Type Of Prosthetic Restoration Research Articles

Criterios para la elección de biomateriales protésicos según sus propiedades fisicoquímicas para los sectores anterior y posterior. Una revisión exhaustiva

Objective: To describe the existing knowledge about metal-free prosthetic biomaterials according to their physicochemical properties and based on this, define criteria for their placement in both the anterior and posterior sectors. Materials and methods: A digital search was carried out in the databases: PubMed/Medline, Scopus, Web of Science and Google Scholar of the literature published in the English language without time restrictions and included original articles such as case reports, retrospective and prospective studies, narrative, comprehensive, systematic reviews and meta-analysis. Meanwhile, short communications, editorials and articles in a language other than English were excluded. Results: 40 articles were evaluated, published between 2000 and 2023. The main characteristics and physicochemical properties of ceramic biomaterials such as zirconia, feldspathic based ceramics, lithium disilicate and alumina, among others, were analyzed and summarized. In addition, certain criteria were defined based on the available scientific evidence on the use of different ceramic systems both in the anterior sector and in the posterior sector for patients who need some type of prosthetic restoration. Conclusions: Among the different metalfree materials used for the construction of fixed dental prostheses, zirconia has been shown to have better aesthetic, biomechanical and biocompatibility properties, which makes it a candidate material for the rehabilitation of partially edentulous patients.

Risk Characteristics of Peri-Implant Infections: A Retrospective Evaluation in a University Consultation Setting

Peri-implantitis is a common biological complication in dentistry. The aim of the present study was to retrospectively analyze risk characteristics in a group of patients referred to a university-based consultation for peri-implantitis. In all, 190 initial cases from 2010 to 2019 were evaluated and descriptively summarized. The evaluation included various parameters such as periodontitis, smoking and oral hygiene status, implant position, type of prosthetic restoration and retention, mucosal quality, and further anamnestic and clinical findings related to the potential risk of developing peri-implantitis. Peri-implantitis was diagnosed in 83% of the cases, with peri-implant mucositis alone in 16% of cases; furthermore, 38% of the patients were diagnosed with active/instable periodontitis, while 14% had stable periodontitis. Residual cement was considered as a potential co-factor of peri-implant inflammation in 43% of cases. Suboptimal implant positioning was found in 19% of patients. Peri-implantitis or peri-implant mucositis was present in about one-third of patients in the absence of smoking and periodontitis factors. Of note, 6% showed no identifiable risk factors. Factors related to an increased risk of peri-implantitis should be taken into consideration when planning implant treatment. Adequate prosthetic implant position, restoration, and cleanability remain important for long-term success.

Prevalence and risk of peri-implant diseases based on the type of prosthetic restoration: A retrospective study after 17 to 23 years

Statement of problemInformation on the epidemiology and etiopathology of peri-implant diseases in reference to prostheses is sparse. PurposeThe purpose of this retrospective clinical study was to analyze the prevalence and risk of peri-implant diseases based on the type of prosthesis. Material and methodsA total of 274 implants in 106 patients were evaluated by clinical and radiological examination. Peri-implant mucositis was defined by bleeding on probing, whereas peri-implantitis was defined by additional bone loss ≥1.5 mm since seating of the definitive prosthesis. Prosthetic design and anamnestic risk factors were assessed in a regression analysis, whereas clinical and radiological differences between the prosthesis groups were compared by the Pearson chi-squared test (α=.05 for all procedures). ResultsThe median observation period was 18 years. Seventy-two implants were restored with single crowns, 138 implants with fixed partial dentures, and 64 implants with removable prostheses. Peri-implant mucositis was diagnosed more often in implants supporting fixed partial dentures (42.8%), whereas peri-implantitis was found more frequently in implants supporting removable prostheses (31.3%) (overall distribution pattern: P<.001). The type of prosthetic restoration was confirmed to be an independent prognostic risk factor regarding peri-implant diseases (P=.005). Additionally, increased bone loss was found with implant-supported removable prostheses, regardless of peri-implantitis (P<.001). ConclusionsThe type of prosthetic restoration was identified as an independent risk factor for the development of peri-implant diseases. Particularly, implants supporting double crown-retained removable prostheses might be at risk.

Peri-Implant Behavior of Tissue Level Dental Implants with a Convergent Neck.

