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The aim of this study was to evaluate the wear of denture teeth and their antagonists produced by two-body and three-body wear tests. Three types of denture teeth, namely feldspathic ceramic (FC), nano-filled composite resin (NCR), and experimental acrylic resin teeth (AR), were tested. For each type two groups of eight upper premolars each were prepared. The first group was tested against cusps from the same material and the second group was tested against human enamel cusps. Each group was loaded with a total of 200,000 chewing cycles (two-body wear 100,000 cycles and three-body wear 100,000 cycles). Wear was analyzed by measuring the maximum depth and volume loss of the denture teeth using a laser scanner and by measuring the vertical loss of the antagonists using an optical macroscope. Statistically, there was no significant difference between the following combinations: FC-FC and NCR-NCR regarding the vertical and volume loss; and FC-enamel and NCR-enamel regarding the total vertical substance loss. The combinations AR-AR and AR-enamel showed higher wear values than the other combinations. For complete dentures, composite resin and ceramic teeth showed similar vertical and volume loss, whereas composite resin teeth seemed to be more suitable for partial dentures opposing natural teeth in terms of wear of teeth and antagonists.

Objective: The aim of this case report was to present a minimally invasive and esthetic treatment approach for the replacement of missing teeth removable partial dentures retained by zirconia ceramic resin-bonded attachments. Method and materials: The resin-bonded attachments were digitally designed and milled using CAD/CAM technology from monolithic 3Y-TZP zirconia ceramic. The resin-bonded attachments had an optimized attachment design approved for zirconia ceramic. The preparation was based on general preparation guidelines for resin-bonded attachments and resin-bonded fixed dental prostheses (RBFDPs). After placement of rubber dam, the resin-bonded attachments were bonded with a phosphate monomer-containing luting resin. Results: The presented resin-bonded attachment-retained removable partial denture was successful over 30 months of clinical observation without any complications. The patient was satisfied with the minimally invasive treatment procedure. Conclusion: Zirconia ceramic resin-bonded attachments fabricated with a special attachment design are an esthetic and minimally invasive treatment approach. However, clinical data on the long-term outcome of zirconia resin-bonded attachments are still needed. [ABSTRACT FROM AUTHOR]

Purpose: To present a minimally invasive treatment approach for the replacement of two missing adjacent teeth with two single-retainer resin-bonded fixed dental prostheses (RBFDPs). Materials and Methods: Two missing adjacent premolars were restored by two RBFDPs with an innovative design of the proximal section. Both RBFDPs were digitally designed and milled from monolithic 3Y-TZP zirconia ceramic using CAD/CAM. Following construction of the anterior RBFDP, a shallow interlock was designed in the area of proximal contact in the same insertion direction as the posterior RBFDP. In this way, different paths of insertion of the RBFDPs could be provided without compromising the proximal hygiene capability. Results: The presented minimally invasive restorations were successful over 5 years of clinical observation without any complications. Conclusion: The presented restoration design secures the transversal position of the RBFDPs while maintaining physiologic tooth mobility. In addition, it allows for varying paths of insertion while improving hygienic conditions. Last, in case of a unilateral debonding of one retainer wing, rebonding might be possible. [ABSTRACT FROM AUTHOR]

Copyright of Implantologie is the property of Quintessenz Verlags GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Preservation and restoration of teeth with little coronal tooth structure due to crown-root fractures or caries lesions, ensuring restoration margins do not encroach on the biologic width, constitute a challenge. Available treatment options include surgical crown lengthening and orthodontic or surgical extrusion. This report presents two patients in which teeth were restored by surgical extrusion with an atraumatic extraction system and prosthetic therapy. [ABSTRACT FROM AUTHOR]

Purpose: This clinical study aimed to evaluate the outcomes of resin-bonded attachments (RBAs) for precision-retained removable dental prostheses (RDPs) after at least two years of clinical maintenance. Methods: Since December 1998, 205 RBAs (44 bonded to posterior teeth, 161 to anterior teeth) have been inserted in 123 patients (62 females and 61 males; mean age, 63.6 ± 9.6 years) who were recalled annually. The abutment teeth underwent a minimally invasive preparation limited to the enamel. RBAs were cast in a cobalt-chromium alloy with a minimum thickness of 0.5 mm and adhesively luted with a luting composite resin (Panavia 21 Ex or Panavia V5, Kuraray, Japan). We evaluated caries activity, plaque index, periodontal condition, and tooth vitality. The Kaplan-Meier survival curves were used to account for the reasons for failure. Results: The mean observation time of RBAs until the last recall visit was 84.5 ± 51.3 months (range, 3.6-270.6). During the observation period, 33 RBAs debonded in 27 patients (16.1%). The 10-year success rate according to the Kaplan-Meier analysis was 58.4%, which dropped to 46.2% after 15 years of observation if debonding was considered a failure. If rebonded RBAs were regarded as surviving, the 10- and 15-year survival rates would be 68.3% and 61%, respectively. Conclusions: The use of RBAs for precision-retained RDPs appears to be a promising alternative to conventionally retained RDPs. As reported in the literature, the survival rate and frequency of complications were comparable with those of conventional crown-retained attachments for RDPs. [ABSTRACT FROM AUTHOR]

Objectives: To present an update on the concept of cantilevered single‐retainer all‐ceramic resin‐bonded fixed dental prostheses (RBFDPs) first presented 25 years ago in the Journal of Esthetic Dentistry. Overview: The initially presented case of the concept was followed clinically over 26 years and is presented along with two additional clinical long‐term cases using varying methods to obtain an esthetic and hygienic ovate pontic design. Veneered alumina and zirconia ceramic (3 mol% yttria–tetragonal zirconia polycrystalline ceramic; 3Y‐TZP) was used and bonded with a phosphate monomer containing luting resin after 50 μm alumina particle air‐abrasion at 0.25 MPa pressure. The restorations replacing incisors did not debond and soft tissues in the pontic area were maintained over 26 years. Conclusions: Cantilevered single‐retainer all‐ceramic RBFDPs today made from veneered 3Y‐TZP zirconia ceramic can be considered a standard of care for the replacement of single incisors and provide an excellent esthetic outcome with a long‐term preservation of soft tissues in the pontic area. Clinical Significance: Bonding nonretentive oxides ceramics such as alumina and zirconia ceramic with phosphate monomer containing luting resins after alumina particle air‐abrasion is durable over decades. This proves that bonding to zirconia ceramic is not of any problem when adequate methods are used. Single‐retainer zirconia ceramic RBFDPs maintain soft tissues in the edentulous area of single missing incisors and often deem implants unessential for this indication. [ABSTRACT FROM AUTHOR]

