The International journal of prosthodontics最新文献

Purpose: To investigate associations between self-reported bruxism, masticatory muscle pain, and bowel symptoms and their relationship to the nine dimensions of the Symptom Checklist-90-Revised (SCL-90-R).

Materials and methods: Data from three separate validated questionnaires-Bowel Symptom Questionnaire (BSQ) to classify bowel status, Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) to determine self-reported bruxism and masticatory muscle pain on palpation, and SCL-90-R for psychometric assessment-were collected for each patient. BSQ used the Rome II criteria to identify the presence or absence of bowel symptoms but did not analyze subsets of bowel symptoms. Chi-square tests were used to test for pairwise associations between bruxism, masticatory muscle pain, and bowel status. Multiple logistic regression analysis was used to identify the independent predictors of bruxism and bowel symptoms.

Results: Data from 246 surveys were collected for self-reported bruxism, muscle pain, and bowel status, of which 191 patients completed the SCL-90-R. There was significant association between self-reported bruxism and muscle pain (P = .004) and betwen self-reported bruxism and bowel symptoms (P = .020). Bowel problems were identified in 53% of patients, and 48% of patients presented with both self-reported bruxism and bowel problems. There was no significant association between bowel symptoms and muscle pain. Multiple logistic regression analysis identified muscle pain and bowel symptoms as independent predictors of self-reported bruxism, and somatization was identified as the sole independent predictor of bowel symptoms.

Conclusions: These data establish a possible relationship between self-reported bruxism and bowel symptoms, necessitating education and the formulation of clinical practice guidelines for interdisciplinary care of this group of patients.

Purpose: To investigate shear bond strengths (SBSs) of denture repair materials using different polymerization methods to a 3D-printed denture base (DLP) compared to an autopolymerized polymethyl methacrylate denture base (PMMA).

Materials and methods: DLP and PMMA disks were fabricated, roughened using #400 silicon carbide abrasive paper, and treated with the primer/bonding of the respective repair material. An autopolymerized denture repair material (PER) or a light-polymerized denture relining material (MRB) was polymerized on the disks. All specimens were stored in distilled water at 37°C for 24 hours. Half of the specimens underwent thermocycling (TC; 5,000 cycles, 5 to 55°C). SBS testing was conducted (n = 20 per group), and the fracture pattern was analyzed. The SBS data were analyzed using nonparametric Kruskal- Wallis tests and Weibull distributions with the maximum likelihood estimation.

Results: MRB specimens showed significantly higher SBS and Weibull characteristic strength values than PER specimens (P < .001), irrespective of the denture base material. No statistical differences were observed in Weibull modulus among the specimens, except PMMA-MRB specimens, which showed the highest values (P < .001). Thermal aging tended to decrease these values; however, no significant differences were observed between the non-TC and TC groups. Adhesive failure was dominantly observed in the specimens, except DLP-MRB specimens, which shifted to cohesive failures within the denture base.

Conclusions: The repairability of the DLP specimens was comparable to those of the PMMA specimens. Thus, denture repair of the DLP denture base could be treated in the same manner as a conventional PMMA denture base.

Purpose: To systematically evaluate and compare the clinical performance of translucent zirconium dioxide 3-, 4-, and 5-unit fixed dental prostheses (FDPs) in the posterior dentition with either a monolithic design or with veneered buccal cutbacks (semimonolithic).

Materials and methods: A total of 31 patients treated by general practitioners received 31 translucent zirconium dioxide FDPs, randomized to be either monolithic or semimonolithic with a porcelain-veneered buccal cutback. The design choice was blinded. Clinical evaluations were made using the California Dental Association (CDA) criteria, and a questionnaire was used to obtain patient-reported outcomes and to compare them to ratings from the dentists.

Results: Mean follow-up time was 48.7 months (SD = 7.7). No FDP fractured during the observation period, and no chip-off fractures could be detected. The overall success rate was 85.2%. One monolithic FDP was found with caries, and one semimonolithic FDP was endodontically treated, giving an overall survival rate of 92.6%. Two FDPs, both semimonolithic, failed due to loss of retention and caries. Both patients and dentists rated the FDPs favorably regarding the esthetic outcome and function, but the patients scored them higher than the dentists in this respect.

