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Objective: To determine the influence of the geometric dimensions of core build‐ups on early core build‐up failure, that is, loss before definitive prosthesis cementation. Materials and Methods: Adhesive core build‐ups of exclusively vital teeth in 114 participants were evaluated (n materials: 40 Rebilda DC, 38 Multicore Flow, 36 Clearfil DC Core; n teeth: 8 incisors, 54 premolars, 52 molars). Impressions of the abutment teeth were made (1) after removal of insufficient restorations/caries and (2) after core build‐up and preparation for a fixed prosthesis. Digitized model surfaces of both situations were aligned (Geomagic Design X) and core build‐up volume (VCBU), remaining hard tissue volume (VAbut), and size of the adhesive surface (Aadh) were assessed. The derived measure dCBU = VCBU/Aadh can be interpreted as mean arithmetic core build‐up thickness. Associations between participant or core build‐up design characteristics and the occurrence of early failures were statistically evaluated (SPSS v27, α = 0.05). Results: A total of six (5.3%) core build‐up failures were registered. Higher participant age, greater core build‐up volume VCBU and greater arithmetic uniform thickness dCBU were associated with a greater incidence of failure in bivariate and univariate, however, not in multivariate statistics. Conclusions: Core build‐up volume and thickness were associated with early success or failure. Clinical Significance: In the case of voluminous/thick core build‐ups in relation to the adhesive surface, additional measures, such as the preparation of retentive elements to increase the bonding area, might be considered to reduce the risk of early core build‐up failure. [ABSTRACT FROM AUTHOR]

Background: This randomized clinical trial was conducted to assess whether sleep bruxism (SB) is associated with an increased rate of technical complications (ceramic defects) in lithium disilicate (LiDi) or zirconia (Z) molar single crowns (SCs). Methods: Adult patients were classified as affected or unaffected by SB based on structured questionnaires, clinical signs, and overnight portable electromyography (BruxOff) and block randomized into four groups according to SB status and crown material (LiDi or Z): LiDi-SB (n = 29), LiDi-no SB (n = 24), Z-SB (n = 23), and Z-no SB (n = 27). Differences in technical complications (main outcome) and survival and success rates (secondary outcomes) one year after crown cementation were assessed using Fisher's exact test with significance level α = 0.05. Results: No technical complications occurred. Restoration survival rates were 100% in the LiDi-SB and LiDi-no SB groups, 95.7% in the Z-SB group, and 96.3% in the Z-no SB group (p > 0.999). Success rates were 96.6% in the LiDi-SB group, 95.8% in the LiDi-no SB group (p > 0.999), 91.3% in the Z-SB group, and 96.3% in the Z-no SB group (p ≥ 0.588). Conclusions: With a limited observation time and sample size, no effect of SB on technical complication, survival, and success rates of molar LiDi and Z SCs was detected. [ABSTRACT FROM AUTHOR]

Background: Reliable and suitable bruxism assessment would be desirable, but available studies presented heterogeneous results. Objective: To determine the agreement of patient self‐reports and clinical signs of sleep bruxism (SB) with electromyographic/electrocardiographic data. Methods: Two hundred individuals from a German dental clinic population (120 women and 80 men) participated in the study. Participants completed different SB questionnaires, had a clinical examination to evaluate bruxism signs and used the Bruxoff® device to record electromyographic/electrocardiographic data for five nights. To investigate interrater reliability for clinical diagnosis of bruxism, 126 of the 200 participants were assessed for clinical signs of bruxism by two independent uncalibrated examiners. Statistical evaluation included calculation of sensitivity, specificity and accuracy and of Cohen's kappa. Results: Based on the Bruxoff® data, 106 participants were identified as bruxers and 94 as non‐bruxers. The 106 bruxers were further classified into 47 moderate and 59 intense bruxers. The highest accuracy and sensitivity values were recorded for the overall score for clinical bruxism signs (accuracy: 72.0% and sensitivity: 70.8%). The best specificity (96.8%) was seen for the question regarding tooth grinding in the last two weeks reported by others, but concurrent sensitivity was very low (3.8%). Analysis of interrater reliability revealed a substantial agreement (Cohen's kappa of 0.6). Conclusion: The study results indicate that self‐report questionnaires and clinical signs have moderate sensitivity, specificity and accuracy for diagnosing bruxism comparing with an ambulatory device for current SB (Bruxoff®). Regarding interrater reliability for clinical signs of SB, substantial agreement was found between the two examiners. Clinical trial no. NCT03039985. [ABSTRACT FROM AUTHOR]

