The International journal of prosthodontics最新文献

Purpose: To review the literature on CAD/CAM removable complete and partial dentures regarding patient- and clinician-reported outcomes.

Materials and methods: We performed an electronic search of the Cochrane Central Register of controlled trials (CENTRAL), MEDLINE (Ovid), EMBASE, Scopus, and Web of Science databases (last update: March 2023). All clinical trials or observational studies investigating CAD/ CAM removable dentures (conventional or implant-retained) were included.

Results: The search yielded 4,035 records and led to 58 included studies. Results suggest that CAD/CAM complete and partial dentures, when compared to the conventional ones, can save time and resources while being rated either noninferior or superior by patients and clinicians in most studies. However, consensus on which workflow offers fewer adjustments and postoperative sessions is still pending.

Conclusions: The literature suggests that CAD/CAM complete and partial dentures can combine substantial time and cost savings, with patient and clinician experiences at least comparable to conventional prostheses. Given the low evidence level of existing studies, future well-designed randomized trials with large sample sizes are required to confirm those advantages.

Purpose: To evaluate the distortion probability in impressions of completely dentate arches when different impression materials are used in relation to operator experience.

Materials and methods: A total of 28 students (Group A) and 7 dentists (Group B) performed three maxillary impressions on 28 participants, each using vinyl siloxane ether (VSE), polyether (PE), and irreversible hydrocolloid (IHC). Gypsum master casts were fabricated and subsequently digitized. Intraoral scans were taken as a control. Differences between master casts and intraoral scans were visualized with heatmaps, and planar deviations were investigated. If planar deviations > 120 μm were found, the impression was rated as 'distorted.' An additional superimposition using the casts from VSE or PE was performed to confirm the presence of distortions. The relative number of surfaces with distortions in each impression was calculated. The procedure was repeated for a distortion threshold of 500 μm. The statistical analyses included repeated measures ANOVA (RMA) and post hoc tests (α < .05).

Results: When 120 μm was considered as the threshold for distortions, IHC impressions showed higher distortion probability than PE impressions in Group A (P = .003) and Group B (P < .0001). In Group B, PE showed a lower distortion probability than VSE (P = .02). There was no significant difference between the study groups (P = .42). Considering 500 μm as a threshold for distortions, there was no difference between impression materials (P = .17) or study groups (P = .53).

Conclusions: There were no statistically significant differences in relation to operator experience. Different impression materials had a significant impact on distortion probability. PE impressions showed the lowest distortion probability.

Purpose: This study evaluates the antibiofilm action of 2.5 mg/mL peracetic acid (PA), 0.5 mg/mL cetylpyridinium chloride (CPC), and 160 mg/mL N-Acetylcysteine (NAC) against multispecies biofilm of Streptococcus mutans, Staphylococcus aureus, Candida albicans, and Candida glabrata, developed on surfaces of heat-polymerizing acrylic resin (AR) and cobaltchromium (Co-Cr) alloy.

Materials and methods: A multispecies biofilm was grown on the surface of AR and Co-Cr specimens (Ø 12×3mm). After biofilm maturation, the specimens were immersed in experimental solutions and evaluated through biofilm viability (CFU) (n=9), biofilm metabolic activity (XTT) (n=9), biofilm-covered areas (Live/Dead) (n=2), effects on the extracellular polymeric substance (EPS) (n=2) and biofilm morphology (n=1). Data were analyzed by ANOVA and the Tukey post-test or Kruskal-Wallis followed by the Dunn post-test (α=.05).

Results: Overall, all evaluated solutions impacted biofilm viability. PA presented wider activity by reducing CFU of all microorganisms on both surfaces, XTT (P<.001) and Live/Dead (P<.001). NAC had a notorious effect in reducing the viability of bacteria without affecting the yeasts. NAC reduced XTT on AR (P=.006) and Co-Cr (P=.003) but did not reduce the aggregated biofilm layer. CPC had distinct effect according to the surface, being most effective in reducing CFU on AR than the Co-Cr surface. However, it did not influence XTT, and the amount of residual aggregated biofilm.

Conclusions: PA provided the greatest antibiofilm action, while CPC and NAC showed intermediate action. Nonetheless, no solution was able to completely remove the biofilm adhered to the surfaces of heat-polymerizing AR and Co-Cr alloy.

Purpose: To compare the masking ability of monolithic CAD/CAM veneers placed over different resin cement shades and substrate colors.

Materials and methods: Veneers were milled from four different monolithic CAD/CAM restorative materials: feldspathic ceramic (VMII), lithium disilicate ceramic (Emax CAD), zirconiareinforced lithium silicate ceramic (VS), and high-translucency zirconia ceramic (YZ-XT). Veneers were luted on natural tooth-colored (ND1) or discolored substrates (ND3 or ND5) using two different resin cement shades (opaque white or translucent). Each CAD/CAM material, resin cement shade, and substrate combination comprised 9 sample veneers (N = 216). Color parameters were obtained using a dental spectrophotometer before and after luting. Color differences (ΔE00) were calculated using CIEDE2000 formula and compared to perceptibility (P = .81 ΔE00 units) and acceptability (AT = 1.77 ΔE00 units) visual thresholds. Color variation data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni-Holm correction (α = .05).

