Biomechanics in Removable Partial Dentures: A Literature Review of FEA-Based Studies.

The present study was aimed at reviewing the studies that used finite element analysis (FEA) to estimate the biomechanical stress arising in removable partial dentures (RPDs) and how to optimize it. A literature survey was conducted for the English full-text articles, which used only FEA to estimate the stress developed in RPDs from Jan 2000 to May 2021. In RPDs, the retaining and supporting structures are subjected to dynamic loads during insertion and removal of the prosthesis as well as during function. The majority of stresses in free-end saddle (FES) RPDs are concentrated in the shoulder of the clasp, the horizontal curvature of the gingival approaching clasp, and the part of the major connector next to terminal abutments. Clasps fabricated from flexible materials were beneficial to eliminate the stress in the abutment, while rigid materials were preferred for major connectors to eliminate the displacement of the prosthesis. In implant-assisted RPD, the implant receive the majority of the load, thereby reducing the stress on the abutment and reducing the displacement of the prosthesis. The amount of stress in the implant decreases with zero or minimal angulation, using long and wide implants, and when the implants are placed in the first molar area.

[A preliminary study on the forming quality of titanium alloy removable partial denture frameworks fabricated by selective laser melting].

Objective: To evaluate the processing accuracy, internal quality and suitability of the titanium alloy frameworks of removable partial denture (RPD) fabricated by selective laser melting (SLM) technique, and to provide reference for clinical application. Methods: The plaster model of one clinical patient was used as the working model, and was scanned and reconstructed into a digital working model. A RPD framework was designed on it. Then, eight corresponding RPD frameworks were fabricated using SLM technique. Three-dimensional (3D) optical scanner was used to scan and obtain the 3D data of the frameworks and the data was compared with the original computer aided design (CAD) model to evaluate their processing precision. The traditional casting pure titanium frameworks was used as the control group, and the internal quality was analyzed by X-ray examination. Finally, the fitness of the frameworks was examined on the plaster model. Results: The overall average deviation of the titanium alloy RPD framework fabricated by SLM technology was (0.089±0.076) mm, the root mean square error was 0.103 mm. No visible pores, cracks and other internal defects was detected in the frameworks. The framework fits on the plaster model completely, and its tissue surface fitted on the plaster model well. There was no obvious movement. Conclusions: The titanium alloy RPD framework fabricated by SLM technology is of good quality.

Clinical Practice Guidelines for Recall and Maintenance of Patients with Tooth-Borne and Implant-Borne Dental Restorations.

PURPOSE: To provide guidelines for patient recall regimen, professional maintenance regimen, and at-home maintenance regimen for patients with tooth- and implant-borne removable and fixed restorations. METHODS: The American College of Prosthodontists (ACP) convened a scientific panel of experts appointed by the ACP, American Dental Association (ADA), Academy of General Dentistry (AGD), and American Dental Hygienists Association (ADHA) who critically evaluated and debated recently published findings from 2 systematic reviews on this topic. The major outcomes and consequences considered during formulation of the clinical practice guidelines (CPGs) were risk for failure of tooth- and implant-borne restorations. The panel conducted a round table discussion of the proposed guidelines, which were debated in detail. Feedback was used to supplement and refine the proposed guidelines, and consensus was attained. RESULTS: A set of CPGs was developed for tooth-borne restorations and implant-borne restorations. Each CPG comprised of 1) patient recall; 2) professional maintenance, and 3) at-home maintenance. For tooth-borne restorations, the professional maintenance and at-home maintenance CPGs were subdivided for removable and fixed restorations. For implant-borne restorations, the professional maintenance CPGs were subdivided for removable and fixed restorations and further divided into biological maintenance and mechanical maintenance for each type of restoration. The at-home maintenance CPGs were subdivided for removable and fixed restorations. CONCLUSION: The clinical practice guidelines presented in this document were initially developed using the 2 systematic reviews. Additional guidelines were developed using expert opinion and consensus, which included discussion of the best clinical practices, clinical feasibility and risk-benefit ratio to the patient. To the authors' knowledge, these are the first CPGs addressing patient recall regimen, professional maintenance regimen, and at-home maintenance regimen for patients with tooth-borne and implant-borne restorations. This document serves as a baseline with the expectation of future modifications when additional evidence becomes available.

