Assessment of reproducibility and influence of different dental specialties on functional implant prosthodontic score: A prospective clinical study analyzing single-unit implant crowns.

AIM: Implant therapy in partially edentulous patients has become the most adapted and predictable treatment modality. The success rate of implants has been measured in terms of esthetic, biological, and technical factors such as radiographic bone loss, prosthetic complications, and stability. Despite the existence of several indices for the esthetic assessment of implant crowns, a need for functional evaluation of the implant crown with an objective and reproducible score has arisen. The study aims to validate the reproducibility of the functional implant prosthodontic score (FIPS) and the influence exerted by different dental specialties while evaluating posterior single-unit implant crowns. STUDY SETTING AND DESIGN: This was a prospective clinical study. MATERIALS AND METHODS: Fifteen patients with cement-retained single-implant crowns in the posterior region of the jaws were included. Eight examiners, two prosthodontists, two periodontists, two oral surgeons, and two orthodontists evaluated 15 photographs of single-unit implant crowns during the 1-year follow-up examination. The examiners assessed the photographs for FIPS, which includes five parameters for objectively evaluating the single-unit implant crowns. Assessments were performed twice at a gap of 4 weeks. STATISTICAL ANALYSIS USED: Pearson's correlation with a 95% confidence interval was calculated for the intra-examiner and the Kruskal-Wallis test for inter-examiner reproducibility. RESULTS: The mean total FIPS scores for all included examiners were 7.133 for time T1 and 7.074 for time T2, showing a strong Pearson correlation coefficient for intra-examiner reproducibility. No significant difference was analyzed among different specialties with statistically significant values of the Kruskal-Wallis test. CONCLUSION: Intra- and inter-examiner analysis showed very consistent results during the reproducibility assessment of FIPS. The results validated the use of FIPS as a long-term predictive functional evaluation tool for the single-implant crowns in posterior sites irrespective of the effect of different dental specialties. It could be used for risk estimation and prognosis for long-term survival and performance of implant crowns.

[Effect of printing orientation on physical and mechanical properties of 3D printing prosthodontic base resin materials].

OBJECTIVE: To analyze the influence of forming direction on the surface characteristics, elastic modulus, bending strength and fracture toughness of printed parts and the relationship between forming direction and force direction, and to provide scientific basis and guidance for the clinical application of oral denture base resin materials. METHODS: The 3D printing technology was used to print denture base resin samples. The shape and size of the samples referred to the current standard for testing conventional denture base materials. The samples used for physical performance testing were cylindrical (with a diameter of 15 mm and a thickness of 1 mm) and printed at different angles along the Z axis (0°, 45°, 90°). Scanning electron microscope was used to observe the microscopic topography of the different samples. The color stability of different samples was observed by color stabilizer. The surface roughness of the samples was analyzed by using surface roughness tester. The Vickers hardness was measured to analyze the hardness of the samples. The samples used for mechanical performance testing were rectangular (elastic modulus and bending strength: A length of 64 mm, a width of 10 mm, and a height of 3.3 mm; fracture toughness: A length of 39 mm, a width of 8 mm, and a height of 4 mm), divided into two groups: W group and H group. The W group was printed from the bottom up along the Z axis with the length × width as the bottom surface parallel to the X, Y axis plane, while the H group printed from the bottom up along the Z axis with the length × height as the bottom surface parallel to the X, Y axis plane. The forming angles of both groups were equally divided into 0°, 45°, and 90°. The elastic modulus, bending strength and fracture toughness of different samples were studied through universal mechanical testing machine. SPSS 22.0 software was used for statistical analysis. RESULTS: The microscopic topography and roughness of different samples were closely related to the printing direction, with significant differences between the 0°, 45°, and 90° specimens. The 0° specimens had the smoothest surface (roughness < 1 µm). The surface of the 45° specimen was the roughest (roughness>3 µm). The microhardness of the 0° sample was the best [(196.13±0.20) MPa], with a significant difference compared with the 90° sample [(186.62±4.81) MPa, P < 0.05]. The mechanical properties of different samples were also closely related to the printing direction. The elastic modulus, bending strength, and fracture toughness of the 45° samples in the W group were the highest compared with the other groups. The results of elastic modulus showed that in the H group, the 45° specimens had the highest elastic mo-dulus, which was significantly different from the 0° and 90° specimens (P < 0.05). The elastic modulus of 0° and 45° specimens in the W group were higher than those in 90° specimens (P < 0.05). The bending strength results showed that there was no significant difference between the specimens from dif-ferent angles in the H group. The bending strength of the 90° specimens in the W group was the smallest, and there was a significant difference between 90° and the 0° and 45° specimens (P < 0.05); And the bendind strength of the 0° and 45° specimens in the W group was significantly higher than that of the 0° and 45° specimens in the H group (P < 0.05). The fracture toughness results showed that the fracture toughness of the H group specimens was lower than 1.9 MPa m1/2, which was specified in the denture base standard. The 45° samples in the W group were the highest, with significant differences compared with the 0° and 90° samples (P < 0.05). And the 90° samples of the W group specimens were lower than 1.9 MPa m1/2. And the fracture toughness of the 45° specimen in the W group was significantly higher than that of all the specimens in the H group (P < 0.05). CONCLUSION: The 0° samples had relatively better physical properties. The 45° samples had the best mechanical properties. But the fracture toughness of specimens (H group and 90° samples of W group) did not yet meet clinical requirements. That indicated that the characteristics of the 3D printing denture base resin were affected by the printing direction. Only when the performance of the printed samples in all directions met the minimum requirements of the standard, they could be used in clinical practice.

