Three-dimensional assessment of facial asymmetry in class III subjects, part 2: evaluating asymmetry index and asymmetry scores.

OBJECTIVES: To evaluate the outcomes of corrective surgical treatment for craniofacial asymmetry using four different methods with the aim of developing the best technique for craniofacial asymmetry assessment. MATERIALS AND METHODS: CBCT images of twenty-one class III subjects with surgically corrected craniofacial asymmetry and twenty-one matched controls were analyzed. Twenty-seven hard tissue landmarks were used to quantify asymmetry using the following methodologies: the asymmetry index (AI), asymmetry scores based on the clinically derived midline (CM), Procrustes analysis (PA), and modified Procrustes analysis (MPA). RESULTS: Modified Procrustes analysis successfully identified pre-operative asymmetry and revealed severe asymmetry at the mandibular regions compared to controls, which was comparable to the asymmetry index and clinically derived midline methods, while Procrustes analysis masked the asymmetric characteristics. Likewise, when comparing the post-surgical outcomes, modified Procrustes analysis not only efficiently determined the changes evidencing decrease in facial asymmetry but also revealed significant residual asymmetry in the mandible, which was congruent with the asymmetry index and clinically derived midline methods but contradictory to the results shown by Procrustes analysis. CONCLUSIONS: In terms of quantifying cranio-facial asymmetry, modified Procrustes analysis has evidenced to produce promising results that were comparable to the asymmetry index and the clinically derived midline, making it a more viable option for craniofacial asymmetry assessment. CLINICAL RELEVANCE: Modified Procrustes analysis is proficient in evaluating cranio-facial asymmetry with more valid clinical representation and has potential applications in assessing asymmetry in a wide spectrum of patients, including syndromic patients.

Which clinical and laboratory procedures should be used to fabricate digital complete dentures? A systematic review.

STATEMENT OF PROBLEM: Digital workflows for digital complete denture fabrication have a variety of clinical and laboratory procedures, but their outcomes and associated complications are currently unknown. PURPOSE: The purpose of this systematic review was to evaluate the clinical and laboratory procedures for digital complete dentures, their outcomes, and associated complications. MATERIAL AND METHODS: Electronic literature searches were conducted on PubMed/Medline, Embase, and Web of Science for studies published from January 2000 to September 2022 and screened by 2 independent reviewers. Information on digital complete denture procedures, materials, their outcomes, and associated complications was extracted. RESULTS: Of 266 screened studies, 39 studies were included. While 26 assessed definitive complete dentures, 7 studies assessed denture bases, 2 assessed trial dentures, and 4 assessed the digital images only. Twenty-four studies used border molded impression technique, 3 studies used a facebow record, and 7 studies used gothic arch tracing. Only 13 studies performed trial denture placement. Twenty-one studies used milling, and 17 studies used 3D printing for denture fabrication. One study reported that the retention of maxillary denture bases fabricated from a border-molded impression (14.5 to 16.1 N) was statistically higher than the retention of those fabricated from intraoral scanning (6.2 to 6.6 N). The maximum occlusal force of digital complete denture wearers was similar across different fabrication procedures. When compared with the conventional workflow, digital complete dentures required statistically shorter clinical time with 205 to 233 minutes saved. Up to 37.5% of participants reported loss of retention and up to 31.3% required a denture remake. In general, ≥1 extra visit and 1 to 4 unscheduled follow-up visits were needed. The outcomes for patient satisfaction and oral health-related quality of life were similar between conventional, milled, and 3D-printed complete dentures. CONCLUSIONS: Making a border-molded impression is still preferred for better retention, and trial denture placement is still recommended to optimize the fabrication of definitive digital complete dentures.

Accuracy of artificial intelligence-designed single-molar dental prostheses: A feasibility study.