Fixed dental prostheses are the standard treatment option for replacing missing teeth when adjacent teeth require crowns or are already restored with crowns. Divergent abutment teeth axes may require invasive teeth preparation to achieve a common path of insertion, which substantially weakens residual tooth structure and increases the risk of pulpal problems. In selected cases with divergent abutment teeth in the buccal-lingual direction, the use of a rotational path of insertion might overcome these problems. This concept is presented via a clinical case history report. [ABSTRACT FROM AUTHOR]

This article describes single-retainer resin-bonded fixed dental prostheses (RBFDPs) as an excellent alternative to orthodontic space closure or tooth replacement with implants or conventional fixed dental prostheses for congenitally and traumatically missing anterior teeth. Although the treatment with RBFDPs is technique sensitive, it is extremely reliable given a correct indication and adequate adhesive procedures. [ABSTRACT FROM AUTHOR]

Copyright of Quintessenz der Zahntechnik is the property of Quintessenz Verlags GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: To investigate the chewing efficiency and oral health‐related quality of life of edentulous patients wearing complete dentures, successively supported by one, two, and three implants in the mandible. Methods: Thirteen (13) edentulous patients of at least 50 years of age received three implants in the mandible. After a conventional submerged healing period, the central implant was uncovered and connected to the denture base using a stud attachment. Two months later, chewing efficacy was evaluated, and the two lateral implants were uncovered and connected to the denture base. The central retention element was replaced by a short healing abutment with no connection to the denture base. Chewing efficiency was evaluated two months later. Afterward, the healing abutment of the central implant was replaced by a stud attachment and again connected to the denture base. Two months later, chewing efficacy was evaluated again. Oral health‐related quality of life (OHRQoL) was measured at each recall visit using the summary score of the oral health impact profile. For statistical analysis of chewing efficacy, the changes from baseline (with no implants) to one, two, and three implants were used and tested by analysis of variance with repeated mesurements. Results: Chewing efficacy clearly increased after implant loading, with a significant increase when two implants were loaded (p ≤.05), compared to the chewing efficacy with no implants. OHRQoL also significantly improved after implant loading. Conclusions: Within the limitations of the present clinical trial regarding the number of patients, chewing efficacy as well OHRQoL of edentulous patients improve after implant placement in the mandible, irrespective of the number of implants. The best chewing efficacy was achieved with two implants. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare the long-term outcomes of two different nonimplant treatments in the bilateral shortened dental arch (SDA).Materials and Methods: In a multicenter randomized controlled clinical trial, patients with complete molar loss in one arch were assigned to one of two different nonimplant treatments. In the partial removable dental prosthesis (PRDP) group, patients were provided with a distal-extension prosthesis retained with precision attachments. In the SDA group, patients were treated according to the SDA concept by preserving or restoring a premolar occlusion.Results: Of the 152 treated patients, 82 reached the 10-year examination independent of their dental or prosthetic status. In the intention-to-treat analysis, the survival rates for tooth loss at 10 years were 0.44 (95% confidence interval [CI]: 0.30 to 0.56) in the PRDP group and 0.52 (95% CI: 0.37 to 0.65) in the SDA group. For tooth loss in the study arch, the survival rates were 0.67 (95% CI: 0.52 to 0.78) in the PRDP group and 0.60 (95% CI: 0.45 to 0.73) in the SDA group. The number of teeth lost was higher than expected. In a multivariate analysis using a multiple Cox regression model, the covariates age (unit: 1 year, Hazard Ratio [HR]: 1.033, P = .03) and DMFT value (unit: 1 tooth, HR: 1.121, P = .03) were significant for time to first tooth loss in the study arch.Conclusion: The results suggest an overestimation of the influence of the prosthetic management of the bilateral SDA. In treatment decisions, patient preferences should be considered with appropriate weight. [ABSTRACT FROM AUTHOR]

Purpose: The main goal of this in-vitro study was to evaluate whether tensile strength and retrievability of cemented implant-retained crowns correlate when using artificial aging.Materials and Methods: A total of 128 crowns were fabricated from a cobalt-chromium alloy for 128 tapered titanium abutments (6 degrees taper, 4.3 mm diameter, 4 mm length, Camlog). The crowns were cemented with glass-ionomer (Ketac Cem, 3M) or resin cements (Multilink Implant, Telio CS Cem [Ivoclar Vivadent], Retrieve [Parkell]). Multilink Implant was used without priming. The experimental groups were subjected to either 37,500 thermal cycles between 5°C and 55°C, 1,200,000 chewing cycles, or a combination of both. Control groups were stored for 10 days in deionized water. The crowns were removed with a universal testing machine or a clinically used removal device (Coronaflex, KaVo). Data were statistically analyzed using nonparametrical tests.Results: Retention values were recorded between 31 N and 362 N. Telio CS Cem showed the lowest retention values, followed by Retrieve, Ketac Cem, and Multilink Implant (P≤.0001). The number of removal attempts with the Coronaflex were not significantly different between the cements (P>.05). Thermal cycling and chewing simulation significantly influenced the retrieval of Retrieve Telio CS Cem, and Ketac Cem specimens (P≤.05). Only for Multilink Implant and Telio CS Cem correlations between removal with the universal testing machine and the Coronaflex could be revealed (P≤.0001).Conclusions: Ketac Cem and Multilink Implant (without silane) can be used for a semipermanent cementation. Retrieve and Telio CS Cem are recommendable for a temporary cementation. [ABSTRACT FROM AUTHOR]

