Patient-reported outcomes of implant-assisted removable partial dentures with magnetic attachments using short implants: A prospective study

PURPOSE

Implant-assisted removable partial dentures (IARPDs) with short implants improve the oral functions of removable partial dentures (RPDs). This study aimed to compare the patient-reported outcomes of RPDs and IARPDs with short implants retained by magnetic attachments.

METHODS

We recruited 30 participants with mandibular Kennedy Class I or II and distal extension defects of three or more teeth. RPDs, IARPDs with a healing cap, and IARPDs with a magnetic attachment were evaluated across stages using patient-reported outcomes. All participants completed questionnaires (oral health-related quality of life [OHRQoL], patient general satisfaction, and patient's denture assessment [PDA]) at each stage. The OHRQoL was evaluated using the Oral Health Impact Profile-J 54 (OHIP-J 54) score. The general patient satisfaction was evaluated using a 100 mm visual analog scale. The Wilcoxon signed-rank test and Bonferroni correction were used to evaluate differences between the groups (α=0.05).

RESULTS

The OHRQoL of IARPDs was significantly higher than that of RPDs. IARPDs with a magnetic attachment had significantly better patient general satisfaction and PDA than IARPDs with a healing cap.

CONCLUSIONS

The OHRQoL, patient general satisfaction, and PDA were improved by IARPD with a short implant using a magnetic attachment.

In Vitro Assessment of the Effect of Implant Position on Biomechanical Behaviors of Implant-Supported Removable Partial Dentures in Kennedy Class II Condition

The purpose of this study was to investigate the effects of implant position and loading position on biomechanical behaviors using implant-supported removable partial denture (ISRPD) models in a simulated Kennedy class Ⅱ partially edentulous mandible. Three types of Kennedy class Ⅱ mandibular acrylic resin models (a conventional RPD without support by an implant—CRPD; models with an implant placed at first molar (#46)—MP-ISRPD— and second molar (#47)—DP-ISRPD) were used to measure vertical displacement of the RPD, mesio-distal displacement of the abutment tooth, and bending moment of the abutment tooth and implant under one-point loading. The variables at three respective loading points (#45, #46 and #47) were compared statistically. Vertical displacement was suppressed in ISRPDs compared to the CRPD, and significant effects were identified under loading at the implant position. The largest meiso-distal displacement was observed in MP-ISRPD under #47 loading. Bending moments of the abutment tooth and implant were significantly higher in MP-ISRPD than in DP-ISPRD. In MP-ISRPD, a higher bending moment of the abutment tooth under #45 and #47 loading was detected, although the bending moment in DP-ISRPD was almost zero. The results of this study suggested that MP-ISRPD shows the specific biomechanical behaviors, although DP-ISRPD might provide biomechanical benefits under all one-point loading conditions.

Influence of mandibular distal extension implant-supported removable partial dentures on the force exerted on maxillary anterior teeth

PURPOSE

This study aimed to determine the influence of mandibular free-end partial edentulism and use of conventional or implant-supported removable dental prostheses in the partially edentulous area on the load exerted on the maxillary anterior teeth.

METHODS

A jaw model with mandibular free-end missing teeth was used, and a distal extension, removable partial dental prosthesis was fabricated to replace the missing posterior teeth. Four experimental conditions were set up: 1) without prosthesis, 2) with a conventional removable partial dental prosthesis, 3) with an implant-supported removable partial dental prosthesis, and 4) with a complete dental arch. Strain gauges were attached to the root surface of the maxillary left central incisor, canine, first premolar, and first molar. The load exerted on them was calculated based on the calibration coefficient. An occlusal load of 49 N was applied, and the forces were compared using a Kruskal-Wallis test (P < 0.05).

RESULTS

The load exerted on the maxillary anterior teeth increased significantly with no prosthesis, decreased significantly with a conventional removable partial dental prosthesis, and decreased even more significantly with an implant-supported removable partial dental prosthesis.