Credibility and Confidence in Your Dental Laboratory Work-How Quality Assurance Systems Can Be Used in the Manufacturing of Individual Custom-Made Dental Devices.

Manufacturing of custom-made dental devices such as removable dentures, fixed prosthodontics and orthodontics are subject to the requirements of the Medical Devices Directive (MDD). Many dental laboratories often enhance these requirements by implementing quality assurance procedures that then provide enhanced consistency. This paper provided a personal view of some of the systems currently being used in dental laboratories to provide a quality assured product and associated issues.

Electronic laboratory quality assurance program: A method of enhancing the prosthodontic curriculum and addressing accreditation standards.

STATEMENT OF PROBLEM: An electronic quality assurance (eQA) program was developed to replace a paper-based system and to address standards introduced by the Commission on Dental Accreditation (CODA) and to improve educational outcomes. This eQA program provides feedback to predoctoral dental students on prosthodontic laboratory steps at New York University College of Dentistry. PURPOSE: The purpose of this study was to compare the eQA program of performing laboratory quality assurance with the former paper-based format. MATERIAL AND METHODS: Fourth-year predoctoral dental students (n=334) who experienced both the paper-based and the electronic version of the quality assurance program were surveyed about their experiences. Additionally, data extracted from the eQA program were analyzed to identify areas of weakness in the curriculum. RESULTS: The study findings revealed that 73.8% of the students preferred the eQA program to the paper-based version. The average number of treatments that did not pass quality assurance standards was 119.5 per month. This indicated a 6.34% laboratory failure rate. Further analysis of these data revealed that 62.1% of the errors were related to fixed prosthodontic treatment, 27.9% to partial removable dental prostheses, and 10% to complete removable dental prostheses in the first 18 months of program implementation. CONCLUSIONS: The eQA program was favored by dental students who have experienced both electronic and paper-based versions of the system. Error type analysis can yield the ability to create customized faculty standardization sessions and refine the didactic and clinical teaching of the predoctoral students. This program was also able to link patient care activity with the student's laboratory activities, thus addressing the latest requirements of the CODA regarding the competence of graduates in evaluating laboratory work related to their patient care.

Connection of functional quality of partial removable dentures and the degree of patients' phonetic adaptation.

INTRODUCTION: Phonetic adaptation is a complex biological phenomenon with a highly individual course, depending on the patient's motivation to use prosthesis, on the functional quality of removable dentures. The aim of the study was to estimate phonetic adaptation in patients with partial dentures, connecting it to alteration in speech quality and dentures functional value. MATERIALS AND METHODS: We examined some peculiarities of phonetic adaptation in 50 patients with removable dentures (50 patients with natural dentition were invited for the control group). The standardized evaluation protocols (12 speech quality determining parameters) were developed separately for Latvian and Russian native speakers. 500 speech video samples were recorded and analysed according to pre-established guidelines. The connection of speech quality and the functional quality of the dentures was assessed. Statistical analysis was performed using SPSS 20.0. P values equal to or less than 0.05 were considered to be statistically significant. RESULTS: In patients with appropriate functional quality of removable dentures distorted speech production was detected in 25% (pk=0.008) cases and in patients with inappropriate functional quality of the prosthesis - in 40% (pk<0.001). Patients with appropriate dentures functional value were satisfied with their speech performance in 96% (pk=0.674), in the group with inappropriate dentures functional value only 59% (p<0.001) rated their speech quality positively. CONCLUSION: Phonetic adaptation to removable dentures depends on the patient's individual adaptation capacity, prosthetic design and functional value. Thus statistically significant correlation between removable partial dentures functional value, duration of usage and the degree of patients' phonetic adaptation (p<0.001) may be considered to be confirmed.