Inlay-retained fixed dental prostheses (IRFDPs) represent a minimally invasive alternative to conventional fixed dental prostheses (FDPs) to replace single posterior missing teeth. The aim of the present review article is to assess the clinical outcome of different IRFDPs in order to derive recommendations regarding their clinical application. Hence, it is essential to highlight important factors that influence the longevity and success of IRFDPs, such as treatment plan, appropriate case selection with proper indications, as well as tooth preparation. Furthermore, a good understanding of bonding technologies and awareness of pretreatment procedures for different materials are indispensable for the long-term success of IRFDPs. [ABSTRACT FROM AUTHOR]

Single-retainer resin-bonded fixed dental prostheses (RBFDPs) present a minimally invasive treatment option as an alternative to implant-retained restorations in the esthetic zone. Advantages such as applicability to juvenile patients who do not come into consideration for implant therapy, and highly predictable and esthetic results make them a valuable treatment modality. This article outlines the treatment procedures with an all-ceramic RBFDP and reviews the existing data on the clinical outcome of this prosthetic therapy. The materials used for fabrication and insertion of the RBFDPs as well as the current scientific data are discussed. [ABSTRACT FROM AUTHOR]

Purpose: This analysis focused on periodontal health in shortened dental arches (SDAs). Methods: In a randomized controlled clinical trial, patients with missing molars in one jaw and at least one premolar and canine on both sides were eligible for participation. In the partial removable dental prosthesis (PRDP) group (n = 79), molars were replaced with a precision attachment retained PRDP. In the SDA group (n = = 71), the SDA up to the second premolars was either left as is or restored with fixed dental prostheses. Outcome variables were vertical clinical attachment loss (CAL-V), pocket probing depth (PPD), bleeding on probing (BOP) and plaque index (PLI). For CAL-V and PPD, the changes at six measuring points per tooth were analyzed. For BOP and PLI, patient related rates were calculated for each point in time. Statistical methods included linear regression analyses. Results: In the intention-to-treat (ITT) analysis for CAL-V in the study jaw, the 10 year patient related mean changes were 0.66 mm in the PRDP group and −0.13 mm in the SDA group. The resulting mean patient related group difference of 0.79 mm (95% CI: 0.20 mm–1.38 mm) was significant (p = 0.01). There were no significant differences in the ITT analyses for PPD. For BOP and PLI, significant group differences with more favorable results for the SDA group were found. Conclusions: In view of lacking substantial differences for CAL-V and PPD, the overall differences were considered of minor clinical relevance. The results add confirmatory evidence to the shortened dental arch concept and its clinical viability (controlled-trials.com ISRCTN97265367). [ABSTRACT FROM AUTHOR]

Objectives: The study evaluated the influence of the number of retention grooves and the retainer wing thickness on the retention of resin-bonded attachments (RBAs). Methods: Overall, 64 extracted human teeth were prepared, whereby the number of retention grooves (4, 2, 1, or no grooves) and the material thickness (0.7 or 0.5 mm) of the RBAs were varied. This resulted in eight groups with eight specimens each. A sample size of eight specimens per group was chosen because the chewing simulator used for dynamic loading can load eight specimens at a time. After the size of the adhesive area was determined, the abutment teeth were provided with RBAs and subjected to a dynamic loading with thermal cycling. Finally, the failure load was examined using a retention test. Results: The mean failure loads ranged from 152 ± 50 N to 228 ± 32 N. There had been a significant interaction between the two main factors, i.e., number of retention grooves and material thickness. Neither the number of retention grooves nor the size of the adhesive area had a significant influence on the failure load. Conclusions: Using a reduced number of retention grooves seems reasonable. However, clinical considerations suggest using two retention grooves to simplify the preparation and bonding procedures. Clinical relevance: The retention of resin-bonded attachments is promising and supports the clinical application of this minimally invasive treatment modality. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Computerized Dentistry is the property of Quintessence Publishing Company Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: To evaluate the wear resistance of artificial denture teeth and their human enamel antagonists in a dual-axis chewing simulator. Method and Materials: Four artificial denture teeth—feldspathic ceramic, nanofilled composite resin, experimental acrylic resin with UDMA/PMMA, and interpenetrating polymer networks (IPN) acrylic resin teeth— were tested in this study. Human enamel cusps were used as antagonists. Wear resistance was analyzed by measuring the vertical substance loss and the volume loss of the denture teeth using a laser scanner after 300,000 chewing cycles. In addition, the vertical substance loss of the antagonists was evaluated using an optical macroscope. Data were statistically analyzed using ANOVA. For qualitative analysis of the wear areas, the teeth were sputter coated with gold and evaluated at magnifications of 50× and 1,000× using SEM. Results: The composite resin teeth exhibited wear that was significantly higher than that of feldspathic ceramic but lower than that of acrylic resin teeth (P < .05). Acrylic resin teeth caused no measurable wear on the enamel antagonists. The wear patterns of the feldspathic ceramic and composite resin teeth can be described as attritional, while a fatigue type of wear was observed in the acrylic resin teeth. Conclusion: The lowest total vertical substance loss was found for the combination composite resin-enamel. Based on the results of this study, composite resin teeth seem to be more suitable for dentures opposing natural teeth than ceramic or acrylic resin teeth in terms of wear resistance. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the retention and the wear of different prefabricated precision ball attachments consecutively during long-term use. Method and Materials: Six commercially available ball attachment systems were selected. The balls were attached to stylized implants fixed in metal casts. The matrices were fixed in a stylized unilaterally removable partial denture (RPD). Using a chewing simulator with 8 units, 50,000 joining and separating cycles of the matrices were performed. After each joining movement, an eccentric load of 100 N was applied to the RPD at a distance of 12 mm from the ball attachment. The retention forces were measured at intervals. Results: Initially, median retentive forces varied between 8.2 N and 14.0 N. During the test, patterns in retention changes were identified. At the end of the test, one group with a matrix using precious alloy lamellae and a titanium ball showed significantly higher median retention forces (10.4 N) than the other ball attachments (1.0 N to 3.7 N). Also, the wear of the ball attachments varied considerably. Conclusion: Within the limitations of this study, the material combination of a precious gold alloy matrix and a titanium ball seems to be favorable for long-term retention. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to correlate the general well-being of patients and their judgment about their dental appearance. Materials and Methods: Based on internationally accepted guidelines regarding dental esthetics, a questionnaire was developed to measure subjective assessments of dental appearance. Fourteen items defined an esthetic sum score (0 = satisfied; 56 = dissatisfied). Further, general wellbeing was evaluated with a long-established and highly reliable test. Eighty participants were included (47 women, 33 men). Participants were drawn from 4 different groups (n = 20): natural dentition (group N), fixed partial dentures (group F), removable partial dentures (group R), and patients who had an esthetic problem with their teeth (group P). Results: Seventy-five participants showed a normal well-being. Five participants showed a depressive state and formed a new group (group D). The medians of the sum scores (25th, 75th percentile) were: group N: 12 (10, 14); group F: 14 (8, 29); group R: 14 (9, 27); group P: 23 (18, 35); group D: 30 (26, 35). Significant differences were found between groups N and P, as well as between group D and groups N, F, and R. Conclusion: Because of the significant difference between groups N and P, basis validation of the sum score was achieved. Further, selfassessments of dental appearance appeared to be more negative for participants with a depressive state compared with the other groups. In clinical studies, selection bias can be prevented by using a test that measures well-being to verify if a study sample includes a normal number of depressive subjects and therefore represents the general population. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this preliminary prospective study was to evaluate the clinical outcome of crown-retained and inlay-retained fixed partial dentures (FPDs) made from a new lithium-disilicate glass-ceramic (IPS e.max Press, Ivoclar Vivadent). Materials and Methods: Eighty-one 3-unit FPDs were placed in 68 patients. The FPDs replaced teeth in the anterior (8%) and posterior region (92%). All teeth were prepared according to a standardized protocol. The size of the proximal connector of the FPDs was 12 mm2 (anterior) or 16 mm² (posterior), respectively. Crown-retained FPDs were cemented either with glass ionomer (n = 20) or resin composite (n = 16), while all inlay-retained FPDs (n = 45) were cemented with resin composite. Initial follow-up was performed at 6 and 12 months and annually thereafter. Results: The mean observation periods were 48 months (for crown-retained FPDs) and 37 months (for inlay-retained FPDs). None of the crown-retained FPDs failed during the observation period, while 6 inlay-retained FPDs (13%) had to be replaced. Six cases failed because of debonding (n = 3) or a combination of debonding and fracture (n = 3). During the observation period, 2 patients died and the status of another 5 patients is unknown. The 4-year survival rate according to Kaplan-Meier was 100% for crownretained FPDs and 89% for inlay-retained FPDs. The differences between the groups were statistically significant. Conclusion: Crown-retained 3-unit FPDs made from a new glass-ceramic have a significantly better outcome up to 5 years than inlayretained 3-unit FPDs over the observation period. [ABSTRACT FROM AUTHOR]

