Showing papers in "International Journal of Prosthodontics in 2003"

Oral health status and treatment satisfaction with mandibular implant overdentures and conventional dentures: a randomized clinical trial in a senior population.

Abstract: Purpose The purpose of this study was to compare elderly patients' satisfaction and oral health-related quality of life with mandibular two-implant overdentures and conventional dentures. Materials and methods Sixty edentulous subjects aged 65 to 75 years were randomly assigned to two groups treated with maxillary conventional dentures and either a mandibular conventional denture (n = 30) or an overdenture supported by two implants with ball retainers (n = 30). Subjects rated their general satisfaction, as well as other features of their dentures (comfort, stability, ability to chew, speech, esthetics, and cleaning ability), prior to treatment and 2 months postdelivery. Changes in ratings on the original Oral Health Impact Profile (OHIP) and its short form (OHIP-EDENT) were also used as indicators of oral health-related quality of life. Results The primary outcome of this study, ratings of general satisfaction 2 months postdelivery, was significantly better in the group treated with mandibular two-implant overdentures (P = .001). In addition, the implant group gave significantly higher ratings on comfort, stability, and ability to chew. Furthermore, using OHIP-EDENT, subjects who received mandibular two-implant overdentures had significantly fewer oral health-related quality of life problems than did the conventional group. Conclusion These short-term results suggest that mandibular two-implant overdentures combined with maxillary conventional dentures provide better function and oral health-related quality of life than conventional dentures.

Implant treatment in the edentulous mandible: a prospective study on Brånemark system implants over more than 20 years.

Abstract: Purpose This prospective investigation studied the clinical and radiographic performance of mandibular fixed prostheses supported by osseointegrated implants over more than 20 years. Materials and methods A total of 273 standard Branemark implants (10 mm long) were placed in 47 patients between 1978 and 1982. Clinical and radiographic data collected at several examinations over the 20-year observation period have been reported previously. This study presents the outcome of the latest follow-up after 20 to 23 years. Results Thirty patients (64%; 75% of those still alive) attended the 20-year follow-up examination. Three implants were lost during the entire observation period, and the 20-year implant cumulative survival rate was 98.9%. All patients had continuous prosthesis function, but two had their mandibular prostheses remade during the 20 years. No implants or prostheses were lost or fractured during the last 5 years, and only a few prosthodontic complications were noted. The mean bone level was 1.6 mm (SD 0.90) below the reference point after 20 years, and mean bone loss was 0.2 mm (SD 0.22) between the 15- and 20-year follow-ups. Thirty-seven implants (24%) showed more than two exposed threads at the 15-year follow-up examination, but only four implants (3%) presented pain and/or bone loss exceeding one thread (0.6 mm) during the last 5 years. Conclusion The successful treatment result after 15 years continued up to more than 20 years in function. During the last 5 years, a majority of the implants with several exposed implant threads could be maintained without any complications, and the frequency of implants showing signs of ongoing peri-implantitis was less than 3%.

Clinical behavior of translucent-fiber posts: a 2-year prospective study.

Abstract: Purpose This study prospectively evaluated the clinical performance of three types of translucent posts over a follow-up period of between 2 and 3 years. Materials and methods Selected were 225 patients with one premolar in need of endodontic treatment, followed by restoration with a fiber post and porcelain crown. The sample was randomly divided into three groups of 75 patients each. The same type of post was used in all patients within a group: group 1 = Aesthetic Plus; group 2 = DT; and group 3 = FRC Postec. For bonding the post, a light-curing adhesive (One-Step) and a dual-curing resin cement (Duo-Link) were applied in group 1 and 2 roots, whereas self-curing materials (Excite DSC as adhesive and MultiLink as resin cement) were used in group 3. After 6, 12, and 24 months, patients were recalled, and a clinical and radiographic examination was performed. For some patients, 30-month follow-up data were also collected. Results Debonding of the post occurrred in eight cases (3.5%); in another six cases, a recurrence of the periapical lesion was reported. Conclusion The statistical analysis did not reveal any significant difference in the survival rate of the tested posts, suggesting that all are equally and sufficiently reliable for clinical use.

Comparing the efficacy of mandibular implant-retained overdentures and conventional dentures among middle-aged edentulous patients: satisfaction and functional assessment.

Abstract: PURPOSE The aim of this randomized clinical trial was to compare the relative efficacy of mandibular overdentures retained by only two implants and a bar attachment with conventional dentures. MATERIALS AND METHODS Edentulous adults, aged 35 to 65 years, were randomly assigned to two groups that received either a mandibular conventional denture (n = 48) or an overdenture supported by two endosseous implants with a connecting bar (n = 54). All subjects rated their general satisfaction and other features of their original dentures and their new prostheses (comfort, stability, ability to chew, speech, esthetics, and cleaning ability) on 100-mm visual analogue scales prior to treatment and 2 months postdelivery. Oral health-related quality of life was also evaluated pre- and posttreatment. RESULTS Multiple regression analysis revealed that the mean general satisfaction was significantly higher in the overdenture group than in the conventional denture group (P = .0001). Age, gender, marital status, and income were not significantly associated with ratings of general satisfaction. Furthermore, the implant group gave significantly higher ratings on three additional measures of the prostheses (comfort, stability, and ease of chewing; P < .05). CONCLUSION A mandibular two-implant overdenture opposed by a maxillary conventional denture is a more satisfactory treatment than conventional dentures for edentulous middle-aged adults.