STATEMENT OF PROBLEM: Computer-aided design and computer-aided manufacturing (CAD-CAM) technology has greatly improved the efficiency of the fabrication of dental prostheses. However, the design process (CAD stage) is still time-consuming and labor intensive. PURPOSE: The purpose of this feasibility study was to investigate the accuracy of a novel artificial intelligence (AI) system in designing biomimetic single-molar dental prostheses by comparing and matching them to the natural molar teeth. MATERIAL AND METHODS: A total of 169 maxillary casts were obtained from healthy dentate participants. The casts were digitized, duplicated, and processed with the removal of the maxillary right first molar. A total of 159 pairs of original and processed casts were input into the Generative Adversarial Networks (GANs) for training. In validation, 10 sets of processed casts were input into the AI system, and 10 AI-designed teeth were generated through backpropagation. Individual AI-designed teeth were then superimposed onto each of the 10 original teeth, and the morphological differences in mean Hausdorff distance were measured. True reconstruction was defined as correct matching between the AI-designed and original teeth with the smallest mean Hausdorff distance. The ratio of true reconstruction was calculated as the Intersection-over-Union. The reconstruction performance of the AI system was determined by the Hausdorff distance and Intersection-over-Union. RESULTS: Data of validation showed that the mean Hausdorff distance ranged from 0.441 to 0.752 mm and the Intersection-over-Union of the system was 0.600 (60%). CONCLUSIONS: This study demonstrated the feasibility of AI in designing single-molar dental prostheses. With further training and optimization of algorithms, the accuracy of biomimetic AI-designed dental prostheses could be further enhanced.

The cumulative effect of error in the digital workflow for complete-arch implant-supported frameworks: An in vitro study.

PURPOSE: To investigate the error accumulation and distribution through various stages of the digital workflow for complete-arch implant-supported framework fabrication. MATERIALS AND METHODS: A resin model of edentulous maxilla with 6 dental implants was scanned using an intraoral scanner for 10 times (Complete-digital group). Ten conventional gypsum casts were made and digitized by a laboratory scanner (Analogue-digital group). Five implant frameworks were designed and milled using CAD-CAM technique for each workflow. Inter-implant distances and angles of the resin model (reference) and frameworks were measured by a coordinate measuring machine, while the scans and virtual frameworks were examined by an inspection software. Effect of type of workflow and the individual stage on the accuracy of the frameworks were analysed by Two-way ANOVA. RESULTS: The expanded uncertainty of both workflows was ~150 µm and ~ 0.8°. The accuracy of the CAD stage was the highest. In the complete-digital workflow, the greatest distortion was found in the data acquisition stage, while in the analogue-digital workflow, it was found in the CAM stage. Compared with the analogue-digital group, the complete-digital group showed a significant higher precision in the first quadrant, but lower trueness in the second quadrant in data acquisition, and a significantly lower precision in the second quadrant at the CAD stage. CONCLUSIONS: Linear distortions of the complete-digital and analogue-digital workflows were clinically acceptable, while angular distortions were not. Distortions were generally derived from data acquisition and CAM stage. The CAD precision depended on the distortions derived from data acquisition. The complete-digital workflow was not as accurate as the analogue-digital in complete-arch implant rehabilitation.

Does the geometry of scan bodies affect the alignment accuracy of computer-aided design in implant digital workflow: An in vitro study?

OBJECTIVES: To compare 2 implant scan bodies with different geometry on the accuracy of the virtual alignment process in the digital workflow. MATERIALS AND METHODS: A master model of the edentulous maxilla with 6 implants and multiunit abutments (MUA) inserted was fabricated. Six dome-shaped and cuboidal scan bodies were mounted on the MUAs, respectively, and consecutively scanned by a laboratory scanner 10 times. The original scans were imported to a dental-specific CAD software and virtually aligned with the default CAD model in the implant library. Thus, 10 aligned models were created. Both the original scans and the aligned models were evaluated by an inspection software for deviation of the scan body surfaces, the centroids of scan body and MUA, the scan body center-axis, and the inter-MUA distances/angles. The two-sample T-test/Mann-Whitney U test were used to analyze the data with the level of significance set at 0.05. RESULTS: The cuboidal group showed significant greater deviations of the model surface (13.9 µm vs. 10.7 µm) and the MUA centroids (31.7 µm vs. 22.8 µm) but smaller deviation of the inter-MUA angle (0.047° vs. 0.070°) than those of the dome-shaped group (p < .05). No significant differences in the deviation of scan body centroids, center-axis, and the inter-MUA distances between the 2 groups were found. CONCLUSIONS: Virtual alignment of implant scan body affected the accuracy of the digital workflow for complete-arch implant-supported prostheses (up to ~30 µm/0.09°). Different geometries of the implant scan body could also influence the transfer accuracy in the CAD process.