CONCLUSIONS

The burden on the maxillary anterior teeth decreased with the use of a removable partial dental prosthesis and decreased even further with the use of an implant-supported dental prosthesis. The use of an implant to support a distal extension removable partial dental prosthesis is potentially effective in preserving the remaining teeth and tissues by reducing excessive stress in patients with mandibular free-end partial edentulism.

Influence of rigidity of retainers on dynamic behavior of implant-supported removable partial dentures

Background

Implant-supported removable partial dentures (ISRPDs) are an effective treatment for partially edentulous patients. ISRPDs improve patients’ satisfaction and oral function to a greater extent than RPDs by improving denture stability and enhancing support. However, the effect of a type of direct retainer on displacement of the abutment teeth and dentures in ISRPDs remains unclear. Therefore, we made a resin mandibular model of unilateral mandibular distal-extension partial edentulism for mechanical simulation and compared the dynamic behavior of the abutment teeth and the denture base among different tooth-borne retainers with various rigidities for RPDs and ISRPDs.

Methods

A resin mandibular model for mechanical simulation that had unilateral mandibular distal-extension edentulism and was missing the first molar, second molar, first premolar, and second premolar, and a denture fabricated from the patient’s computed tomography images were used. Three types of direct retainers with different connecting rigidities were evaluated. The vertical displacement of the denture base and buccal and lingual sides and the mesial displacement of the abutment teeth were measured.

Results

Regardless of the rigidity of the direct retainers and loading positions, the displacement of the denture bases in the ISRPDs was significantly smaller than that in the RPDs (P < 0.001). There was no significant difference in vertical displacement of the denture bases among direct retainers with various connecting rigidities in the ISRPDs. Conversely, horizontal displacement of the abutment teeth in both the RPDs and ISRPDs tended to be larger with the cone crown telescope, which has high rigidity, than with the cast cingulum rest and wire clasp, which have much lower rigidities.

Conclusion

Our results suggested that cast cingulum rest and wire clasps as direct retainers are appropriate ISRPDs to minimize denture movement and suppress displacement of the remaining teeth in patients with unilateral mandibular distal-extension partial edentulism.

Retrospective clinical evaluation of implant-assisted removable partial dentures combined with implant surveyed prostheses

STATEMENT OF PROBLEM

Implant-assisted removable partial dentures (IARPDs) have been proposed as a treatment option for partially edentulous patients. However, evidence regarding the outcome of implant-assisted removable partial dentures with implant surveyed prostheses is limited.

PURPOSE

The purpose of this retrospective clinical study was to evaluate the clinical status and complications of IARPDs combined with implant surveyed prostheses in terms of clinical tissue condition, marginal bone resorption, and prosthetic complications.

MATERIAL AND METHODS

Patients treated with IARPDs combined with implant surveyed prostheses who had worn an IARPD for at least 12 months were included. Twenty-four participants (25 prostheses, 12 maxillary, and 13 mandibular) were evaluated, with 80 implants used as abutments for IARPDs. The average follow-up period was 27.6 months, and the maximum follow-up was 78 months. Implant cumulative survival rate, marginal bone resorption, probing depth, peri-implant inflammation, bleeding, plaque, calculus, and complications were evaluated.

RESULTS

No implant failure occurred, and all implants functioned without clinical mobility. Mean marginal bone resorption of implants at 1 year after loading was 0.77 ±0.63 mm, and mean probing depth was 3.4 ±0.1 mm. No patient developed peri-implantitis, and no implant failed. Two clasp fractures, 1 rest fracture, 1 decementation, and 1 fracture of porcelain on an implant surveyed prosthesis were detected at 12 months after loading.

CONCLUSIONS

Well-planned IARPDs using implant surveyed prostheses were clinically successful. Longitudinal and systematic clinical studies are necessary to confirm these results.

Immediate versus delayed loading of strategic mini-implants under existing removable partial dentures: patient satisfaction in a multi-center randomized clinical trial

OBJECTIVE

The purpose of this study was to evaluate and compare the effects of the immediate and delayed loading of strategic mini-implants (MIs) on the satisfaction of patients with removable partial dentures (RPDs).