Marginal and internal fit of Cerec 3 CAD/CAM all-ceramic crowns.

Abstract: PURPOSE The purpose of this study was to examine the effects of the occlusal convergence angle of the abutment and the computer's luting space setting on the marginal and internal fit of Cerec 3 computer-aided design/manufacturing (CAD/CAM) all-ceramic crowns. MATERIALS AND METHODS Mandibular second premolar all-ceramic crowns were fabricated for nine different conditions using Cerec 3: all combinations of abutments with three different total occlusal convergence angles (4, 8, and 12 degrees) with three different luting space settings (10, 30, and 50 microm). The completed crowns were seated on the abutments, and the marginal gaps were measured. The internal gaps between the crowns and abutments were also measured, using test-fit silicone paste. RESULTS When the luting space was set to 10 microm, the marginal gaps of the crowns were greater than when it was set to 30 or 50 microm. When the luting space was set to 30 or 50 microm, the marginal gaps ranged from 53 to 67 microm and were not affected by the occlusal convergence angle of the abutment. The internal gaps were within a range of 116 to 162 microm and tended to decrease as the occlusal convergence angle of the abutment decreased. CONCLUSION When the luting space was set to 30 microm, crowns with a good fit could be fabricated on the Cerec 3 system, regardless of the occlusal convergence angle of the abutment.

In vitro study of a mandibular implant overdenture retained with ball, magnet, or bar attachments: Comparison of load transfer and denture stability

Abstract: PURPOSE When implants are used to support a removable overdenture, the optimal stress distribution to minimize both forces on the implants and denture movement is desirable. This study compared the stress patterns generated around implants and denture movement among three retention systems. MATERIALS AND METHODS Two root-form implants were anchored in a mandibular model made of resin, and a removable overdenture on which all experiments were performed was fabricated. The surface of the model was covered with a layer of impression material to simulate oral mucosa. Ball/ O-ring, bar/clip, and magnetic attachments were used. A vertical force was applied to the left first molar and gradually increased from 0 to 50 N in 5-N steps. The resultant stress distribution and denture movement were evaluated. RESULTS The ball/O-ring attachment transferred the least stress to both implants and produced less bending moment than the bar/clip attachment. Vertical force applied to the bar/clip attachment created immediate stress patterns of greater magnitude and concentration on both implants. CONCLUSION This in vitro study suggested that the use of the ball/O-ring attachment could be advantageous for implant-supported overdentures with regard to optimizing stress and minimizing denture movement.

Clinical evaluation of teeth restored with quartz fiber-reinforced epoxy resin posts.

Abstract: Purpose: This prospective clinical follow-up evaluated the acceptability of quartz fiber‐reinforced epoxy posts used in endodontically treated teeth over a 30-month period. Materials and Methods: In 132 patients, 180 endodontically treated teeth were restored using AEstheti-Plus quartz-fiber posts. The posts were luted with the All-Bond 2 adhesive system and CB core or root fracture; and crown or prosthesis decementation. Patients were reevaluated at 6, 12, 24, and 30 months. Results: One cohesive failure involving a margin of the composite core was observed after 2 weeks, and two adhesive fractures were seen after 2 months. These failures were located between the cement and the dentin walls of the canals. All three failures occurred during removal of the temporary crown. The percentage of failures was thus 1.7% over a 30-month period, but it was possible to successfully replace the restoration in all three failed cases. Conclusion: Over a 30-month period, the rehabilitation of endodontically treated teeth using quartz-fiber posts showed good clinical results. No crown or prosthesis decementation was observed, and no post, core, or root fractures were recorded. Int J Prosthodont 2003;16:39‐44.

Comparisons of precision of fit between cast and CNC-milled titanium implant frameworks for the edentulous mandible.

Abstract: Purpose The purpose of this study was to investigate and compare the precision of fabrication in repeatqdly produced computer numeric controlled (CNC)-milled frameworks with consventional castings, and to analyze the distortion from application of different veneering materials. Materials and methods Twenty identical titanium frameworks were fabricated by means of a CNC milling technique for the same master model. Five conventional frameworks were cast as a control group to the same model. The frames were measured with regard to fit in a coordinate measuring machine linked to a computer. Measurements were made during different stages of handling of the titanium framework, and after veneering materials had been applied. Results The CNC frameworks showed a statistically better fit and precision of fabrication compared to conventional castings (P .05). Conclusion It is possible to fabricate implant-supported frameworks by means of the present CNC technique with a very high precision and repeatability.