Purpose: To prospectively compare the clinical performance of posterior inlay‐retained and wing‐retained monolithic zirconia fixed partial dentures (FPDs). Materials and methods: After simple randomization, 30 participants received either one inlay‐retained (n = 15; mean age: 56.38 ± 12.70 years; 10 men [66.7%]) or one wing‐retained (n = 15; mean age: 45.90 ±13.24 years; 7 men [46.7%]) FPD. The restorations, which predominantly replaced first molars, were fabricated from translucent, 3 mol% yttria‐stabilized zirconia and attached with self‐etching resin cement. Restorations and abutment teeth were clinically followed up for complications one week and 3, 6, and 12 months after cementation. Plaque and gingival scores, probing pocket depths, and attachment levels were recorded for the abutment and contralateral reference teeth both before treatment and during follow‐up examinations. The restorations were also assessed in accordance with FDI World Dental Federation criteria. Statistical analyses were conducted with R (α = 0.05). An adaptive, 2‐stage study design based on the incidence of failure‐free survival in the groups after 12 months (stage 1) was implemented. Predefined decision rules were used to determine whether further recruitment (stage 2) would enable the detection of a statistically significant difference between the restoration designs with sufficient power. Results: During 12 months, only one wing retainer debonded which required removal of the FPD. Failure‐free survival was thus 93.3% for wing‐retained and 100% for inlay‐retained FPDs (log‐rank test, p = 0.317). Moderate aftercare resulted in intervention‐free rates of 78.8% and 86.7% for inlay‐retained and wing‐retained restorations, respectively (log‐rank test, p = 0.605). Based on FDI World Dental Federation criteria, all restorations were acceptable at the 12‐month follow‐up (Fisher‐Boschloo test, p = 0.161). Plaque, gingival, and periodontal scores remained practically unchanged from before treatment to the 12‐month follow‐up. Recruitment was stopped after stage 1 because, based on the small difference in the incidence of failure‐free survival in the groups, it was accepted that it would not be possible to recruit the necessary number of participants to show a statistically significant difference between the retainer designs. Conclusions: Both inlay‐retained and wing‐retained monolithic zirconia resin‐bonded FPDs performed well for the 12‐month, short‐term follow‐up period. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the clinical performance of zirconia-based cantilever fixed dental prostheses (FDPs). Method and Materials: Twenty-one cantilever FDPs with three or four units were designed to replace one premolar or incisor (no canines). The FDPs were divided into 11 zirconia cantilever FDPs (test group) and 10 metal-ceramic cantilever FDPs (control group) and randomly assigned to patients. The results documented included failures, complications, plaque accumulation, and esthetic performance. Statistical analysis was performed using the Mann-Whitney U and chi-square tests. Results: During the 2-year observation period, a total of five clinically relevant complications in four patients occurred: three endodontic problems (two in the test group and one in the control group) and two veneer chippings (both in the test group). Plaque accumulation on the abutment teeth was not significantly different among groups. The esthetic performance of all FDPs was acceptable. Conclusion: Stability and esthetic performance were acceptable for all-ceramic cantilever FDPs fabricated with zirconia. A longer observation period and larger sample size are necessary to make valid predictions about the longevity of these restorations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the fracture-load values of cantilevered allceramic fixed partial dentures (FPDs). Fifty FPDs were manufactured using a zirconia frame to replace a missing molar. The FPDs were divided into five groups, each with a different framework design. After thermocycling and mechanical loading, the load to fracture was measured. The Mann-Whitney U test was used for statistical analysis. The mean fracture-load values for the test groups ranged from 346 to 548 N. Reinforcement of the shoulder on the oral side of the occlusal wall resulted in higher fracture load values, while increasing the wall thickness of the distal abutment did not improve fracture resistance. The results indicate that all-ceramic cantilever FPDs cannot yet be recommended for clinical replacement of a missing molar. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the fracture resistance of teeth restored using an adhesive core material placed under artificial crowns without pins or posts and to assess the effect of different preparation designs and cementation techniques (glass ionomer compared with adhesive cementation) used for the crowns. Materials and Methods: Eighty-three intact molars were collected. Sixty-seven teeth were decoronated (test groups and one control group), a 2-mm circular ferrule design was prepared, and four different preparation designs (2-mm- or 1-mm-deep cavities and 2-mm- or 1-mm-thick walls) were used. Three control groups were also established. Cores were built up using an adhesive material. After preparation, standardized artificial crowns (cobalt-chromium alloy) were fabricated. Half of the crowns in the test group (n = 32) were cemented using Panavia (P group); glass-ionomer cement was used for the other half (KC group). All teeth were exposed to 10,000 thermal cycles and loaded until fracture. Statistical analysis was performed, including nonparametric tests (Mann-Whitney U-test) and ANOVA. Results: In the P group, the fracture strength was significantly (p = 0.004) higher (591.75 ± 177.95 N) than in the KC group (430.18 ± 193.67 N). The effect of the preparation design was more pronounced in the KC group. In all groups simulating the most moderate type of tooth decay (2-mm-deep cavity and a 2-mm-thick wall), the fracture strength was comparable with that of intact teeth. Results from ANOVA showed that the type of cementation of the crowns affected fracture strength. Conclusion: Fracture strengths of adhesive core/crown complexes are greater when an adequate cavity for retention (at least 2 mm deep) is prepared and the crown is luted. [ABSTRACT FROM AUTHOR]

Purpose:The aim of this prospective randomized controlled trial was to evaluate the influence of clinical baseline characteristics on the survival of 2 post systems. Materials and Methods:One hundred patients needing a post were included. Half the patients received a glass fiber--reinforced post (FRP), and the other half received metal screw posts (MSP). The posts were assigned randomly. In addition to demographic data, the following parameters were recorded: type of tooth (incisor/canine versus molar/premolar), length of the post in relation to root length (percentage), extent of coronal tooth destruction (percentage), ferrule height (in millimeters), type of restoration (fixed or removable partial denture), and presence of antagonistic contacts (yes/no). After at least 1 year (mean: 13.84 months), the patients were recalled. Statistical analysis was performed using the log-rank test and Cox regression analysis. Results:The survival rate of FRPs was 93.5%. In the MSP group, the survival rate was significantly lower (75.6%; log-rank test, P = .049). Additionally, the metal posts were associated with more unfavorable complications, for example, root fracture. The type of the tooth and the degree of coronal tooth destruction influenced the survival of MSPs, whereas no influence of these variables could be seen for FRPs. Conclusion: FRPs are superior to MSPs with respect to short-term clinical performance. Especially for MSPs, clinical survival depends on several variables. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the ability of clinical and magnetic resonance imaging (MRI) diagnoses to predict pain in the temporomandibular joint (TMJ). Materials and Methods: One hundred forty-nine patients were examined by 2 calibrated examiners in strict accordance with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). All patients who presented with a defined clinical RDC/TMD diagnosis were included and underwent bilateral coronal and sagittal MRI of the TMJ. Two raters blinded to the clinical diagnosis interpreted the MRI scans for TMJ pathology. The results were tested against the clinical diagnosis according to the RDC/TMD, including pain-related disability and psychosocial status, for associations to TMJ arthralgia using logistic regression analysis (GENMOD procedure, P < .05). Results: MRI-depicted anatomic changes, such as joint effusions, disc displacement, and osteoarthrosis, were not significantly correlated with the presence of pain in the TMJ. However, a significant relationship between pain on palpation of the masseter muscle origin (P = .0050) and psychosocial factors (P = .0452) and pain in the TMJ was demonstrated. Conclusions: Pain in the TMJ caused by the anatomic proximity of the muscle masseter origin and the lateral TMJ pole and the possible existence of trigger points in the musculature may lead to a false-positive or a false-negative diagnosis of arthralgia. Additionally, clinicians must consider the psychosocial aspects of pain in ideal treatment planning. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of gender, antagonistic teeth, and type of denture on clinical wear of denture teeth. Wear measurements were made on gypsum replicas of 204 posterior denture teeth after 6 months using an optical 3-dimensional profilometer. Data were analyzed using univariate and mixed regression procedures. The mean wear of all denture teeth was -20.5 µm (± 14.6). Males demonstrated significantly higher wear than females. Interactions of the variables "gender" and "type of denture" and "antagonist material" and "type of denture" also showed significant influences on wear. The results indicate that some clinical parameters may affect wear of denture teeth. [ABSTRACT FROM AUTHOR]

This study aimed to assess the correlation between self-rated denture function and oral health--related quality of life (OHRQoL) in different age groups. Subjects' OHRQoL was measured using the Oral Health Impact Profile, and self-ratings of denture function were assessed on a Likert-type scale for patients with fixed and removable partial dentures in 3 age groups (N = 253). For subjects with fixed partial dentures, all correlations were significant for the younger patients but not for higher age groups, whereas the opposite was true for subjects with removable partial dentures. The importance of self-perception of denture function in OHRQoL is different in various groups of patients, depending on age and dental status. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this randomized clinical study was to evaluate the clinical performance of posterior, metal-free polymer crowns after follow-up for up to six years, and to compare it with the performance of metal-ceramic crowns. Methods: Eighty single crowns, manufactured from a polymer composite resin, were set on posterior teeth. Half of these received a glass-fibre framework (group 1) whereas half were prepared without framework stabilization (group 2). As the control group, 40 conventional metal-ceramic crowns were inserted. Primary endpoints were incidence of complications, investigated on a time-to-event basis, plaque status, and aesthetic performance. Results: Thirty clinically relevant complications occurred after a median time of 2.3 years. Median follow-up time was four years. The most frequent complications were delamination (n = 24) and root-canal treatment (n = 4) of the crowns; the incidence of complications was not significantly different among crown materials ( p = 0.60). Twenty crowns had to be replaced (six polymer crowns in group 1, nine polymer crowns in group 2, four crowns in the control group, and one tooth (in group 1) had to be extracted). Mean plaque and gingival indexes for the test groups did not differ from those for the control group. Conclusions: Within a median follow-up period of four years, the clinical performance of posterior polymer crowns with and without a glass-fibre framework was not significantly different from that of metal-ceramic crowns, although the number of catastrophic failures of composite crowns was higher than that of the metal-ceramic crowns. Clinical significance: On the basis of the study results, posterior polymer crowns may be an alternative to metal-ceramic crowns, although additional research is needed before they can be recommended, without reservation, as permanent restorations. [ABSTRACT FROM AUTHOR]

To compare differences between the wear behavior of two types of metal-free resin composite crown with a control after three years in clinical service. Sixty-six participants needing one to three posterior single crowns were fitted with 120 crowns. Abutment teeth were randomly assigned to three groups: 40 resin composite crowns with fiber-reinforced framework, 40 resin composite crowns without fiber-reinforced framework, and 40 metal-ceramic crowns. To assess wear, gypsum replicas of the crowns were fabricated and scanned with a 3D laser scanner at baseline and after three years. Differences between the groups were analyzed by use of mixed-effects regression models. Wear of resin composite crowns with fiber-reinforced framework (p=0.0043) and resin composite crowns without framework (p=0.0246) was significantly greater than in the metal-ceramic group. Wear of metal-free resin composite crowns after three years was significantly greater than that of metal-ceramic crowns, but the wear was still clinically acceptable. [ABSTRACT FROM AUTHOR]