To investigate the impact of inlay design and number of retainer wings on the failure load of all-ceramic resin-bonded inlay-retained cantilever fixed dental prostheses (IRCFDPs) made from a computer-aided design/computer-aided manufacturing (CAD/CAM) yttrium-oxide partially-stabilized zirconia framework(Y-TZP). Sixty-four extracted human first molars were divided according to preparation design into four groups. Teeth were provided with IRCFDPs representing a premolar pontic and a retainer of variable design: (R1S) shallow inlay/one lingual retainer wing, (R2S) shallow inlay/two retainer wings (lingual/buccal), (R1D) deep inlay/one lingual retainer wing and (R2D) deep inlay/two retainer wings (lingual/buccal). All IRCFDPs were cemented using adhesive resin. Quasi-static fracture strength (QSFS) was tested for 32 specimens after 3 days in a universal testing machine (UTM). The other specimens were stored in a water bath (150 days/37 °C) and thermocycled (37,500 times, 5–55 °C); then exposed to dynamic loading in a chewing simulator (50 N/1,200,000 cycles). The median QSFS (N) for the different designs were: R1S:105.1, R1D:167.5, R2S:147.9, R2D:232.3. The number of retainer wings had a statistically significant influence on the fracture load of both groups, whereas the inlay design had an impact only in the double-retainer wing group. Under dynamic loading, lower failure loads within all groups were reported except for the group R2S. The number of retainer wings continued to significantly influence the failure loads of both groups, whereas no influence of inlay design could be revealed. Double-retainer IRCFDPs showed promising results for replacing single premolars. The inlay design seems to have no significant influence on the fracture strength of these restorations. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this prospective clinical study was to compare the maintenance interventions required for solely implant‐retained overdentures (I‐OD) with that of overdentures retained by a combination of telescopic crowns and implants (T/I‐OD). Materials and methods: The participants in this study were 22 patients who initially presented either with a removable complete denture (n = 11) or with an overdenture retained by 1 to 2 telescopic crowns on natural teeth (n = 11). Subsequently, the total number of abutments was increased to 5 to 6 (maxilla) or 4 to 5 (mandible) by placing implants in strategically advantageous regions, generating two distinct groups: I‐OD and T/I‐OD. Ball attachments were connected to the implants and integrated into the existing denture. The maintenance aspects were analyzed according to the type of treatment (preventive, biological, and technical) and to the severity of treatment (minimal, moderate, and extensive). Results: During a mean observation time of 6.5 years, the tooth survival rate was 89% (T/I‐OD) and the implant survival rate 100% (both groups). The survival rates of the overdentures ranged from 90.9% (I‐OD) to 100% (T/I‐OD). A mean number of 0.6 (I‐ODs) and 2.0 (T/I‐OD) treatments were performed for biological reasons; and 8.2 (I‐ODs) and 9.6 (T/I‐OD) for technical reasons, per patient, during the observation time. From biological aspects, significantly more extensive maintenance was found to be necessary in the T/I‐OD group than in the I‐OD group. Conclusions: The therapeutic concept of implant placement under existing prostheses was promising when performed in indicated cases. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the wear resistance of artificial teeth when opposed by antagonists made from the same material. The artificial teeth tested included ceramic teeth, nanofilled composite resin teeth, acrylic resin teeth, and experimental acrylic resin teeth. After 600,000 chewing cycles, the mean total vertical substance loss and mean volume loss for acrylic resin and experimental acrylic resin teeth were significantly lower than for ceramic and composite resin teeth. Composite resin teeth showed more wear than ceramic teeth, while acrylic resin teeth showed less wear than ceramic teeth. However, scanning electron microscopy and laser-scanner observations showed that acrylic resin teeth exhibited deformation at the contact surfaces. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: This review evaluated the survival rate of single retainer anterior resin‐bonded fixed dental prostheses (RBFDPs) to determine whether the choice of material affects their clinical outcome. Materials and Methods: An electronic search of the English peer‐reviewed dental literature in PubMed was conducted to identify all publications reporting on cantilever RBFDPs until May 2016. Study information extraction and methodological quality assessments were accomplished by two reviewers independently. The searched keywords were as follows: “resin‐bonded, single retainer, all‐ceramic resin‐bonded fixed dental prostheses (RBFDPs), all‐ceramic RBFDPs, cantilever resin, RBFDPs, cantilever resin‐bonded bridge, two units cantilevered, two‐unit cantilevered, metal‐ceramic cantilever, and metal‐ceramic.” Furthermore, the ‘‘Related Articles’’ feature of PubMed was used to identify further references of interest within the primary search. The bibliographies of the obtained references were used to identify pertinent secondary references. Review articles were also used to identify relevant articles. After the application of exclusion criteria, the definitive list of articles was screened to extract the qualitative data, and the results were analyzed. Results: Overall 2588 articles were dedicated at the first review phase; however, only 311 studies were left after the elimination of duplicates and unrelated studies. Seventeen studies passed the second review phase. Five studies were excluded because they were follow‐up studies of the same study cohort. Twelve studies were finally selected. Conclusions: The use of cantilever RBFDPs showed promising results and high survival rates. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the condylar displacement after mounting working casts using different interocclusal recording materials and to analyze the influence of the storage time and the recording technique on the displacement caused by the interocclusal record. Materials and Methods Eight interocclusal records were made in each of the following groups: G1: Aluwax (aluminum wax), G2: Beauty Pink wax (hydrocarbon wax compound), G3: Futar D Fast, G4: Futar Scan (G3, G4: vinylpolysiloxane), G5: Ramitec (polyether), G6: LuxaBite (composite resin based on bis-acryl), G7: LuxaBite corrected with Aluwax. A condylar-positioning indicator measured the condylar displacement in the three planes after storage of the records for two periods of 1 and 48 hours. Two-way ANOVA was used to determine the influences of recording materials and each of the following factors: (1) region (record and non-record side), (2) storage time, and (3) recording technique. The statistical significance level was set at p < 0.05. Results The vertical displacement caused by the interocclusal records in the record side after storage time of 1 hour ranged between 0.29 mm (Aluwax) and 0.14 mm (Futar Scan). The lateral displacement ranged between 0.13 mm (Aluwax) and 0.02 mm (Ramitec) while the anteroposterior displacement ranged between 0.15 mm (Ramitec) and 0.04 mm (Futar Scan). The corrected resin record showed generally lower displacement values than other materials tested (0.03, 0.02, and 0.07, respectively). On the non-record side, the values were lower than that on the record side. The condylar displacement increased after a storage time of 48 hours for all materials. Both factors, storage time and recording technique, had statistically significant influence on the condylar displacement. Conclusions Based on the results, the vertical displacement of the condyle caused by the interocclusal records was higher than the lateral or the anteroposterior displacement. Elastomers caused statistically significantly less condylar displacement than waxes or uncorrected composite resin. Corrected LuxaBite records with Aluwax showed significantly less condylar displacement than all other materials. [ABSTRACT FROM AUTHOR]