EFFECT OF SURFACE ABRASION AND TEMPERATURE TREATMENT ON METASTABLE TETRAGONAL ZIRCONIUM DIOXIDE (EXPERIMENTAL STUDY).

One of the significant drawbacks of using zirconium dioxide as a framework for prosthodontic structures is its propensity for breakage. Paradoxically, the higher the optical performance of zirconium dioxide, the more its mechanical durability tends to decrease and vice versa. A detailed analysis of the technological process has uncovered divergent opinions and significant disparities in recommendations concerning the fabrication of zirconium dioxide prosthodontic constructs. There are different recommendations regarding the need for abrasive blasting and regeneration firing. Consequently, conducting an in-depth experimental study on this matter and implementing the resulting findings will significantly contribute to addressing the challenges of prosthodontic rehabilitation for patients utilizing zirconium dioxide.

The chance and challenge of creating virtual patients in prosthodontics.

In the field of prosthodontics, the use of virtual patients for biomimetic restoration holds great promise for various applications. Virtual patients consist of digitized data that encompasses details on the morphology, structure, and spatial relationships within the maxillofacial and intraoral regions. Nonetheless, there are several challenges associated with acquiring digital data, achieving accurate alignment, and recording and transferring dynamic jaw movements. This paper aims to concentrate on the process of constructing virtual patients, highlight the key and challenging aspects of virtual patient construction, and advocate for the extensive adoption and utilization of virtual patient technology.

[Advances in the application of dynamic virtual patients in prosthodontics].

With the development and application of technologies such as facial scanning, intraoral scanning, virtual facebow and mandibular movement tracking in prosthodontics, dynamic virtual patients are gradually applied to preoperative analysis, esthetic diagnosis, treatment planning, and restorative implementation, becoming a research hotspot in recent years. This review focuses on data acquisition, construction of dynamic virtual patients and their application advantages, aiming to provide a reference for the clinical application of related digital technologies.

Translucency of recent zirconia materials and material-related variables affecting their translucency: a systematic review and meta-analysis.

BACKGROUND: Recent forms of translucent zirconia material have been developed, offering a wide range of options and varieties for enhancing aesthetics, making it a preferred choice in the field of prosthetic dentistry. However, there is insufficient understanding regarding the recent types of zirconia materials and their optical behavior. Understanding the variables that influence the translucency of zirconia and identifying strategies to enhance its esthetics are crucial. PURPOSE: The current systemic review highlights a comprehensive understanding of different zirconia generations in relation to their optical characteristics and evaluates material-related variables affecting their translucency. METHODS: The present review studied in-vitro studies that evaluated the optical characteristics of different yttria content of yttria stabilized materials. The topics explored were: (1) the different zirconia material generations and their optical behavior; (2) material-related factors that affect their translucency. The research was restricted to online publication in the English language from July 1, 2010, to July 31, 2023, using PubMed, Scopus, and Science Direct resources. The search key terms and their combinations were "zirconia," "translucent zirconia," "cubic zirconia," "highly translucent zirconia," "yttria partially stabilized zirconia," "monolithic zirconia," "translucency," "optical properties," and "light transmission." RESULTS: The data obtained from fifty-three studies addressed the optical characteristics of various zirconia generations. They reported that changing yttria content had a significant impact on translucency. Different kinds of zirconia ceramics of the same generation have varying translucencies. Achieving optimum aesthetics with monolithic zirconia is challenging due to factors related to material aspects such as the presence of additives, point defects, microstructure, thickness, phase distribution, and sintering conditions. CONCLUSIONS: Newly developed monolithic dental zirconia ceramics have improved aesthetics and translucency. However, additional research is necessary to evaluate their performance and long-term durability. TRIAL REGISTRATION: This systematic review was registered in PROSPERO, under number CRD42023474482.