Microleakage assessment of CAD-CAM Cobalt-Chrome and Zirconia abutments on a conical connection dental implant: A comparative in vitro study.

OBJECTIVE: To assess the marginal and bacterial microleakage in zirconia and CAD-CAM or cast Co-Cr implant abutments. METHODS: Sixty-four conical connection implants with their respective abutments were divided into four groups (Co-Cr (milled, laser-sintered, and cast) and Zirconia (milled)). All specimens were subjected to a chewing simulation and thermocycling. After aging process, specimens were submerged in a 0.2% methylene blue solution with Porphyromonas gingivalis (P.g) for 48 h. The marginal microleakage was measured using a 40× optical microscopy at the internal part of the implant, and when positive microleakage was observed, a DNA isolation with a polymerase chain reaction (PCR) test was used. The microbiological assessment was based on colony forming units (CFUs). RESULTS: Thirty (47%) implant-abutments presented microleakage and the PCR was performed on those specimens (1 Zirconia, 1 Co-Cr milled, 14 Co-Cr laser-sintered and 14 cast). Seven specimens (1 Co-Cr laser-sintered and six cast) presented values below the PCR detection limit (< 100 CFUs). The lowest CFUs count occurred in the Co-Cr milled group (5.17E+02 CFUs/ml) followed by zirconia (7.70E+03 CFUs/ml). The Co-Cr cast (9.39E+03 CFUs/ml) and laser-sintered (2.4E+05 CFUs/ml) groups had higher bacterial count. The CFU count comparison performed between Co-Cr cast and laser-sintered resulted in a statistically significant differences in favor of Co-CrCL (p < .05). CONCLUSIONS: The abutment material and fabrication technique affected the implant-abutment microleakage. Although the CAD-CAM abutments presented favorable results, all tested groups presented microleakage.

Three-dimensional assessment of facial asymmetry in Class III subjects. Part 1: a retrospective study evaluating postsurgical outcomes.

OBJECTIVE: The present study aimed to determine the site and severity of maxillomandibular asymmetry before and after orthognathic surgery in asymmetric patients. MATERIALS AND METHODS: Presurgery and postsurgery cone beam computed tomography (CBCT) data of 21 facial asymmetry patients (7 males and 14 females, mean age: 23.0 ± 3.36 years) with soft tissue chin deviation ≥ 3 mm who had undergone bimaxillary surgery were evaluated. Seven midline and twenty bilateral hard tissue landmarks were identified for the evaluation of facial asymmetry and outcomes were assessed against age- and gender-matched control subjects. RESULTS: In the asymmetry group, bilateral landmarks exhibited significant deviation in the mandible and midface regions. Before surgery, asymmetry was more severe at the mandibular midline and sites close to it, in the asymmetry group. Bimaxillary surgery proved to be highly effective, with a significant correction of the menton to a clinically normal value (2.90 mm, p < 0.001). After surgery, significant residual asymmetry was observed at the mental foramen (p = 0.001) in the R-L direction. Moreover, significant asymmetry persisted at the sigmoid notch (p = 0.001) in the S-I direction. CONCLUSIONS: Mandibular midline landmarks and chin peripheral regions contribute significantly to overall facial asymmetry characteristics. Despite significant correction after bimaxillary surgery, asymmetry persisted at several sites, thereby requiring secondary correction. Comprehensive 3D presurgical planning is central for asymmetry correction in a single surgery. CLINICAL RELEVANCE: The present study specifies the location of residual asymmetry sites and advocates the correction of those sites during initial surgery.

