Digital versus conventional complete dentures: A randomized, controlled, blinded study.

STATEMENT OF PROBLEM: Several manufacturers have developed a digital workflow for removable prosthodontics. The Baltic Denture System is a 2-visit procedure for the digital production of complete dentures, but clinical studies comparing the system with conventional methods are lacking. PURPOSE: The purpose of this randomized, controlled, blinded crossover trial was to evaluate the impact of the digital versus conventional production of complete dentures on oral health-related quality of life (OHRQoL) measures. MATERIAL AND METHODS: Sixteen participants received 2 sets of new complete dentures produced with a digital (2 visits) and conventional (5 visits) workflow. Each complete denture was in clinical service for an observation period of 3 months. The order of the dentures was randomized, starting with digital or conventional followed by changing the set of dentures after 3 months. The primary outcome was the time-dependent change in the OHRQoL, assessed by using the Oral Health Impact Profile, German version (OHIP-G49), comparing the digital with the conventional workflow. The secondary outcome was the time needed for the fabrication process. The median values of OHIP-G49 total sum scores and OHIP-G49 dimensions were calculated for baseline and 14 days and 3 months after insertion of the dentures. Changes of sum scores over time and differences between the workflows were analyzed by using the Wilcoxon signed-rank test (α=.05). RESULTS: The data of 16 participants (11 men and 5 women; 66 ±8.5 years) were evaluated. The median values of the total OHIP-G49 sum scores and the sum scores of OHIP-G49 dimensions did not differ between workflows (P>.05). With digital dentures, more physical pain was observed after 2 weeks (P=.039). Participants with conventional dentures had less functional limitation after 14 days and felt less handicapped after 3 months (P=.036). Digital dentures were fabricated within 4 hours, whereas fabrication of conventional dentures took 10.5 hours for dentists and dental laboratory technicians. CONCLUSIONS: From the perspective of the participants, the fabrication method of the complete dentures had no significant influence on OHRQoL. However, digital dentures needed only 2 visits, 1 hour less chair time, and 5 hours less time for the dental laboratory technicians.

Digital versus conventional complete dentures: A randomized, controlled, double-blinded crossover trial.

STATEMENT OF PROBLEM: The Baltic Denture System provides a digital way to fabricate complete dentures in 2 visits. Conventional dentures using injection or compression molding require additional visits and complex laboratory procedures. However, how the fabrication method affects clinical outcomes is unclear. PURPOSE: The purpose of this clinical, randomized, controlled, double-blinded crossover trial was to evaluate the impact of the fabrication method (digital versus conventional production) of complete dentures on clinical outcomes. MATERIAL AND METHODS: Sixteen participants received 2 pairs of new complete dentures, produced in a digital and a conventional workflow. Each complete denture was worn for an observation period of 3 months. The order of the dentures was randomized. The primary outcome was the clinical assessment of the dentures by a blinded examiner, including peripheral extension, cutout for buccal and labial frenula, denture extension, and denture thickness. Denture esthetics were evaluated by the midline, position of anterior teeth, buccal corridor, and smile arc, and occlusal relationships were evaluated by the vertical dimension, sagittal relation, the Camper plane, and occlusion. In addition, the retention of maxillary and mandibular dentures and phonetics was evaluated. Differences between the prostheses were statistically analyzed with the McNemar test (α=.05). RESULTS: The borders of the digital dentures were significantly more often overextended at the time of insertion (P=.021), reducing the retention of the digital dentures, especially the maxillary dentures (P=.016). The borders of the dentures could be corrected so that after 2 weeks and 3 months, no significant differences could be seen between digital dentures and conventional dentures. CONCLUSIONS: The fabrication method has a significant influence only on the dimension of the denture border. It was significantly more often overextended in digital dentures and impaired retention, especially of the maxillary dentures, at the time of insertion. As this parameter is correctable, no significant clinical differences could be observed over the observation time of 3 months between digital dentures and conventional dentures.