Objectives: Being a secondary outcome in a multicenter randomized controlled trial, the present analysis focused on interdental spacing in the shortened dental arch (SDA). The aim was to evaluate changes in interdental spacing in dependence of two different treatments after an observation period of up to 5 years. Material and methods: Patients were either treated with a partial removable dental prosthesis (PRDP) for molar replacement (PRDP group) or according to the SDA concept aiming at a premolar occlusion (SDA group) in a randomized manner. Interdental spacing in the anterior region was measured with gauges and categorized as '0' (<0.1 mm), '1' (<0.5 mm), '2' (0.5-1 mm), and '3' (>1 mm). The statistical analysis was performed with analysis of variance models followed by linear contrast. Results: Ninety-one patients (SDA n = 41, PRDP n = 50) were included. Changes of interdental spacing were detected in 70.7 % of all cases. A significant difference between the mean score changes was found in the mandible comparing the PRDP group and the SDA group. The respective mean score changes from baseline to 5 years were 0.23 ( SD 0.49) for the PRDP group and 0.02 ( SD 0.30) for the SDA group ( p = 0.023). Conclusions: Major interdental spacing could be observed in neither of the groups. The SDA concept resulted in a slightly better outcome. Clinical relevance: When deciding whether to replace missing molars, the present results give further support to the SDA concept. [ABSTRACT FROM AUTHOR]

The article discusses the author's views about resin-bonded fixed dental prostheses (RBFDPs) and single-tooth replacement techniques, and it mentions his book entitled "RBFDPs: Resin-Bonded Fixed Dental Prostheses--Minimally Invasive--Esthetic--Reliable." Tissue resorption and dental ceramics are addressed, along with dental implant complications and dental bonding methods. The success and reliability of zirconia ceramic single-retainer RBFDPs are assessed.