Improving intraoral implant scanning with a novel auxiliary device: An in-vitro study.

OBJECTIVES: To develop a novel auxiliary device for improving the accuracy of intraoral implant scanning in the complete-edentulous arch. MATERIALS AND METHODS: A standard model of edentulous maxilla with six dummy implants was prepared. Scan bodies were attached to the model, which was scanned by a laboratory scanner. A simulated mucosa (Group 0), a resin base (Group 1), a resin base with a cuboidal reference block and 4 fiduciary spheres (Group 2) or artificial teeth (Group 3) in between the implants were mounted on the model, respectively. Each group were consecutively scanned using an intraoral scanner (n = 10). The scans were analysed for trueness and precision in inter-implant distances and angles by inspection software. Effects of the auxiliary device and different quadrants on the accuracy of complete-arch intraoral scanning were analysed by two-way ANOVA. RESULTS: Significant effects of the auxiliary device and quadrant were found on both linear and angular accuracies. The lowest linear accuracy was found in group 0. Group 1 and group 3 showed the best linear accuracy in quadrant 1 and quadrant 2, respectively. Group 2 showed the least angular precision among the three groups. CONCLUSIONS: The three designs of auxiliary devices significantly improved the accuracy of complete-arch intraoral implant scanning. The base-only design showed good scanning accuracy in a single quadrant, while the base with tooth-shaped landmarks design showed better accuracy in cross-arch. The fiduciary spheres might compromise the precision of scanning.

Dental students' preference and perception on intraoral scanning and impression making.

BACKGROUND: To investigate the preference and perception on intraoral scanning and impression making among dental students. METHODS: Final-year dental students from the 2019 and 2020 cohorts were invited to complete an online questionnaire via Google-Form. Their preference on the intraoral-scanning/impression making techniques and their perception on these techniques including the ease of defect identification, ease of infection control, need of chairside support, ease to master the technique as a beginner, efficiency in their hands and ease to handle the scanner software (yes/no) were collected. The results were analysed using McNemar tests and binary logistic regression test. All tests were performed at significance level α = 0.05. RESULTS: Ninety-seven students participated in this study with a response rate of 96.0 %. Eighty-one students (83.5 %) have tried intraoral scanning on peers. Fifty-three (54.6 %) students preferred intraoral-scanning and were categorized as Pro-scanning group. Forty-four (45.4 %) students either preferred impression-making (n = 21) or not sure (n = 23) were categorized as Others. More than half of students in both groups felt that intraoral-scanning is easier to identify defect, easier in infection control and require less chairside support. Higher proportion of students in the Pro-scanning group felt that intraoral-scanning requires less chairside support, easier to master as a beginner, more efficient in their hands and they can deal well with the scanner software than that in Others (P < 0.05). Regression shown that students preferred a technique that they perceived is more efficient (P = 0.000). CONCLUSIONS: While intraoral scanning has perceived advantages, many students still prefer impression making that works more efficient to them.

Photogrammetric and Intraoral Digital Impression Technique for the Rehabilitation of Multiple Unfavorably Positioned Dental Implants: A Clinical Report.

The aim of this clinical report is to describe the use of the photogrammetric system and intraoral scanning as a reliable technique to record the 3-dimensional implant positions of a full-arch maxillary implant-supported fixed rehabilitation in which the implants were unfavorably positioned. The stereo camera of the photogrammetric system was used to capture the 3-dimensional panoramic position of the implants. The information on soft tissues was obtained with an intraoral scanner. Then, the 2 digital files (standard tessellation language [STL] files) were subsequently superimposed using a best-fit alignment function to generate the definitive digital model with information on teeth, soft tissues, and implants.

A clinical technique for virtual articulator mounting with natural head position by using calibrated stereophotogrammetry.