Direct restoration of endodontically treated maxillary central incisors: post or no post at all?

OBJECTIVES: The aim of this ex-vivo study was to evaluate the impact of cavity size and glass-fiber post (GFP) placement on the load capability of endodontically treated maxillary incisors directly restored with resin composite. MATERIALS AND METHODS: Ninety-six extracted human maxillary central incisors were endodontically treated and distributed to four groups (n = 24): access cavity (A), access cavity and uni-proximal class III cavity (U), access cavity and bi-proximal class III cavity (B), and decoronated tooth (D). Specimens were restored with resin composite, and 12 specimen of each group received an adhesively placed glass-fiber post (P). Prior to linear loading, specimens were exposed to thermo-mechanical loading (TCML). Statistical analysis was performed using log-rank test after TCML, Kruskall-Wallis and Mann-Whitney U test to compare load capabilities (Fmax). RESULTS: Significantly more failures occurred in group D for specimens without GFP during TCML (p = 0.001). Fmax (mean (SD) in N was (A) 513 (124), (AP) 554 (201), (U) 438 (171), (UP) 537 (232) (B) 483 (219), (BP) 536 (281), D 143 (181), and DP 500 (331), and differed significantly among groups (p = 0.003). Pair-wise comparison revealed lower Fmax values for group D compared to all other groups (p < 0.034) except group DP. CONCLUSIONS: Endodontically treated maxillary central incisors with cavity sizes up to bi-proximal class III may be successfully directly restored with resin composite. Post placement shows no additional effect except for decoronated endodontically treated incisors. CLINICAL RELEVANCE: Endodontically treated incisors with access cavities to class III cavities can be successfully restored with resin composite. Post placement for decoronated ETT is recommended.

Impact of endodontic post material on longitudinal changes in interproximal bone level: a randomized controlled pilot trial.

OBJECTIVES: Aim was to evaluate the impact of glass fiber versus titanium endodontic posts on the interproximal bone level around severely damaged endodontically treated teeth. MATERIALS AND METHODS: Thirty-eight participants of a randomized controlled trial on glass fiber (n = 18) and titanium post-endodontic restorations (n = 20) received radiographs at two different times after post placement (T0 = <12 months and T1 = 36-72 months after post placement). A total of 76 radiographs were analyzed with an image-editing software. Medians of changes in mesial and distal interproximal bone level (∆MBL, ∆DBL) were calculated and tested for statistical significance with respect to post material using Mann-Whitney U test (p < 0.05). Impact of post material on bone level changes was assessed in multilevel mixed-effect linear regression models. RESULTS: The mean observation period was 54 months for glass fiber and 50 months for titanium posts. Interproximal bone loss was small in both groups during the study period with no significant differences between groups (glass-fiber group, ∆MBL = - 0.03 mm and ∆DBL = - 0.06 mm; titanium group, ∆MBL = - 0.07 mm and ∆DBL = - 0.17 mm; both p > 0.05). Overall, impact of post material on bone loss was almost negligible with a nonsignificant difference between materials of 0.10 mm during the entire study period. CONCLUSION: The rigidity of endodontic post material has no impact on the level of alveolar bone support of severely damaged endodontically treated teeth. CLINICAL RELEVANCE: Post-endodontic restorations of severely damaged teeth can achieve steady levels of periodontal bone support as a parameter of periodontal health, irrespective of post material.

Patients' self-report on post-retained restoration is more valuable than expected! Explorative analysis of an 11-year follow-up.