Conclusions: Within the limitations of the study, both monolithic and semimonolithic yttria-stabilized zirconium dioxide FDPs seem to be a reliable choice of treatment for 3- to 5-unit restorations in the posterior dentition. The esthetic advantages of a porcelain veneer compared to a monolithic design might, however, be of less importance in the posterior regions for most patients.

Purpose: To study the clinical performance of chairside CAD/CAM-fabricated lithium disilicate crowns (IPS e.max CAD, Ivoclar) over 10 years of service.

Materials and methods: A total of 100 CAD/CAM lithium disilicate crowns were fabricated using the CEREC 3 system (Dentsply Sirona). The crowns were adhesively bonded in consecutive groups with one of three cements: self-etching bonding agent and resin cement (ML; MultiLink-Automix, Ivoclar); self-adhesive resin cement (EC; Experimental Cement, Ivoclar); and self-adhesive, light-cured resin cement (SC; SpeedCem, Ivoclar).

Results: Mild sensitivity was reported on 15% of the teeth at 1 week. All sensitivity resolved by 3 weeks. At 6 months, two (8.7%) of the crowns cemented with ML and three (7.7%) of the crowns cemented with EC were described as slightly sensitive by the patient. No patients required treatment for sensitivity, and there was no reported sensitivity at any subsequent recalls. The percent alpha scores were above 95% for color match and marginal adaptation at all recall intervals. Four crowns debonded: three cemented with EC (13, 20, and 36 months) and one cemented with ML (36 months). A second MultiLink crown debonded at 110 months (9 years, 2 months). There were four reported cases of crown fracture between 6 years, 3 months and 9 years, 9 months. There were two biologic failures: one due to endodontic treatment and one due to fracture and loss of the core.

Conclusions: The lithium disilicate crowns performed very well over 10 years.

Purpose: To examine the effect of gastric acid on the surface roughness of additive and subtractive manufacturing resin.

Materials and methods: In this study, two subtractive-manufacturing CAD/CAM resin nanoceramics (Cerasmart 270 [CS], Lava Ultimate [LU]) and two additive-manufacturing 3D-printing permanent resins (VarseoSmile Crownplus [VSP], Crowntec [CT]) were used. CS and LU samples were turned into 10-mm-diameter cylinders with a scraper and cut into 2-mm slices on the cutting device. CT and VSP samples were produced on a 3D printer (2-mm thickness, 10-mm diameter; n = 15). All samples were exposed to a cycle of 60 seconds of gastric acid, 5 seconds of distilled water, and 30 minutes of artificial saliva, six times a day for 10 days. Surface roughness mean (Ra) and depth (Rz) were measured with a contact profilometer at baseline and after gastric acid cycling. Data were analyzed using SPSS (version 22.0), one-way ANOVA, post-hoc Tukey, and independent t tests (P < .05).

Results: Ra and Rz values of CT and VSP were significantly higher than CS and LU at baseline and after the gastric acid cycle (P < .05). After the gastric acid cycle, the Ra and Rz values of all materials increased significantly compared to baseline (P < .05), but the Ra values of all materials were at a clinically acceptable level (< 0.2 µm).

Conclusions: Although additive-manufacturing 3D-printing permanent resins offered higher roughness values, they were still at a clinically acceptable level. Therefore, they can be used as an alternative to subtractive-manufacturing CAD/CAM resin nanoceramics.

Purpose: To investigate the effect of layer thickness, printing orientation, and post-curing time on the optical properties including the Commission Internationale de L'ecraige (CIE) color coordinates (L*, a*, and b*), color difference (ΔE00) with target shade, relative translucency parameter (RTP00), and opalescence parameter (OP) of additively manufactured resin material for interim fixed dental restorations.

Materials and methods: A total of 270 disc specimens were additively manufactured using biocompatible interim resin material (TEMP, Power Resins) with varying layer thicknesses (25, 50, and 100 µm), printing orientations (0, 45, and 90 degrees), and post-curing times (10, 20, and 30 minutes; n = 10). Optical properties were measured using a spectrophotometer. Data were analyzed using three-way ANOVA, Tukey HSD, and Bonferroni post-hoc tests (α = .05).