Accurate articulator-mounted casts are essential for occlusion analysis and for fabrication of dental prostheses. Although the axis orbital plane has been commonly used as the reference horizontal plane, some clinicians prefer to register the horizontal plane with a spirit level when the patient is in the natural head position (NHP) to avoid anatomic landmark variations. This article presents a digital workflow for registering the patient's horizontal plane in NHP on a virtual articulator. An orientation reference board is used to calibrate a stereophotogrammetry device and a 3-dimensional facial photograph with the patient in NHP. The horizontal plane can then be automatically registered to the patient's virtual model and aligned to the virtual articulator at the transverse horizontal axis level. This technique showed good repeatability with positional differences of less than 1 degree and 1 mm in 5 repeated measurements in 1 patient.

A 2-part facebow for CAD-CAM dentistry.

Converting the patient's clinical information into the virtual world is a prerequisite for the computer-aided design and computer-aided manufacturing (CAD-CAM) of dental restorations. This article describes a modified facebow which facilitates the radiation-free registration of the maxillary teeth to a 3-dimensional face image for transfer to a virtual articulator. This facebow can be easily fabricated with minimal materials and adjusted to fit different patients; its error in tooth registration was demonstrated to be less than 1 mm.

Impact of complications of single tooth restorations on oral health-related quality of life.

OBJECTIVE: To compare oral health-related quality of life (OHRQoL) among subjects who received implant-supported crowns (ISC) and 2-unit cantilevered resin-bonded bridges (cRBB) in a bounded single tooth space (BSTS) after at least 5 years and to investigate factors associated with their OHRQoL. METHODS: A case-control study among 78 subjects who received ISC or cRBB rehabilitation at a teaching hospital (39 ISCs and 39 cRBBs). OHRQoL was measured using the Oral Health Impact Profile (OHIP-49) and compared between treatment modality. Variations in OHIP scores with respect to "minor complications" (repair of the original "survived" restorations) and "major complications" (replacement of "failed" restorations); and number of complications were determined in bivariate and multivariate analyses (negative binominal regression) controlling for socio-demographic and clinical factors. RESULTS: Oral Health Impact Profile scores were similar among those who received ISC and cRBB (P = 0.53). Among subjects with complicated restorations, those with major complications reported significantly higher OHIP scores (poorer OHRQoL) than those with minor complications (P = 0.02). Subjects who experienced multiple complications had significantly higher OHIP scores (poorer OHRQoL) than those with a single complication (P = 0.04). In regression analyses (which considered OHIP scores of those with complications), the nature of complications (P < 0.01), treatment modality (P = 0.04), and gender (P = 0.02) emerged as significant factors. CONCLUSION: In the rehabilitation of a BSTS patients, OHRQoL was similar irrespective of treatment modality (ISC or cRBB). Among those who experienced complications their OHRQoL was associated with the nature of complications, treatment modality and gender.

Denture Plaque Biofilm Visual Assessment Methods: A Systematic Review.

Denture plaque, a biofilm that develops on denture surfaces, could contribute to many oral and systemic afflictions. Hence, a quantitative assessment of denture plaque is important to evaluate the denture hygiene of denture wearers, particularly to prevent plaque biofilm-associated diseases. The aim of this systematic review, therefore, was to review and summarize the visual denture hygiene assessment methods using denture plaque indices and with planimetries published in the literature. English language studies published up to March 2022 in four electronic databases, PubMed, Medline, Embase, and Cochrane Library, were searched, followed by a manual search of Google Scholar by two assessors. The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) whenever possible. Details of the visual assessment methods, including the types of denture assessed, its materials and its surfaces, as well as the use of a disclosing agent, were the main outcomes. Of 492 screened studies, 74 were included per the inclusion and exclusion criteria. Of these, 60 studies utilized various denture plaque indices while 18 used planimetries. 43 out of 60 studies with indices and 17 out of 18 studies with planimetries used disclosing agents for visual evaluation of plaque. A total of 21 indices were described in the included studies, of which seven graded a divided denture surface, while the remainder graded entire denture surface. Of the 18 planimetric assessments, one study quantified squares of the disclosed plaques on denture images, 16 studies quantified such pixels with computer programs, and a single study quantified points, pixels, and contour of plaque areas. In summary, denture plaque indices appear to be popular in denture plaque assessment due to their simplicity. Computerized planimetric assessment, though more time-consuming, provides a more accurate assessment of plaque load as it is less prone to subjectivity and assessor errors.