Objective: Assessment of long-term clinical data regarding post-endodontic restorations is essential for the evaluation of different post-and-core concepts. The aim of the present study was to assess the diagnostic accuracy of patient self-reporting on post-endodontic restorations after 11 years of clinical service.Materials and methods: Twenty-nine patients (61 ± 15 years old) with endodontic glass-fibre and titanium post-endodontic restorations were examined within the 11-year follow-up of a randomized controlled trial. Restorations were assessed by self-reports during a telephone interview (one item), the completion of a four-item questionnaire and clinical and radiographic examination. A gold standard for restoration in situ or 'failure' was defined by clinical and radiographic examination. Diagnostic accuracy of patients' self-reports was evaluated by calculating the sensitivity, specificity, and positive (PPV) and negative predictive values (NPV).Results: After a mean observation time of 137 months (min/max: 125/154 months), 25 (86.2%) restorations were in situ and 4 (13.8%) failures were detected. Self-report during a telephone interview and the four-item questionnaire correctly identified all in situ restorations (specificity = both 100%, NPV = 92.6%/96.2%). Self-report during a telephone interview identified two out of four failures (sensitivity = 50%, PPV = 100%), and self-report on the four-item questionnaire identified three out of four failures (sensitivity = 75%, PPV = 100%).Conclusions: When the clinical examination is not feasible, patients' self-report shows valuable diagnostic potential in the identification of the post-endodontic failure.

Clinical outcomes of partial and full-arch all-ceramic implant-supported fixed dental prostheses. A systematic review and meta-analysis.

OBJECTIVE: To assess the survival and technical complication rate of partial and full-arch all-ceramic implant-supported fixed dental prostheses (P-FDP/FA-FDP) and supporting implants. MATERIALS AND METHODS: An electronic search through three databases (MEDLINE/Pubmed, Cochrane Library, Embase) was conducted to identify relevant clinical studies with an observation period of at least 12 months, including ≥15 patients. Reconstruction and implant survival rates, technical complications and confounding variables such as processed/installed materials, retention mode and location in the mouth were obtained. Failure and complication rates were analyzed using standard Poisson regression models to calculate 5-year survival and complication estimates. RESULTS: A total of five studies for the P-FDP group and seven studies for the FA-FDP group were included, throughout evaluating veneered zirconia reconstructions. In the P-FDP group, reconstructions were located in posterior regions. Meta-analysis indicated survival estimates on the reconstruction level of 98.3% and 97.7% for P- and FA-FDPs after 5 years. However, chipping of the veneering ceramic was frequent, resulting in estimated 5-year complication rates of 22.8% (P-FDPs) and 34.8% (FA-FDPs). Five-year survival estimates of implants supporting P-FDPs and FA-FDPs of 98.5% and 99.4% were calculated, respectively. Including a total of 540 FDPs, one screw-loosening and 11 de-cementations were reported. Confounding variables were not found to have a significant influence on survival and complication rates. CONCLUSIONS: All-ceramic implant-supported P- and FA-FDPs comprising veneered zirconia frameworks showed high survival but clinically inacceptable fracture rates of the veneering ceramic. Their suitability with regard to this indication and a successful long-term outcome needs to be further evaluated.

Direct or Indirect Restoration of Endodontically Treated Maxillary Central Incisors with Class III Defects? Composite vs Veneer or Crown Restoration.

PURPOSE: The aim of this ex-vivo study was to evaluate the load capacity of direct or indirect endodontically restored maxillary central incisors with Class III defects, with or without glass-fiber posts. MATERIALS AND METHODS: Seventy-two extracted human maxillary central incisors were endodontically treated and bi-proximal Class III cavities were prepared. Specimens were randomly allocated to six groups (n = 12): direct restoration with composite (C); direct restoration with composite and additional glass-fiber post (CP); ceramic veneer restoration (V), ceramic veneer restoration and additional glass-fiber post (VP), ceramic crown restoration (Cr), ceramic crown restoration and additional glass-fiber post (CrP). Specimens were exposed to thermomechanical loading (TML: 1.2 million cycles, 1 to 50 N; 6000 thermal cycles between 5°C and 55°C for 1 min each), and subsequently linearly loaded until failure (Fmax [N]) at an angle of 135 degrees 3 mm below the incisal edge on the palatal side. Statistical tests were performed using the Kruskall-Wallis and Mann-Whitney U-Test. RESULTS: During dynamic loading by TML, one early failure occurred in group C, CP, and CrP. Subsequent linear loading resulted in mean fracture load values [N] of C = 483 ± 219, CP = 536 ± 281, V = 908 ± 293, VP = 775 ± 333, Cr = 549 ± 258, CrP = 593 ± 259. The Kruskal-Wallis test showed significant differences of load capacity between groups (p < 0.05). Mann-Whitney U-test revealed significantly lower maximum fracture load values of group C compared to group V (p = 0.014), after Bonferroni-Holm correction. Non-restorable root fracture was the most frequent type of failure. CONCLUSION: Endodontically treated maxillary central incisors with Class III defects directly restored with composite are as loadable as indirect crown restorations. Compared to full-coverage restorations, less invasive veneers appear to be more beneficial. Additional placement of glass-fiber posts shows no positive effect.