Recent advances in additive manufacturing of patient-specific devices for dental and maxillofacial rehabilitation.

OBJECTIVES: Customization and the production of patient-specific devices, tailoring the unique anatomy of each patient's jaw and facial structures, are the new frontiers in dentistry and maxillofacial surgery. As a technological advancement, additive manufacturing has been applied to produce customized objects based on 3D computerized models. Therefore, this paper presents advances in additive manufacturing strategies for patient-specific devices in diverse dental specialties. METHODS: This paper overviews current 3D printing techniques to fabricate dental and maxillofacial devices. Then, the most recent literature (2018-2023) available in scientific databases reporting advances in 3D-printed patient-specific devices for dental and maxillofacial applications is critically discussed, focusing on the major outcomes, material-related details, and potential clinical advantages. RESULTS: The recent application of 3D-printed customized devices in oral prosthodontics, implantology and maxillofacial surgery, periodontics, orthodontics, and endodontics are presented. Moreover, the potential application of 4D printing as an advanced manufacturing technology and the challenges and future perspectives for additive manufacturing in the dental and maxillofacial area are reported. SIGNIFICANCE: Additive manufacturing techniques have been designed to benefit several areas of dentistry, and the technologies, materials, and devices continue to be optimized. Image-based and accurately printed patient-specific devices to replace, repair, and regenerate dental and maxillofacial structures hold significant potential to maximize the standard of care in dentistry.

ChatGPT performance in prosthodontics: Assessment of accuracy and repeatability in answer generation.

STATEMENT OF PROBLEM: The artificial intelligence (AI) software program ChatGPT is based on large language models (LLMs) and is widely accessible. However, in prosthodontics, little is known about its performance in generating answers. PURPOSE: The purpose of this study was to determine the performance of ChatGPT in generating answers about removable dental prostheses (RDPs) and tooth-supported fixed dental prostheses (FDPs). MATERIAL AND METHODS: Thirty short questions were designed about RDPs and tooth-supported FDP, and 30 answers were generated for each of the questions using ChatGPT-4 in October 2023. The 900 generated answers were independently graded by experts using a 3-point Likert scale. The relative frequency and absolute percentage of answers were described. Accuracy was assessed using the Wald binomial method, while repeatability was evaluated using percentage agreement, Brennan and Prediger coefficient, Conger generalized Cohen kappa, Fleiss kappa, Gwet AC, and Krippendorff alpha methods. Confidence intervals were set at 95%. Statistical analysis was performed using the STATA software program. RESULTS: The performance of ChatGPT in generating answers related to RDP and tooth-supported FDP was limited. The answers showed a reliability of 25.6%, with a confidence range between 22.9% and 28.6%. The repeatability ranged from substantial to moderate. CONCLUSIONS: The results show that currently ChatGPT has limited ability to generate answers related to RDPs and tooth-supported FDPs. Therefore, ChatGPT cannot replace a dentist, and, if professionals were to use it, they should be aware of its limitations.

Psychometric properties of the Arabic version of the perceived prosthodontic treatment need scale: Exploratory and confirmatory factor analyses.

BACKGROUND: It is crucial to take into account the concerns of dental patients about their prosthodontic needs when planning the course of treatment. However, there is a dearth of research that examines these needs among adult dental patients. OBJECTIVES: This study aims to translate and validate the perceived prosthodontic treatment need scale (PPTN) in Arabic. METHODS: The 17-item PPTN scale was translated from English into Arabic and completed by 206 patients seeking prosthodontic treatment in a dental hospital in Saudi Arabia. Data collection was carried out in September and October 2023. Exploratory factor analysis (EFA) was used to ascertain the underlying factor structure; a unidimensional scale was hypothesised and tested using confirmatory factor analysis (CFA), including several multiple model fit indices. The assessment of reliability was conducted using Cronbach's alpha. The convergent and discriminant validity of the final scale were examined. RESULTS: EFA produced an 11-item scale distributed into three factors that explain 65.43% of the total variance with eigenvalues > 1. All items showed acceptable reliability, ranging from 0.65 to 0.84. The first factor pertained to social issues, while the second item was concerning dental appearance. Lastly, the third factor included functional difficulties associated with tooth loss or dental problems. The results of the CFA demonstrate a satisfactory level of model fit, with the standardised factor loadings ranging from 0.51 to 0.89. Convergent and discriminant validity of the model factors were established. CONCLUSION: The translated questionnaire was deemed legitimate and would be useful in comprehending patients' perceived treatment requirements, hence contributing to the advancement of prosthodontic research and practical implementation.