[Removable prosthesis insertion steps: controls-qualifications]. / Les étapes de i'insertion d'une prothèse amovible: contrôles-qualités.

Support a prosthetic edentulous patient aims to optimize the rudimentary functions of mastication and phonation. Knowing the routine procedures in dentistry is needed. These prostheses can be a source of criticism in terms of the quality of life they provide. Chronologically, several steps must be followed when delivered: Reception at the dental office of the prosthesis, with its technical specifications, Meticulous checks prosthetic surfaces, Introduction in the oral cavity of dentures smoothly, The stability of the prosthesis is tested initially, Second occlusion is checked, The esthetic of the prosthesis previously endorsed in the fittings, is popular again, Phonetic tests are performed to help verify the positioning of the teeth in relation to the lips, Tests for judging the ability to swallow, to incise and biting at the posterior teeth are made by the patient, Check alignment of mounting the entire face, Follow the recommendations for proper use of the prosthesis. The complementarily of these steps determines the integration of the prosthesis, but the patient must be informed early in the treatment of functional and aesthetic limits of its future prosthesis.

The Burdens in Prosthetic Dentistry Questionnaire (BiPD-Q): development and validation of a patient-based measure for process-related quality of care in prosthetic dentistry.

PURPOSE: To develop and validate an instrument for the assessment of patient-based measures of process-related quality of care in prosthodontic patients. MATERIALS AND METHODS: In this nonrandomized study, the new Burdens in Prosthetic Dentistry Questionnaire (BiPD-Q) was developed in two steps using a total of 128 prosthodontic patients in a mixed-method approach, combining quantitative-qualitative methodologies. First, the item pool for the instrument was created using semistructured interviews and a group of experts in prosthodontics. This resulted in a preliminary version of the questionnaire. Second, an assessment of redundancy, completion rates, face validity, difficulty, and distribution of the core set of the items was performed. The final version of the BiPD-Q had psychometric core properties (reliability and validity) evaluated. RESULTS: The BiPD-Q consisted of 25 items. Reliability was satisfactory (Cronbach's alpha = .87). The mean score of all items of the BiPD-Q was significantly correlated with mean perceived burdens during treatment as rated by the clinician (r = 0.26; P < .01) and with overall satisfaction with the treatment procedures as rated by patients (r = .31; P < .01), indicating sufficient convergent validity. CONCLUSION: A reliable and valid instrument for the assessment of patient-based process-related quality of care in prosthodontics has been developed. The BiPD-Q allows comparisons of different dental procedures within a treatment course and of different treatment providers. The use of this type of questionnaire appears to be a valuable tool for dental health care research. The outcomes of research using the BiPD-Q may result in a more pleasant treatment experience for future patients.

The quality of removable prostheses in dentate, community-dwelling elderly residing in Puerto Rico.

PURPOSE: Edentulism has been decreasing in the US elderly population; however, due to the increasing number of elderly, the need for prostheses has been projected to rise over the next several decades. One of the aims of the Puerto Rican Elderly Dental Health Study (PREDHS) was to assess the quality of removable prostheses (RP) in the Puerto Rican (PR) elderly (>69 years of age) population. METHODS: A cross-sectional design, using a subgroup from the Puerto Rican Elderly: Health Conditions (PREHCO) study of dentate, community-dwelling older adults from the greater San Juan area was employed. Eligible participants were administered structured questionnaires and examined in their homes by three trained and calibrated dentists using National Institute of Dental and Craniofacial Research (NIDCR) criteria. RESULTS: One hundred and eighty three (183) participants were examined (61 males, 122 females) (p < 0.001). Overall, 64% were found to have a prosthetic problem with no statistical difference between genders. Unadjusted and age-adjusted logistic models were employed. Increasing age was associated with both upper and lower clinically defined abraded prostheses, (p = 0.007; p = 0.041, respectively). Maxillary (23%) and mandibular (27%) prostheses needed replacement due to deficiencies. CONCLUSION: RP deficiencies were found in almost two-thirds of a representative sample of dentate 70+ year-old people residing in PR. There was no difference in the proportion of deficiencies between elderly who reported a dental visit in the preceding year or not having seen a dentist. A quarter of the prostheses required replacement. The findings from this and the NHANES studies demonstrate that an engaged and recognized prosthodontic dental school faculty continues to be as important now as it was a generation ago.