Objective. Evaluation of the effect of different framework designs and of fatigue on the fracture-load values of cantilevered fixed dental prostheses (FDPs). The load values were compared with those for lithium disilicate ceramic and metal-ceramic FDPs. Materials and methods. Fifty cantilevered FDPs were manufactured using a zirconia framework veneered with a feldspathic ceramic. Ten FDPs were made from a lithium disilicate ceramic and 10 were designed as metal-ceramic FDPs. All FDPs were anchored by two premolar crowns to replace a missing premolar. Twenty of the 50 zirconia FDPs were regarded as the control groups; these were divided into two groups-with and without fatigue. The other 30 zirconia FDPs were divided into three test groups with different framework designs. The load to fracture was measured and fracture sites were identified. The Kruskal-Wallis test and the Mann-Whitney U-test were used for statistical analysis. Results. Most of the all-ceramic FDPs fractured within the distal wall of the terminal crown abutment. The mean fracture-load ranged between 346-493 N for the FDPs with the 0.7 mm framework. Mean values for the three zirconia test groups ranged from 529-590 N. Reinforcement of the framework resulted in significantly higher fracture-loads than for the control group. Values for lithium disilicate restorations were significantly lower than those for the test groups and the values for the metal-ceramic group were significantly higher than those for the test groups. Conclusion. Although reinforcement of the distal crown core might enhance the fracture resistance of all-ceramic cantilever FPDs, they cannot yet be unreservedly recommended for clinical use. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effect of different thicknesses of porcelain at the gingival of pontics, on the fracture load of zirconia-based, all-ceramic fixed dental prostheses (FDPs), anchored by inlays. Methods: Box inlay cavities were prepared on mandibular molars and premolars. 40 FDPs with yttrium-stabilized zirconia frameworks of identical dimensions were manufactured using a CAD/CAM system and veneered with a press ceramic. The FDPs, replacing a premolar and a molar, were divided into four groups. In Group FR, the framework was all around unveneered. The next three groups received a 1 mm ceramic veneer on the buccal, occlusal and lingual side, but differed in the thickness of the ceramic veneer in the gingival, tensile zone of the pontics. In Group B-0, the gingival veneering was 0 mm, in Group B 1 mm and in Group B-2, 2 mm of gingival porcelain. A group of inlay-retained metal-ceramic FDPs (mc) served as control. All FDPs were subjected to thermal cycling and 600,000 cycles of mechanical load of 50 N. The load to fracture (N) was measured and fracture sites were evaluated macroscopically. A single-factor Analysis of Variance was used to analyze the data. Results: None of the FDPs debonded after thermal cycling or mechanical loading and no signs of fractures or other defects were observed. The mean fracture loads and standard deviations in parentheses were: 647 N (123) for Group B-0, 716 N (102) for Group FR, 812 N (48) for Group B-i, 934 N (129) for Group B-2 and 1005 N (SD 81) for Group MC. Means for Groups B-0 and FR were not shown to differ, and the same for mean fracture strength of Groups B-2 and MC. [ABSTRACT FROM AUTHOR]

Objective. Evaluation of the fracture resistance of all-ceramic cantilever fixed dental prostheses (FDPs) manufactured from zirconia frameworks and veneered with a press ceramic. Material and Methods. Two mandibular premolars were prepared either with a box inlay cavity or with a full crown chamfer preparation and then duplicated. 40-three-unit cantilever FDPs replacing one premolar, with a group size of eight for each design, were manufactured. In group i-i the cantilever FDPs were retained by two inlays, in group i-c by an inlay-crown combination, and in group c-c by two crowns. The frameworks in groups i-c-R and c-c-R were reinforced by an additional shoulder on the oral side of the zirconia frameworks. All FDPs were subjected to thermal cycling (TC) and 600,000 cycles of mechanical loading (ML) with 50 N. The load to fracture was measured and fracture sites were evaluated. Results. The mean fracture values ranged from 172 N to 792 N. Fracture-strength values were significantly lower for the i-i retained FDPs than for the i-c and c-c combinations. There was no significant effect of the reinforcing shoulder in groups i-c-R and c-c-R. For FDPs with a crown on the terminal tooth, fractures were usually within the distal wall of the distal crown. Conclusions. Inlay-inlay retained cantilever FDPs cannot withstand the mastication forces expected. Fracture load values for inlay-crown and crown-crown-retained FDPs encourage further clinical investigation. The mode of fracture indicates that reinforcement of the distal crown wall might enhance fracture resistance. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate in vitro the fracture load of fixed partial dentures (FPDs) anchored by use of composite inlays. The effects of span length, silica-coating, mechanical loading and framework material were also tested. Methods: Defined box inlay cavities were made on a mandibular molar and a premolar. Fifty-six FPDs were manufactured using a polymer composite material and received an industrial prefabricated polymethylmethacrylate (PMMA) frame for stabilization. All FPDs underwent thermal cycling. The FPDs were divided into test groups simulating the effect of different span length (7 or 12 mm), tribochemically silicoating (yes or no) and mechanical loading (yes or no). The load to fracture was measured and fracture sites were evaluated. As a control group for the PMMA frame, a metal alloy frame was used, and evaluated under the most unfavorable conditions. The Mann-Whitney U-test followed by the Bonferroni correction was used for statistical analysis. Results: The span length significantly affected the fracture load. Values ranged from 413 N for the 12 mm span length to 706 N for the 7 mm span length. Thermal cycling and mechanical loading significantly reduced fracture load values for FPDs with the 12 mm span length, but there were no significant effects for FPDs with 7 mm span length. Silicoating pretreatment of the metal abutments significantly reduced fracture load values. Replacement of the PMMA frame with a metal frame increased fracture load values up to 1,075 N. [ABSTRACT FROM AUTHOR]

Aims: The aim of this in vitro study was to evaluate the fracture load of zircon frames veneered with a polymer glass holding box inlay-retained fixed partial dentures (FPDs). The influence of the position of the frame and the span length was tested. Additionally, the fracture load values of zircon frames veneered with a press ceramic were evaluated.Material and Methods: Box inlay cavities were prepared on mandibular molars and premolars. Forty-eight FPDs were manufactured using industrially prefabricated zircon frames veneered with the polymer glass Artglass. Sixteen FPDs received individually manufactured CAD/CAM zircon frames veneered with a press ceramic. All FPDs underwent thermal cycling and mechanical loading (ML). The load to fracture was measured and fracture sites were evaluated.Results: Four polymer veneered FPDs showed fractures in the veneering material after ML. The mean fracture resistance ranged from 531 N to 727 N. No significant influence of frame localization could be observed. Significantly greater fracture resistance values were found in the ceramic veneered FPDs (1276 N to 1413 N). There was no significant effect of span length in the polymer veneered group or in the all-ceramic group, with the exception of a significant peak in fracture load value for intermediate span lengths in the polymer group with a localized occlusal zircon frame.Conclusions: Polymer veneered FPDs with Y-TZP frames showed acceptable fracture resistance values, but they cannot yet be unreservedly recommended for clinical use. Fracture values for CAD/CAM manufactured Y-TZP frames combined with a press ceramic deserve further clinical investigation. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the reliability between different examiners when using the axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The hypothesis was that the standardized RDC/TMD examination protocol enables calibrated examiners to evaluate all examination items reliably. After calibration training by the RDC/TMD calibration team including the calibration of palpation pressure and the performance of the standardized examination protocol, four examiners, blinded to the patients' medical histories examined 24 subjects in a randomized sequence. One experienced examiner was the standard (hierarchical calibration). The recorded measurements strictly followed the RDC/TMD. Intraclass correlation coefficients (ICC), bias and precision were calculated to estimate interrater reliability. Acceptable (0.75 > or = CC > 0.4) to excellent (ICC > 0.75) reliability was found for 20 of the 23 (87%) examinations. Only sub-retromandibular muscle palpation and joint sound vibration recordings on lateral excursion showed poor-results (ICC < or = 0.4). The RDC/TMD examination protocol enables calibrated examiners to perform most (87%) examination items with satisfactory reliability. Therefore multi-site studies based on the RDC/TMD examination protocol may become feasible, keeping in mind the unsatisfactory reliability of 13% of the items (clicking during laterotrusion to the ipsilateral side, palpation of the posterior and submandibular region). [ABSTRACT FROM AUTHOR]