Introduction: The aim of this retrospective study was to analyze the radiographic peri-implant bone loss of bone level implants and tissue level implants with a convergent neck in screw-retained single crowns and in screw-retained fixed partial prostheses, after two years of functional loading. Materials and methods: The sample was divided into two groups according to their type: Group I: supracrestal implants with convergent transmucosal neck; Group II: crestal implants. In each group we distinguish two subgroups according to the type of prosthetic restoration: single crowns and a three-piece fixed partial prosthesis on two implants. To quantify bone loss, parallelized periapical radiographs were analyzed at the time of implant placement and after two years of functional load. Results: A total of 120 implants were placed in 53 patients. After statistical analysis it was observed that for each type of implant bone loss was 0.97 ± 0.91 mm for bone level and 0.31 ± 0.48 mm for tissue level. No significant differences were found regarding the type of prosthesis and the location (maxilla or mandible) of the implants. Conclusions: Tissue level implants with a convergent transepithelial neck exhibit less peri-implant bone loss than bone level implants regardless of the type of prosthesis.

The Technology of Obtaining Flexible Dentures in Dental Practice, Theoretical and Practical Aspects

Abstract Flexible dentures are an increasingly interesting prosthetic alternative both for dental practitioners (dentists and dental technicians), but also for patients. This type of prosthetic restoration can rehabilitate a wide range of edentulous, but the financial effort that patients have to make is more consistent than in the case of a partial acrylic dentures. In this study, we will try to present some essential aspects in the technology of creating flexible partial dentures.

Influence of Biologically Oriented Preparation Technique on Peri-Implant Tissues; Prospective Randomized Clinical Trial with Three-Year Follow-Up. Part II: Soft Tissues.

Purpose: The objective of this prospective randomized clinical trial (RCT) was to analyze and compare the clinical behavior of three types of prosthesis supported by single implants in the posterior region after three years of functional loading. Materials and methods: Seventy-five implants were divided into three groups according to the type of prosthetic restoration: screw-retained crown (group GS); cemented crown without finishing line (biologically oriented preparation technique) (group GBOPT); and conventional cemented crown with finishing line (group GCC). After three years in function, clinical parameters (presence of keratinized mucosa, probing depths, bleeding on probing, and radiographic bone loss) were compared between the three experimental groups. The possible correlation between soft tissue clinical parameters and bone loss was also analyzed. Results: Statistical analysis found significant differences in clinical parameters between the different types of crown, with the cemented restoration without finishing line (BOPT) presenting fewer complications and better peri-implant health outcomes including: significantly different KMW data (mm), with significant differences between groups GBOPT and GCC (p < 0.001, Kruskal–Wallis test), with GBOPT obtaining larger quantities of keratinized mucosa (KM); statistically significant differences in probing depth (PD) values between groups GBOPT and GCC (p = 0.010, Kruskal–Wallis test); significant differences in bleeding on probing (BOP) between groups GBOPT and GCC (p = 0.018, Chi2 test) in favor of GBOPT. Conclusions: Soft tissue behavior around implants is related to the type of prosthetic restoration used, with cemented prostheses with BOPT presenting better peri-implant soft tissue behavior.

Satisfaction analysis of patients with single implant treatments based on a questionnaire survey.

Background: The factors influencing satisfaction of the patients with implant treatments are still unclear. This study aims to evaluate the patients’ satisfaction and to identify influencing factors, which will improve the medical quality of oral implantology.Materials and methods: Patients who lost single teeth and received implant treatments were enrolled in Nanjing Stomatological Hospital between February 2016 and March 2018. A questionnaire survey was performed to assess patient satisfaction and data were collected at four time points. Information included gender, age, educational level, application of bone augmentation, type of prosthetic restoration, period of teeth loss, dentist qualification, and tooth position. Meanwhile, the satisfaction of the patients was evaluated by visual analog scale.Results: A total of 373 patients completed the questionnaires. The mean of overall satisfaction score was 69.05±7.10. Lower overall satisfaction score was found in patients who received bone augmentation (P<0.001) and those with a longer period of teeth loss (P<0.05). In the bone augmentation group, the elements of pain and complication were significantly associated with a decrease in the median satisfaction score (P<0.001), and a similar result was obtained form the duration of operative time and healing response (P<0.001). On the other hand, the satisfaction scores for elements including the duration of operative time and healing response (P<0.05), aesthetics and psychology (P<0.05), and chewing function (P<0.05) decreased with an extended period of teeth loss. Meanwhile, over half of respondents were more concerned about the survival time (40.70%) and success rate (20.49%) of implants.Conclusion: Bone augmentation and the period of teeth loss are negative factors affecting patient satisfaction, and the success rate and survival time of implants are considerable aspects for patients. It is essential to raise general awareness of oral hygiene and optimize the dental implant therapeutic process.