Objectives: The aim of this multi-center, randomized controlled trial was to assess the impact of missing posterior support on the risk for temporomandibular disorder (TMD) pain by comparing patients with either shortened dental arches (SDA) or molar replacement by removable dental prostheses (RDP). Methods: A sample of 215 patients with bilateral molar loss in at least one jaw was consecutively recruited in 14 prosthodontic departments of dental schools in Germany. Of the initial sample, 152 patients (mean age: 59.7 years; 53.9 % female) received randomly allocated interventions (SDA: n = 71; RDP: n = 81). Presence of TMD pain was assessed using patients' self-reports and was verified by physical examination and by pain intensity, as the mean of current pain, worst pain, and average pain in the last 6 months, with 10-point ordinal rating scales. Assessments were performed before treatment and at follow-ups until 60 months after treatment. Impact of interventions on TMD risk and pain intensity was computed by applying logistic and linear random-intercept models. Results: Tooth replacement (RDP) did not significantly change the risk for self-reported (odds ratio [OR]: 1.1; confidence interval [CI]: 0.4 to 3.4) or clinically verified (OR: 0.7; CI: 0.1 to 4.3) TMD pain compared to no tooth replacement (SDA). Mean characteristic pain intensity was virtually identical in both groups (Coeff: 0.01; CI: −0.30 to 0.32). Conclusion: Retaining or preservation of an SDA is not a major risk factor for TMD pain over the course of 5 years when compared to molar replacement with RPDs. Clinical relevance: Seemingly, missing molars do not have to be replaced in order to prevent TMD pain. [ABSTRACT FROM AUTHOR]

The purpose of this in-vitro study was to evaluate the influence of the framework design on the durability of inlay-retained cantilever fixed dental prostheses ( IR- FDPs), made from zirconia ceramic, after artificial ageing. Forty-eight caries-free human premolars were prepared as abutments for all-ceramic cantilevered IR- FDPs using six framework designs: occlusal-distal ( OD) inlay, OD inlay with an oral retainer wing, OD inlay with two retainer wings, mesial-occlusal-distal ( MOD) inlay, MOD inlay with an oral retainer ring, and veneer partial coping with a distal box ( VB). Zirconia IR- FDPs were fabricated via computer-aided design/computer-aided manufacturing ( CAD/ CAM) technology. The bonding surfaces were air-abraded (50 μm alumina/0.1 MPa), and the frameworks were bonded with adhesive resin cement. Specimens were stored for 150 d in a 37°C water bath during which they were thermocycled between 5 and 55°C for 37,500 cycles; thereafter, they were exposed to 600,000 cycles of dynamic loading with a 5-kg load in a chewing simulator. All surviving specimens were loaded onto the pontic and tested until failure using a universal testing machine. The mean failure load of the groups ranged from 260.8 to 746.7 N. Statistical analysis showed that both MOD groups exhibited significantly higher failure loads compared with the other groups (i.e. the three OD groups and the VB group) and that there was no significant difference in the failure load among the OD groups and the VB group. In conclusion, zirconia IR- FDPs with a modified design exhibited promising failure modes. [ABSTRACT FROM AUTHOR]

Objectives: This article is part of a randomized clinical trial on different treatments in the shortened dental arch (SDA). It focused on the abutment tooth prognosis with cantilevered fixed dental prostheses (CFDPs). Methods: Sixty-two patients with a bilaterally SDA up to the first or second premolar in the mandible or maxilla were evaluated. In 57 of 124 quadrants, second premolars were replaced by a CFDP (cantilever group). In the remaining 67 quadrants, a natural second premolar was present and thus no need for a CFDP was given (non-cantilever group). Patients were recalled annually up to 5 years. Results: The mean observation period was 56.3 months (min. 3.0, max. 76.2, SD 16.1). Kaplan-Meier survival rates concerning tooth loss and tooth fracture were 93.9%/94.0% in the cantilever group and 91.9%/92.8% in the non-cantilever group. Differences between both groups were not significant. The survival rate concerning loss of retention of CFDP retainers was 92.1% in the cantilever group. Conclusion: After 5 years of clinical service, CFDPs for the replacement of the second premolar showed no negative impact on the abutment tooth prognosis. Clinical significance: Cantilevered fixed dental prostheses present a viable treatment option in the shortened dental arch without compromising the medium-term abutment tooth prognosis. [ABSTRACT FROM AUTHOR]

Objective One aim of this prospective clinical study was to measure the effects of strategicimplant placement under removable partial dental prostheses ( RPDPs) and among removable complete dental prostheses ( RCDPs) on oral health-related quality of life ( OHRQo L). Materials and methods Twenty-three patients participated in this study restored with RCDPs ( n = 12) or RPDPs retained by telescopic crowns with 1-2 abutment teeth ( n = 11). The total number of abutments was increased to 5-6 (maxilla) or to 4 (mandible) by placing implants in strategically advantageous regions. Ball attachments were attached to the implants and integrated in the existing denture. The Oral Health Impact Profile (49 questions) was completed by patients before implant placement, at baseline (integration of ball attachments), and during 12- and 24-month follow-up visits. Results There were marked reductions of impacts in both groups when comparing pre-treatment scores and scores at baseline ( P < 0.0001), 12-month ( P < 0.0001), and 24-month follow-up visits ( P < 0.0001), respectively. For none of the visits, a significant difference between the two groups was detected ( P > 0.05). Conclusion It can be concluded that a strategic placement of implants under the existing dental prostheses improves OHRQoL in both treatment groups. [ABSTRACT FROM AUTHOR]

The purpose of this prospective study was to evaluate the clinical outcome of three- to four-unit posterior all-ceramic fixed dental prostheses (FDPs) made of yttria-stabilized tetragonal zirconia-polycrystal ceramic frameworks (CerconBase; Degudent). Fifty-eight restorations were placed in 48 patients. Twenty-four FDPs had an end abutment design (EAD) replacing 3 premolars and 21 molars. Thirty-four FDPs had a cantilever design (CD) replacing 11 premolars and 23 molars. The frameworks had a minimum proximal connector dimension of 3 × 3 mm. The fixed dental prostheses were cemented with glass-ionomer cement after air-abrading the inner crown surfaces. Three FDPs were defined as drop-outs. The mean observation period was 48 ± 7 months for the EAD (21 patients/24 FDPs) and 50 ± 14 months for the CD (25 patients/31 FDPs). The 4-yr survival rate, according to the Kaplan–Meier analyses, was 96% for the EAD and 92% for the CD. The technical complication rate was 13% for the EAD and 12% for the CD, and the biological complication rate was 21% for the EAD and 15% for the CD. For none of the analyses were significant differences found between both groups. After 4 yr the clinical outcome of three- to four-unit posterior FDPs with EAD and CD was promising. [ABSTRACT FROM AUTHOR]