Influence of a face-bow on oral health-related quality of life after changing the vertical dimension in the articulator: a randomized controlled trial. Part II.

OBJECTIVES: In a double-blind randomized controlled clinical trial, the impact of face-bow registration for remounting complete dentures (CDs) on oral health-related quality of life (OHRQoL) was evaluated. MATERIALS AND METHODS: New CDs of 32 subjects were clinically remounted using intraoral pin registration. CDs were transferred into a semi-adjustable articulator corresponding to group #1: mean settings with Bonwill triangle and Balkwill angle, and group #2: arbitrary hinge axis with a face-bow registration. After occlusal adjustment, subjects were followed up after 3 (T1) and 84 (T2) days. The primary outcome was the change of OHRQoL by OHIP-G49, while as secondary outcome, mucosal alterations were evaluated over time. Mean values of OHIP-G49 total sum scores and OHIP-dimensions were calculated for baseline (T0) and days 3 (T1) and 84 (T2) after intervention. Based on bootstrapping methods (changes of total OHIP sum score) and the Wilcoxon test (changes of sum scores of OHIP dimensions), analyses of between-group differences were performed. RESULTS: Mean values (MV) of OHIP-G49 sum scores decreased in both groups from T0 (#1 48.56; #2 45.46) to T1 (#1 31.43 (p = 0.012); #2 43.20) and to T2 (#1 29.06; #2 29.40), which represents an improvement in OHRQoL. MV of OHIP-dimension sum scores decreased from T0 to T1 in both groups (#1 seven dimensions; #2 four dimensions); the decrease of sum scores was tested as not statistically significant (p > 0.05). CONCLUSIONS: From the patient's perspective, mean-value-based remounting methods are of value. The use of a face-bow was not perceived as superior. CLINICAL RELEVANCE: From the patient's perspective, remounting of CDs will be positively perceived, irrespective of the use of a face-bow.

Does a face-bow lead to better occlusion in complete dentures? A randomized controlled trial: part I.

OBJECTIVES: In a double-blinded randomized controlled clinical trial, the impact of face-bow registration for remounting complete dentures (CDs) on the occlusal parameters (part I) was evaluated. MATERIALS AND METHODS: New CDs of 32 patients were duplicated and mounted after intraoral pin registration according to mean settings (group 1) and (group 2) using a face-bow (arbitrary hinge axis). The vertical dimension was reduced to the first occlusal contact point, and a bite record was fabricated in the articulator. The number of contacts and the number of teeth in contact were evaluated by a computer program (laboratory result). After randomization, half of the CDs were adjusted according to protocol of group 1 and group 2 and delivered to the patients. After 3 days (T1) and 84 days (T2), clinical static contact points and teeth in contact were counted. Contact points and teeth in contact of both groups (laboratory results) and at different moments (clinical results) were analyzed statistically with the F test and bootstrapping. RESULTS: Laboratory: No. 2 (face-bow) showed more occlusal contact points than no. 1 (mean setting), p > 0.05. The number of teeth with at least one occlusal contact was significantly higher in no. 2 (p = 0.027). Clinic: The mean number of teeth with at least one clinical contact point was significantly higher in no. 1 (no. 1 = 7.13, no. 2 = 5.31; p = 0.042). Extent of the vertical shift poorly correlated with number of laboratory occlusal contact points (R 2 = 0.017). CONCLUSIONS: Considering the complex multistep study design, a limited number of participants, and referring to one specific arbitrary face-bow, the following conclusion could be drawn: no substantial difference by the use of the arbitrary face-bow compared to a mean setting could be determined, when changing the vertical dimension in the articulator within a remounting procedure of complete dentures. CLINICAL RELEVANCE: Further research is necessary to determine the effects of different arbitrary face-bows on the fabrication and adaptation of removable dentures.