The aim of this study was to identify correlations between sleep bruxism (SB) and temporomandibular disorders (TMD) as diagnosed by means of the research diagnostic criteria for temporomandibular disorders (RDC/TMD). Sleep bruxism was diagnosed on the basis of I) validated questionnaires, II) clinical symptoms, and III) electromyographic/electrocardiographic data. A total of 110 subjects were included in the study. Fifty-eight patients were identified as bruxers and 52 as nonbruxers. A psychosocial assessment was also performed. An RDC/TMD group-I diagnosis (myofascial pain) was made for 10 out of 58 bruxers, whereas none of the nonbruxers received a diagnosis of this type. No significant differences were found between bruxers and nonbruxers with regard to RDC/TMD group-II (disc displacement) and group-III (arthralgia, arthritis, arthrosis) diagnoses. Somatization was significantly more common among bruxers than nonbruxers. Multivariate logistic regression analysis revealed that somatization was the only factor significantly correlated with the diagnosis of myofascial pain. The results of this study indicate a correlation between myofascial pain, as diagnosed using the RDC/TMD, and somatization. It seems that somatization is a stronger predictor of an RDC/TMD diagnosis of myofascial pain than sleep bruxism is. [ABSTRACT FROM AUTHOR]

Background: This randomized clinical trial was conducted to assess whether sleep bruxism (SB) is associated with an increased rate of technical complications (ceramic defects) in lithium disilicate (LiDi) or zirconia (Z) molar single crowns (SCs). Methods: Adult patients were classified as affected or unaffected by SB based on structured questionnaires, clinical signs, and overnight portable electromyography (BruxOff) and block randomized into four groups according to SB status and crown material (LiDi or Z): LiDi-SB (n = 29), LiDi-no SB (n = 24), Z-SB (n = 23), and Z-no SB (n = 27). Differences in technical complications (main outcome) and survival and success rates (secondary outcomes) one year after crown cementation were assessed using Fisher’s exact test with significance level α = 0.05. Results: No technical complications occurred. Restoration survival rates were 100% in the LiDi-SB and LiDi-no SB groups, 95.7% in the Z-SB group, and 96.3% in the Z-no SB group (p > 0.999). Success rates were 96.6% in the LiDi-SB group, 95.8% in the LiDi-no SB group (p > 0.999), 91.3% in the Z-SB group, and 96.3% in the Z-no SB group (p ≥ 0.588). Conclusions: With a limited observation time and sample size, no effect of SB on technical complication, survival, and success rates of molar LiDi and Z SCs was detected.

Objectives: The purpose of this study was to identify associations between definite sleep bruxism, as defined by the American academy of sleep medicine, and chronic stress and sleep quality., Methods: Sleep bruxism was determined by use of questionnaires, assessment of clinical symptoms, and recording of electromyographic and electrocardiographic data (recorded by the Bruxoff ® device). The study included 67 participants. Of these, 38 were identified as bruxers and 29 as non-bruxers. The 38 bruxers were further classified as 17 moderate and 21 intense bruxers. Self-reported stress and self-reported sleep quality were determined by use of the validated questionnaires "Trier Inventory for the Assessment of Chronic Stress" (TICS) and the "Pittsburgh Sleep Quality Index" (PSQI)., Results: No statistically significant association was found between sleep bruxism and self-reported stress or sleep quality. However, a significant association between specific items of chronic stress and poor sleep quality was identified., Conclusions: The results of this study indicate an association between subjective sleep quality and subjective chronic stress, irrespective of the presence or absence of sleep bruxism., Clinical Significance: Chronic stress and sleep quality do not seem to be associated with sleep bruxism. (clinical trial no. NCT03039985)., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: The purpose of this study was to evaluate the 10-year clinical performance of zirconia-based inlay-retained fixed dental prostheses (IRFDP)., Methods: For