The purpose of this in vitro study was to compare the quasi-static load-bearing capacity of all-ceramic resin-bonded three-unit inlay-retained fixed dental prostheses (IRFDPs) made from computer-aided design/computer-aided manufacturing (CAD/CAM)-manufactured yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) frameworks with two different connector dimensions, with and without fatigue loading. Twelve IRFDPs each were made with connector dimensions 3 × 3 mm2 (width × height) (control group) and 3 × 2 mm2 (test group). Inlay-retained fixed dental prostheses were adhesively cemented on identical metal-models using composite resin cement. Subgroups of six specimens each were fatigued with maximal 1,200,000 loading cycles in a chewing simulator with a weight load of 25 kg and a load frequency of 1.5 Hz. The load-bearing capacity was tested in a universal testing machine for IRFDPs without fatigue loading and for IRFDPs that had not already fractured during fatigue loading. During fatigue testing one IRFDP (17%) of the test group failed. Under both loading conditions, IRFDPs of the control group exhibited statistically significantly higher load-bearing capacities than the test group. Fatigue loading reduced the load-bearing capacity in both groups. Considering the maximum chewing forces in the molar region, it seems possible to use zirconia ceramic as a core material for IRFDPs with a minimum connector dimension of 9 mm2. A further reduction of the connector dimensions to 6 mm2 results in a significant reduction of the load-bearing capacity. [ABSTRACT FROM AUTHOR]

Objectives: Failures of implant–abutment connections are relatively frequent clinical problems. The aim of this study was to evaluate the influence of long-term dynamic loading on the fracture strength of different implant–abutment connections. Material and methods: Six implant systems were tested: two systems with external connections (Brånemark, Compress) and four systems with internal connections (Frialit-2, Replace-Select, Camlog, Screw-Vent). Fracture strength was tested in two subgroups for each system: one subgroup with ( dyn) and the other without prior dynamic loading ( contr). Each subgroup consisted of eight specimens with standard implant–abutment combinations for single molar crowns. Dynamic loading was performed in a two-axis chewing simulator with 1,200,000 load cycles at 120 N. Results: Median fracture strengths in Newton (N) and 25th and 75th percentiles [in brackets] were: Brånemark: dyn=729 [0;802]/ contr=782 [771;811], Frialit-2: dyn=0 [0;611]/ contr=887 [798;941], Replace-Select: dyn=1439 [1403;1465]/ contr=1542 [1466;1623], Camlog: dyn=1482 [1394;1544]/ contr=1467 [1394;1598], Screw-Vent: dyn=0 [0;526]/ contr=780 [762;847] and Compress: dyn=818[0;917]/ contr=1008 [983;1028]. In some dyn subgroups, failures of the implant–abutment connection occurred already during dynamic loading: three specimens of the Brånemark and Compress groups and six specimens of the Screw-Vent and the Frialit-2 groups failed during dynamic loading. Statistically significant differences ( P≤0.05) in fracture strength could be found between groups with different connection designs. Conclusion: Implant systems with long internal tube-in-tube connections and cam–slot fixation showed advantages with regard to longevity and fracture strength compared with systems with shorter internal or external connection designs. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of different preparation and framework designs on the retention of posterior resin bonded fixed dental prostheses (RBFDPs) made from monolithic zirconia ceramic. Forty-eight caries-free upper premolars and forty-eight upper third molars were used in this study. The teeth were randomly divided into six main groups (n = 8 each) according to the preparation design of two-retainer RBFDPs: narrow or wide rest, combined with 0, 1 or 2 retainer wings. All RBFDPs were milled from monolithic zirconia (KATANA Zirconia ML). They were bonded using Panavia V5 with its corresponding primer, and underwent thermodynamic loading (98 N, 1,200,000 cycles). Retention was evaluated for the surviving RBFDPs in a universal testing machine by means of a debonding test. Failure modes were evaluated using a light microscope. Data was statistically analyzed by Kruskal-Shapiro-Wilk followed by Mann-Whitney with Bonferroni correction for multiple testing. The survival rates after the chewing simulation were 75% (group narrow rest/no retainer wing), 62.5% (group wide rest/no retainer wing) and 100% (the other groups). The mean retention ranged from 31 N to 766 N. Designs with two retainer wings showed significantly higher bond strength than the other designs (p ≤ 0.05). The rest width did not show a significant effect on the retention. Posterior RBFDPs with a modified design (occlusal rest and two retainer wings) exhibited promising durability and retention. Designs with two additional retainer wings should be preferred over designs with one or no retainer wing, irrespectively of the rest width. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Ten-Year Outcome of Three-Unit Fixed Dental Prostheses Made From Monolithic Lithium Disilicate Ceramic," by Matthias Kern and colleagues in March 2012 issue of the journal; a response by the author to the letter is also presented.

