Journal of Prosthetic Dentistry最新文献

Statement of problem: The mastication ability of the elderly greatly affects their health-related quality of life. However, studies investigating the impact of peri-oral muscular strength on the performance of mastication in older adults are lacking.

Purpose: The purpose of this cross-sectional clinical study in older adults was to formulate an equation relating to the mastication pattern and tongue pressure to estimate the correlation between tongue pressure and habitual mastication patterns, including mastication strokes and mastication time.

Material and methods: A total of 98 healthy adults over 65 years old who were independent in daily activities and had no swallowing difficulties were enrolled. Tongue pressure was measured with the Iowa Oral Performance Instrument (IOPI), which assesses pressure generated by squeezing a bulb between the tongue and palate. The mastication pattern was evaluated by counting strokes and measuring the time required to consume a cornstarch cookie. Statistical analysis used linear regression (α=.05).

Results: The sample included 48 women and 50 men with an average age of 71.7 years. Tongue pressure demonstrated a significant correlation with both mastication time and mastication strokes (P=.03 and.04, respectively). The findings led to a linear regression model linking tongue pressure (x) to mastication time (y₁) and mastication strokes (y₂), expressed as y₁=-0.2976x + 33.907 and y₂=-0.4134x + 45.624.

Conclusions: In older adults, a correlation was found between tongue pressure and both mastication time and mastication strokes. Based on this correlation, measuring tongue pressure might provide insight into mastication patterns, while estimating mastication time and mastication strokes could help gauge tongue strength in an aging population. Mastication ability could then be assessed and appropriate food textures chosen for elderly individuals. This formula could also help determine the optimal tongue pressure value for enhancing the mastication pattern by serving as a guide for tongue training or rehabilitation initiatives.

Statement of problem: Thiourethane has high chemical affinity with polymeric materials and its addition has been suggested for improving adhesives and composite resin. However, a systematic review of thiourethane addition is lacking.

Purpose: The purpose of this systematic review was to analyze the articles in the dental literature that studied the effect of thiourethane added to the resin matrix of dental materials related to polymerization shrinkage and mechanical properties.

Material and methods: The systematic review was prepared in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines and was registered in the Open Science Framework (osf.io/sb9my). The population, intervention, comparison, outcome, and study design (PICOS) were the following: composite resin, thiourethane addition, composite resin without addition, evaluation of polymerization and mechanical properties, and in vitro experimental studies. Initially, 204 articles were found, 150 of which were excluded because of duplication. After reading the titles and abstracts based on the application of eligibility criteria, 21 articles were selected for reading in full, and all were included in the systematic review. Three reviewers evaluated the articles independently in 2 phases based on the eligibility criteria (selection of the title and reading of the article in full), with the reviewers' doubts and discrepancies being analyzed and resolved in a meeting with the authors.

Results: Most of the articles reported a significant improvement in the polymerization shrinkage and mechanical properties of experimental polymeric materials with the addition of oligomers.

Conclusions: Thiourethane added to resin dental materials improved their polymerization shrinkage values and mechanical properties.

Statement of problem: The outcome of posterior nonvital teeth depends not only on endodontic factors but also on the effectiveness of the restoration. The growing trend in minimally invasive dentistry has led to increasing interest in 1-piece endodontic crowns as an alternative restoration. Nevertheless, their indications and longevity lack extensive exploration, thereby limiting their widespread acceptance in dental practice.

Purpose: The purpose of this overview was to synthesize the available evidence from systematic reviews (SRs) about 1-piece endodontic crowns and to identify clinical outcomes such as survival, success rates, and patient-reported outcome measures (PROMs).

Material and methods: A systematic search was performed in the electronic databases MEDLINE/PubMed, Cochrane, Web of Science, and OpenGrey, as well as a manual search, up to June 2024, with no language or time restriction. SRs that addressed clinical studies related to 1-piece endodontic crowns or endocrowns were included. The risk of bias and methodological quality was measured using the ROBIS and AMSTAR-2 tools, respectively.

Results: The search identified 468 articles, of which 9 SRs were included. The best evidence reported in the SRs was that survival or success rates for ceramic and indirect resin 1-piece endodontic crowns were high at 5 years, similar to those for conventional crowns. Loss of retention was the main cause of failure with similar failure rates for molars and premolars. Evidence for the use of zirconia and metal 1-piece endodontic crowns is limited, and no SR was found that addressed PROMs. Methodological quality was considered low or critically low in most SRs. However, the risk of bias was low for 2 of the 3 SRs that provided the best evidence in the meta-analysis for ceramic and indirect resin 1-piece endodontic crowns. Overlap in the included studies was very high.