Are fibre posts associated with the occurrence of prosthetic complications?

Data sourcesThe Pubmed, Evidence-Based Dentistry, BMJ Clinical Evidence, EmbaseDynamed, and www.opengrey.eu databases and manual search of reference lists.Study selectionRandomised clinical trials (RCTs) were accepted if they had: participants with no periodontal disease and teeth restored with SCs or FDPs and compared fibre posts and other prosthetic systems and evaluated the prosthetic complications with a minimum observational period of 36 months.Data extraction and synthesisTitles and abstracts were evaluated independently by two reviewers, any disagreement was discussed with a third reviewer. The agreement for the two reviewers was 97%. The quality and the risk of bias of the studies included was assessed following the Cochrane Handbook considering the domains of randomisation, sample size, inclusion and exclusion criteria, follow-up achieved, blinding, withdrawing and groups' compatibility for quality assessment, and for the risk of bias the domains evaluated were allocation concealment, blinding of outcome assessor and follow-up.ResultsThe database search yielded 4,230 records; after duplications removal, 3,670 records were reviewed independently by the authors, and four articles were chosen to include in the systematic review.The most frequently reported failures in the available studies were as follows: fibre post debonding, loss of retention of single crowns and marginal gaps. Less frequently, chippings and fractures were recorded in SCs. No studies about complications related to FDPs were found.The failure rate ranged from 0 to 28.2%.ConclusionsA correlation between the failure rates of fibre posts and the type of prosthetic restoration (SCs or FDPs ) cannot be found. Further RCTs are required to achieve evidence-based conclusions, particularly about the use of fibre posts with FDPs.

The Relationship Between Marginal Bone Loss Around Dental Implants and the Specific Characteristics of Implant-Prosthetic Treatment

Abstract The marginal bone loss around dental implants is an important indicator that helps to evaluate the course and the final outcome of implant-prosthetic treatment. It is, therefore, important to understand the factors that may affect this. The aim of the study was to assess the impact of the specific characteristics of implant-prosthetic treatment on the marginal bone loss around implants. The study included 28 patients, aged 37-66 years, treated with dental implants. Every patient received at least one of the two types of implants: with Morse taper connection and with internal hexagonal connection. The average marginal bone loss around the implants was evaluated on the basis of the panoramic radiographs. The maximum follow-up period after implantation was 46 months. The peri-implant marginal bone loss was evaluated taking into consideration the implant localisation, the procedure of sinus lift with bone augmentation, implant type, implant diameter, vertical implant position relative to the compact bone level and the type of prosthetic restoration, the time between implantation and loading with prosthetic restoration, as well as the time between loading and the measurement of marginal bone loss. The correlation between bone loss and the selected characteristics of the treatment was assessed using generalised estimating equations (GEE). An objective analysis was enabled via the applied research model: evaluation of an impact of the specific implant-prosthetic treatment characteristics on peri-implant marginal bone loss in patients treated with implants with different implant-abutment interface systems. The results of the study showed that peri-implant marginal bone loss increased significantly with implant localisation in canine sites (compared to the localization in premolar sites), as well as with prosthetic restorations in the form of dentures (compared to bridges), and decreased when implants were placed below the compact bone level (compared to those placed at the bone level). At the same time, marginal bone loss was not significantly related to implant diameter or to the sinus lift procedure. The results obtained seem extremely useful in everyday clinical practice

Post-Retained Single Crowns versus Fixed Dental Prostheses: A 7-Year Prospective Clinical Study

