Digital workflow and virtual validation of a 3D-printed definitive hollow obturator for a large palatal defect.

This clinical report describes how a hollow obturator prosthesis was designed and fabricated for an 82-year-old partially edentulous patient with a large palatal defect. Computer-aided design (CAD) was used to design, articulate, and align the mandibular denture with the obturator prosthesis. The prosthesis was printed, adjusted chairside, rescanned, and made hollow by using a CAD software program. The prosthesis was printed in resin with a dental 3D printer. Quantitative evaluations of clinical (prosthesis dimensions, rest, and occlusal vertical dimensions) and virtual (surface area, volume, weight, interpoint mismatches, spatial overlap) parameters found that the 3D-printed prosthesis required an additional 5% chairside modification. The greatest differences in volume (24.7% less) and weight (22.2% less) were observed when the modified obturator bulb was made hollow via CAD. Hollowing the bulb, therefore, reduced the spatial overlap in volume by 16.8%.

Clinical outcomes of implant-supported and tooth-supported fixed prostheses fabricated from digital versus analogue impression: a systematic review and meta-analysis.

OBJECTIVE: To analyze the clinical outcomes of implant-supported prostheses and tooth-supported fixed prostheses, fabricated from digital and conventional impression. MATERIALS AND METHODS: The literature search was carried out on two electronic databases (PubMed and Cochrane Library). Randomized controlled trials (RCT) published from January 2011 to September 2022 were included. The bias risk was evaluated using Cochrane Risk of Bias Tool 2.0. Further screening was done for meta-analysis according to modified Newcastle-Ottawa scoring criteria. Forest plot was generated using a statistical method of inverse variance of random effect with 95% confidence interval. RESULTS: A total of 8 randomized controlled trials were included for systematic review out of which four studies were based on tooth-supported fixed prosthesis and remaining four were based on implant-supported prosthesis. Further screening was conducted and three studies were eligible for meta-analysis. Tooth-supported fixed prosthesis fabricated from digital impression showed no significant difference in the marginal fit in any region measured, except for occlusal region where conventional impression showed more favorable marginal fit. Implant-supported prosthesis fabricated from digital impression showed survival rates ranging from 97.3 to 100% and there was no statistically significant difference in marginal bone loss (p = 0.14). CONCLUSION: Implant-supported prostheses fabricated from digital and conventional impressions show no significant differences in their clinical outcomes. Tooth-supported fixed prostheses fabricated from digital impression have shown favorable findings in terms of marginal fit. Despite that, there is still lack of clinical trials with larger sample size and longer follow-up periods. Future studies that fulfill these two criteria are deemed necessary.

Percentage of mesh reduction appropriate for designing digital obturator prostheses on personal computers.

STATEMENT OF PROBLEM: Computer-aided design (CAD) of maxillofacial prostheses is a hardware-intensive process. The greater the mesh detail is, the more processing power is required from the computer. A reduction in mesh quality has been shown to reduce workload on computers, yet no reference value of reduction is present for intraoral prostheses that can be applied during the design. PURPOSE: The purpose of this simulation study was to establish a reference percentage value that can be used to effectively reduce the size and polygons of the 3D mesh without drastically affecting the dimensions of the prosthesis itself. MATERIAL AND METHODS: Fifteen different maxillary palatal defects were simulated on a dental cast and scanned to create 3D casts. Digital bulbs were fabricated from the casts. Conventional bulbs for the defects were fabricated, scanned, and compared with the digital bulb to serve as a control. The polygon parameters of digital bulbs were then reduced by different percentages (75%, 50%, 25%, 10%, 5%, and 1% of the original mesh) which created a total of 105 meshes across 7 mesh groups. The reduced mesh files were compared individually with the original design in an open-source point cloud comparison software program. The parameters of comparison used in this study were Hausdorff distance (HD), Dice similarity coefficient (DSC), and volume. RESULTS: The reduction in file size was directly proportional to the amount of mesh reduction. There were minute yet insignificant differences in volume (P>.05) across all mesh groups, with significant differences (P<.001) in HD. The differences were, however, only found with DB1. DSC showed a progressive dissimilarity until DB25 (0.17%), after which the increase was more prominent (0.46% to 4.02%). CONCLUSIONS: A reduction of up to 75% polygons (25% of the original mesh) was effectively carried out on simulated casts without substantially affecting the amount of similarity in volume and geometry.