Effect of Final Irrigation Protocol and Etching Mode on Bond Strength of a Multimode Adhesive in the Root Canal.

PURPOSE: To analyze the effects of ethanol for final post space irrigation and etching mode on the bond strength of fiber posts luted with a mild multimode adhesive (pH 2.3) as compared with a reference group using a self-adhesive resin cement (SAR). MATERIALS AND METHODS: Human anterior teeth were endodontically treated. After post space preparation, the root canals were irrigated using 1% sodium hypochlorite (NaOCl) applied with passive ultrasonic irrigation, followed by either distilled water (control) or distilled water and ethanol 99% as final post space irrigation. Fiber posts were luted using Futurabond U in self-etch mode (FU-SE), Futurabond U in etch-and-rinse mode (FU-ER), or Futurabond DC (SE) in combination with a dual-curing core buildup material (Grandio Core, all VOCO); alternatively, posts were inserted using a self-adhesive composite cement (RelyX Unicem 2, 3M ESPE). Bond strengths were evaluated using push-out tests following thermocycling (TC) and storage in 0.9% NaCl for 3 months. RESULTS: Mean push-out bond strengths (MPa) were significantly affected by the luting system (p < 0.0005) but not by the irrigation protocol (p = 0.068; ANOVA), although a significant interaction between the factors "luting agent" and "pre-treatment" was observed. FU E&R (21.28 [4.34]) and RX (20.12 [7.32]) revealed significantly higher bond strengths compared to FU SE (15.9 [6.02]), whereas F DC (18.8 [6.9]) did not differ significantly from all other groups. Ethanol pre-treatment increased bond strength in the apical part of the root canal for all materials, with the exception of FU E&R. CONCLUSION: Mild multimode adhesives exhibit comparable mean bond strengths to a SAR cement within the root canal for luting fiber posts if applied in an etch-and-rinse mode. Using this approach, ethanol application has no positive effects on bond strength.

Implant or tooth? - A cost-time analysis of managing "unrestorable" teeth✰.

OBJECTIVES: Retaining and restoring severely compromised teeth with subcrestal defect extensions or removing and replacing them using implant-supported crowns (ISC) remains controversial, and economic analyses comparing both strategies remain scarce. We performed a cost-time analysis, comparing the expenditures for retaining "unrestorable" teeth using forced orthodontic extrusion and restoration (FOE) versus extraction and ISC, in a clinical prospective cohort study. METHODS: Forty-two patients (n = 21 per group) were enrolled from clinical routine at a university into this study. Direct medical and indirect costs (opportunity costs) were assessed for all relevant steps (initial care, active care, restorative care, supportive care) using the private payer's perspective in German healthcare based on a micro-costing approach and/or national fee items. Statistical comparison was performed with Mann-Whitney-U test. RESULTS: Patients were followed up for at least one year after initial treatment (n = 40). The drop-out rate was 5% (n = 2). Total direct medical costs were higher for ISC (median: 3439.05€) than FOE (median: 1601.46€) with p<0.001. We observed a higher number of appointments (p = 0.002) for ISC (median: 14.5) in comparison to FOE (median: 12), while cumulatively, FOE patients spent more time in treatment (median: 402.5 min) in comparison to ISC (median: 250 min) with p<0.001, resulting in comparable opportunity costs for both treatment groups (FOE: 304.50€; ISC: 328.98€). CONCLUSIONS: ISC generated higher costs than FOE. More in-depth and long-term exploration of cost-effectiveness is warranted. CLINICAL SIGNIFICANCE: ISCs were associated with higher initial medical costs and required more appointments than the restoration of severely compromised teeth after FOE. Treatment time was higher for patients with FOE, resulting in similar opportunity costs for both treatment approaches. Future research needs to investigate long-term cost-effectiveness.