An assessment of preclinical removable prosthodontics based on multiple-choice questions: Stakeholders' perceptions.

PURPOSE: Item analysis of multiple-choice questions (MCQs) is an essential tool for identifying items that can be stored, revised, or discarded to build a quality MCQ bank. This study analyzed MCQs based on item analysis to develop a pool of valid and reliable items and investigate stakeholders' perceptions regarding MCQs in a written summative assessment (WSA) based on this item analysis. METHODS: In this descriptive study, 55 questions each from 2016 to 2019 of WSA in preclinical removable prosthodontics for fourth-year undergraduate dentistry students were analyzed for item analysis. Items were categorized according to their difficulty index (DIF I) and discrimination index (DI). Students (2021-2022) were assessed using this question bank. Students' perceptions of and feedback from faculty members concerning this assessment were collected using a questionnaire with a five-point Likert scale. RESULTS: Of 220 items when both indices (DIF I and DI) were combined, 144 (65.5%) were retained in the question bank, 66 (30%) required revision before incorporation into the question bank, and only 10 (4.5%) were discarded. The mean DIF I and DI values were 69% (standard deviation [Std.Dev] = 19) and 0.22 (Std.Dev = 0.16), respectively, for 220 MCQs. The mean scores from the questionnaire for students and feedback from faculty members ranged from 3.50 to 4.04 and from 4 to 5, respectively, indicating that stakeholders tended to agree and strongly agree, respectively, with the proposed statements. CONCLUSION: This study assisted the prosthodontics department in creating a set of prevalidated questions with known difficulty and discrimination capacity.

Exam evaluation in prosthodontics across preclinical and clinical years from students' perspective: A cross-sectional study.

INTRODUCTION: The purpose of this study was to explore the students' perceptions and performance in prosthodontics theory exam. METHODS: A cross-sectional descriptive study was conducted on 560 (80.82%) students of different levels (third, fourth and fifth years) to explore their opinions and performance with regard to a number of issues on a prosthodontics theory exam (exam evaluation, exam preparation, exam material, exam timing). Demographic data were also collected. Descriptive statistics were generated and Chi-square test, independent sample t-test, ANOVA test and Pearson's correlation coefficient were used to examine the associations between different variables. The significance level was set at p < .05. RESULTS: Students' responses regarding exam evaluation was influenced by their gender, study level, high-school Grade Point Average (GPA) and undergraduate cumulative GPA. Perceived exam difficulty was significantly affected by gender (p = .03) and study level (p < .001), and negatively correlated to both high-school GPA (p < .001) and university GPA (p = .03). The vast majority (88.2%) depended on lecture hand-outs and lecture notes for study. Exam material and preparation were not significantly affected by any of the demographic variables with most respondents (76.8%) thinking that the lectures blended with prosthodontics laboratories/clinics would improve their understanding of the exam material. The suggested best time to conduct the exam was early afternoon (31.6%). Student performance was significantly affected by the study level (p < .001) and cumulative GPA (p < .001) with significant positive correlation between the high-school GPA and the mark in the exam (r = .29, p < .001) and by the amount of time students spent for exam preparation (p < .001). Those students who reported using textbooks to prepare for the exam got significantly higher marks (66.1 ± 8.7) compared to the students who did not (62.8 ± 9.7) (p = .03). CONCLUSIONS: Course level, GPA and gender were identified as the most influential factors in different aspects of exam evaluation and students' performance. Regular study and use of textbooks were demonstrated to improve academic performance. Additional orientation and guidance relating to the exam (especially for third year students) would be welcomed, as would alternate teaching methods such as small group discussions or study groups.

Perio-prosthodontic pontic site management, part II: Pontic site reconstruction strategies to enhance the esthetic and biological outcomes.

