Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry最新文献

Obstructive sleep apnea (OSA) is characterized by intermittent cessation of breathing during sleep due to the collapse of oropharyngeal tissues. This review examines the role of craniofacial growth in OSA and evaluates the efficacy of orthodontic and orthognathic treatments. Maxillary expansion and orthognathic surgery have demonstrated significant reductions in sleep apneas and hypopneas, although they do not consistently achieve cure levels, particularly in the presence of obesity and connective tissue disorders. Understanding the multifaceted pathophysiology of OSA and addressing confounding factors such as obesity and muscle tone are essential for enhancing treatment outcomes.

Recent focus has shifted toward refining the soft tissue emergence profile to enhance aesthetics, support peri-implant health, and ensure long-term success. Traditionally, titanium stock healing abutments or chairside-customized abutments were used to shape peri-implant tissues and develop the emergence profile for implant-supported prostheses. However, advancements in digital dentistry now allow for more precise customization and increased treatment efficiency. This case report introduces a novel approach to shape the peri-implant tissues using a 3D-printed emergence profile former retained by a titanium stock healing abutment. The 3D-printed emergence profile former reduced chairside time and simplified registering the gingival tissue contours and implant position with an intraoral scanner. Following removal, the peri-implant soft tissues displayed enhanced volume buccally, creating an aesthetically pleasing restoration in a site with a notable horizontal tissue deficiency.

Purpose: This study aims to evaluate the effectiveness of a case-based reasoning (CBR) system in predicting the design of definitive obturator prostheses for maxillectomy patients.

Materials and methods: Data from 209 maxillectomy cases, including extraoral images of obturator prostheses and occlusal images of maxillectomy defects, were collected from Institute of Science Tokyo Hospital. These cases were organized into a structured database using Python's pandas library. The CBR system was designed to match new cases with similar historical cases based on specific attributes such as aramany class, abutment details, defect extension, and oronasal connection size. The system's performance was evaluated by clinicians who assessed the accuracy of prosthesis designs generated for 33 test cases.

Results: A correlation analysis demonstrated a significant positive relationship (ρ = 0.84, p < 0.0001) between the CBR system's confidence scores and the number of correct prosthesis designs identified by clinicians. The median precision at five cases was 0.8, indicating that the system effectively retrieved relevant designs for new cases.

Conclusions: The study shows that the developed CBR system effectively predicts the design of obturator prostheses for maxillectomy patients. Clinically, the system is expected to reduce clinician workload, simplify the design process, and enhance patient engagement by providing prompt insights into their final prosthetic design.

Purpose: To compare digitally fabricated complete dentures to conventionally fabricated dentures using patient- and clinician-reported outcome measures.

Methods: This review was structured according to PRISMA guidelines with the protocol registered in the PROSPERO database (CRD42024526069). An electronic search of the databases with a defined search strategy was completed within PubMed/MEDLINE and Web of Science from January 2000 to March 2024. Grey literature and article references were searched. Articles were screened by title and abstract, and the remaining articles were screened by full-text review. Articles accepted for inclusion were subjected to a risk-of-bias assessment using Cochrane Collaboration tools (RoB 2 and ROBINS-I).

Results: From an initial pool of 704 articles, 15 studies met the selection criteria, of which the majority were published within the past 3 years. Within the included studies, there was inconsistency in the assessment methods of patient- and clinician-reported outcomes, making it challenging to draw definitive conclusions. Generally, digital dentures had superior cost-effectiveness and prosthesis fabrication time. Patient satisfaction and denture quality were not consistently improved with digital technology.

Conclusions: Studies showed indications of patient satisfaction with digital and conventional dentures. Digital technology may enhance clinical workflows. A trend emerged that milled dentures performed better than printed dentures. Clinicians adopting digital technology into removable prosthodontics may have a learning curve to overcome, and they should consider the patient-clinician relationship in addition to clinical outcomes to achieve patient satisfaction. Additional studies with standardized tools for assessing patient satisfaction are required to enable meaningful comparisons between digital and conventional workflows.

Purpose: Metal-ceramic screw-retained implant restorations persist as a fundamental choice in specific clinical scenarios. Little is known about the effects of fabrication steps and aging on their structural properties. This study aimed to investigate how laboratory fabrication procedures and thermomechanical loading affect the structural properties of screw-retained metal-ceramic implant restorations.