Long-term Survival of Adhesively Luted Post-endodontic Restorations.

INTRODUCTION: The objective of this prospective clinical study was to investigate survival for endodontically treated teeth restored with adhesively luted prefabricated dentinlike or rigid posts. METHODS: Data were recorded for glass-fiber posts (GFPs) and compared with historical controls evaluating glass-fiber (GFP I) and titanium posts (TPs) for 128 patients. Three groups were defined based on the type of post system used: group 1, GFP I (n = 41); group 2, GFP II (n = 41); and group 3, TP (n = 46). Posts were adhesively luted with self-adhesive resin, adhesive composite core buildups were performed, and all teeth were restored with full-coverage restorations. The primary end point was restoration survival at recall. Outcome was assessed after 6, 12, 24 and up to 178 months clinically and radiographically. Data were analyzed by the Kaplan-Meier log-rank test and Cox regression analysis. RESULTS: After up to 178 months of observation, 26 restorations failed (GFP I: 10, GFP II: 9, and TP: 7) and 49 (GFP I: 18, GFP II: 12, and TP: 19) were in situ. Cumulative survival probabilities were 57.1% for the GFP I, 56.5% for the GFP II, and 71.8% for the TP groups. In bivariate Cox regression, the factors tooth type and grade of abrasion were significantly assfociated with failure. In multivariate Cox regression, none of the investigated factors were significantly associated with failure. The post system had no significant impact on tooth survival (P > .05). CONCLUSIONS: Comparing GFPs and TPs, the post system had no impact on tooth survival up to 15 years. This study indicates that the effect size of post material on survival is low.

Fracture Resistance of Zirconia Oral Implants In Vitro: A Systematic Review and Meta-Analysis.

Various protocols are available to preclinically assess the fracture resistance of zirconia oral implants. The objective of the present review was to determine the impact of different treatments (dynamic loading, hydrothermal aging) and implant features (e.g., material, design or manufacturing) on the fracture resistance of zirconia implants. An electronic screening of two databases (MEDLINE/Pubmed, Embase) was performed. Investigations including > 5 screw-shaped implants providing information to calculate the bending moment at the time point of static loading to fracture were considered. Data was extracted and meta-analyses were conducted using multilevel mixed-effects generalized linear models (GLMs). The Sidák method was used to correct for multiple testing. The initial search resulted in 1864 articles, and finally 19 investigations loading 731 zirconia implants to fracture were analyzed. In general, fracture resistance was affected by the implant design (1-piece > 2-piece, p = 0.004), material (alumina-toughened zirconia/ATZ > yttria-stabilized tetragonal zirconia polycrystal/Y-TZP, p = 0.002) and abutment preparation (untouched > modified/grinded, p < 0.001). In case of 2-piece implants, the amount of dynamic loading cycles prior to static loading (p < 0.001) or anatomical crown supply (p < 0.001) negatively affected the outcome. No impact was found for hydrothermal aging. Heterogeneous findings of the present review highlight the importance of thoroughly and individually evaluating the fracture resistance of every zirconia implant system prior to market release.

Amalgam Alternatives Critically Evaluated: Effect of Long-term Thermomechanical Loading on Marginal Quality, Wear, and Fracture Behavior.