MATERIALS AND METHODS

In this multi-center randomized clinical trial, strategic MIs were inserted under 79 RPDs in 76 participants. Two questionnaires, one for the upper jaw and one for the lower jaw, were given before surgical intervention and 2 weeks, 4 months, 4.5 months, 1 year, 2 years, and 3 years after implant insertion. To estimate the loading effect (immediate vs. delayed) in terms of the odds ratio, an ordinal logistic regression model was used. The Wilcoxon matched-pairs signed-rank test, which was corrected for clusters in the patient population, was used to evaluate changes in patient satisfaction.

RESULTS

After 4 months, a statistically significant difference in favor of the immediate loading group was recognized in terms of the overall satisfaction score. The patient satisfaction scores recorded after 4.5 months and 1, 2, and 3 years showed substantial improvements compared with the scores recorded before implant insertion in both groups. At the item level, substantial improvements were noted in the following domains: general satisfaction, RPD retention, stability, support, eating, speaking, and aesthetics.

CONCLUSIONS

Strategic MIs improved the satisfaction of patients with RPDs during the medium-term follow-up period. An earlier improvement in the satisfaction of patients with RPDs was seen after immediate loading of the MIs as compared with delayed loading.

CLINICAL RELEVANCE

Inserting MIs under existing RPDs can improve patients' satisfaction with their RPDs in several domains.

Impact of Wearing Two Different Types of Partial Dentures on Oral Health-related Quality of Life in Geriatric Diabetic Patients – A Crossover Study

OBJECTIVE: This study aimed to evaluate oral health-related quality of life (OHRQoL) of partially edentulous elderly diabetic patients before and after wearing heat-cured acrylic resin and flexible partial dentures. BACKGROUND: In the past two decades, an increased concern about the effect of oral conditions on a patient’s quality of life leads to the development of a wide range of OHRQoL measurements. There is a necessity for evaluation required for setting the measurements that are recommended to be used for different needs of geriatric patients. MATERIALS AND METHODS: One hundred partially edentulous bilateral free-end saddle diabetic elderly patients have been randomly selected from the outpatient clinics of the Excellence Centre at National Research Centre. Heat-cured acrylic resin partial denture and flexible removable partial dentures were made for all patients. General oral health assessment questionnaire was completed before and after wearing the two types of partial dentures. The criteria of assessment were speech, mastication and associated pain, esthetics and physiological status, and general life satisfaction and practicing daily activity. RESULTS: The results revealed a significant improvement regarding all aspects of OHRQoL after wearing both partial dentures for diabetic elderly patients. More improvement was observed after wearing the flexible one. CONCLUSIONS: Our findings indicated that OHRQoL in diabetic elderly patients was markedly improved by restoring edentulous spaces using flexible partial dentures than using heat-cured acrylic resin partial dentures.

Mechanical behavior of implant assisted removable partial denture for Kennedy class II

Background

This study evaluated the mechanical response of a removable partial denture (RPD) in Kennedy Class II according to being associated or not with implants.

Material and Methods

Four RPDs were manufactured for a Kennedy Class II: CRPD - Conventional RPD, RPD+1M, RPD+2M and RPD+12M, respectively, signifying implant assisted RPDs with the implant installed in the first molar, second molar, and in the first and second molars. The finite element method was used to determine the most damaged support tooth under compressive load (300N, 10s) and strain gauge analysis was used to evaluate the microstrain. All groups were submitted to a retentive force analysis (0.5 mm/mm, 100kgf). Microstrain and retentive force data were submitted to One-way ANOVA and the Tukey test, all with α=5%.

Results

High microstrain was observed in the second premolar adjacent to the edentulous space under compression load (p< 0.01). RPD+12M presented lower microstrain, however being similar to RPD+2M. RPD+1M presented a higher mean value of retentive force, but similar to RPD+12M. FEM showed RPD assisted by implants concentrates less stress in the periodontal ligament. The association of two implants was sufficient to decrease the stress generated in the implants. The most stressed region for the o-ring abutment was the threads, and the group with two implants showed the lowest stress concentration.