replacement of a molar in 27 patients, 30 IRFDP were luted by use of different cements, Panavia F (Kuraray Europe GmbH) or Multilink Automix (Ivoclar Vivadent GmbH), with use of inlay/inlay, inlay/full-crown, or inlay/partial-crown retainers for anchorage. Frameworks were milled from yttria-stabilized zirconia (IPS e.maxZirCAD; Ivoclar Vivadent GmbH) and fully veneered with pressable ceramic (IPS e.max ZirPress; Ivoclar Vivadent GmbH). Before luting, the IRFDP were silica-coated (Rocatec; 3M Espe) and silanized (Monobond S; Ivoclar Vivadent GmbH). Complications (for example, chipping or delamination of the veneering ceramic, debonding, secondary caries, endodontic treatment, and abutment tooth fracture) and failure were reported, by use of standardized report forms, 2 weeks, 6 months, and 1, 2, and 10 years after cementation. Statistical analysis included Kaplan-Meier survival and success (complication-free survival) and Cox regression analysis (α=0.05 for all)., Results: During the 10-year observation period, the complications most often observed were chipping of the veneer and debonding. Twenty-five restorations failed and one participant dropped out. Cumulative 10-year survival and success were 12.1% and 0%, respectively. The design of the retainer, use of a dental dam, choice of cement, and location in the dental arch had no statistically significant effect on the occurrence of complications., Conclusions: Use of fully veneered zirconia-based IRFDP with this technique cannot be recommended., Clinical Significance: A large incidence of complications and poor survival were observed for fully veneered zirconia-based IRFDP, revealing an urgent need for further design improvements for this type of restoration. This, again, emphasizes the need for testing of new restoration designs in clinical trials before implementation in general dental practice., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: To determine the prevalence of temporomandibular disorders (TMD) in scuba divers and to identify the risk factors for the development of pain in the stomatognathic system before and after diving by the use of a questionnaire., Design: : Retrospective cohort study based on questionnaires., Participants: A total of 296 active divers, aged 18 to 65 years, participating in scuba diving meetings in Heidelberg, Germany., Interventions: Each diver answered a questionnaire containing 29 questions, predominantly on symptoms of TMD., Main Outcome Measures: The data collected from the divers were calculated by the use of logistic regression tests. Risk factors for the development of TMD were evaluated., Results: Clenching seemed to be the greatest risk factor for pain while holding the mouthpiece and for pain in the masticatory muscle system after diving. Limited mouth opening and clenching were responsible for the development of pain in the temporomandibular joint after the dive. The prevalence of TMD-related symptoms was higher in women before, during, and after the dive., Conclusions: Individuals exhibiting TMD-related symptoms seem to be at the greatest risk of developing pain in the masticatory muscle system and/or the temporomandibular joint during or after the dive.

The aim of this study was to investigate the reliability between different examiners when using the axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The hypothesis was that the standardized RDC/TMD examination protocol enables calibrated examiners to evaluate all examination items reliably. After calibration training by the RDC/TMD calibration team including the calibration of palpation pressure and the performance of the standardized examination protocol, four examiners, blinded to the patients' medical histories examined 24 subjects in a randomized sequence. One experienced examiner was the standard (hierarchical calibration). The recorded measurements strictly followed the RDC/TMD. Intraclass correlation coefficients (ICC), bias and precision were calculated to estimate interrater reliability. Acceptable (0.75 > or = CC > 0.4) to excellent (ICC > 0.75) reliability was found for 20 of the 23 (87%) examinations. Only sub-retromandibular muscle palpation and joint sound vibration recordings on lateral excursion showed poor-results (ICC < or = 0.4). The RDC/TMD examination protocol enables calibrated examiners to perform most (87%) examination items with satisfactory reliability. Therefore multi-site studies based on the RDC/TMD examination protocol may become feasible, keeping in mind the unsatisfactory reliability of 13% of the items (clicking during laterotrusion to the ipsilateral side, palpation of the posterior and submandibular region).