Ion release of the glass ionomer restoration with silver diamine fluoride dentin pretreatment.

OBJECTIVE: To assess the fluoride and silver ion release of glass ionomer cement (GIC) restorations, including conventional GIC (CGIC) and resin-modified GIC (RMGIC) restorations, with 38 % silver diamine fluoride (SDF) solution dentin pretreatment. METHODS: Eighty dentin blocks were allocated into 4 groups and restored with SDF+CGIC, CGIC, SDF+RMGIC and RMGIC, respectively. Each block was stored in deionized water at 37 °C for 2 years. Fluoride and silver ion concentration in storage solution was measured using ion-selective electrode and inductively coupled plasma-optical emission spectrometry for up to 2 years. The cross-sectional surfaces of restored dentin blocks were assessed by X-Ray diffraction analysis (XRD), scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDS) after 1 week and 2 years, respectively. RESULTS: The mean ± standard deviation (SD) of accumulative fluoride releasing in SDF+CGIC, CGIC, SDF+RMGIC and RMGIC for 2 years were 0.13±0.005 mg, 0.09±0.006 mg, 0.15±0.008 mg and 0.05±0.003 mg, respectively (Groups SDF+RMGIC > SDF+CGIC > CGIC >RMGIC, p < 0.05). The mean ± SD of accumulative silver releasing in SDF+CGIC, CGIC, SDF+RMGIC and RMGIC for 2 years were 0.03±0.009 mg, 0.00±0.00 mg, 0.01±0.003 mg, and 0.00±0.00 mg, respectively (Groups SDF+CGIC > SDF+RMGIC > CGIC&RMGIC, p < 0.05). Groups SDF+CGIC and SDF+RMGIC showed sustainably higher fluoride and silver releasing compared to Groups CGIC and RMGIC (p < 0.05). XRD analysis indicated the fluorapatite and silver chloride were observed only in Groups SDF+CGIC and SDF+RMGIC, but not in Groups CGIC and RMGIC. SEM images of the cross-sectional view of the dentin blocks showed silver crystals within dentinal tubules 1 week and 2-year in Groups with SDF pretreatment. CONCLUSION: The 38 % SDF dentin pretreatment sustainably increased the fluoride and silver release of GIC and RMGIC restorations for up to 2 years.

Silver diamine fluoride in preventing enamel erosion: An in vitro study with salivary pellicle.

OBJECTIVES: To compare the prevention of enamel erosion and discolouring effect with a single and two weekly topical applications of silver diamine fluoride (SDF) solution. METHODS: Human enamel blocks were divided into four groups. Group 1 (SDF2) received two weekly applications of SDF solution (Advantage Arrest: 260,000 ppm Ag, 44,300 ppm F, pH 9.1). Group 2 (SDF1) received a single application of SDF solution. Group 3 (SNF, Positive Control) received daily application of stannous-chloride/amine-fluoride/sodium-fluoride solution (Elmex® Enamel professional: 800 ppm Sn(II), 500 ppm F, pH 4.5). Group 4 (DW, Negative Control) received daily application of deionised water. The treated blocks were subjected to a 14-day erosive challenge. Crystal characteristics, elemental composition, surface morphology, percentage of surface microhardness loss (%SMHL), surface loss, and total colour change (ΔE) of the blocks were investigated using X-ray diffraction (XRD), energy-dispersive spectrometry (EDS) and scanning electron microscopy (SEM), Vickers' hardness testing, non-contact profilometry, and digital spectrophotometry, respectively. RESULTS: XRD and EDS revealed precipitates of silver for SDF2 and SDF1 and tin for SNF. SEM showed prominent etched enamel pattern on DW than the other three groups. The%SMHL (%) of SDF2, SDF1, SNF, and DW were 26.6 ± 2.9, 33.6 ± 2.8, 38.9 ± 2.9, and 50.5 ± 2.8 (SDF2SDF1=SNF>DW, p < 0.05). CONCLUSION: Two weekly applications was more effective than a single application of SDF in preventing enamel erosion, though it caused more discolouration. CLINICAL SIGNIFICANCE: Topical application of 38 % SDF with two weekly applications protocol is effective in preventing enamel erosion.

