Removable Partial Dentures Group Research Articles

Survival time analysis of remaining teeth following replacement of unilateral free-end missing teeth: A comparison between fixed implant-supported prostheses and removable partial dentures.

This retrospective study aimed to investigate the differences in tooth loss rate between fixed implant-supported prostheses (FISPs) and removable partial dentures (RPDs) in cases of unilateral free-end missing teeth. The data of 324 patients who underwent treatment with FISPs or RPDs for unilateral free-end missing teeth and satisfied the applicable criteria, were evaluated (47 in the FISPs group and 277 in the RPDs group). After propensity score (PS) matching, which was used to extract patients with similar background factors related to prosthetic selection at baseline, survival time analyses were performed with tooth loss as the endpoint. The adjusted variables were age, sex, number of restored teeth, periodontal status, and the practicing dentist's experience in years. The remaining teeth were classified into subcategories in relation to the missing molars. Overall, 58 patients (29 in each group) selected by PS matching were evaluated in the final analysis. The total number of lost teeth was 35 (FISPs group: n = 10; RPDs group: n = 25). The mean (±SD) period to tooth loss and the 10-year survival rates in the FISPs and RPDs groups were 51.6 (±30.1) months and 42.3 (±29.7) months, 70.5% and 16.4%, respectively. The log-rank test showed that significantly longer survival time in FISPs compared with RPDs. After adjustments for confounding factors using PS matching, replacing unilateral free-end missing teeth with FISPs may exhibit a lower tooth loss rate in adjacent and contralateral teeth compared to replacing with RPDs.

Traditional Removable Partial Dentures versus Implant-Supported Removable Partial Dentures: A Retrospective, Observational Oral Health-Related Quality-of-Life Study

Removable partial dentures (RPD) are still a valid alternative for the restoration of missing teeth. Additionally, implant-supported removable partial dentures (ISRPD) represent a valid alternative as it allows to avoid the use of clasps and increase stability. The objective of this study was to evaluate through an OHIP-14 questionnaire the level of satisfaction and quality of life (QoL) of patients treated before RPD and then with ISRPD. Twenty patients were rehabilitated with traditional RPDs, and after one year the prosthesis was modified into ISRPD, by inserting an implant and a ball or locator attachment. At the end of both phases, patients completed the Oral Health Impact Profile (OHIP-14) questionnaire. The collected data were statistically analyzed through the Wilcoxon U test, as overall OHIP score and difference between treatments. The mean of the OHIP summary (range from 0 to 56) in the RPD Group was 20.95 (±5.27). In the ISRPD Group it was 13.95 (±3.91), with a statistically significant difference (p < 0.05) between the two Groups. The same findings were highlighted for the differences between groups in every domain question. Patients showed significant improvements after rehabilitation in all areas of investigation, stating how the transformation of a removable prosthesis into an implant-supported one can improve patients’ QoL with benefits in chewing ability, aesthetics and self-satisfaction.

Periodontal health in the shortened dental arch.

Design Multi-centre randomised controlled clinical trial with two prosthetic intervention arms conducted in 14 dental schools and universities in Germany from October 2000.Case selection Adults aged ≥35 years with bilateral missing molars, both canines and at least one premolar present on each side in one jaw were eligible for inclusion. Participants were randomly allocated to restoration of posterior teeth using a removable partial denture (RPD), or a fixed prosthesis (that is, a bridge) adhering to the concepts of the shortened dental arch (SDA) principles (no replacement posterior to the second molar). Randomisation was completed centrally using randomly permuted blocks stratified by age. Data were collected at baseline (following pre-prosthetic treatment) and patients were followed up at six months, annually for five years, eight years and ten years.Data analysis In total, 215 participants were randomised and allocated to either RPD group (n = 109) or SDA group (n = 106). Intention to treat (ITT) and modified per-protocol analysis were performed on both the RPD group (n = 79) and SDA group (n = 71). Per-protocol analysis was also undertaken on both the RPD group (n = 25) and SDA group (n = 22). The level of significance was set to a two-sided p value of 0.05. The confidence interval was set at 95%.Results When considering the differences in ten-year vertical clinical attachment loss measurements, ITT analysis showed the differences between the RPD and SDA groups were statistically significant (p ≤0.05) in both the study jaw (0.79 mm) and in all teeth (0.69 mm) in favour of the SDA group. Furthermore, the SDA group also performed more favourably in both bleeding on probing and plaque index parameters, with statistically significant changes demonstrated using positive regression coefficients.Conclusions There is evidence of reduced impact on the periodontium from an SDA approach compared to an RPD approach, although the difference is unlikely to be clinically significant.