Materials and methods: Ten screw-retained metal-ceramic restorations were conventionally cast using UCLA chromium-cobalt overcast abutments. After 500 cycles of thermocycling and 500,000 cycles of mechanical loading, changes in connection dimensions and rotational freedom (RF) were measured and compared at various fabrication steps and post-thermomechanical loading. A generalized estimating equations (GEE) model was employed to analyze trends across the studied time points within the fabrication stage and after thermomechanical loading, with LSD post-hoc tests applied for pairwise comparisons. The level of significance was set at α = 0.05.

Results: Significant changes were observed across the analyzed time points: the average hexagonal side length (L) decreased (p < 0.001), and the average hexagonal angle deformation (P) increased, with notable differences observed in most comparisons between different fabrication steps (p < 0.001). Short (T1) and long (T2) diagonals of the hexagon showed downward trends (p < 0.001), while concentricity (O) and RF increased (p < 0.001), except between porcelain firing and loading steps for RF (p = 0.637). Casting had the greatest impact on variations in O (93.33%), T1 (88.88%), and T2 (45%), while porcelain firing significantly affected L (71.42%), P (71.42%), with the greatest effect on RF (75.32%).

Conclusions: The fabrication processes and simulated clinical use adversely impacted the structural integrity and RF of abutments in screw-retained chromium-cobalt overcast implant restorations.

Purpose: To evaluate the effect of material type on dimensional stability, occlusal surface wear, fracture resistance, and failure behavior of resin-based onlay restorations.

Material and methods: A mandibular right first molar typodont was prepared and digitized using an intraoral scanner to virtually design an onlay restoration with the minimum occlusal thickness of 1.5 mm. Resin-based onlay restorations (n = 15 per group) were fabricated either additively from 2 different resins indicated either for definitive or interim use or subtractively with a composite resin. After cementing onlays to corresponding dies, each of them was digitized before and after thermomechanical aging (B-STL and A-STL), and then subjected to load-to-failure test to evaluate fracture resistance. The B-STL and A-STL of each onlay were also compared to assess the dimensional stability and occlusal surface wear. One-way analysis of variance and Tukey honestly significant difference tests were used to evaluate dimensional stability, occlusal surface wear, and fracture resistance. The chi-square test was used to evaluate the Weibull modulus and characteristic strength among the groups (α = 0.05).

Results: Material type affected investigated outcomes (p < 0.001). The additively manufactured resin indicated for definitive use led to the highest external surface deviations and the additively manufactured resin indicated for interim use led to the highest mesiodistal width deviations (p ≤ 0.033). The onlays fabricated from the additively manufactured resin indicated for definitive use had the highest occlusal surface wear, while those in composite resin had the lowest (p ≤ 0.006). The composite resin onlays had the highest fracture resistance values and reliability (p ≤ 0.035).

Conclusions: Tested subtractively manufactured composite resin had the lowest occlusal surface wear with the highest fracture resistance and reliability. Additively manufactured resins had lower dimensional stability, while tested resin for additively manufactured definitive restorations had the highest occlusal surface wear.

Purpose: To evaluate the impact of glazing denture base resins (heat-polymerized and 3D-printed) on surface, mechanical, and microbiological properties.

Materials and methods: Discs (10 × 3 mm) and bars (64 × 10 × 3.3 ± 0.2 mm) were manufactured using heat-polymerized denture base resin (CT) and 3D-printed denture base resin (Yller [YL], Prizma [PZ] and PrintaX [PX]). These were divided into two groups: unglazed and glazed. Surface roughness (Ra), wettability (contact angle), brightness (GU), and topography (via scanning electron microscopy) were assessed, along with microbiological analysis of dual-species biofilms (Streptococcus mitis and Candida albicans) and Knoop microhardness on discs (n = 10). Flexural strength testing was conducted separately on bars (n = 20). Half of the specimens subjected to surface and mechanical characterizations were thermocycled (10,000 cycles). Mann-Whitney test (p < 0.05) and simple and multiple linear regression analysis (p < 0.20) were employed to evaluate the impact of glazing on denture base resins.

Results: The application of glaze reduced roughness by 0.33 µm and water contact angle by 8.47º, while increasing brightness by 21.30 units (p < 0.001) for 3D-printed resins compared to CT. After thermal cycling, roughness and wettability increased, while brightness decreased (p < 0.05). The glaze also increased hardness, with no adverse effects from thermal cycling (p < 0.001), and enhanced flexural strength for PZ compared to CT (p < 0.001). Additionally, C. albicans colonization decreased by 7.79 log CFU/mL in mixed biofilms for 3D-printed resins compared to CT (p < 0.05).

Conclusions: The application of glaze resulted in smoother, brighter, and harder surfaces for the 3D-printed resins, while also reducing biofilm colonization.