Results: The highest ΔE00 value was obtained in the VMII group placed over a discolored substrate, followed by the Emax CAD, YZ-XT, and VS groups. The effect of material types on ΔE00 values was significantly observed when the veneers were luted on discolored substrates using translucent resin cement (P < .05).

Conclusions: Restorative material type, substrate color, and resin cement shade affect the masking ability of monolithic CAD/CAM laminate veneers.

This paper presents an efficient method for fabricating a full-arch implant prosthesis within one day, using a verification index through a three-dimensional (3D)-printed surgical guide. The technique involves the use of simple impression coping and laboratory analogs to ensure accurate prosthesis placement. Directly using 3D-printed surgical guides as a verification index simplifies and streamlines the procedure, offering a significant clinical advantage. This approach provides a clinically relevant advancement in prosthodontic practices by demonstrating a practical and instructive approach to enhance treatment outcomes.

Treatment of acute cases of amelogenesis imperfecta (AI) is challenging in children due to the absence of a consensus statement on therapeutic recommendations. This article presents the effectiveness of an interdisciplinary approach-including orthodontics, orthognathic surgery, and prosthodontics using digital technology-in a child with AI and skeletal deformities. The early management over a 6-year period had a very positive impact on the quality of life related to oral health. The full-mouth rehabilitation in adulthood with all-ceramic crowns showed a fully satisfactory result after 60 months of follow-up.

Purpose: To investigate the effect of irradiation time and zirconia thickness using low power Er,Cr:YSGG laser irradia)on (for debonding purposes) on the thermal changes and shear bond strength (SBS) of resin-bonded 3% mol yIrium oxide stabilized tetragonal zirconia polycrystal (3YTZP) specimens.

Materials and methods: 3Y-TZP slices of 0.5-, 2-, and 3- mm thick were used. The temperatures during laser irradiation using single spot irradiation at different times (30 seconds, 60 seconds, 90 seconds, and 120 seconds) and line scanning irradiation from one spot to another at three different distances (2, 4, and 6 mm) were recorded. Single spot and line scanning irradiation data were analyzed using three-way ANOVA (α = .05) and generalized linear mixed model, respectively. Nonirradiated (control) and irradiated resin-bonded 3Y-TZP specimens were shear tested, and the data were analyzed using two-way ANOVA (α = .05).

Results: Under single spot irradiation, the laser-induced temperature was higher through thin 3Y-TZP at any time compared to thick 3Y-TZP. For the line scanning method, short distances (2 and 4 mm) resulted in a significant increase in temperature for 0.5-mm thick specimens. Laser irradiation significantly decreased the SBS of the 0.5-mm group compared to the nonirradiated group. After irradiation, the bond strength of the 2- and 3-mm thick 3Y-TZP was similar to the nonirradiated group.

Conclusions: The temperature and bond strength of low-power laser irradiated 3Y-TZP specimens was affected by the specimen thickness but not by the irradiation time tested. Low-power laser irradiation is an effective debonding method for thin Y-TZP restorations.

Lab-side-fabricated abutments and hybrid zirconia crowns, which are bonded to titanium bases with resin-based composites, require disinfection before insertion. This study investigated the effect of cleaning procedures (ultrasonic, autoclaving) and aging methods (24h, 90d, thermocycling) on the shear bond strength between alumina particle air-abraded titanium and zirconia (3Y-, 4Y- and 5Y-TZP) specimens luted with phosphate monomer containing adhesive systems and resin-based composite. Autoclaving significantly improved SBS (F (27,231) = 17.265, p < .001) compared to no cleaning and three-stage disinfection. No differences were identified with regard to zirconia or aging methods. Bond strength initially benefits from autoclaving but continuously approaches the comparative values over longer periods.

Purpose: To investigate temporomandibular disorder (TMD) prevalence as well as potential TMD risk factors among postgraduate students.

Materials and methods: In this cross-sectional and correlation study, 1,255 postgraduate students from different universities were recruited to answer Fonseca's Anamnestic Index (FAI) in addition to collected demographic data and relevant dental history. FAI was used to classify TMD severity. Of the 1,255 participants included, 593 had previous clinical/radiographic TMD reports. Chi-square and Fisher exact tests investigated the relation between each predictor and TMD at P ≤ .05. A logistic binary regression analysis examined the model fit using -2Log likelihood and Pseudo R2 tests at P ≤ .05.

Results: Based on previous clinical/radiographic reports and FAI, 73.4% of the participants had TMDs, of whom 57% had mild dysfunction, followed by moderate (31.7%) and severe (11.3%). There was a statistically significant association between sex, depression, lip/object biting, and clenching with TMDs (P < .001), where women were 2.302 times more likely to develop TMDs than men. The combination of lip biting and clenching in women dramatically increased the risk of TMDs (-2Log Likelihood = 385.7, P < .001 and a Cox and Snell value = 0.315 and a Nagelkerke value = 0.395).

Conclusions: TMDs seem to be highly prevalent among postgraduate students in Egypt, and female postgraduate students who bite their lips or grind their teeth are particularly highly prone to the condition. Object biting and depression could also be considered risk factors.