The impacts of prosthetic interventions on mastication predominance in Kennedy Class Ⅱ patients.

Purpose The purpose of this study was to investigate the effects of prosthetic interventions in patients with Kennedy Class Ⅱ (unilateral missing posterior teeth) on mastication predominance.Methods The subjects comprised patients with Kennedy Class II and healthy dentate volunteers (HD group). The subjects were asked to freely chew the test foods (chewing gum, beef jerky, and peanuts). Electromyographic activity of the bilateral masseter muscles was recorded twice (before and after prosthetic intervention). The chewing side (right or left) was judged by the level of the root mean square electromyographic amplitude. Mastication predominance was assessed using the mastication predominance index (MPI; range 0-100%). Each patient was restored with a removable partial denture (RPD) or an implant-supported fixed prosthesis (IFP). The effects of prosthetic interventions were statistically evaluated by the differences between MPI before and after prosthetic interventions (pre-MPI and post-MPI , respectively).Results There was a significant difference between pre-MPI of patients with Kennedy Class II and MPI of the HD group (HD-MPI) for all test foods (P < 0.0001). Statistical analysis also demonstrated a significant difference between pre-MPI and post-MPI measured with each of the three food items in both the RPD and IFP groups (P < 0.0001). Multiple comparisons revealed that post-MPI in the IFP group, but not in the RPD group, was statistically comparable with HD-MPI, although there were no significant differences among the three groups when MPIs were calculated using peanuts.Conclusions Prosthetic interventions improved mastication predominance in patients with Kennedy Class Ⅱ patients. Depending on the food type, IFP might contribute to better improvement of mastication predominance than RPD depending on food.

Masticatory force and electromyographic activity of the mandibular elevators muscles in different rehabilitation treatments.

The masticatory function is one of the most complex neuropsychological mechanisms in human motor performance and it depends on several factors, such as bite force, muscle coordination, morphology, and number of teeth in occlusion. Purpose: to evaluate the influence of different rehabilitation treatments such as complete and partial dentures, masticatory forces, and the dynamics of mandibular elevator muscles. Material and Methods: the maximum bite force (force transducer) and electrical activity (superficial electromyography) associated with the masseter and temporal muscles were quantified. These factors were evaluated at rest position and isometric contraction. The data were subjected to descriptive statistics and compared based on the experimental groups, through ANOVA and Tukey’s tests. Results: for bite force, the ANOVA test showed statistical difference between groups and Tukey’s test showed that the force measured in the removable partial dentures group was 44.75% lower than that of the control group, while for complete denture wearers, there was a reduction of 74.4% in bite force in relation to the control group. For electromyographic activity, there was no statistical difference between groups. Pearson’s correlation test (?=5%) showed positive correlation between the variables of bite force and electromyographic activity only for the control group. Conclusion: it was concluded that the loss of dental elements and their replacement with either partial or complete dentures has a great influence on bite force and electromyographic activity of the masseter and temporal muscles.