Evaluation of golden percentage in natural maxillary anterior teeth width: A systematic review.

STATEMENT OF PROBLEM: The color and form of teeth are 2 of the 3 main determinants of success in an esthetic restoration; the third is dental proportion. A recent systematic review of the literature devoted to the evaluation of dental proportion is lacking. PURPOSE: The purpose of this systematic review was to investigate the quality and outcome of studies into maxillary anterior tooth proportion and to determine whether dental proportion ratios based on different geographic regions are appropriate. MATERIAL AND METHODS: An electronic search was conducted using PubMed, MEDLINE, Google Scholar, Embase, Scopus, Cochrane Library, Web of Science, and Science Direct databases. English-language articles reporting with the specific combination of medical subject heading (MeSH) key words were analyzed by 2 investigators. The titles, full text, and abstracts were scanned by investigators independently to identify articles that fulfilled the inclusion criteria. The general characteristics, outcomes, and quality of each study were reviewed and analyzed systematically. RESULTS: The search plan resulted in a total of 73 articles until September 2020; of which, 16 articles fulfilling the inclusion criteria were selected. The geographic distribution of the selected article revealed 12 articles from Asia, 2 from Continental Europe, and 2 from the United Kingdom. Golden percentage values of 25%, 15%, and 10% for central, lateral incisor, and canine teeth were not found. The mean predicted dental percentage was either larger or smaller than the successive widths of maxillary natural anterior teeth. CONCLUSIONS: The golden percentage could not be used to formulate a smile design. Rather, the dental ratios should be set on a racial and ethnic basis for a population.

A virtual analysis of the precision and accuracy of 3-dimensional ear casts generated from smartphone camera images.

STATEMENT OF PROBLEM: The anatomic complexity of the ear challenges conventional maxillofacial prosthetic rehabilitation. The introduction of specialized scanning hardware integrated into computer-aided design and computer-aided manufacturing (CAD-CAM) workflows has mitigated these challenges. Currently, the scanning hardware required for digital data acquisition is expensive and not readily available for prosthodontists in developing regions. PURPOSE: The purpose of this virtual analysis study was to compare the accuracy and precision of 3-dimensional (3D) ear models generated by scanning gypsum casts with a smartphone camera and a desktop laser scanner. MATERIAL AND METHODS: Six ear casts were fabricated from green dental gypsum and scanned with a laser scanner. The resultant 3D models were exported as standard tessellation language (STL) files. A stereophotogrammetry system was fabricated by using a motorized turntable and an automated microcontroller photograph capturing interface. A total of 48 images were captured from 2 angles on the arc (20 degrees and 40 degrees from the base of the turntable) with an image overlap of 15 degrees, controlled by a stepper motor. Ear 1 was placed on the turntable and captured 5 times with smartphone 1 and tested for precision. Then, ears 1 to 6 were scanned once with a laser scanner and with smartphones 1 and 2. The images were converted into 3D casts and compared for accuracy against their laser scanned counterparts for surface area, volume, interpoint mismatches, and spatial overlap. Acceptability thresholds were set at <0.5 mm for interpoint mismatches and >0.70 for spatial overlap. RESULTS: The test for smartphone precision in comparison with that of the laser scanner showed a difference in surface area of 774.22 ±295.27 mm2 (6.9% less area) and in volume of 4228.60 ±2276.89 mm3 (13.4% more volume). Both acceptability thresholds were also met. The test for accuracy among smartphones 1, 2, and the laser scanner showed no statistically significant differences (P>.05) in all 4 parameters among the groups while also meeting both acceptability thresholds. CONCLUSIONS: Smartphone cameras used to capture 48 overlapping gypsum cast ear images in a controlled environment generated 3D models parametrically similar to those produced by standard laser scanners.

Effect of tropical outdoor weathering on the surface roughness and mechanical properties of maxillofacial silicones.