OBJECTIVE: Ridge deformities are present in most patients after tooth extraction; these defects make the management of future implant and pontic sites challenging to deal with. The restorative team should be able to diagnose and treat these deformities to allow for successful outcomes. Many approaches have been described to reconstruct pontic sites, each with specific indications. This article describes the different approaches to reconstructing pontic sites and their indications to allow for a proper esthetic and biological environment for future restorations. CLINICAL CONSIDERATIONS: Depending on the severity of the defect, location, and the esthetic necessity, pontic site enhancement can be done through different approaches, some requiring soft tissue grafting, hard tissue grafting, or both. Understanding the indications of the treatment options is essential to allow the clinician to make the right therapeutic decision and achieve the best possible perio-prosthodontic outcomes. CONCLUSIONS: An adequate balance between the soft tissue and prosthetics is essential to achieve successful results on implant-supported or tooth-supported fixed dental prostheses (FDPs). Selecting the right approach to treat ridge deformities is necessary to increase treatment success, reduce over-treatment, and create a biologically sound environment for restorations. CLINICAL SIGNIFICANCE: Pontic site enhancement through reconstructive surgery will allow for esthetically pleasing and biologically stable results, allowing restorations to emulate natural structures lost after tooth extraction.

Setting the boundaries and scope of practice for the two sister specialities of dentistry: Operative dentistry-endodontics and prosthodontics.

Dental academia in Pakistan has recently achieved an important milestone. The name of Operative Dentistry speciality has been changed to Operative Dentistry & Endodontics (ODE). It was a much-needed change that was first felt about two decades ago. However, with the correction of name, there are certain challenges that this speciality has to manage now. These include improving the curriculum, setting up standards, and lastly, setting up its boundaries and scope of practice as some of its scope overlaps with a sister speciality called Prosthodontics. This overlapping of the boundaries of dental disciplines is a problem that is unique to Pakistan, India, and some East Asian countries where Operative Dentistry or Conservative Dentistry is combined with Endodontics. This paper aims to discuss the objective delineation of dental procedures and suggest a model of peaceful co-existence of sister dental specialities.

Identifying barriers and strategies for achieving competency in removable prosthodontics in undergraduate dental students: a mixed-method study.

BACKGROUND: Developing competency in removable prosthodontics (RP) is challenging for undergraduate dental students because it involves threshold concepts and tacit knowledge. Understanding this process can enhance learning and professional development in RP. The objective of this study was to identify the barriers hindering knowledge (threshold concept) and skill (tacit knowledge) development, and to propose strategies for achieving RP competency. METHODS: Adopting critical theory, quantitative and qualitative approaches were implemented. The participants were third- to sixth-year dental students and recent dental school graduates. An online questionnaire was used to investigate the knowledge and skills required for achieving RP competency and barriers to RP competency development. Four focus groups were conducted to gather in-depth information. The data was analyzed using descriptive statistics and thematic analysis. RESULTS: A total of 322 respondents completed the questionnaire (67% response rate), and 26 of them participated in focus group interviews. The four threshold concepts to achieve RP competency were the basic principles of RP, removable partial denture design, occlusion, and dental materials. The two main tacit knowledges were impression making and material handling skills. The curriculum should integrate strategies to assist dental students in overcoming intrinsic barriers such as self-experience, revision, and spatial-temporal relationship, along with extrinsic factors such as clinical correlations of content, discussions, and immediate feedback. CONCLUSIONS: Threshold concepts and tacit knowledge in RP for undergraduate dental students have been proposed The strategies to overcome barriers comprise intrinsic and extrinsic factors that include the adoption of experiential learning. This study suggests effective teaching methods and learning strategies to maximize student learning and RP competency development when designing the undergraduate RP curriculum in dental education.

Prosthodontic rehabilitation of patients with a unilateral subtotal maxillectomy using a customised subperiosteal zygomatic implant: a post-COVID-19 mucormycosis.

Restoring the maxillary resection defect involving the alveolar process, the hard and soft palate and the paranasal sinuses in terms of phonetics, mastication and deglutition is more challenging, especially with young patients with aesthetic concerns.This case report describes the prosthodontic rehabilitation of a young patient with a unilateral subtotal maxillectomy due to post-COVID-19 mucormycosis. A patient-specific subperiosteal implant was planned to rehabilitate the patient's bony defect. Using postsurgical CT, a customised subperiosteal titanium framework was fabricated by the direct metal laser sintering method using grade IV titanium alloy. The fabricated framework was implanted over the patient's zygomatic anatomic contour. Three months later, the patient-specific implant was unveiled to the oral cavity, an open-tray impression was made and the fixed implant prosthesis was fabricated.This case report opens a new realm of rehabilitation for severely compromised maxillary bony defects and impaired oral functioning with no other viable conventional reconstruction options.