Patient satisfaction with mandibular implant overdentures and conventional dentures 6 months after delivery.

Abstract: Purpose This study examined patient satisfaction with conventional complete dentures and mandibular implant overdentures opposing conventional maxillary dentures 6 months after delivery. Materials and methods Sixty edentulous subjects (aged 65 to 75 years) were randomly assigned to either a mandibular conventional denture or an overdenture supported by two implants with ball-shaped retentive anchors. Patients rated their general satisfaction and other features of their prostheses, together with their ability to eat certain food items, on 100-mm visual analogue scales before assignment, and after 2 and 6 months. Results Both treatment groups reported greater satisfaction with their new prostheses at 6 months. General satisfaction ratings were higher in the implant group than in the conventional denture group by approximately 36% (mean difference 22.3 mm). The implant group also rated comfort (mean difference 22.4 mm), stability (mean difference 28.5 mm), and ability to chew (mean difference 17.3 mm) significantly higher. Significantly higher scores were also given by the implant group for their ability to chew certain hard foods. A trend for an increase in the differences between the groups, in favor of the implant group, was observed between the 2- and 6-month recalls, although the increase was only significant for ease of cleaning. The primary influence on general satisfaction 6 months after the delivery of the prostheses was the provision of the two-implant overdenture. Conclusion Edentulous seniors who received mandibular implant overdentures opposing a conventional denture rated their general satisfaction approximately 36% higher than did a comparable group provided with new conventional dentures.

The impact of dental appearance on the appraisal of personal characteristics

Abstract: Purpose The purpose of this study was to ascertain the influence of dental appearance upon subjective ratings of personal characteristics, specifically social competence, intellectual ability, and psychologic adjustment. Materials and methods A cross-sectional analytic interview study was conducted with 201 undergraduates. Each participant was asked to make judgments about the personal characteristics of the subject of a single color photograph. Eight photographs of four different men were used, each with one of two degrees of dental status (visible disease, no visible disease). Outcome measures were participants' judgments of the social competence, intellectual ability, and psychologic adjustment of the subjects of the photographs. Results Participants judged subjects with less dental disease to be more socially competent, to show greater intellectual achievement, and to have better psychologic adjustment. Conclusion In the absence of other information, the judgments an individual makes concerning the personal characteristics of others are influenced by dental appearance.

Clinical Evaluation of Marginal Fit of a New Experimental All-Ceramic System Before and After Cementation

Abstract: PURPOSE The purpose of this in vivo study was to evaluate the marginal fit of inlay and crown abutments for fixed partial dentures (FPD) made from a new all-ceramic material. MATERIALS AND METHODS Sixteen patients were selected for the study. After abutment preparation, impressions were made and master dies were fabricated. FPDs were made with the experimental heat-pressed lithium-disilicate glass-ceramic following the manufacturer's recommendations. At random, one abutment of each FPD was chosen for evaluation (11 crown and 8 inlay abutments). Impressions of the restoration margins were taken before and after adhesive cementation. Replicas of the abutment margins were investigated by SEM. The marginal discrepancies were evaluated in sections of 200 microm. The highest value of each section was applied, and the mean of all sections of each replica was used for statistical analysis. RESULTS The median of the marginal discrepancies before cementation was 96 microm for crowns and 89 microm for inlays. After adhesive cementation, the median increased for crowns to 130 microm and for inlays to 92 microm, a significant increase in the marginal discrepancies caused by cementation for crowns, but not for inlays. There were no significant differences between the discrepancies of crowns and inlays before or after cementation. CONCLUSION The maximum marginal discrepancies found in this study were between 50 and 265 microm before cementation and between 70 and 285 microm after cementation, with no significant differences between the means for crowns and inlays. Adhesive cementation caused a significant increase of the marginal discrepancies for crown, but not inlay, abutments.

Ceramic implant abutments for short-span FPDs: a prospective 5-year multicenter study.

Abstract: Purpose A prospective, randomized, controlled 5-year multicenter study evaluated the long-term clinical function of CerAdapt ceramic abutments compared to titanium abutments on Branemark implants supporting short-span fixed partial dentures (FPD). Materials and methods Initially, 105 Branemark implants were placed in a total of 32 patients at three different clinics; 103 implants remained after initial healing. Fifty-three ceramic and 50 titanium abutments were connected to support 36 FPDs, 19 on ceramic and 17 on titanium abutments. Results Thirty patients with 29 FPDs were examined after 5 years. There was a cumulative success rate of 97.2% for FPDs (94.7% for ceramic and 100% for titanium abutment-supported FPDs). One of 53 ceramic and none of 50 titanium abutments failed, giving survival rates of 98.1% and 100%, respectively. There was a mean marginal bone loss of 0.3 mm and 0.4 mm, respectively, for ceramic and titanium abutments. Soft tissues around abutments and adjacent teeth appeared healthy, and no significant differences were recorded for mucosal bleeding and plaque between ceramic and titanium abutments. Crown margins at FPD insertion were positioned as follows: 21% submucosally, 33% at the mucosal margin, and 46% supramucosally. Changes in mucosal level were recorded at 12% of the abutments, with 73% of all changes recorded at ceramic abutments. There was a balance between more or less exposed crown margins during the first 2 years, in contrast to the 2- to 5-year period, when all changes meant less exposed margins. Conclusion Safe long-term functional and esthetic results can be achieved with CerAdapt alumina ceramic abutments on Branemark implants for short-span FPDs.