Attachment versus Clasp retained Removable Partial Dentures –A Randomized Controlled Clinical Trial

Purpose: to compare two retainer designs for free end removable partial dentures (RPDs) by measuring the patient satisfaction, abutment tooth survival, bone height loss and pocket depth.Materials and Methods: Group 1: Fourteen patients receiving attachment-retained RPDs while group 2: Fourteen patients receiving clasp-retained RPDs. The assessment included patient satisfaction, survival of the terminal abutments, bone height loss and pocket depth. All patients were evaluated clinically and radiographically at the time of RPD insertion, twelve months and 24 months thereafter. Mann Whitney U test for independent samples was used for comparison of % change of patient satisfaction. Wilcoxon signed rank test for paired (matched) samples was used within group comparison of patient satisfaction before and after treatment. Survival analysis was done using Kaplan Meier statistics. For bone height, independent t-test was used and student’s t- test was used for pocket depth comparison.Results: There was a significant difference before and after treatment scores in Oral Health Impact Profile-14(OHIP-14), Orofacial Esthetic Scale (OES) and Chewing Function Questionnaire (CFQ) questionnaires in the clasp retained RPD group with P value = (0.001, 0.001 and 0.003) respectively. Regarding the attachment retained RPD group, there was a significant difference before and after treatment scores with P value = 0.001 for the three questionnaires. Within group comparison it was found that there was a significant difference in OHIP-14 (P= 0.002) and OES (P<0.001) while there was no significant difference in CFQ between both groups (P=0.191). There was no statistically significant difference between both groups in terminal abutment survival (P=0.149) and percent change of the mean probing pocket depth from baseline to 24 months (P=0.05). However, regarding the effect of time on bone height change percentage for each group, a significant difference was found between groups at baseline-twenty-four month’s interval (P-value < 0.05).Conclusion: Within the limitations of the present study, all patients have shown improvement in OHRQoL, esthetics and chewing function after treatment with RPDs with better results in the attachment retained RPD. However, regarding the terminal abutment survival, mean probing pocket depth and bone height change, clinically significant better results were revealed in clasp-retained RPD compared to attachment-retained RPDs.

An In Vitro Investigation of Accuracy and Fit of Conventional and CAD/CAM Removable Partial Denture Frameworks.

To evaluate the overall accuracy and fit of conventional versus computer-aided design/computer-aided manufactured (CAD/CAM) removable partial denture (RPD) frameworks based on standard tessellation language (STL) data analysis, and to evaluate the accuracy and fit of each component of the RPD framework. A maxillary metal framework was designed for a Kennedy class III Modification I arch. The master model was scanned and used to compare the fit and accuracy of RPD frameworks. Forty impressions (conventional and digital) of the master cast were made and divided into 4 groups based on fabrication method: group I, lost-wax technique (conventional technique), group II, CAD-printing, group III, CAD-printing from stone cast, and group IV, lost-wax technique from resin-printed model. RPD frameworks were fabricated in cobalt-chromium alloy. All frameworks were scanned, and the gap distance between the framework and scanned master model was measured at 8 locations. Color mapping was conducted using comprehensive metrology software. Data were statistically analyzed using the Kruskall-Wallis test, followed by the Bonferroni method for pairwise comparisons (α = 0.05). Color mapping revealed distinct discrepancies in major connectors among the groups. When compared to 3D-printed frameworks, conventional cast frameworks fabricated using dental stone or printed resin models revealed significantly better fit (p < 0.05) particularly in the major connectors and guide plates. The biggest gap (0.33mm ± 0.20 mm) was observed with the anterior strap of the major connector with the printed frameworks (groups II and III). The method of fabrication did not affect the adaptation of the rests or reciprocation plates. Although both conventional and 3D-printing methods of framework fabrication revealed clinically acceptable adaptation, the conventional cast RPD groups revealed better overall fit and accuracy.

Impact of oral rehabilitation on the quality of life of partially dentate elders in a randomised controlled clinical trial: 2 year follow-up.