Conclusions

In cases of Kennedy Class II, the association of RPD with implants in the molar region is a favorable option for patient rehabilitation, reducing the movement of the direct retainer adjacent to the edentulous space, increasing the removal force and decreasing the stress magnitude in the periodontal ligament. Key words:Removable partial denture, Finite element analysis, Prosthetic dentistry, Implant-assisted RPD, Distal extension RPD considerations.

Evaluation of two interforaminal implants and implant-assisted removable dentures on stress distribution: an in vitro study

Objectives

In mandibular edentulism, the treatment option with a two-interforaminal implant-retained bridge and a removable partial denture is rarely evaluated in literature. The aim of this in vitro study was to evaluate the stress distribution of this treatment option by comparing it with traditional treatment options with interforaminal implants in the edentulous mandible.

Materials and Methods

Two interforaminal implants were placed in a formalin-fixed cadaver mandible, and overdentures with three different types of attachments were fabricated: (1) two ball attachments and an overdenture, (2) a Dolder bar and an overdenture, and (3) screw-retained two-implant inter-canine porcelain fused to a metal bridge and an implant-assisted removable denture (IARD) with precision attachments. Three biting conditions were generated for each denture type, and the strains were documented under vertical loading of 100 N.

Results

The calculated strain values from measured strains in all measurement sites and loading conditions for the screw-retained two-implant inter-canine porcelain fused to a metal bridge and a cast framework partial denture with precision attachments situation were lower than in the other scenarios (P<0.05).

Conclusion

Within the limitations of the present study, it can be concluded that an IARD may be a reasonable and valuable alternative to ball attachments or a bar in two interforaminal implants, especially when the patients prefer to be able to show their teeth even when they take out their removable dentures.

Patient satisfaction and preference with thermoplastic resin removable partial dentures: a randomised cross-over trial

PURPOSE

This randomised cross-over trial aimed to comparatively investigate patient preference and satisfaction with thermoplastic resin removable partial dentures (TR-RPDs) and conventional metal clasp-retained removable partial dentures (MC-RPDs).

METHODS

Twenty-eight partially dentate subjects were enrolled and randomised to receive MC-RPDs followed by TR-RPDs or vice versa (n=14, each group). The subjects were asked to score overall satisfaction and denture-related parameters 3 months after delivery of each denture. Additionally, they were asked to choose their preferred denture type at the end of the trial.

RESULTS

Of the 28 subjects, 24 (86%; mean age, 67.3 years) completed the trial. The overall satisfaction scores and ratings for oral appearance with TR-RPDs were significantly higher than those with MC-RPDs (P<0.05). Moreover, 75% (18/24) and 83% (20/24) of the subjects reported greater overall satisfaction and better oral appearance with TR-RPDs than with MC-RPDs (P<0.001, both). Scores for mucosal pain and food impaction were significantly better with TR-RPDs than with MC-RPDs (P<0.05). Relative to MC-RPDs, TR-RPDs provided slightly better oral comfort and speech, although the differences were not statistically significant (P>0.05). Scores for chewing ability, denture stability, and ease of denture cleaning were almost identical for both types of dentures.

CONCLUSIONS

These results suggest that TR-RPDs hold an advantage over MC-RPDs in terms of oral appearance and can offer greater satisfaction than MC-RPDs in partially dentate arches with at least an occluding pair in the posterior region.

CLINICAL TRIAL REGISTRATION

UMIN Clinical Trials Registry (UMIN000007310).

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.

Mini Dental Implant-Retained Removable Partial Dentures: Treatment Effect Size and 6-Months Follow-up

Objective

The aim was to compare esthetic outcomes, masticatory performance and a comfort of removable partial denture (RPD) wearing after receiving: clasp-retained RPD (C-RPD) or mini dental implant-retained RPD (MDI-RPD) in the mandible.