Marginal discrepancies and leakage of all-ceramic crowns: influence of luting agents and aging conditions.

Abstract: PURPOSE This study evaluated the marginal discrepancies and leakage of all-ceramic crowns cemented with different luting agents after fatigue tests. MATERIALS AND METHODS Forty-eight all-ceramic crowns were cemented onto natural molars. Zinc-phosphate cement, compomer cement, and an adhesive composite resin luting system were used in 16 specimens each. Sixteen metal-ceramic crowns were cemented with zinc-phosphate cement as a control. Half of the specimens in each group were fatigued in a chewing simulator for 600,000 loading cycles with 3,500 thermocycles. The others received the 3,500 thermocycles only. An impression-replica technique and SEM were used for evaluation of the marginal discrepancies. Leakage of the specimens was microscopically assessed. RESULTS There were no significant differences between marginal discrepancies of the groups, with the exception of porcelain shoulder margins in the metal-ceramic group, which had significantly larger discrepancies (P < .01). There was no significant effect of the fatigue tests on marginal discrepancies. However, significant differences of leakage were found between the groups cemented with the different luting agents after both fatigue tests. The adhesive composite resin luting system demonstrated the least leakage. The compomer cement showed an intermediate level of leakage, and the zinc-phosphate cement showed severe leakage that extended through the dentinal tubules to the pulp chambers. No significantly different effect of the two fatigue tests on the leakage was found. CONCLUSION The adhesive composite resin luting system showed clinically acceptable marginal discrepancies and an excellent ability to minimize leakage of all-ceramic crowns.

Comparison of the marginal fit of Procera AllCeram crowns with two finish lines.

Abstract: Purpose The purpose of this study was to determine the influence of two finish line configurations on the marginal accuracy of Procera AllCeram crowns. Materials and methods Twenty mechanized specimens of brass were fabricated for complete-coverage crowns. Two finish line designs were used: chamfer and rounded shoulder. AllCeram crowns were fabricated, and the fit of the crowns to the dies was recorded from the buccal and lingual margins. An image-analysis program was used to measure the gap. The results were subjected to statistical analysis using a Student's t test for separate samples and Student's paired t test. Results No significant differences were observed between the buccal and lingual measurements. When the values of the buccal and lingual measurements were averaged, there were no significant differences in the marginal gap, horizontal discrepancy, or internal adaptation of the axial wall, but there were significant differences in the vertical discrepancy, absolute marginal discrepancy, and internal discrepancy between the two finish line designs. Conclusion The marginal gap was within the range of clinical acceptability. Some of the variables were influenced by the two finish lines tested.

A long-term retrospective and clinical follow-up study of In-Ceram Alumina FPDs.

Abstract: Purpose The purpose of this study was to evaluate the long-term outcome of In-Ceram Alumina fixed partial dentures (FPD) performed in a general dental practice from 1992 to 1996. Materials and methods The study was conducted as a retrospective assessment of up to 9 years of patient records and a clinical follow-up examination of patients treated with In-Ceram Alumina FPDs. In 37 patients, 42 FPDs had been inserted during the selected period. After randomized selection, 16 patients with 18 FPDs were examined clinically. The most common restorations comprised two and three units. Cantilever extensions were present on 64% of the FPDs. Sixty-two percent of the FPDs extended into the posterior region. Results The mean time in function for the 42 FPDs was 76 months (range 2 to 110 months), with 86% being followed for > 5 years. No adverse effects to either periodontal or pulpal tissues were recorded. The technical quality was very good, and patient satisfaction very high. Five FPDs fractured during the observation period, resulting in a total failure rate of 12%. Two of these FPDs fractured as a consequence of external trauma. Excluding these, the total survival rate during the observation period was 93%. Cumulative survival rate according to life table analysis was 93% after 5 years and 83% after 10 years. Conclusion The results suggest that the In-Ceram Alumina short-span FPD is a viable prosthetic alternative.

Influence of surface conditions and silane agent on the bond of resin to IPS Empress 2 ceramic.