ObjectiveThis randomised clinical trial aimed to compare the impact of two different tooth replacement strategies for partially dentate older patients namely; removable partial dentures (RPDs) and functionally orientated treatment based on the shortened dental arch (SDA) concept, on Oral Health-related Quality of Life (OHrQOL).Methods89 patients completed a randomised clinical trial. Patients were recruited in two centres: Cork University Dental Hospital (CUDH) and a Geriatric Day Hospital (SFDH). 44 patients were randomly allocated to the RPD group and 45 to the SDA group where adhesive bridgework was used to provide 10 pairs of occluding contacts. The impact of treatment on OHrQOL was used as the primary outcome measure. Each patient completed the Oral Health Impact Profile (OHIP-14) at baseline, 1, 6, 12 and 24 months after treatment.ResultsBoth treatment groups reported improvements in OHIP-14 scores at 24 months (p<0.05). For the SDA group OHIP-14 scores improved by 8.0 scale points at 12 months (p<0.001) and 5.9 scale points at 24 months (p<0.05). For the RPD group OHIP-14 scores improved by 5.7 scale points at 12 months (p<0.05) and 4.2 scale points at 24 months (p<0.05). Analysis using ANCOVA showed that there were significant between group differences recorded in both treatment centres. 24 months after intervention the SDA group recorded better OHIP-14 scores by an average of 2.9 points in CUDH (p<0.0001) and by an average of 7.9 points in SFDH (p<0.0001) compared to the RPD group.ConclusionsPatients in the SDA group maintained their improvements in OHrQOL scores throughout the 24 month study period. For the RPD group the initial improvement in OHrQOL score began to diminish after 6 months, particularly for those treated in SFDH. Thus, the benefits of functionally orientated treatment increased over time, particularly for the older, more systemically unwell cohort in SFDH.

Evaluation of Different Removable Denture Materials in Kennedy Class I Partially Edentulous Situation Mostafa Abosrie(1), Maged El saadawy (2) and Mohamed Aboshama(3) Codex

BACKGROUND: Although Cast Chromium Cobalt alloy has been the material of choice for fabricating Removable Partial Dentures (RPDs) but it has certain drawbacks. New material like the flexible Nylon based Super Polyamide has been introduced to overcome these drawbacks. The present study compared the above two materials for three clinical parameters. MATERIALS AND METHODS: The study was carried out on 15 patients, the selected cases were Kennedy Class I, with missing teeth first, second and third molars in each distal extension side. These fifteen patients received three RPDs; each one was used for six months. Three types of RPDs were made from different base materials; cobalt chromium alloy and thermoplastic denture base materials, (Group A): RPDs made of cast Cr-Co alloy incorporating RPI clasping system with denture base made of heat cured acrylic resin. (Group B): RPDs made of flexible nylon based super polyamide resin incorporating flexible circumferential clasps and denture bases made of flexible nylon, with metal occlusal rests. (Group C): RPDs made of flexible nylon based super polyamide resin. After insertion of each denture, their Clinical performances were evaluated periodically for six months for the following parameters (Gingival index, plaque index and pocket depth). RESULTS: Statistically significant results were obtained in favor of flexible RPDs, in the parameters of (Gingival index, plaque index and pocket depth).Both groups B and C showed less similar values for (Gingival index, plaque index and pocket depth). during usage’ with the incidence being slightly higher for patients wearing the cast RPDs (Group A). CONCLUSION: Based on the favorable results of this study, it can be summarized that the flexible RPDs is a viable alternative to cast RPDs in Kennedy class I partially edentulous situation in the short term.

Patient‐based outcome measures of mandibular implant assisted removable partial dentures in Kennedy Class I patients‐ A systematic review and meta‐analysis