STATEMENT OF PROBLEM: The climate of tropical Southeast Asia includes high humidity and ultraviolet radiation that reduce the lifespan of silicone prostheses by inducing changes in their mechanical properties and color stability. Studies on the surface roughness (SR) and mechanical properties of different silicone elastomers (SEs) subjected to the natural tropical weather of Southeast Asia are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the SR, tensile strength (TS), and percentage elongation (% E) of different SEs subjected to outdoor weathering in the Malaysian climate. MATERIAL AND METHODS: Type-II dumbbell-shaped specimens (N-120) (nonweathered=15, weathered=15) were made from 3 room-temperature vulcanized (A-2000, A-2006, and A-103) and 1 heat-temperature vulcanized (M-511) silicone (Factor II). For 6 months, weathered specimens were subjected to outdoor weathering inside a custom exposure rack. Simultaneously, the nonweathered specimens were kept in a dehumidifier. Subsequently, the SR was measured with a profilometer; TS and % E were measured by using a universal testing machine. Two-way ANOVA was used to compare the means of the tested properties of the nonweathered and weathered specimens, and pairwise comparison was carried out between the silicones (α=.05). RESULTS: After outdoor weathering, the SR, TS, and % E were adversely affected by weathering in the Malaysian environment. Among the silicone materials, A-2000 showed the least TS changes (2.51 MPa), while A-2006 demonstrated significant changes in percentage elongation after outdoor weathering (266.5%). M-511 exhibited the highest mean value (2.50 µm) for SR changes. In addition, A-103 SE showed statistically significant differences in most pairwise comparisons for all 3 dependent variables. CONCLUSIONS: Based on the evaluation of mechanical properties, A-103 can be suggested as a suitable silicone for maxillofacial prostheses fabricated for tropical climates. However, A-2000 can be a suitable alternative, although significant changes to surface roughness were detected after outdoor weathering.

Pulpal and Periapical Status of the Vital Teeth Used as Abutment for Fixed Prosthesis-A Systematic Review and Meta-Analysis.

PURPOSE: This is a systematic review to identify the incidence of pulp necrosis and/or periapical changes among vital teeth which are used as an abutment for crown and fixed partial dentures (FPDs). MATERIALS AND METHODS: Two reviewers independently searched two electronic databases, PubMed and Scopus. The search was complemented from references of included studies and published reviews. Studies published in the English language through January 2021 that had assessed and documented the clinical and radiographic failure of crown or FPD in vital permanent teeth due to pulpal or periapical pathology with a follow-up of at least 12 months were selected. Data screening, data collection and extraction of data was performed. Quality of studies involved was analyzed using the Newcastle-Ottawa Quality Assessment Scale for cohort studies. Meta-analysis was done using random effects model. Publication bias was assessed using funnel plots. RESULTS: Electronic searches provided 10,075 records among which 20 studies were selected for systematic review and 7 studies were selected for meta-analysis. With respect to quality assessment, all the studies involved were considered as high quality as the score in scale ranged between 6 and 9 as per the Newcastle-Ottawa Quality Assessment Scale for cohort studies. The meta-analyses showed that there was no statistically significant difference in the incidence of the loss of pulp vitality or pulp necrosis through clinical and radiographic examination with the follow up period of 5 years: p < 0.001, 95% CI: 0.96-1.00, I2 = 77.84%; 10 years: p < 0.001, 95% CI: 0.88-0.95, I2 = 93.59%; 15 years: p < 0.001, 95% CI: 0.92-0.96, I2 = 94.83%; and 20 years: p < 0.001, 95% CI: 0.94-0.96, I2 = 95.01%. CONCLUSIONS: The meta-analysis revealed clinical and radiographic success rate ranging between 92% to 98% at different follow up periods ranging between 5 years and 20 years. Future high-quality randomized clinical controlled trials with a larger population are required to confirm the evidence as only observational studies were considered in this paper.

Evaluation of the Differences Between Conventional and Digitally Developed Models Used for Prosthetic Rehabilitation in a Case of Untreated Palatal Cleft.