Abstract: Purpose: The aim of this study was to evaluate the effect of different ceramic surface treatments on the tensile bond strength between IPS Empress 2 ceramic framework and Rely X adhesive resin cement, with or without the application of a silane coupling agent. Materials and Methods: One hundred twenty disks were made, embedded in resin, and randomly divided into six groups: group 1 = sandblasting (100 mum), no silanation; group 2 = sandblasting (100 pm), silane treatment; group 3 = sandblasting (50 pm), no silanation; group 4 = sandblasting (50 pm), silane treatment; group 5 = hydrofluoric acid etching, no silanation; and group 6 = hydrofluoric acid etching, silane treatment. The disks were bonded into pairs with adhesive resin cement. All samples were stored in distilled water at 37degreesC for 24 hours and then thermocycled. The samples were submitted to tensile testing. Results: The use of silane improved the bond strength in relation to the groups in which silane was not applied (P < .05). The most effective surface treatment was etching with 10% hydrofluoric acid, both with (25.6 MPa) and without silane application (16.4 MPa); these values showed a statistically significant difference compared to sandblasting with 50- and 100-mum Al2O3. Sandblasting with 50-mum Al2O3, with (11.8 MPa) and without silane (5.4 MPa), demonstrated significantly higher tensile bond strength than sandblasting with 100-pm Al2O3, with (8.3 MPa) and without silane (3.8 MPa). Conclusion: Combined application of 10% hydrofluoric acid and silane enhanced the bond strength between the IPS Empress 2 ceramic framework and resin agent.

Evaluation of custom-made procera ceramic abutments for single-implant tooth replacement: a prospective 1-year follow-up study.

Abstract: PURPOSE The aim of this study was to evaluate the clinical performance of customized ceramic single-implant abutments in combination with two different techniques for fabricating crowns. MATERIALS AND METHODS Twenty consecutive patients were provided with 24 single-implant restorations with customized ceramic abutments. The restorations were either cemented to the abutment (n = 13) or fabricated with the veneering material fused directly onto the ceramic abutment (n = 11). The patients were evaluated at 6 and 12 months with radiographs and clinical parameters for complications and soft tissue response. RESULTS All implants and restorations were still in function after 1 year. Few clinical problems were reported during the follow-up period. The interproximal soft tissue recovered to near normal size. The mean marginal bone loss was similar for both groups, reaching an average of 0.3 mm (SD 0.71) after 1 year in function. CONCLUSION The short-term results indicate that customized ceramic abutments are successful and have comparable function, regardless of fabrication method.

An up to 15-year longitudinal study of 515 metal-ceramic FPDs: Part 2. Modes of failure and influence of various clinical characteristics.

Abstract: Purpose This study reported on the modes of failure and the influence of various clinical characteristics on the outcome of 515 metal-ceramic fixed partial dentures (FPD) involving 1,209 abutment and 885 pontics placed by one operator in a specialist prosthodontic practice between January 1984 and December 1997. Materials and methods Fifty-three percent of maxillary and 84% of mandibular FPDs involved one or more nonrigid abutment-pontic connections. Patients were recalled in 1993 (review 1) and 1998 (review 2) and clinically examined by the author. The modes of failure and influence of clinical characteristics, including abutment-pontic connection, post design in nonvital abutments, and regularity of professional maintenance, were evaluated. Results At review 2, 80% of the FPDs were still in function, while 9% required retreatment. Tooth fracture accounted for 38%, caries for 11%, loss of retention for 13%, and periodontal breakdown for 27% of retreatments. Nonrigid abutment-pontic connection in posterior FPDs and regular professional maintenance were associated with significantly reduced failure rates. Except in posterior molars, there was no difference in failure rates between parallel-sided preformed stainless steel serrated posts and cast-gold alloy posts. Conclusion Tooth fracture was the most common reason for retreatment of the FPDs, although the rate of periodontal breakdown and caries increased significantly with time. Nonrigid abutment-pontic connection and regular professional maintenance were associated with significantly reduced failure rates. Post design and composition were not related to outcome.

Fiber-reinforced composite crowns and FPDs: a clinical report.

Abstract: PURPOSE This clinical study reports on the results of single molar crowns, three-unit inlay fixed partial dentures (FPD), and complete-coverage FPDs made of the glass-fiber composite system Targis/Vectris with an observation period up to 4.4 years. MATERIALS AND METHODS In total, 38 restorations were inserted in 19 patients. Of these, 17 were adhesively fixed three-unit inlay FPDs, five were conventionally cemented complete-coverage three-unit FPDs, and 16 were single molar crowns (six adhesively, ten conventionally cemented). The mean observation period was 2.5 +/- 1.0 years. Events like fracture of the framework or veneer, loss of cementation, signs of wear, and outward discoloration were noted and rated according to modified Ryge criteria. RESULTS During the observation time, neither loss of cementation nor framework fracture were noted. However, six facings (36%) of the inlay FPDs fractured. The number of cases with discoloration or wear increased over time for all types of restorations. The wear culminated in fiber exposure of two molar crowns (24 months) and one inlay FPD (54 months). One of the five complete-coverage FPDs was replaced at the request of the patient (discoloration). The cumulative survival rate after 36 months was estimated to be 82% for molar crowns and 72% for inlay FPDs. CONCLUSION Fiber-reinforced composite restorations need further improvement of the veneering composites. Because of the increasing wear, discoloration, fractures of the facings, and fiber exposure, fiber-reinforced composites should only be used for provisional restorations.