Mandibular implant-supported removable partial denture with distal extension: a systematic review.

The aim of this article is to investigate patient satisfaction, survival rate of implants, and prosthetic complications or maintenance for rehabilitation with removable partial dentures associated with implants in mandibular Kennedy class I and II cases. A systematic literature review was conducted by three independent reviewers including articles published from January 1981 through September 2011. Medline and Cochrane Library electronic databases were used in addition to hand searching to assess clinical outcomes for mandibular implant-supported removable partial denture with distal extension. This review yielded 1751 records that were narrowed down to 5. The studies revealed implant survival rates ranging from 95% to 100% with one failure reported of 98 implants. The removable partial dentures associated with implant in mandibular free-end arches showed some complications and need of repair for relining, pitting of the healing abutment, replacement of resilient component of the attachment, damage in framework, screw loosening and damage in acrylic denture base. Patient satisfaction was evaluated through a five-point questionnaire, and results ranged between 4.12 and 5.0, considering 1 as the least favourable situation. The literature review showed increase in patient satisfaction and high survival rates of implants associated with mandibular removable partial dentures with distal extensions. However, some complications and need of prosthetic repair were reported. Although this treatment approach could represent a low-cost and beneficial rehabilitation for free-end mandibular ridges, the lack of controlled and randomised well-designed clinical trials suggests further studies with more representative samples to validate the outcomes of this treatment modality.

Interventions for replacing missing teeth: partially absent dentition.

BACKGROUND: Management of individuals presenting with partial loss of teeth is a common task for dentists. Outcomes important to the management of missing teeth in the partially absent dentition should be systematically summarized. This review recognizes both the challenges associated with such a summarization and the critical nature of the information for patients. OBJECTIVES: To assess the effects of different prostheses for the treatment of partially absent dentition in terms of the following outcomes: long-term success, function, morbidity and patient satisfaction. SEARCH METHODS: We searched the Cochrane Oral Health Group's Trials Register (to 21 March 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 1), MEDLINE via OVID (1950 to March 2011) and EMBASE via OVID (1980 to March 2011). There were no restrictions regarding language or date of publication. We contacted several authors to identify non-published trials. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing different methods (including the design and materials used) of treating partial edentulism, with clinically relevant outcomes, were included in this review. Trials reporting only surrogate outcomes, such as plaque accumulation or gingival volume, were excluded from this review. DATA COLLECTION AND ANALYSIS: Two review authors independently carried out the screening of eligible studies, assessment of dimensions of quality of trials, and data extraction. Results were expressed as mean differences for continuous data, risk ratios for dichotomous outcomes, and hazard ratios with 95% confidence intervals for time-to-event data. MAIN RESULTS: Twenty-one trials met the inclusion criteria for this review. Twenty-four per cent of these were assessed as being at high risk of bias and the remainder were at unclear risk of bias. The clinical heterogeneity among the included studies precluded any attempt at meta-analysis. There was insufficient evidence to determine whether one type of removable dental prosthesis (RDP) was better or worse than another. With fixed dental prostheses (FDPs), there was no evidence that high gold alloys are better or worse than other alloys, nor that gold alloys or frameworks are better or worse than titanium. There is insufficient evidence to determine whether zirconia is better or worse that other FDP materials, that ceramic abutments are better or worse than titanium, or that one cement was better or worse than another in retaining FDPs. There is insufficient evidence to determine the relative effectiveness of FDPs and RDPs in patients with shortened dental arch or to determine the relative advantages of implant supported FDPs versus tooth/implant supported FDPs. AUTHORS' CONCLUSIONS: Based on trials meeting the inclusion criteria for this review, there is insufficient evidence to recommend a particular method of tooth replacement for partially edentulous patients.