Background Distal-extension removable partial dentures (RPDs) were associated with several problems related to its limited stability, retention, and masticatory efficiency. The placement of a distal implant associated with a RPD has been reported to make this rehabilitation more stable. It has been suggested that it may overcome some of the common problems. However, no reports have proved the superiority of one treatment option over the other, especially in terms of patient-centric outcome measures. Aim/Hypothesis The purpose of this systematic review was to evaluate the evidence supporting the placement of a distal implant associated with a RPD to improve patient-based treatment outcome by meta-analysis. Material and Methods We used multiple comprehensive databases to find literature. This study is based on the Cochrane Review Methods. The focus question is “ Are implant assisted removable partial dentures (ISRPD) superior to conventional removable partial denture (CRPD) on mandibular Kennedy class I partial edentulous patients in terms of patient-reported outcome measures (patient quality of life and patient satisfaction) (PROMs)?” We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and Scopus in May 2017. The inclusion of all studies was independently decided by two reviewers (J.P. and H.K.) based on the selection criteria. The following studies were included in our meta-analysis – (1) Clinical studies (before and after study) of ISRPD reporting a comparison of patient-reported outcome measures, (2) patient with mandibular Kennedy class I PRDPs, and (3) articles to allow mining of quantitative data. Results In total, 5603 non-duplicate articles were identified from database searches. Of which 29 were eligible for full-text searching. The 24 articles that did not meet the inclusion criteria were excluded. Therefore a total of five studies were used for meta-analysis, including 4 studies reporting VAS and 2 studies reporting OHIP. As a result, general patient satisfaction (VAS) and the total OHIP index showed better results in ISRPD compared to conventional RPD. As for the detailed items, there were no statistical differences for esthetics and cleaning, but patient satisfaction was improved in comfort, chewing, and speaking. There was also a significant statistical improvement in the quality of life in terms of physical pain and physical disability. Conclusions and Clinical Implications The implant assisted removable partial dentures group performed better in regards to patient satisfaction as measured using the VAS and OHIP questionnaire. Further studies are required to identify superiority between the two treatment options. Acknowledgement This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number – HI17C2218).

Comparison of Treatment Outcomes in Partially Edentulous Patients with Implant-Supported Fixed Prostheses and Removable Partial Dentures

The aim of this study was to compare masticatory performance, occlusal force, and oral health-related quality of life (OHRQoL) in patients with mandibular distal-extension edentulism between those with implant-supported fixed prostheses (ISFPs) and those with removable partial dentures (RPDs), and to evaluate relationships among them. Subjects were recruited from patients using ISFPs or RPDs for mandibular distal-extension edentulism. Masticatory performance was evaluated based on the glucose extracted from chewed gummy jelly. Occlusal force was measured with a pressure-sensitive sheet, and data were subjected to computer analysis. The Japanese version of the Oral Health Impact Profile (OHIP-J) was used to evaluate OHRQoL. The masticatory performance, occlusal force, and OHIP-J scores of the ISFP and RPD groups were compared using the Wilcoxon rank-sum test. The relationships among the variables were analyzed using the Spearman rank correlation coefficient test. Multivariate logistic regression analysis was employed with the OHIP-J score as a dependent variable. Nineteen patients with ISFPs and 25 patients with RPDs participated in this study. No significant difference was observed between the two groups with regard to masticatory performance and occlusal force. The OHIP-J score was significantly lower in the ISFP group than in the RPD group. The OHIP-J score had no significant correlation with masticatory performance, but was significantly correlated with occlusal force and the prosthetic method. Multivariate logistic regression analysis showed that younger age, RPDs, and lower occlusal force were significantly associated with a higher OHIP-J summary score. The present results suggest that the difference in masticatory performance and occlusal force between ISFPs and RPDs is small, but ISFPs are superior to RPDs with regard to OHRQoL in patients with mandibular distal-extension edentulism. In addition, there appears to be a slight correlation between the OHIP-J and occlusal force in these patients.

Assessment of Various Nutritional Parameters in Geriatric Patients Who underwent Different Prosthodontic Treatments.