Results: Layer thickness, printing orientation, and post-curing time significantly influenced the optical properties (P < .05). All three-way interactions were significant (P < .05), except for L* and b* parameters (P > .05). Increasing layer thickness, printing orientation, and post-curing time resulted in increased yellowness and ΔE00, while lightness and OP decreased. A greater layer thickness increased redness and decreased RTP00, while increased printing orientation and post-curing times decreased redness and increased RTP00.

Conclusions: The optical properties of additively manufactured resin are significantly affected by the printing parameters. The most favorable optical properties were observed with 25-µm thickness, 0-degree orientation, and 10 minutes of post-curing. Adjusting these parameters facilitates the optimization of esthetic outcomes while necessitating consideration of the associated changes in optical properties.

Purpose: To evaluate color changes in 3D-printed acrylic restorations of varying thicknesses and exposed to different post-curing durations.

Materials and methods: Three virtual full-contour maxillary central incisor crowns with different buccal thicknesses (1.0, 1.5, and 2.0 mm) were designed and manufactured using a 3D printer and a photopolymer (n = 9 per thickness group). The lightness, hue, and chroma of the restorations were measured at baseline (prior to post-curing) and again at 5-minute intervals up to 30 minutes during the post-curing process using a spectrophotometer. Color changes (ΔE) were calculated by comparing the CIE L*, a*, b* coordinates at different time points to the baseline values. Repeated-measures ANOVA and Tukey post-hoc tests were used for statistical analysis (α = .05).

Results: The ΔE increased significantly within the first 5 minutes of post-curing and was more gradual thereafter in all thickness groups. The ΔE values were significantly higher in the 1.5- and 2.0-mm-thickness groups compared to the 1.0-mm-thickness group. The C* coordinate was seen to increase significantly within the first 5 minutes of post-curing and did not change significantly afterward.

Conclusions: During post-curing, the hue of 3D-printed polymeric restorations changed to yellowish and reddish shades, the brightness decreased, and the saturation increased. Most color changes occurred within the first 5 minutes of post-curing and were also more noticeable in thicker restorations.

Purpose: To provide a comprehensive overview of the two-color chewing gum mixing ability test's use across dental and medical fields, highlighting its potential for standardizing masticatory performance (MP) assessment and improving clinical decision-making.

Materials and methods: A scoping review was conducted on PubMed/MEDLINE, following the PRISMA-ScR guidelines. Abstracts of research papers were screened for suitability, and full-text articles were obtained for those that satisfied the inclusion criteria.

Results: After the screening, 73 articles were selected and considered eligible for this review in addition to another 11 studies identified from manual searching. A total of 84 studies were therefore included in this scoping review. Overall, 20 articles related to the development and the improvement of the two-color chewing gum mixing ability test over the years were identified and discussed. Additionally, 64 studies investigated the test's application to assess MP in different fields of dentistry and medicine.

Conclusions: The two-color chewing gum mixing ability test has been successfully adopted in the assessment of masticatory function not only in dentistry but also in general medicine.

Purpose: The investigation into the capacity of PEEK material clasps to deliver sufficient retention force, maintain morphological stability, and exhibit fatigue resistance over prolonged periods is of significant importance.

Material and methods: This study employed a fatigue testing machine to simulate clinical scenarios with varying concave depths (0.25mm, 0.50mm, 0.75mm) and conducted 7200 cycles of fatigue tests on clasps made of different materials. The initial retention force, dynamic changes in retention force, and deformation values of the clasps were measured and analyzed, and their surface morphology was observed using Scanning Electron Microscopy (SEM).

Results: The initial retention force of A-type PEEK clasps exhibited an increase with the concave depth, whereas no significant difference was observed in the initial retention force of B-type PEEK clasps at different concave depths. Following fatigue cycling, the retention force of PEEK clasps decreased more gradually compared to metal clasps, with PEEK-A clasps demonstrating more stable retention force in deeper concave conditions. Furthermore, after prolonged fatigue cycles, PEEK clasps exhibited smaller permanent deformation than metal clasps, and their surface remained smoother without evident wear or cracks.

Conclusions: In comparison to metal clasps, PEEK clasps offer more stable retention force and reduced permanent deformation in long-term clinical applications, making them more suitable for periodontal disease abutments with deeper concavity.