Survey of partial removable dental prosthesis (partial RDP) types in a distinct patient population.

STATEMENT OF PROBLEM: Current demographic information on the number and types of removable partial dentures is lacking in the prosthodontic literature. PURPOSE: This study was designed to investigate patterns of tooth loss in patients receiving removable partial dentures (RPDs) in eastern Wisconsin. MATERIAL AND METHODS: Digital images (1502) of casts at 5 dental laboratories in eastern Wisconsin were collected. Any prescription requesting fabrication of a removable partial denture was photographed twice. The first photograph was made immediately upon arrival at the laboratory, while the second photograph was made immediately before being returned to the prescribing dentist for the first time. A calibrated investigator analyzed all the photographs for Kennedy Classification, type of RPD, major connector, and other details. Data were analyzed with descriptive statistics. Fisher's exact test was used to confirm repeatability. RESULTS: Kennedy Class I was the most common RPD with a frequency of 38.4%. More than 40% of prescriptions had no design input from the dentist. One in 3 RPDs used acrylic resin or flexible frameworks. One in 5 RPDs had no rests. The horseshoe major connector was the most common maxillary major connector, while the lingual plate was the most common in the mandible. CONCLUSIONS: RPDs remain a common prosthodontic treatment in this region. Non-metal RPD frameworks are a common treatment type and rarely include rests. These data indicate a changing partially edentulous patient population and a variable commitment to standard levels of prosthodontic care.

Denture quality has a minimal effect on health-related quality of life in patients with removable dentures.

The present study examined the association of denture quality and health-related quality of life (HRQoL) in patients with removable dentures. In a study of 171 consecutive patients with removable partial dentures or complete dentures (mean age: 68·0 ± 9·3 years) at a university-based prosthodontic clinic, dentists rated two aspects of denture quality (stability and aesthetics) using a 100-mm visual analog scale (VAS). HRQoL was evaluated using the mental and physical component summary (MCS and PCS) scores of the Medical Outcomes Study Short-Form 36-Item Health Survey (SF-36). Oral health-related quality of life (OHRQoL) was evaluated using the Oral Health Impact Profile-Japanese version (OHIP-J). The associations among denture quality, OHRQoL, and HRQoL were examined by linear regression models. Bivariable linear regression analyses revealed that denture stability was significantly associated with the SF-36 MCS [regression coefficient = 0·52 for a 10-unit increase in denture stability on a 0-100 VAS, 95% confidence interval (CI): 0·03-1·00, P = 0·04], but not with the PCS (0·11, 95% CI: -0·49 to 0·70). Denture aesthetics was not related to the PCS or the MCS (0·22, 95% CI: -0·44 to 0·88 or 0·07, 95%CI: -0·47 to 0·62). When OHIP-J was added to the regression model, this variable was substantially and significantly associated with the MCS and PCS summary scores; in addition, the regression coefficient for denture quality decreased in magnitude and was statistically nonsignificant in all analyses. The quality of removable dentures had a minimal effect on HRQoL in patients with removable dentures, and this association was mediated by OHRQoL.

[Treatment of removable partial dentures. 1. Legislation, rules of conduct, care plan and treatment plan]. / Behandeling met een partiële gebitsprothese. 1. Regelgeving, zorg- en behandelplan.