Global Research Trends in the Detection and Diagnosis of Dental Caries: A Bibliometric Analysis.

This study aims to provide an overview of the global research trends in the detection and diagnosis of dental caries in the past 20 years. A literature search was conducted in the Scopus Database to retrieve studies on the diagnostic approaches for dental caries published from January 2003 to December 2023. The diagnostic approaches in the retrieved studies were examined and the studies were categorized according to the diagnostic approaches investigated. Bibliometric data including journals, countries, affiliations, authors, and numbers of citations of the publications were summarised. The publications' keyword co-occurrence was analysed using VOSviewer. This bibliometric analysis included 1879 publications investigating seven categories of caries diagnostic approaches, including visual and/or tactile (n = 459; 19%), radiation-based (n = 662; 27%), light-based (n = 771; 32%), ultrasound-based (n = 28; 1%), electric-based (n = 51; 2%), molecular-based (n = 196; 8%) diagnostic approaches, as well as AI-based diagnostic interpretation aids (n = 265; 11%). An increase in the annual number of publications on caries diagnostic approaches was observed in the past 20 years. Caries Research (n = 103) presented the highest number of publications on caries diagnostic approaches. The country with the highest number of publications was the United States (n = 1092). The University of São Paulo was the institution that published the highest number of articles (n = 195). The publication with the highest citation has been cited 932 times. VOS viewer revealed that the most frequently occurring keywords were 'Deep Learning', 'Artificial Intelligence', 'Laser Fluorescence' and 'Radiography'. This bibliometric analysis highlighted an emerging global research trend in the detection and diagnosis approaches for dental caries in the past 20 years. An evident increase in publications on molecular-based caries diagnostic approaches and AI-based diagnostic interpretation aids was perceived over the last 5 years.

Performance of Generative Artificial Intelligence in Dental Licensing Examinations.

OBJECTIVES: Generative artificial intelligence (GenAI), including large language models (LLMs), has vast potential applications in health care and education. However, it is unclear how proficient LLMs are in interpreting written input and providing accurate answers in dentistry. This study aims to investigate the accuracy of GenAI in answering questions from dental licensing examinations. METHODS: A total of 1461 multiple-choice questions from question books for the US and the UK dental licensing examinations were input into 2 versions of ChatGPT 3.5 and 4.0. The passing rates of the US and UK dental examinations were 75.0% and 50.0%, respectively. The performance of the 2 versions of GenAI in individual examinations and dental subjects was analysed and compared. RESULTS: ChatGPT 3.5 correctly answered 68.3% (n = 509) and 43.3% (n = 296) of questions from the US and UK dental licensing examinations, respectively. The scores for ChatGPT 4.0 were 80.7% (n = 601) and 62.7% (n = 429), respectively. ChatGPT 4.0 passed both written dental licensing examinations, whilst ChatGPT 3.5 failed. ChatGPT 4.0 answered 327 more questions correctly and 102 incorrectly compared to ChatGPT 3.5 when comparing the 2 versions. CONCLUSIONS: The newer version of GenAI has shown good proficiency in answering multiple-choice questions from dental licensing examinations. Whilst the more recent version of GenAI generally performed better, this observation may not hold true in all scenarios, and further improvements are necessary. The use of GenAI in dentistry will have significant implications for dentist-patient communication and the training of dental professionals.

Preventing proximal enamel caries in neighboring tooth with glass ionomer cement restoration and silver diamine fluoride pretreatment.