PURPOSE: This in vitro study evaluated marginal integrity, 2-body wear, and fracture behavior of an array of bonded and nonbonded posterior restorative materials after thermomechanical loading (TML). MATERIALS AND METHODS: Eighty-eight MOD cavities with one proximal box beneath the CEJ were prepared in extracted human third molars according to a well-established protocol. Direct restorations were made using the following materials: amalgam (Dispersalloy), Ketac Molar Quick, Surefil One (with or without light curing), Activa, AdheSE Universal/Heliomolar, Fuji II LC improved, Equia Forte, Scotchbond Universal/Filtek Supreme, Xeno V+/CeramX.mono+, Prime&Bond active/Spectra ST CeramX HV, Prime&Bond elect/Spectra ST CeramX HV. Before and after thermomechanical loading (2500/5000/12,500 thermocycles between 5°C and 55°C + 100,000/ 200,000/500,000 x 50 N), marginal gaps and 2-body wear depths were analyzed on epoxy resin replicas using SEM and CLSM. Fractures were observed under a light microscope (20X). Results were analyzed with Kruskal-Wallis and Mann-Whitney U-tests (p < 0.05). RESULTS: For marginal quality, Surefil One showed promising in vitro behavior close to that of resin composite bonded with a self-etch adhesive (p > 0.05). For wear, amalgam and resin composites with recent filler technology were still superior (p < 0.05), but Surefil One LC outperformed Activa, Ketac Molar Quick, Equia Forte Fil, and Fuji II LC (p < 0.05). When Surefil One was occlusally light cured, no fractures occured, even after 500,000 cycles of TML. CONCLUSION: The novel self-adhesive posterior restorative Surefil One did not exhibit superior outcomes for all evaluated aspects. However, it showed stable fracture behavior, good marginal quality, and acceptable wear resistance in vitro.

Effect of Application Mode on Bond Strength of Adhesively Luted Glass-fiber Bundles Inside the Root Canal.

PURPOSE: The aim of the present study was to measure the bond strength of adhesively luted glass-fiber bundles inside the root canal with respect to the application procedure in comparison to conventional solid glass-fiber posts. MATERIALS AND METHODS: 104 human anterior teeth were endodontically treated, root filled and divided into 8 groups (n = 13). After post space preparation, fiber bundles consisting of 6 and 12 glass fibers, respectively, were luted adhesively with a multi-mode adhesive (Futurabond U; Voco, Cuxhaven, Germany) and a dual-curing composite (Rebilda DC, Voco) with the following application modes into the root canal: (1) direct application with tweezers, (2) distribution of the fibers using a spreader, (3) application of ultrasound after insertion of fibers. Two different solid posts (Rebilda DC, Voco; and DentinPost, Komet, Lemgo, Germany) were used as controls. Roots were sectioned into 6 slices per root (thickness 1 mm). Bond strengths were measured using thin-slice push-out tests for 3 slices 24 h after post insertion and for 3 slices per sample following thermocycling (TC) for 6000 cycles and storage in 0.9% NaCl for 6 months. Homogeneity of the slices was analyzed using a stereomicroscope and, for representative samples, micro-computed tomography (µCT). RESULTS: Mean push-out bond strengths (MPa) were significantly affected by post system (p < 0.0005) and location inside the root canal (p = 0.004) but not by application mode (p = 0.544) or TC (p = 0.098; repeated measurement ANOVA). Fiber bundles consisting of 6 (13.2 ± 4.7) and 12 fibers (14.5 ± 4.3) revealed bond strength comparable to that of Rebilda Post (13.67 ± 3.2) but significantly higher than that of Dentin Posts (8.7 ± 3.02). Inhomogeneities were detected among 35.5% to 43.1% of the fiber-bundle samples, irrespective of number of fibers and application mode, and among 24.4% to 27.3% of the solid posts (p = 0.010; chi-squared test). µCT revealed voids inside the composite bulk between the fibers as well as between composite and dentin of adhesively luted fiber bundles. CONCLUSION: Adhesively luted fiber bundles achieved bond strengths comparable to those of solid fiber posts for one investigated post type, and even higher values compared to another post type. Inhomogeneities were frequently detected irrespective of application mode.