Biomechanical integrity of endodontically treated teeth (ETT) is often compromised. Degree of hard tissue loss and type of final prosthetic restoration should be carefully considered when making a treatment plan. The objective of this prospective clinical trial was to assess the influence of the type of prosthetic restoration as well as the degree of hard tissue loss on 7-y clinical performance of ETT restored with fiber posts. Two groups (n = 60) were defined depending on the type of prosthetic restoration needed: 1) single unit porcelain-fused-to-metal (PFM) crowns (SCs) and 2) 3- to 4-unit PFM fixed dental prostheses (FDPs), with 1 healthy and 1 endodontically treated and fiber post-restored abutment. Within each group, samples were divided into 2 subgroups (n = 30) according to the amount of residual coronal tissues after abutment buildup and final preparation: A) >50% of coronal residual structure or B) equal to or <50% of coronal residual structure. The clinical outcome was assessed based on clinical and intraoral radiographic examinations at the recalls after 6, 12, 24, 36, 48, and 84 mo. Data were analyzed by Kaplan-Meier log-rank test and Cox regression analysis (P < 0.05). The overall 7-y survival rate of ETT restored with fiber post and either SCs or FDPs was 69.2%. The highest 84-mo survival rate was recorded in group 1A (90%), whereas teeth in group 2B exhibited the lowest performance (56.7% survival rate). The log-rank test detected statistically significant differences in survival rates among the groups (P = 0.048). Cox regression analysis revealed that the amount of residual coronal structure (P = 0.041; hazard ratio [HR], 2.026; 95% confidence interval [CI] for HR, 1.031–3.982) and the interaction between the type of prosthetic restoration and the amount of residual coronal structure (P = 0.024; HR, 1.372; 95% CI for HR, 1.042–1.806) were statistically significant factors for survival (ClinicalTrials.gov NCT01532947).

Amputation and prosthesis attachment of the lower extremities

Approximately 61,000 amputations are performed in Germany per year. In most cases the lower limbs are affected. The reasons for amputations are arteriosclerosis, diabetes mellitus, severe infections, tumors and complex trauma to the extremities. A decision must be made concerning whether a salvage procedure or amputation is appropriate, specially after trauma. In cases where the need for amputation is clear, the site of amputation needs to be planned in advance with the aim of creating a stump which allows sufficient prosthetic attachment. Adjuvant pain therapy is mandatory, especially in order to avoid subsequent phantom pain. The type of prosthetic restoration is influenced by the grade of mobility and personal requirements of patients. Moreover, aftercare and adjusted rehabilitation are recommended.

Esthetic evaluation of single‐tooth implants in the anterior mandible

Single-tooth replacement of anterior mandibular teeth is frequently complicated by insufficient bucco-lingual bone width and limited mesio-distal space available for implant placement. The aim of the present study was to assess implant esthetics in the partially edentulous anterior mandible. Esthetic evaluation of 43 anterior mandibular single-tooth implants in 15 women and 28 men was performed using esthetic indices (PES=Pink Esthetic Score, PI=Papilla Index, SES=Subjective Esthetic Score) as well as subjective patients' Visual Analogue Scale (VAS) ratings. Clinical and radiological parameters (implant and crown dimensions, pocket depth, bleeding on probing, plaque, keratinized mucosa, marginal bone level, and distance to adjacent teeth) were tested for influence. Implant esthetics were judged satisfactory (PES ≤10) in 42% of implants compared with a patient satisfaction rate of 87%. Correlation between objective indices (PES/PI: rs =0.62, PES/SES: rs =-0.73, PI/SES: rs =-0.48) was highly significant (P≤0.001); however, no association to subjective patients' ratings could be observed. Type of prosthetic restoration (single crown vs. tulip-shaped double crowns), mesio-distal crown width as well as anatomic crown length significantly affected esthetic scores. Patients' judgment, by contrast, could not be associated to any prognostic factor. Subjective patient satisfaction with implant esthetics in the partially edentulous anterior mandible is high, however, remains hard to predict or objectively quantify.

Kennedy Classification and Treatment Options: A Study of Partially Edentulous Patients Being Treated in a Specialized Prosthetic Clinic

This study was done under the auspices of the Swedish International Development Cooperation Agency, whose aim is to improve living conditions in developing countries, including dental aid. Each year the number of medical staff from the European Union willing to help in developing countries increases, and it is thus important to highlight issues of development. From the Middle Asian region, the Republic of Kazakhstan was chosen. At present, few studies have evaluated the prevalence of various types of partial edentulism in this region, and no research has investigated the prosthetic treatment choice in the various types of partial edentulism. The purpose of this study was to determine (i) the prevalence of various types of partial edentulism in patients seeking dental care and (ii) the type of prosthetic restoration most commonly chosen to treat these patients. One hundred twelve patient records, together with panoramic radiographs, were studied. Various types of partial edentulism were grouped into four Kennedy classes. Patient records were used to examine which treatment option was chosen for each patient. The most prevalent type of partial edentulism in this patient sample was Kennedy type III, in both the maxilla (50.0%) and the mandible (41.1%). Partial edentulism was most frequently managed by fixed partial dentures (FPDs) in both jaws. Kennedy IV was the least prevalent (7.1% in the maxilla, 5.6% in the mandible) and in most cases treated with removable partial dentures (RPDs) in both jaws. Our results are consistent with previous research on the prevalence of Kennedy classes in Kazakhstan. RPDs were the most common type of prosthetic management for partial edentulism.