Conclusions: Although the evidence generated by multiple RS only determined that ceramic and indirect resin 1-piece endodontic crowns can be a suitable and reliable option for restoring endodontically treated premolars and molars, with high success and survival rates comparable with those of complete crowns with posts, this overview concluded that it was not possible to provide firm conclusions regarding the outcomes of 1-piece endodontic crowns because of the lack of adequate high-quality primary studies with different materials, heterogenicity of the studies, variations in follow-up, preparation, and operative steps, and very high overlap of studies. Thus, additional well-designed clinical trials are necessary rather than SRs to strengthen the evidence in this area.

Statement of problem: Despite the increasing number of publications on applying artificial intelligence (AI) in the dental field, clarity regarding the performance of different approaches for nasoalveolar molding (NAM) planning and designing is lacking. Additionally, the overall robustness of the evidence in this field remains uncertain.

Purpose: The purpose of this systematic review was to evaluate the role of AI in automating the prediction of anatomic landmarks and the design of NAM appliances.

Material and methods: A comprehensive literature search was conducted in major databases up to April 2024 without language restrictions. Studies applying AI algorithms for NAM landmark detection or appliance design were included. Data on study characteristics, AI methods, outcomes, and limitations were extracted.

Results: Six studies met the eligibility criteria. AI algorithms demonstrated high accuracy in automatically detecting landmarks and designing NAM appliances. Approaches ranged from fully automated to semi-automated workflows. Most studies reported significant time savings compared with manual methods.

Conclusions: AI applications in NAM demonstrate substantial potential in improving workflow design, as demonstrated by the high accuracy reported in various studies. The incorporation of AI in NAM planning leads to a significant reduction in treatment appointment times when compared with conventional manual methods, thereby potentially decreasing the overall duration of treatment. Nevertheless, additional research is required to foster better collaboration between dental professionals and AI experts, ultimately facilitating more efficient clinical integration.

Statement of problem: Postoperative swelling following guided bone regeneration (GBR) may affect the dimensions of interim restorations and/or delivery timing. However, quantitative assessment of post-GBR swelling or its evaluation for possible impact on regenerative outcomes is lacking.

Purpose: The purpose of this prospective clinical study was to quantify post-GBR swelling and correlate it with clinical parameters and outcomes.

Material and methods: Participants (n=25) undergoing standardized extraction and GBR protocol were recruited. Site-specific swelling was measured as ridge width, height, and volume changes based on intraoral scans recorded preoperatively, immediately postoperatively (IP), and at 2 days, 7 days, 14 days, and 4 months. The parameters and outcomes assessed were gingival and mucosal thickness, flap advancement, surgery duration, wound opening, and bone gain. The Friedman 2-way analysis of variance by ranks was performed, and the Spearman correlation coefficients (ρ) were computed (α=.05).

Results: Ridge width and height peaked at 2 days (2.1 mm for both from IP; P<.001 for both) and reached IP levels by 7 days and 14 days (P>.999 and P=.888, respectively). At 4 months, both decreased significantly compared with IP (-4.2 mm and -1.9 mm respectively, P<.001). Volume increases peaked at 2 days (19%, P<.001), and peak swelling (2 days) preceded maximum wound opening (7 days). Bone width at 4 months was correlated with gingival thickness (ρ=0.45, P=.043), mucosal thickness (ρ=0.51, P=.021), and flap advancement (ρ=0.58, P=.008).

Conclusions: Following GBR, site-specific swelling peaked on postoperative day 2 and subsided by day 7 (width) or 14 (height). Soft tissue thickness and flap advancement affected post-GBR bone width.

Statement of problem: The integration of computer-aided design and computer-aided manufacture (CAD-CAM) technology has revolutionized restorative dentistry, offering both additive and subtractive manufacturing methods. Despite extensive research on 3-dimensionally (3D) printed materials, uncertainties remain regarding the impact of print orientation on their mechanical properties, especially for definitive resin materials, necessitating further investigation to ensure clinical efficacy.

Purpose: The purpose of this in vitro study was to investigate the influence of print orientation and artificial aging on the flexural strength (FS) and flexural modulus (FM) of 3D printed resin materials indicated for definitive and interim restorations.