Some relation exists between oral and general health with progressive aging. Certain risk factors are common between oral and systemic diseases. Absence of teeth also affects the oral health by altering the quality of life. Hence, the nutritional changes occurring in elderly patients following prosthodontic rehabilitation are evaluated. A total of 250 patients who underwent prosthodontic treatment for missing teeth were included for the study. Twice measurement of nutritional parameters was done: Initially at the time of diagnosis and then 5 months following commencement of the prosthodontic treatment. Dental analysis, evaluation of the diet, anthropometric assessment, and analysis of serum biochemical values were done in all the patients and tabulated records were maintained. Independent Student's t test and Tukey's test were done to assess the level of significance. A total of 250 patients were included for the study. The complete denture (CD) group showed the highest alteration in the mean values of the nutritional parameters followed by the removable partial denture group. A significant change was seen in the body mass index, protein, carbohydrate, and iron levels among the different patients who were grouped based on the mode of treatment modality. The CD group showed significantly higher mean change in carbohydrates value compared with mean change in patients receiving fixed treatment. Both nutrition and diet form an integral part of the prosthodontic treatment to maintain the health of elderly population. With the advancement in the level of edentulism, rehabilitation by prosthetic treatment has become progressively important to restore and improve dietary parameters.

Impact of Different Prosthodontic Treatment Modalities on Nutritional Parameters of Elderly Patients.

To assess dietary and nutritional changes among the elderly following pros-thodontic rehabilitation. Another objective was to study the relationship, if any, between diet and nutrition, with extent of edentulism and different types of prosthodontic treatment. One hundred and thirty-five patients who satisfied the inclu-sion and exclusion criteria and agreed to be a part of the study after informed consent were recruited to this longitudinal study. Following selection, they were investigated on four aspects: dental examination, dietary assessment, anthropometric assessment, and serum biochemical assessment. All measurements were collected twice, first at baseline and then 6 months following prosthodontic rehabilitation. Treatment modalities included were complete denture (CD), removable partial denture (RPD), and fixed partial denture (FPD). The RPD group was of two types: distal extension prosthesis (RPDD) and tooth-supported prosthesis (RPDT). Change (post-pre) in outcome measures was compared by one-way ANOVA, and significance of mean difference between the groups was done by Tukey's honestly significance difference post hoc test. The improvement in diet was found to be: CD > RPDD > RPDT > FPD. Significant improvement in weight (p < 0.001), BMI (p < 0.001), protein (p < 0.001), carbohydrate (p = 0.021), calorie (p < 0.001), iron (p = 0.002), and vitamin B (p < 0.001) in group CD as compared to partially edentulous patients (group RPDD + RPDT + FPD) was noted. The protein and calorie intake increased significantly in group RPD as compared to group FPD in partially edentulous patients. Prosthetic rehabilitation becomes increasingly important as the level of edentulism increases to improve dietary, anthropometric, and biochemical parameters.

The impact of rehabilitation using removable partial dentures and functionally orientated treatment on oral health-related quality of life: A randomised controlled clinical trial

ObjectivesThis study aimed to compare two different tooth replacement strategies for partially dentate older patients; namely functionally orientated treatment according to the principles of the shortened dental arch (SDA) and conventional treatment using removable partial dentures (RPDs) using a randomised controlled clinical trial. The primary outcome measure for this study was impact on oral health-related quality of life (OHRQoL) measured using the short form of the oral health impact profile (OHIP-14). MethodsPatients aged 65 years and older were randomly allocated to two different treatment groups: the RPD group and the SDA group. For the RPD group each patient was restored to complete arches with cobalt–chromium RPDs used to replace missing teeth. For the SDA group, patients were restored to a premolar occlusion of 10 occluding pairs of natural and replacement teeth using resin bonded bridgework (RBB). OHRQoL was measured using the OHIP-14 questionnaire administered at baseline, 1 month, 6 months and 12 months after treatment intervention. ResultsIn total, 89 patients completed the RCT: 44 from the RPD group and 45 from the SDA group. Analysis using a mixed model of covariance (ANCOVA) illustrated that treatment according to the SDA concept resulted in significantly better mean OHIP-14 scores compared with RPD treatment (p<0.05). This result was replicated in both treatment centres used in the study. ConclusionsIn terms of impact on OHRQoL, treatment based on the SDA concept achieved significantly better results than that based on RPDs 12 months after treatment intervention (trial registration no. ISRCTN26302774). Clinical significanceFunctionally orientated treatment delivery resulted in significantly better outcomes compared to removable dentures in terms of impact on OHRQoL.