Impact of facial form on the relationship between conventional or implant-assisted mandibular dentures and masticatory function

It is not clear if the interaction of craniofacial form with type of prosthetic restoration (conventional or implant-assisted) is related to masticatory function in complete denture patients. The purpose of this study was to investigate the relationships among facial form, skeletal class, alveolar residual ridge heights and masticatory function in subjects treated with implant-assisted or conventional mandibular dentures with lateral cephalometric evaluation. Data from a previously reported randomized controlled clinical trial were accessed to compare treatment success rates, functional and perceptual outcomes, dietary intake, and craniofacial relationships between mandibular complete dentures and implant overdentures in edentulous diabetic subjects. Evaluation of the digitized post-insertion lateral cephalometric radiographs provided measures of facial form (mesocephalic "medium", brachycephalic "broad and square", dolichocephalic "vertical and long"), skeletal class (Class I, Class II, Class III), and alveolar ridge height (mm), which were compared to results of standardized masticatory tests as evaluated using MANOVA and REGW post-hoc evaluation (α=.05). Masticatory performance on the preferred side was slightly reduced in the dolichocephalic group, compared to brachycephalic and mesocephalic groups (P=.085). Swallowing threshold performance was significantly less in skeletal Class II subjects compared to Class I (P=.034). Maxillary residual alveolar ridge height was significantly less in the brachycephalic group compared to the dolichocephalic group (P<.001). No differences in mandibular ridge height were seen associated with facial form or skeletal class groups. Facial form may be related to masticatory function with conventional and implant-assisted mandibular dentures, but larger controlled studies are needed to confirm this relationship. Alveolar ridge height is reduced in edentulous subjects with a brachycephalic facial form.

Survival rate and potential influential factors for two transitional implant systems in edentulous patients: a prospective clinical study

The aim of this present study was to evaluate the success of immediately loaded transitional implants and to identify possible influential factors. A total of 64 patients were recruited in a private specialist implant practice. Two different implant systems were evaluated (IPI, Nobel Biocare, Sweden; I-Plant, Unor, Switzerland). Primary stability, survival rate, gender, location, the type of prosthetic restoration and the tooth status of the opposite jaw were analysed using Kaplan-Meier or Pearson Chi-Square test. A total of 254 transitional implants were placed, thereof 216 were IPI implants and 38 I-Plant implants. The overall observation period ranged between 2 and 426 days. The results demonstrated a survival rate of 82·4% for the IPI system and 84·2% for the I-Plant system. None of the transitional implants with a good primary stability were lost during the observation period. The primary stability showed significant influence on the implant survival. There was no significant difference in survival of the implants between the two implant systems. Neither the gender, the kind of superstructure, the location of the implant, the tooth status of the opposing jaw or the immediate prosthetic superstructure had an influence on the survival of the implants. Both implant systems proved to be sufficient alternatives for the support of provisional restorations.

Osseotite implants inserted into fresh frozen bone grafts

In the last decade, several investigators have reported that double etched implants have achieved excellent results. However, no report regarding double etched implants inserted into fresh frozen bone is available. We planned to perform a retrospective study on double etched implants inserted into fresh frozen bone grafts. 28 patients (17 females and 11 males with a median age of 52 years) were operated on and 114 double etched implants inserted. Implant diameter and length ranged from 3.25 to 5.0 mm and from 10.0 to 15 mm, respectively. Implants were inserted to replace 14 incisors, 5 cuspids, 47 premolars and 48 molars. Since only 4 out of 114 implants were lost (i.e. Survival Rate SVR = 96.5%) and no statistical differences were detected among the studied variables. The type of prosthetic restoration (i.e. fixed prostheses) correlated with a statistically significant lower delta Implant Abutment Junction (i.e. reduced crestal bone loss) and thus a better clinical outcome. Double etched implants inserted into fresh frozen bone had a high survival and success rate similar to those reported in previous studies of two-stage procedures in non-grafted bone, although a higher marginal bone loss has to be expected when removable prosthetic restorations are used.