Material and methods: Specimens (2×2×25 mm) were additively manufactured in 3 orientations (0, 45, and 90 degrees) using five 3D printed resins: VarseoSmile Crownplus (VCP), Crowntec (CT), Nextdent C&B MFH (ND), Dima C&B temp (DT), and GC temp print (GC). A DLP 3D printer (ASIGA MAX UV) was used with postprocessing parameters as per the manufacturer recommendations. FS and FM were tested after storage in distilled water (DW) and artificial saliva (AS) for 24 hours, 1 month, and 3 months at 37 °C. Additional 2×2×16-mm specimens printed at 90 degrees were compared with the milled materials Lava Ultimate (LU) and Telio CAD (TC) after 24 hours of storage in AS at 37 °C (n=10). Measurements were conducted using a universal testing machine (Z020; Zwick/Roell) following the International Organization for Standardization (ISO) 4049 standard. Multiple way ANOVA, 1-way ANOVA, and Tukey HSD post hoc tests (α=.05) were used to analyze the data.

Results: Print orientation significantly influenced the FS and FM of 3D printed resin materials, with the 90-degree orientation exhibiting superior mechanical properties (P<.05). Definitive resins (CT and VCP) exhibited higher FS and FM compared with interim resins (ND, DT, GC) at all time points (P<.001). LU had significantly higher FS and FM compared with other resins (P<.001), while TC had similar FS to definitive 3D printed resins. Aging time and media influenced FS and FM, with varying effects observed across different materials and time points. Strong positive correlations were found between filler weight and both FS (r=.83, P=.019) and FM. All materials met the minimum FS requirement of 80 MPa (ISO 4049) when printed at 90 degrees.

Conclusions: The 90-degree orientation produced specimens with higher FS than 0- and 45-degree orientations. CT recommended for definitive restorations displayed higher FS compared with VCP and those intended for interim use after 3 months of aging. LU exhibited higher FS and FM than 3D printed resins, while TC had similar FS and FM to the latter. Aging effects on 3D printed resins were minimal and were material specific.

Statement of problem: Although tapered and cylindrical implants have been widely used, a consensus on which macrogeometry offers better clinical performance is lacking.

Purpose: The purpose of this systematic review and meta-analysis was to evaluate the influence of different macrogeometries (tapered and cylindrical) on the clinical performance of dental implants.

Material and methods: The study was registered in the international prospective register of systematic reviews (PROSPERO) database (CRD42022347436). A search for clinical studies was conducted in 6 databases to identify randomized controlled clinical trials that evaluated the effectiveness of tapered and cylindrical implants placed in the maxilla or mandible of adult patients that had at least 1 clinical performance parameter as outcome. The risk of bias was evaluated using the revised Cochrane Risk-of-Bias Tool (RoB 2) tool. Meta-analyses on implant survival and success, marginal bone loss (MBL), implant stability (ISQ), and torque insertion (TI) were performed, with the certainty of evidence evaluated using the grading of recommendations, assessment, development, and evaluations (GRADE) checklist.

Results: Of the 18 included studies, 7 had a low risk, 6 had some concerns, and 5 had a high risk of bias. Meta-analyses of survival (RR 0.99 [0.97, 1.01]; P=.38; I2=0%), implant success (RR 1.06 [0.99, 1.13] P=.08 I2=0%), 1-month MBL (MD -0.11 [-0.33, 0.10] P=.31 I2=98%), 3 months MBL (MD -0.21 [-0.27, 0.16] P=.26 I2=98%), 6 months MBL (MD -0.29 [-0.60, 0.01] P=.06 I²=74%), 1-year MBL (MD 0.01 [-0.07, 0.09] P=.77 I2=98%) and after 2 years MBL (MD -0.04 [-0.14, 0.07] P=.52 I2=0%), ISQ at implant installation (MD 0.35 [-0.72, 1.42] P=.52 I2=0%), %), after 2 months (MD 0.90 [-1.08, 2.87] P=.37 I2=0%) and at 1 year (MD -0.02 [-1.07, 1.03] P=.97 I2=0%), and insertion torque (MD 3.10 [-1.71, 7.92] P=.21 I2=80%) were statistically similar. However, tapered implants showed higher ISQ than cylindrical implants after 3 months (MD 1.20 [0.39, 2.01] P=.004 I2=17%). The certainty of evidence for the analyzed parameters ranged from high to very low.

Conclusions: Both macrogeometries present good clinical performance, with certainty of evidence ranging from high to very low. Tapered implants showed better secondary stability at 3 months after implant installation, but with low certainty of evidence.