A Study of Patient Satisfaction with Maxillary Anterior Teeth Restorations and Desirable Esthetic Treatment Options

Method:650 patients participated in the study , divided into 4 age groups. A structured, interviewer- guided questionnaire was used to identify patient satisfaction with their general dental appearance, cosmetic elements and desired treatments .Their maxillary anterior teeth status was classified into 4 groups: (1) Composite filling group (CFG) (2) Porcelain jacket crown group (PJCG) (3) Fixed partial denture group (FPDG) (4) Removable partial denture group (RPDG). The participants judged appearance and tooth colour using 3-point scale: dissatisfied, moderately dissatisfied and satisfied. Their desired esthetic treatment options were assessed. Results: The overall rating of satisfaction was moderate; almost 39.5% patients were completely satisfied with their dental appearance and tooth colour. A significant difference was observed for both the dental appearance and the tooth colour between different maxillary anterior teeth status groups and between different age groups (p < 0.05) .The majority of individuals with CFG and FPDG were completely satisfied, while those with PJCG and RPDG were dissatisfied with their dental appearance and tooth colour (p < 0.05). 50.9% patients wished to have their teeth whitened. Conclusion: Aesthetic attitudes towards the maxillary anterior teeth appearance and colour differed both between different age groups and different maxillary anterior teeth status groups. Dissatisfaction with tooth color,protruding teeth and unesthetic fillings were common and females were more dissatisfied than males in appearance.Tooth whitening was the most desired treatment to improve the esthetics.

Effect of complete and partial removable dentures on chewing movements

Partial or complete edentulism impairs mastication. However, it is unclear how the chewing cycle is affected by prosthetics. We evaluated the chewing movements of patients fitted with complete (CD) or removable partial denture (RPD). A total of 29 subjects were kinesiographically evaluated during chewing of peanuts and Optocal portions in a random sequence. The subjects were divided into two groups according to prosthesis type. Group RPD was composed of 14 partially edentulous patients using a lower distal extension RPD (mean age 61±8years), and group CD contained 15 completely edentulous patients using CD (mean age 65·9±7·9years) in both jaws. Opening, closing, occlusal and masticatory cycle times, movement angle (opening and closing), maximum velocity (opening and closing), total area and chewing cycle amplitudes were evaluated. The results were subjected to anova and Tukey's HSD test at a significance level of 5%. The RPD group exhibited shorter opening and closing phases and masticatory cycle time (P<0·05). Maximum velocities were also higher in the RPD group, irrespective of the test material (P<0·05). The area and amplitude of the chewing envelope was smaller in the CD group (P<0·0001). The test material did not influence chewing cycles in any of the parameters evaluated (P>0·05). RPD wearers use a faster chewing sequence with greater vertical and lateral jaw excursions compared with CD wearers.

Retrospective investigation of the remaining teeth status of patients with implant-supported fixed partial dentures in unilateral free-end edentulism

PurposeThis study aimed to compare the various complication-free rates and survival rates of remaining teeth among implant-supported fixed dentures (IFDs), removable partial dentures (RPDs) and no-restoration (NR) patients with unilateral free-end edentulism. Material and methodsThe study subjects were selected among those who received prosthodontic treatment at Okayama University Dental Hospital for their unilateral free-end edentulism (2 or 3 missing teeth). Thirty-three patients were included in the IFD group, 41 matched patients in the RPD group, and 10 patients who received RPDs but refused their use were regarded as NR group. The remaining dentition was classified into five subcategories in relation to the missing portion: adjacent teeth to the missing portion (AD), contralateral posterior dentition in the same jaw (CS) and in the opposite jaw (CO), ipsilateral opposing posterior dentition (IO), and anterior dentition (AN). Complications were defined as tooth extraction, periodontal lesions, periapical lesions or loss of retention of the prosthesis and were assessed by one examiner based on the hospital chart records. ResultsThe cumulative complication-free rates in the remaining teeth were significantly different among each of the three groups (p<0.01), with a significantly lower incidence rate in the IFD group. Regarding the cumulative survival rate of the remaining teeth, there was a significant difference only between IFD and NR group (p=0.01), especially in the CO region (p=0.04). ConclusionsStable posterior occlusal support obtained with IFD treatment for unilateral free-end edentulism may reduce the incidence of complications in the remaining teeth, by decreasing the adverse mechanical stress.