An invasive treatment, such as the treatment involving a removable partial denture, requires a well-structured approach. Regulations governing the communication between a healthcare professional and a patient in the Netherlands can be found in the Dutch Medical Treatment Act and the Rules of Conduct for Dentists of the Dutch Society for the Advancement of Dentistry (NMT). According to the regulations in these sources, a healthcare provider needs a patient's informed consent for any medical treatment and he is required to maintain a file of medical records. Consent should be based on efficacious communication and explanation of treatment options, risks and costs. With regard to the duty to maintain records, a care plan and a treatment plan are required for an invasive treatment. A standard structure and sequence of points for the care plan and the treatment plan will reduce the risk of overlooking essential issues.

[Treatment of removable partial dentures. 2. Causes and consequences of a reduced occlusal system]. / Behandeling met een partiële gebitsprothese 2. Oorzaken en gevolgen van een gereduceerd occlusiesysteem.

The occlusal system is part of the orofacial system and consists of the maxillary and mandibular alveolar ridge and teeth which are occluding or not or the removable denture teeth. The most prevalent causes of loss of teeth are insufficient oral self care or inadequate professional oral healthcare service. A reduced dentition can be described in terms of diastemas in the anterior region and number of occluding pairs of (pre)molars, differentiated as interrupted or shortened dental arches. Characteristic of a healthy functional occlusal system are the absence of pathology and the possibility to practice all oral functions without inconvenience. The consequences of a reduced occlusal system may be overload and/or migration of teeth, mandibular instability, and impaired esthetics and chewing function. Morphological and functional alterations can be considered to be adaptations to changed situations or to be pathological. The distinction between adaptation and pathology cannot be sharply defined. If prosthetic replacement of teeth is needed, the trend is to avoid removable partial dentures.

Designing cobalt chromium removable partial dentures for patients with shortened dental arches: a pilot survey.

The aim of this survey was to investigate the quality of prescription for the fabrication of cobalt chromium removable partial dentures (RPDs) that are used to extend the shortened dental arches (SDAs). A survey of four commercial dental laboratories located in northern England was conducted. The target of this survey was cobalt chromium RPDs that were requested to restore SDAs comprising the anterior teeth and 2-4 premolars. Dentists' prescriptions were scrutinised, and a special data collection form was completed accordingly. A total of 94 dentists' prescriptions and associated SDA casts were examined. Almost all the requested cobalt chromium RPDs were clasp-retained RPDs (97%). Scrutinising the 91 prescriptions for clasp-retained cobalt chromium RPDs showed that dentists' prescriptions did not have any instructions about the design of the partial denture in a considerable proportion of the cases (32%). Teeth to be clasped were identified clearly in 45% of the prescriptions. A majority of the dentists (64%) failed to provide any instructions about the design of the rests to be placed on the most posterior premolar abutment teeth. A considerable proportion of the dentists delegated the task of selecting the type of the major connector to the dental technician (41%). Only 21 (23%) of the examined casts had clearly defined rest seat preparation. The outcome of this pilot survey shows inadequate quality of prescription in designing RPDs for patients with SDAs. This finding has an ethical and clinical bearing and does not fit with current legal guidelines relevant to designing RPDs.

Removable partial dentures--treatment now and for the future.

The use of a removable partial denture (RPD) in clinical practice remains a viable treatment modality. Various advancements have improved the quality of a RPD, subsequently improving the quality of life for the individuals that use them. This article describes four removable partial denture treatment modalities that provide valuable treatment for the partially edentulous patient. These modalities include: the implant supported RPD, attachment use in RPDs, rotational path RPDs, and Titanium and CAD/CAM RPDs. Data on future needs for RPDs indicate that while there is a decline in tooth loss in the U.S., the need for RPDs will actually increase as the population increases and ages. With the growth in the geriatric population, which includes a high percentage of partially edentulous patients, the use of RPDs in clinical treatment will continue to be predictable treatment option in clinical dentistry.

Effect of the quality of removable prostheses on patient satisfaction.