OBJECTIVE: To investigate caries preventive effects of 38 % silver diamine fluoride (SDF) pretreatment on neighboring tooth proximal to glass ionomer cement (GIC), including conventional GIC (CGIC) and resin-modified GIC (RMGIC) restorations in an in vitro model. METHODS: HUMAN TOOTH BLOCKS WERE RESTORED WITH: SDF+CGIC (Group 1), CGIC (Group 2), SDF+RMGIC (Group 3) or RMGIC (Group 4). Enamel specimen simulating proximal surface of neighboring tooth was placed in proximity to the restorations. The specimen underwent cariogenic challenge with cross-kingdom biofilm of Streptococcus mutans, Lacticaseibacillus casei and Candida albicans. After cariogenic challenge, the biofilm's growth kinetics, viability, and morphology were evaluated by propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR), confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), respectively. The enamel lesion depth, surface morphology and crystal characteristics were determined by micro-computed tomography (micro-CT), SEM and X-ray diffraction (XRD), respectively. RESULTS: PMA-qPCR demonstrated lower microbial growth in Group 1 and 3 compared with Group 2 and 4 (p < 0.05). CLSM showed the dead-to-live ratio in Groups 1-4 were 1.15±0.12, 0.53±0.13, 1.10±0.24 and 0.63±0.10, respectively (Group 1,3 > 2,4, p < 0.05). SEM revealed Groups 1 and 3 had scattered biofilm whereas Group 2 and 4 had confluent biofilm. Micro-CT showed the enamel lesion depths (µm) were 98±9, 126±7, 103±6 and 128±7 for Group 1 to 4, respectively (Group 1,3 < 2,4, p < 0.05). SEM revealed oriented and ordered enamel prismatic patterns in Group 1 and 3, not in Group 2 and 4. XRD showed the reflections of hydroxyapatite in Groups 1 and 3 were sharper than Groups 2 and 4. CONCLUSION: SDF pretreatment enhances the preventive effect of GIC on proximal enamel surface on neighboring tooth through inhibiting cariogenic biofilm, reducing enamel demineralization and promoting enamel remineralization. CLINICAL SIGNIFICANCE: SDF pretreatment of GIC restorations can help prevent caries on neighboring teeth, particular for patients with high caries risk.

Posterior two-unit cantilevered zirconia resin-bonded fixed partial dentures: A 3-year prospective single-arm clinical trial.

OBJECTIVES: To evaluate the longevity of cantilevered zirconia-based resin-bonded fixed partial dentures (RBFPDs) in replacing missing posterior teeth, as well as the quality of life and patient satisfaction experienced by those receiving zirconia RBFPDs. METHODS: A prospective single-arm uncontrolled clinical trial was conducted to replace one or more missing premolars or molars with a span of 5 to 8 mm using cantilevered zirconia RBFPDs. Thirty-six participants with 40 prostheses were recruited and underwent a 3-year clinical evaluation. The retainer designs included a minimum thickness of 0.8 mm, a minimum of 200° circumferential wraparound with an occlusal bar, and a connector dimension of 3 × 3 mm. Patient-reported outcomes, including patient satisfaction and Oral Health Impact Profile (OHIP), were assessed. RESULTS: The average age of participants was 45.8 years, and 72.5 % were women. The success rate of the posterior zirconia RBFPDs was 76.2 %, with an estimated mean success duration of 46.1 months. The survival rate was 88.1 %, with an estimated mean survival duration of 49.4 months. Participants were highly satisfied with the treatment, achieving an average satisfaction score of 80.8 ± 11.9. Participants' total OHIP scores decreased from 52.3 to 39.6 after 3 years, indicating a significant improvement in oral health-related quality of life (P = 0.009). CONCLUSIONS: After 3 years, a moderately high survival rate and favourable patient-reported outcomes of posterior cantilevered zirconia RBFPDs were achieved. Therefore, it can be recommended as a conservative treatment option to replace missing posterior teeth, provided that retainer design considerations are taken into account. CLINICAL SIGNIFICANCE: Cantilevered zirconia RBFPDs for posterior teeth can serve as a conservative treatment option that is both aesthetically pleasing and biocompatible. It offers a more cost-effective alternative compared to dental implants, which are often prohibitively expensive for the majority of patients. This approach has the potential to greatly improve patient-reported outcomes.