Patient satisfaction following restoration of shortened mandibular dental arches in a randomized controlled trial.

Abstract: Purpose Removable partial dentures (RPD) used to restore the severely shortened mandible may adversely affect the remaining natural teeth and are associated with a low prevalence of use This pilot study investigated patient satisfaction following restoration of mandibular shortened dental arches Materials and methods Sixty subjects with mandibular shortened dental arches entered a randomized controlled trial comparing two types of mandibular prostheses: bilateral free-end saddle RPDs and distal cantilever resin-bonded fixed partial dentures (FPD) Patient satisfaction was assessed using self-administered questionnaires before (baseline), 3 months after, and 1 year after provision of new prostheses Results Improvements in levels of general satisfaction with teeth, appearance of teeth, and perceived masticatory ability were significant for the FPD group Significant improvements in perceived masticatory ability were noted for both groups There were also significant improvements in perceived levels of comfort of mandibular prostheses in both groups Changes in summary satisfaction scores indicated improved satisfaction for both treatment groups but suggested a larger clinical effect for the FPD group Significant differences between treatment groups were not established Conclusion Patient-based outcomes reported suggested that resin-bonded cantilever FPDs are an effective means of restoring the shortened mandibular dental arch in terms of patient comfort and acceptance

Relationship between prosthodontic evaluation and patient ratings of mandibular conventional and implant prostheses.

Abstract: PURPOSE The purpose of this study was to compare clinicians' ratings of the state of oral tissues and their satisfaction with treatment to edentulous patients' ratings of treatment success after provision of mandibular implant overdentures or conventional dentures. MATERIALS AND METHODS Sixty subjects randomly received either mandibular overdentures retained by two implants (n = 30) or new conventional mandibular complete dentures (n = 30). All were given new conventional maxillary dentures. Baseline measures included clinical evaluation of the oral soft and hard tissues. Patients rated their general satisfaction before and after treatment, as well as their satisfaction with stability, speech, and esthetics on visual analogue scales. The treating prosthodontist rated the dentures for the same categories. Patient and clinician ratings were compared using correlations, t tests, and linear regression. RESULTS None of the clinical variables were significantly correlated with patient satisfaction before or after treatment. The prosthodontist rated mandibular implant overdentures significantly better than conventional dentures regarding general satisfaction, stability, speech, and esthetics. Implant overdentures were also easier to fabricate (P < .0001). The prosthodontists' scores were not significantly correlated with patient scores for any question. CONCLUSION Clinicians' assessments of the quality of denture-supporting tissues are poor predictors of patient satisfaction with mandibular implant or conventional prostheses. Prosthodontists and patients both rate mandibular implant overdentures as significantly superior to conventional dentures, but patients and clinicians do not usually agree when evaluating individual prostheses.

Integration of laser surface digitizing with CAD/CAM techniques for developing facial prostheses. Part 1: Design and fabrication of prosthesis replicas.

Abstract: Purpose This article presents a novel manufacturing approach that integrates laser surface digitizing/scanning and computer-aided design (CAD) and manufacturing (CAM) to achieve automated fabrication of spatially and anatomically accurate extraoral facial prostheses. Materials and methods Topologic data of the patient's face, including the site of deformity and the anatomy of a healthy "donor" organ, were acquired using laser surface digitizing. Two different CAD data manipulation techniques were developed to alleviate problems encountered in laser-digitized data sets. To reduce patient involvement, fitting of the prosthesis was conducted using a computer model of the patient's face. Once finalized, rapid prototyping techniques were employed to fabricate a master pattern to cast the final prosthesis. Results Three case studies involving different facial prostheses were conducted to evaluate the integrated manufacturing system. The results demonstrated the many advantages of the system for facial prosthesis production. Conclusion With the new manufacturing approach, reduced patient discomfort, minimal dependence on the artistic skills of the prosthetist, and short turnaround times for prosthesis production can be expected.

In vivo forces on implants influenced by occlusal scheme and food consistency.