Materials and Methods

A sample of 88 patients (Kennedy Class I) with all posterior teeth missing and a linear support for a RPD participated. A total of 52 patients (36 females, 16 males; 56 to 84 years old) participated in the C-RPD group and 36 patients (26 females, 10 males; 43 to 81 years old) in the MDI-RPD group. All MDIs were placed adjacent to the last remaining mandibular anterior tooth or one tooth length posteriorly. The new RPDs had Co-Cr frameworks with lingual plate major connectors; the MDI-RPDs were retained by O-ball matrices and the C-RPDs with clasps. Patients answered questions at pre-treatment and post-treatment stages and after 6-months follow-up: how satisfied they had been with esthetic appearance, how confident they were while chewing hard food, how satisfied they were with food comminution and they also evaluated a comfort of RPD wearing. The 0-10 visual-analogue scale was used. Statistics included descriptive methods, t-tests and the standardized effect-size calculation.

Results

The MDI-RPD wearers were more satisfied with their post-treatment esthetics, food comminution, a comfort with RPDs and had better confidence while chewing than the C-RPD wearers. The MDI-RPD wearers reported larger positive effect of the treatment. The results were consistent throughout the first 6-months period.

Conclusion

The MDI-RPD patients showed superior outcomes than the C-RPD patients after the treatment and over the 6-month period.

Three-dimensional finite element analysis of implant-assisted removable partial dentures

STATEMENT OF PROBLEM

Whether the implant abutment in implant-assisted removable partial dentures (IARPDs) functions as a natural removable partial denture (RPD) tooth abutment is unknown.

PURPOSE

The purpose of this 3-dimensional finite element study was to analyze the biomechanical behavior of implant crown, bone, RPD, and IARPD.

MATERIAL AND METHODS

Finite element models of the partial maxilla, teeth, and prostheses were generated on the basis of a patient's computed tomographic data. The teeth, surveyed crowns, and RPDs were created in the model. With the generated components, four 3-dimensional finite element models of the partial maxilla were constructed: tooth-supported RPD (TB), implant-supported RPD (IB), tooth-tissue-supported RPD (TT), and implant-tissue-supported RPD (IT) models. Oblique loading of 300 N was applied on the crowns and denture teeth. The von Mises stress and displacement of the denture abutment tooth and implant system were identified.

RESULTS

The highest von Mises stress values of both IARPDs occurred on the implants, while those of both natural tooth RPDs occurred on the frameworks of the RPDs. The highest von Mises stress of model IT was about twice that of model IB, while the value of model TT was similar to that of model TB. The maximum displacement was greater in models TB and TT than in models IB and IT. Among the 4 models, the highest maximum displacement value was observed in the model TT and the lowest value was in the model IB.

CONCLUSIONS

Finite element analysis revealed that the stress distribution pattern of the IARPDs was different from that of the natural tooth RPDs and the stress distribution of implant-supported RPD was different from that of implant-tissue-supported RPD. When implants are used for RPD abutments, more consideration concerning the RPD design and the number or location of the implant is necessary.

Technique for transferring the path of insertion of a removable partial denture to a CAD-CAM-generated implant surgical template

A technique is described that uses a surveyor, gutta percha points, and a computer-aided design and computer-aided manufacturing (CAD-CAM)-guided implant surgery system to predetermine and transfer the ideal angulation of the implant to be placed.

Immediate versus delayed loading of strategic mini dental implants for the stabilization of partial removable dental prostheses: a patient cluster randomized, parallel-group 3-year trial

Background

Acceptable short-term survival rates (>90 %) of mini-implants (diameter < 3.0 mm) are only documented for mandibular overdentures. Sound data for mini-implants as strategic abutments for a better retention of partial removable dental prosthesis (PRDP) are not available.