Retrospective Study of Standard-Diameter Implants Inserted Into Allografts

In the last decade, several investigators reported that standard-diameter implants (SDIs) achieved excellent results. However, no report is available regarding SDIs inserted into fresh-frozen bone (FFB). We conducted a retrospective study on a series of SDIs (diameter, 3.75 mm) inserted into homologous FFB to evaluate their clinical outcome. The SDIs inserted with FFB were analyzed. Several variables were investigated regarding patients, anatomic sites, implants, and prosthetic restoration. Implant failure and peri-implant bone resorption were considered predictors of clinical outcome. A Kaplan-Meier algorithm and Cox regression were performed to detect those variables statistically associated with clinical outcomes. One hundred thirty-three SDIs were inserted in 41 patients. Implant length ranged from 10 to 15 mm. Implants were inserted to replace 6 incisors, 13 cuspids, 60 premolars, and 54 molars. The mean follow-up was 23 months. Only 1 of 133 implants was lost (ie, survival rate=99.2%), and no differences were detected among study variables. On the contrary, crestal bone resorption correlates with type of prosthetic restoration, with a better outcome for removable dentures. The SDIs had high survival and success rates, similar to those reported in previous studies of 2-stage procedures in nongrafted bone. The SDIs inserted into FFB are reliable, although a greater marginal bone loss is to be expected if fixed prosthetic restorations are used.

Survival time of cast post and cores: A 10-year retrospective study

The aim of this retrospective, longitudinal study was to examine the survival time of custom-fabricated, cast post and cores and to evaluate, which covariates influence the risk of failures over a period of up to 10 years based on a large patient collective. The files of 565 patients, who had been fitted with a total of 802 custom-fabricated, cast post and cores using a standardised technique, were analysed. The following parameters were used in the evaluation: age of the post and cores, fabrication technique (direct, indirect), type of prosthetic restoration, location (upper, lower jaw), type of tooth (anterior, premolar, molar), number of root posts, luting material, post and core alloy and cause of failure. The survival probability was assessed using Kaplan-Meyer analysis. Cox regression was used to assess the risk of failure and identify possible covariates. The average survival time of the post and cores was 7.3 years. The cumulative failure rate was 11.2%. The most common complication was loss of retention of the post and cores. High-gold-content posts had a lower risk of failure than posts made from semi-precious alloy. The type of restoration fitted had a significant influence on the survival probability. Post and cores custom-fabricated using a standardised fabrication technique have a good long-term prognosis. The most common cause of failure is loss of retention. The durability of posts with low friction at the try-in stage cannot be compensated for by using glass ionomer cement as the luting material.

Changes in the edentulous maxilla in persons wearing implant-retained mandibular overdentures

Statement of Problem: It has been suggested that risk for severe resorption in the anterior maxilla is increased in persons wearing mandibular implant-retained overdentures. However, little information is available about the changes in the edentulous maxilla after mandibular implant treatment. Purpose: This study determined the possible changes in the width of the maxillary residual ridge 6 years after receiving mandibular implant-supported or implant-mucosa–supported overdentures and evaluated the association between the anatomic changes and subjective complaints with maxillary complete dentures. Methods and Material: The subjects for this study (n = 55), enrolled among the participants of a prospective clinical trial, were randomly assigned into 3 groups treated with: (a) implant-supported overdentures on a transmandibular implant system (n = 21); (b) implant-mucosa–supported overdentures on 2 IMZ implants (n = 20); or (c) conventional complete dentures (n = 14). A lingual contact occlusion concept with anterior open bite was used for tooth arrangement in all subjects. Diagnostic casts were made at baseline, and again at the 6-year follow-up. Most prominent points perpendicular to the crest of residual ridge were located in the incisor, canine, and premolar regions, after which the width of the ridge was recorded at these points with a Boley gage. Subjects’ opinions on their dentures were evaluated with a questionnaire. Results: Significant reduction in the width of the ridge was found in all measurement areas (mean difference = 0.4 to 0.6 mm; P <.0001). However, changes were small and not associated with the type of prosthetic restoration in the mandible. In subjects with implant-mucosa–supported overdentures, complaint of loose maxillary denture correlated with the decrement of residual ridge width. Conclusion: The width of residual ridge decreases with time, despite the type of mandibular prosthetic restoration. (J Prosthet Dent 2000;84:43-9.)