Abstract: Purpose The aim of this study was to investigate whether systematic modifications of occlusal features or food consistency are suitable to reduce the loading of implants. Materials and methods Ten healthy subjects, each of whom had a gap in the chewing center (second premolar or first molar) of one lateral dental arch, were provided with fixed partial dentures (FPD) on two ITI implants. Strain gauges attached to the abutments recorded forces in three dimensions. In each person, the original FPD was successively replaced by three FPDs with different occlusal schemes: The first had steep cusps, the second had flat cusps, and the third had the same cuspal inclination as the first but a narrow occlusal surface. Subjects chewed gummy bears and bread as a tough and a soft bolus, respectively. Results In chewing of gummy bears, the mean vertical forces of the three FPDs ranged between 264 and 284 N and were not significantly different. The mean bending moments amounted to 27 Ncm and 24 Ncm with steep and flat occlusal slopes, respectively. With the narrow occlusal surface, the bending moments were reduced by 48%, to a mean of 11 Ncm. Chewing of bread yielded similar relations with lower mean vertical forces and bending moments. Conclusion Narrowing the orovestibular width of the occlusal surface by 30% caused a significant reduction of lateral force components. A reduced orovestibular width of the occlusal surface is recommended in unfavorable loading conditions. In addition, the chewing of soft food is suggested during the healing period in cases of immediate loading.

Correlation between patient satisfaction with complete dentures and denture quality, oral condition, and flow rate of submandibular/sublingual salivary glands.

Abstract: Purpose The purpose of this study was to examine the correlation between patient satisfaction with complete dentures and parameters of denture quality, oral condition, and flow rate of the submandibular and sublingual salivary glands. Materials and methods The parameters were evaluated on 50 denture wearers using semiquantitative scales and a recently described submandibular/sublingual saliva collector. Results Most patients had a medication-induced reduced salivary flow rate (mean 0.024 mL/min/gland; SD 0.040). Submandibular/sublingual salivary flow rate correlated statistically with six denture satisfaction parameters: maxillary denture retention and comfort, mandibular denture retention and comfort, abilities of chewing, and speech. Residual alveolar ridge resilience, maxillary ridge shape, and denture quality did not significantly correlate with denture satisfaction. Characteristics of musculature correlated significantly only with subjective maxillary denture retention, and mandibular ridge shape correlated with comfort. Conclusion Submandibular/sublingual salivary flow rate is an important factor in denture satisfaction. The retention of the maxillary denture was correlated to the oral musculature characteristics, and the mandibular denture comfort was correlated to the mandibular ridge shape. Denture satisfaction was not affected by other anatomic or denture quality-related parameters.

Signs and symptoms associated with TMD in adults with shortened dental arches.

Abstract: Purpose: This study investigated the prevalence of signs and symptoms associated with temporomandibular disorders (TMD) in adults with shortened dental arches in Tanzania. Materials and Methods: The shortened dental arch group comprised 725 subjects with an intact anterior region and zero to eight occluding pairs of teeth posteriorly. They were categorized into five groups according to length and symmetry of the dental arches. A control group of 125 subjects with complete dental arches was included. The subjects were interviewed with questions related to pain and sounds within the temporomandibular joints and restricted mobility of the mandible. Clinical examination consisted of registration of clicking or crepitation of the joints, measuring maximum mouth opening, and assessing occlusal tooth wear. Results: Joint sounds were reported significantly more frequently by subjects with posterior support only unilaterally (17%) and by subjects with no posterior support (10%) compared to other categories of dental arches (3% to 5%). No significant differences were found between categories of dental arches with respect to pain (2% to 9%), restricted mobility of the mandible (0% to 1%), maximum mouth opening < 40 mm (0% to 3%), or clicking or crepitation of the joints (12% to 23%). For the younger age group (≥ 20 and < 40 years), tooth wear occurred significantly more often in subjects with no posterior support. For the older age group (≥ 40 years), tooth wear increased significantly with decrease of posterior support. Conclusion: No evidence was found that shortened dental arches provoke signs and symptoms associated with TMD. However, when all posterior support is unilaterally or bilaterally absent, the risk for pain and joint

Implant-supported fixed partial prostheses: a retrospective study.

Abstract: Purpose The purpose of this retrospective study was to present treatment outcome and patient reactions to rehabilitation with implant-supported fixed partial prostheses. Materials and methods Eighty-three patients were consecutively treated with implant-supported fixed partial prostheses (Branemark system) from 1986 to 1995. Seventy-six of these 83 patients were examined (66 maxillary and 31 mandibular prostheses). The mean observation time was 53.9 months. In total, 285 implants were placed. Eleven implants were lost before loading. The first 41 prostheses were removed and the implants examined regarding the criteria for "success" and tightness of the screw joints. Only one implant had lost integration. Results The survival rate before and after loading was 96%, which included implants placed in augmented bone. All prostheses were stable at the time of examination. In prostheses with cantilevers (98 implants), 12% of the gold screws and 17% of the abutment screws showed a "not acceptable" loosening, compared to none in the prostheses without cantilevers (17 implants). The difference was not statistically significant. The mean marginal bone loss was 0.4 mm for the first year after prosthesis insertion and less than 0.1 mm per year in the following years. The most frequent prosthesis design was one pontic supported by two implants. Prostheses made in gold acrylic and titanium acrylic had more complications and showed a higher need for repair than metal-ceramic restorations. Patients reacted very positively to the esthetic results and comfort with eating, and were overall satisfied with their prostheses. Conclusion Implant-supported fixed partial prostheses seem to have a very good prognosis and are well-accepted by patients.