Methods/design

The purpose of this study is to test the hypothesis that immediately loaded mini-implants show more bone loss and less success than strategic mini-implants with delayed loading. In this four-center (one university hospital, three dental practices in Germany), parallel-group, controlled clinical trial, which is cluster randomized on patient level, a total of 80 partially edentulous patients with unfavourable number and distribution of remaining abutment teeth in at least one jaw will receive supplementary min-implants to stabilize their PRDP. The mini-implant are either immediately loaded after implant placement (test group) or delayed after four months (control group). Follow-up of the patients will be performed for 36 months. The primary outcome is the radiographic bone level changes at implants. The secondary outcome is the implant success as a composite variable. Tertiary outcomes include clinical, subjective (quality of life, satisfaction, chewing ability) and dental or technical complications.

Discussion

Strategic implants under an existing PRDP are only documented for standard-diameter implants. Mini-implants could be a minimal invasive and low cost solution for this treatment modality.

Trial registration

The trial is registered at Deutsches Register Klinischer Studien (German register of clinical trials) under DRKS-ID: DRKS00007589 (www.germanctr.de) on January 13^th, 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-016-0259-z) contains supplementary material, which is available to authorized users.

Patients' satisfaction and maintenance of fixed partial denture

Objectives:

The aims of this study were to evaluate patient satisfaction with fixed prosthesis following placement and to assess the oral health and oral hygiene practices awareness by survey questionnaire.

Materials and Methods:

One hundred and ninety-two questionnaires were filled by patients wearing fixed prosthesis; the questionnaire included the subjective perception of treatment with fixed prosthesis, patients' perception of clinical outcome, regarding esthetics, masticatory function, speech, and together patient's attitude toward oral hygiene measures.

Results:

Results showed that 84% of the patients were satisfied with their fixed prosthesis, while only 46.4% of patients were satisfied with the chewing ability. In concern, with esthetic outcome, 80% of patients showed that they were satisfied with the esthetic. The results showed that a high significantly number of patients did not use any form of interdental aids' to clean their fixed prosthesis (94%). The main reason for not using any dental aids' (91.1%) was a lack of post fixed prosthodontics instructions and not been informed by the dentist.

Conclusion:

High percentages of patients were satisfied with their fixed prosthesis. The most important finding of this study was that majority of patients showed a lack of knowledge regarding post fixed prosthodontics instructions and the significance of maintenance of fixed prosthesis using dental aids'. Of particular concern was the majority of dentists did not pay attention to the post treatment instructions concerning the maintenance of fixed prosthesis.

Cost-effectiveness of implant-supported mandibular removable partial dentures

OBJECTIVES

The aim of this study was to conduct a cost-effectiveness analysis comparing conventional removable partial dentures (RPDs) and implant-supported RPDs (ISRPDs) treatment in patients with an edentulous maxilla and a bilateral free-ending situation in the mandible.

MATERIAL AND METHODS

Thirty subjects were included. A new RPD was made and implant support was provided 3 months later. Treatment costs (opportunity costs and costs based on tariffs) were calculated. Treatment effect was expressed by means of the Dutch Oral Health Impact Profile questionnaire (OHIP-NL49), a chewing ability test (Mixing Ability Index, MAI) and a short-form health survey measuring perceived general health (SF-36), which was subsequently converted into quality-adjusted-life-years (QALYs). The incremental cost-effectiveness ratio (ICER) was the primary outcome measure of cost-effectiveness, comparing both treatment strategies.

RESULTS

The mean total opportunity costs were €981 (95% CI €971-€991) for the RPD treatment and €2.480 (95% CI €2.461-€2.500) for the ISRPD treatment. The total costs derived from the national tariff structure were €850 for the RPD treatment and €2.610 for the ISRPD treatment. The ICER for OHIP-NL49 and MAI using the opportunity costs was €80 and €786, respectively. When using the tariff structure, corresponding ICERs were €94 and €921. The effect of supporting an RPD with implants when expressed in QALYs was negligible; hence an ICER was not determined.

CONCLUSIONS

It is concluded that depending on the choice of outcome measure and monetary threshold, supporting an RPD with implants is cost-effective when payers are willing to pay more than €80 per OHIP point gained. Per MAI point gained, an additional €786 has to be invested.