Survival rates and complication behaviour of tooth implant-supported, fixed dental prostheses: A systematic review and meta-analysis.

OBJECTIVE: To assess the survival and complication rates of tooth-implant supported fixed dental prostheses (T-I FDPs). SOURCES: An electronic search in MEDLINE/PubMed, Cochrane Library, and Embase was conducted using MeSH terms to identify randomised controlled trials (RCTs) or prospective studies with an observation period of at least 3 years, including at least 10 participants. STUDY SELECTION: Included studies were qualitatively assessed. Survival rates of T-I FDPs and implants as well as technical and biological complications were obtained. Failure and complication rates were pooled by weighting each rate in inverse proportion to its variance. DATA: A total of eight studies were considered for qualitative analysis; seven studies with a minimum follow-up of five years were included for quantitative analysis. Estimated survival rates of T-I FDPs were 90.8% (95% CI: 86.4-93.8%) after five years and 82.5% (95% CI: 74.7-88.0%) after 10 years. Implant survival estimates were 94.8% (90.9-97.0%) and 89.8% (82.7-99.4%) after 5 and 10 years, respectively. From a total of 185 T-I FDPs, 21 (11.4%) minor and 23 (12.4%) major biological complications were observed, whereas 23 (12.4%) minor and three (1.6%) major technical complications occurred. CONCLUSIONS: Due to the lack of well-designed studies exceeding a 10-year follow-up, prognosis for the long -term can hardly be given. Considering the inclusion criteria of this systematic review, T-I FDP-supported fixed dental prostheses show acceptable survival rates after five and 10 years. Rigidly constructed T-I FDPs should be preferred. With regard to the available data, these conclusions are valid only for three- to four-unit T-I FDPs. CLINICAL SIGNIFICANCE: Tooth-implant supported fixed dental prostheses are a recommendable treatment option in partial dentition. Based on the current literature, they should be rigidly constructed with a maximum number of four units.

Dentin-like versus Rigid Endodontic Post: 11-year Randomized Controlled Pilot Trial on No-wall to 2-wall Defects.

INTRODUCTION: This is the first long-term randomized controlled trial to evaluate dentin-like glass fiber posts (GFPs) compared with rather rigid titanium posts (TPs) for post-endodontic restoration of severely damaged endodontically treated teeth with 2 or fewer remaining cavity walls. METHODS: Ninety-one subjects in need of post-endodontic restorations were randomly assigned to receive either a tapered GFP (n = 45) or TP (n = 46). Posts were adhesively luted by using self-adhesive resin cement, followed by composite core build-up and preparation of 2-mm ferrule design. Primary end point was loss of restoration for any reason. Kaplan-Meier curves were constructed, and log-rank test was calculated (P < .05). RESULTS: After a follow-up of 132 months, 17 GFP and 20 TP restorations survived, and 19 failed (12 GFP, 7 TP). Failure modes for GFP were root fracture (n = 4), core fracture (n = 1), secondary caries (n = 1), endodontic failure (n = 2), extraction because of tooth mobility grade III associated with insufficient design of removable partial denture (n = 1), tooth fracture (n = 1), and changes in treatment plan (n = 2); failure modes for TP were endodontic failure (n = 5), root fracture (n = 1), and 1 extraction for other reasons. Cumulative survival probability was 58.7% for GFP and 74.2% for TP. CONCLUSIONS: When using self-adhesively luted prefabricated posts, resin composite core build-up, and 2-mm ferrule to reconstruct severely damaged endodontically treated teeth, tooth survival is not influenced by post rigidity. Survival decreased rapidly after 8 years of observation in both groups.