Effectiveness of Microwave Sterilization on Three Hard Chairside Reline Resins

Abstract: PURPOSE The aim of this study was to evaluate the effectiveness of microwave irradiation sterilization on hard chairside reline resins. MATERIALS AND METHODS Specimens of three reline resins (Kooliner, Tokuso Rebase, and Ufi Gel Hard) were fabricated and subjected to ethylene oxide sterilization. The specimens were then individually inoculated (10(7) cfu/mL) with Tryptic Soy Broth media containing one of the tested microorganisms (C albicans, S aureus, B subtilis, and P aeruginosa). After 48 hours at 37 degrees C, the samples were vortexed for 1 minute and allowed to stand for 9 minutes, followed by a short vortex to resuspend any organisms present. After inoculation, 40 specimens of each material were immersed in 200 mL of water and subjected to microwave irradiation at 650 W for 6 minutes. Forty non-irradiated specimens were used as positive controls. Replicate specimens (25 microL) of suspension were plated at dilutions of 10(-3) to 10(-6) on plates of selective media appropriate for each organism. All plates were incubated at 37 degrees C for 48 hours. After incubation, colonies were counted, and the data were statistically analyzed by the Kruskal-Wallis test. Twelve specimens of each material were prepared for SEM. RESULTS All immersed specimens showed consistent sterilization of all the individual organisms after microwave irradiation. SEM examination indicated an alteration in cell morphology after microwave irradiation. CONCLUSION Microwave sterilization for 6 minutes at 650 W proved to be effective for the sterilization of hard chairside reline resins.

Depth of light-initiated polymerization of glass fiber-reinforced composite in a simulated root canal.

Abstract: Purpose The possibility of polymerizing glass fiber-reinforced composite (FRC) material into the root canal was preliminarily evaluated by determining the depth of light-initiated polymerization of FRC. Materials and methods The material used was polymer-preimpregnated E-glass fiber reinforcement, which was further impregnated with light-polymerizable dimethacrylate monomer resin. The same resin without fiber reinforcement was used as a control. Six different lengths (range 4 to 24 mm) of light-protected cylinders filled with the test materials were light polymerized from one end. The degree of monomer conversion was determined from the other end by FT-IR spectrometry. Infrared spectra were recorded at six time points from the beginning of polymerization. The microhardness of the test materials was measured from the light-exposure surface toward the other end of the cylinder. Results Both groups showed a reduction in the degree of conversion with increased lengths of the cylinder. The FRC group showed a higher degree of conversion in the longest sample group compared to the resin group. Microhardness measurement confirmed the constant reduction of the degree of conversion by the reduced Vickers hardness values with increased cylinder length of the FRC. Conclusion Generally, the glass FRC showed an almost equal degree of conversion after light curing as monomer resin without fibers. However, in the longest cylinders, FRC showed a slightly higher degree of conversion compared to resin only; this might be due to the fibers' ability to conduct light.

Longevity and quality of FPDs: a retrospective study of restorations 30, 20, and 10 years after insertion.

Abstract: PURPOSE: The aim of this retrospective study was to investigate the longevity and clinical performance of fixed partial dentures (FPD) 30, 20, and 10 years after insertion. MATERIALS AND METHODS: A ...

A retrospective analysis of factors associated with the periapical status of restored, endodontically treated teeth.

Abstract: Purpose The purpose of this study was to explore possible associations between prosthodontic, occlusal, endodontic, and periodontal factors and the endodontic status of endodontically treated teeth Materials and methods Forty-six patients who had received endodontic treatment followed by a fixed restoration for at least one of their teeth were recalled and examined clinically and radiographically according to a predetermined set of evaluation criteria A total of 89 teeth were included, and data obtained included assessments of the coronal restoration and post and core, occlusal contact relationships, a number of endodontic parameters, and periodontal status of the study teeth For the latter assessment, 54 contralateral teeth were available for purposes of comparison Teeth were grouped into those with and without periapical radiolucencies, and differences between the groups, with respect to all parameters, were analyzed by logistic regression Results Three factors were significantly associated with the presence of radiolucency: confirmed occlusal contact, by virtue of the tooth being either involved in group function or the only contact in working-side and protrusive movements, and endodontic filling and crown margins of poor quality None of the other independent variables showed significant associations with the dependent variable of periapical radiographic appearance Contralateral teeth had better periodontal conditions than restored study teeth Conclusion The finding that a good-quality endodontic filling and crown margin improve endodontic outcome corroborates many other similar reports; however, with occlusal contact shown to be associated with failing endodontic treatment, the range of factors that may influence endodontic outcome appears to have widened