The purpose of this study was to investigate the survival rate, the debonding resistance, and the failure modes of different occlusal veneer designs when used as a retainer for posterior cantilever, resin-bonded fixed dental prostheses (RBFDPs) at two tooth wear levels. Four test groups were assigned: two groups with occlusal-proximal preparation (PT1 and PT2 for grade 2 and 3 wear), and two groups for occlusal-proximal and lingual preparation (PLT1 and PLT2 for grade 2 and 3 wear) Monolithic zirconia ceramic (3Y-TZP) RBFDPs were luted with an adhesive bonding system (Panavia V5). The specimens underwent a chewing simulation for 1.200.000 cycles with a load of 5 kg and thermocycling for 7500 cycles between 5 °C and 55 °C. The surviving restorations were debonded under quasi-static conditions. The results were analyzed with ANOVA. The specimens exhibited a 100 % survival rate after thermomechanical fatigue loading. The debonding resistance was statistically significant higher for group PLT1 than for group PT1 (P = 0.004), and higher for group PT2 than group PT1 (P ≤ 0.001). However, the debonding resistance showed no statistically significant difference between groups PT2 and PLT2 (P = 0.343), and groups PLT1 and PLT2 (P = 0.222). Groups PT1 and PT2 showed favorable failure modes in 62.5 % and 0.00 % of the specimens, respectively. While groups PLT1 and PLT2 presented 25 % favorable failure modes. Occlusal veneers showed promising results as a retainer for cantilever RBFDPs. The lingual extension might increase debonding resistance. Nevertheless, conservative designs with lingual and proximal bevels are to be recommended, irrespective of the level of tooth wear. • The occlusal veneers as retainers for posterior cantilever RBFDPs showed 100 % success and survival rates. • Conservative tooth preparation with occlusal bevels is to be recommended for occlusal veneers as retainers for cantilever RBFDPs. • Monolithic zirconia (3Y-TZP) performed well as a material of choice for occlusal veneer retainer when air abraded with alumina particles and bonded with a phosphate monomer (10-MDP)containing adhesive system. • The tooth wear severity does not affect the survival rate and the debonding resistance of cantilever RBFDPs, with the presence of enough circumferential enamel. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: This study evaluated the clinical outcome of all-ceramic resin-bonded fixed partial dentures (RBFPDs) with a cantilevered single-retainer design. Methods: Thirty anterior zirconia ceramic RBFPDs were inserted using either a phosphate monomer containing resin (Panavia 21 TC; N =16) or an adhesive bonding system with a phosphoric acid acrylate primer (Multilink–Automix with Metal/Zirconia primer; N =14). Results: During a mean observation time of 41.7 months one debonding occurred in each group. Both RBFPDs could be rebonded successfully resulting in a three-year survival rate of 100%. Conclusion: Independent of the bonding system cantilevered zirconia ceramic RBFPDs showed promising results during the first three years. Clinical significance: Single-retainer zirconia ceramic RBFPD present an alternative treatment option offering good aesthetics, a minimal invasive preparation, a high biocompatibility and can even be used to treat juvenile patients who do not yet come into consideration for implant placement. No significant influence of the bonding system used was detected so far. [Copyright &y& Elsevier]

Objective The aim of this laboratory study was to evaluate the horizontal and vertical effects of the polymerization shrinkage of three-unit temporary fixed dental prostheses (FDPs) on the position of the prepared teeth. In addition, the reduction of these effects by using different fabrication techniques was evaluated. Methods A total of 192 temporary FDPs were fabricated using one methacrylate (MA) and two dimethacrylate (DMA) materials. Each material group (n = 64) was divided into two groups according to the fabrication methods (M1: curing on the prepared teeth, M2: curing in a silicone mold). Each fabrication group was divided into four subgroups (n = 8) according to the relining method used (B: no relining, S: spacer foil 300 μm, DG: grinding-out with 500 μm cutting depth, and FG: free grinding). The experimental apparatus consisted of two abutment teeth lowered at right angles into a silicone mold. One prepared tooth was embedded in silicone to simulate the periodontium and permit slight horizontal tooth movement. The dimensional changes were recorded with an optical microscope. The test images were superimposed and measured using image analysis software. Results The statistical analysis showed that there were significantly higher horizontal changes for the MA than the DMA resins in M1, while there was none in M2. Regarding the vertical changes, there were significant differences between the baseline group and all relining and fabrication groups in all materials. Significance Relining of directly fabricated temporary FDPs significantly reduces the effect of polymerization shrinkage and thus secures the position of the prepared teeth. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The aim of this preliminary prospective study was to evaluate the clinical outcome, the oral health-related quality of life (OHRQoL), and the subjective chewing ability of patients with mandibular complete dentures retained by a single implant placed in the mandible midline. Methods: Patients wearing complete dentures were treated with a single implant in the mandible, followed by relining of the dentures and incorporation of ball attachments for implant retention. Implant outcome, prosthodontic maintenance, subjective chewing ability, and the oral health impact profile of the patients were assessed at baseline and at four weeks after connecting the denture and implant. Results: Eleven patients were enrolled in this investigation, and the mean observation period was 43.4 months (minimum period: 35, maximum period: 52 months). No implants were lost during observation period, but four dentures needed repair because of the fracture of the denture base in the midline area. A significant improvement was observed in the OHRQoL of the patients after the attachment of the mandibular dentures with a single midline implant. Furthermore, the subjective chewing ability of the patients was significantly improved after implant connection. Conclusions: Within the limitations of this preliminary prospective clinical study, single implant-supported mandibular overdentures were a successful treatment option for older edentulous patients who showed improvements in their OHRQoL and chewing ability. [Copyright &y& Elsevier]

Abstract: Objectives: The purpose of this prospective study was to evaluate the clinical outcome of crown-retained fixed dental prostheses (FDPs) made from a lithium-disilicate glass–ceramic (IPS e.max Press, Ivoclar-Vivadent). Methods: Thirty-six three-unit FDPs were placed in 28 patients. The FDPs replaced teeth in the anterior (16%) and posterior (84%) regions. All teeth were prepared following a standardized protocol. The size of the proximal connector of the FDPs was 12mm2 (anterior) or 16mm2 (posterior). FDPs were cemented either with glass-ionomer cement (n =19) or composite resin (n =17). The following parameters were evaluated at baseline, 6 months after cementation and then annually (at abutment and contralateral teeth): probing pocket depth, plaque index, bleeding on probing, and tooth vitality. Results: Three FDPs were defined as drop-out. The mean observation period of the remaining 33 FDPs was 86 months (range: 67–98 months): two FDPs in two patients had to be replaced (6%) because of fractures. The 8-year survival rate according to Kaplan–Meier was 93%. In addition, chipping of the veneering material was found in two FDPs (6%). Two abutments (3%) of two restorations had to be treated endodontically; and two FDPs (6%) lost retention and had to be recemented. These complications did not affect the function of the involved restorations clinically. There were no significant differences between the periodontal parameters of the test and control teeth. Significance: Short-span crown-retained three-unit FDPs made from lithium-disilicate glass–ceramic can be used clinically irrespective of an adhesive or conventional cementation. [Copyright &y& Elsevier]