AIM: The objective of this study was to evaluate patient satisfaction with removable prostheses and its relationship with denture quality. METHODS AND MATERIALS: Sixty-seven patients who received 119 new removable prostheses over a period of one year at the College of Dentistry, King Saud University, were recalled for an interview with regard to their satisfaction with their dentures and a clinical examination. Prosthetic quality was determined using the California Dental Association criteria. RESULTS: Results showed 75% and 66% of upper and lower dentures, respectively, were reported by patients as satisfactory. Of all the upper prostheses rated as being of acceptable quality, 94% were also reported by patients as satisfactory, but of those of unacceptable quality, only 52% were reported by patients as unsatisfactory. The corresponding figures for lower dentures were 91% and 71%, respectively. No significant associations were found between patient satisfaction and age, or denture experience. CONCLUSION: Although acceptable quality of removable prostheses usually resulted in patient satisfaction, the finding that some patients were satisfied with their prostheses despite unacceptable quality suggests other factors besides quality affect outcomes. CLINICAL SIGNIFICANCE: Patient satisfaction with removable dentures cannot be fully predicted from only the quality standards of those dentures.

Does removable partial denture quality affect individuals' oral health?

The impact of oral disorders and interventions on individuals' perceived oral health and oral-health-related quality of life (OHRQoL) is being increasingly recognized as an important health component. This study examined the association between denture quality and OHRQoL in individuals wearing removable partial dentures (RPDs). The study participants were 245 consecutive patients (mean age: 63.3 +/- 8.7 yrs) at a university-based prosthodontic clinic who wore RPDs for more than one month. RPD quality and OHRQoL were determined by means of a 100-mm visual analog scale (VAS) and the 49-item Oral Health Impact Profile-Japanese version (OHIP-J49), respectively. Linear regression analysis between RPD quality and OHRQoL revealed that a 10-mm VAS increase in RPD quality rating was related to -2.8 OHIP-J49 units (95% confidence interval: -4.5 to -1.1, p = 0.001), which represents an improvement in OHRQoL. The results suggest that RPD quality influences individuals' OHRQoL to a clinically significant extent.

The strength of multiple major connector designs under simulated functional loading.

STATEMENT OF PROBLEM: The design of a removable dental prosthesis (RDP) must balance functional strength, comfort to the patient, and the health of the tissue. While research has been conducted to enhance the strength of major connectors, little has been done to determine if the dimensions of major connectors can be reduced in order to enhance patient comfort and tissue health. PURPOSE: The purpose of this study was to determine the minimum major connector dimensions of 1 mandibular and 2 maxillary major connectors that would provide adequate functional strength. MATERIAL AND METHODS: Sixty chromium-cobalt alloy (Vitallium) RDP frameworks were fabricated. The major connector designs were: a mandibular lingual bar, a maxillary palatal strap, and a maxillary anterior-posterior (A-P) palatal strap. Four groups of 5 frameworks with diminishing dimensions were fabricated for each major connector design. The lingual bar was tested at 4, 3, 2.5, and 2 mm in height, occlusogingivally, and 1.6 mm in thickness; the palatal strap at 8, 6, 4, and 2 mm, anteroposteriorly; and the A-P palatal strap at 10 x 6, 8 x 4, 6 x 2.5, and 4 x 2 mm, anteroposteriorly. All maxillary frameworks were 0.65 mm in thickness. The frameworks were of a Kennedy Class II Mod I design with 3 widely separated vertical reference points to measure deformation. Two tests were conducted to evaluate the functional strength for each framework. The first test was masticatory simulation, or torsional force. The second test was a drop test from a height of 3 feet. Permanent deformation was then determined after each test. The Cochran-Armitage test (alpha=.05) was used for both the torsion test and the drop test. RESULTS: A statistically significant difference in permanent deformation was found for the palatal strap design among the 4 different dimensions for the compressive test (P=.015) and the drop test (P=.044). CONCLUSION: It is safe to reduce the dimensions of some major connectors under normal loads. The reduced size of the connectors places the removable partial denture at increased risk for deformation when dropped from a height.