A retrospective comparative ten-year study of cumulative survival rates of remaining teeth in large edentulism treated with implant-supported fixed partial dentures or removable partial dentures

PurposeThis study aimed to compare the survival rates of remaining teeth between implant-supported fixed dentures (IFDs) and removable partial dentures (RPDs) in patients with large edentulous cases. The second goal was to assess the risk factors for remaining tooth loss. Materials and methodsThe study subjects were selected among those who received prosthodontic treatment at Okayama University Dental Hospital for their edentulous space exceeding at least four continuous missing teeth. Twenty-one patients were included in the IFD group and 82 patients were included in the RPD group. Survival rates of remaining teeth were calculated in three subcategories: (1) whole remaining teeth, (2) adjacent teeth to intended edentulous space, and (3) opposing teeth to intended edentulous space. ResultsThe ten-year cumulative survival rate of the whole remaining teeth was significantly higher in the IFD group (40.0%) than in the RPD group (24.4%). On the other hand, there was no significant difference between two groups in the survival rate of teeth adjacent or opposing to intended edentulous space. A Cox proportional hazard analysis revealed that RPD restoration and gender (male) were the significant risk factors for remaining tooth loss (whole remaining teeth). ConclusionsThese results suggest that IFD treatment can reduce the incidence of remaining tooth loss in large edentulous cases.

Does the Presence of Anterior Mandibular Teeth Increase the Incidence of Denture Stomatitis?

To compare the frequency of denture stomatitis (DS) under maxillary complete dentures (CDs) in patients with opposing mandibular distal extension removable partial dentures (RPDs) and CDs. Participants included 365 maxillary CD wearers (241 women, mean age 70.5 ± 13.2 years; 124 men, mean age 71.5 ± 10.4 years) from 7 rest homes in Istanbul. A total of 268 had mandibular CDs; 97 had mandibular distal extension RPDs. Two independent, calibrated examiners performed oral examinations. Presence of maxillary denture-related stomatitis and the effect of risk factors on DS were evaluated and recorded. The frequency of palatal DS (Newton I-III) was 45.1% (n = 121) in the mandibular CD group and 49.5% (n = 48) in the mandibular distal extension RPD group, a statistically insignificant difference (p= 0.4). Factors significantly associated with palatal DS were maxillary denture age (p= 0.02), reduced occlusal vertical dimension (p= 0.04), and nocturnal denture wear (p= 0.03). In this study, DS beneath maxillary CDs did not differ between mandibular distal extension RPD and CD wearers. The presence of mandibular anterior teeth did not influence the occurrence of palatal DS.

Location of main occluding areas and masticatory ability in patients with implant‐supported prostheses

The purpose of this study was to locate the main occluding area when the reduced posterior occlusal support was treated with an implant-supported prosthesis and to evaluate the subsequent improvement in the masticatory ability as compared with removable partial dentures. Twenty-six patients with implant prostheses and 24 patients with removable partial dentures were recruited for this study. All patients had partially lost their posterior occlusal support. The first molar region in any quadrant was always included in the prosthetic region. Each subject was instructed to clench a piece of temporary stopping as a test food on the occluding area that was preferably used during mastication. The main occluding area was judged by locating the tooth on which the temporary stopping rested during clenching. Subjective masticatory ability was self-assessed by means of a questionnaire. The main occluding area of the subjects in the implant group was located more posterior compared with the removable partial denture group. The level of masticatory ability in the implant group was the same as that in the control group. The location of the main occluding area and the masticatory ability of the subjects with implants were equivalent to those with healthy natural dentition.