OBJECTIVE: The virtual cone beam computed tomography-derived 3-dimensional model was compared with the scanned conventional model used in the fabrication of a palatal obturator for a patient with a large palatal defect. DESIGN: A digitally derived 3-dimensional maxillary model incorporating the palatal defect was generated from the patient's existing cone beam computerized tomography data and compared with the scanned cast from the conventional impression for linear dimensions, area, and volume. The digitally derived cast was 3-dimensionally printed and the obturator fabricated using traditional techniques. Similarly, an obturator was fabricated from the conventional cast and the fit of both final obturator bulbs were compared in vivo. RESULTS: The digitally derived model produced more accurate volumes and surface areas within the defect. The defect margins and peripheries were overestimated which was reflected clinically. CONCLUSION: The digitally derived model provided advantages in the fabrication of the palatal obturator; however, further clinical research is required to refine consistency.

Optimization of Prosthodontic Computer-Aided Designed Models: A Virtual Evaluation of Mesh Quality Reduction Using Open Source Software.

PURPOSE: Mesh optimization reduces the texture quality of 3D models in order to reduce storage file size and computational load on a personal computer. This study aims to explore mesh optimization using open source (free) software in the context of prosthodontic application. MATERIALS AND METHODS: An auricular prosthesis, a complete denture, and anterior and posterior crowns were constructed using conventional methods and laser scanned to create computerized 3D meshes. The meshes were optimized independently by four computer-aided design software (Meshmixer, Meshlab, Blender, and SculptGL) to 100%, 90%, 75%, 50%, and 25% levels of original file size. Upon optimization, the following parameters were virtually evaluated and compared; mesh vertices, file size, mesh surface area (SA), mesh volume (V), interpoint discrepancies (geometric similarity based on virtual point overlapping), and spatial similarity (volumetric similarity based on shape overlapping). The influence of software and optimization on surface area and volume of each prosthesis was evaluated independently using multiple linear regression. RESULTS: There were clear observable differences in vertices, file size, surface area, and volume. The choice of software significantly influenced the overall virtual parameters of auricular prosthesis [SA: F(4,15) = 12.93, R2 = 0.67, p < 0.001. V: F(4,15) = 9.33, R2 = 0.64, p < 0.001] and complete denture [SA: F(4,15) = 10.81, R2 = 0.67, p < 0.001. V: F(4,15) = 3.50, R2 = 0.34, p = 0.030] across optimization levels. Interpoint discrepancies were however limited to <0.1mm and volumetric similarity was >97%. CONCLUSION: Open-source mesh optimization of smaller dental prostheses in this study produced minimal loss of geometric and volumetric details. SculptGL models were most influenced by the amount of optimization performed.

Effect of Aging and Weathering on the Physical Properties of Maxillofacial Silicone Elastomers: A Systematic Review and Meta-Analysis.

PURPOSE: This systematic review aims to identify and interpret results of studies that evaluated the changes in the physical properties of maxillofacial prosthetic materials (1) without aging, (2) after natural or artificial accelerated aging, and (3) after outdoor weathering. METHODS: Relevant articles written in English only, before January 15, 2017, were identified using an electronic search in the PubMed, Scopus, and Google Scholar databases. Furthermore, a manual search of the related major journals was also conducted to identify more pertinent articles. The relevancy of the articles was verified by screening the title, abstract, and full text if they met the inclusion criteria. A total of 37 articles satisfied the criteria, from which data were extracted for qualitative synthesis. RESULTS: Among the 37 included articles, 14 were without aging, 15 were natural or artificial accelerated aging, 7 were outdoor weathering, and 1 contained both artificial aging and outdoor weathering. Only 4 studies out of the 14 without aging had significant observations; whereas 9 articles with natural or artificial aging published significant results, and 3 out of 7 outdoor weathering articles showed significant changes in the evaluated silicone elastomers. CONCLUSIONS: Despite the varying research, it seems that the single "ideal" maxillofacial prosthetic material that can provide sufficient resistance against different aging conditions is yet to be identified. Therefore, it is imperative for standardization organizations, the scientific community, and academia to develop modified prosthetic silicones possessing improved physical properties and color stability, limiting the clinical problems regarding degradation of maxillofacial prostheses.

Knowledge and attitude regarding obstructive sleep apnoea among medical and dental practitioners working in North-Eastern Peninsular Malaysia: A comparative cross-sectional study.

BACKGROUND: Obstructive Sleep Apnea (OSA) is a temporary airflow obstruction during periods of sleep. Patients with OSA often suffer from poor work performance, compromised sleep quality, and low quality of life which may lead to a life-threatening event. Adequate knowledge and a positive attitude toward OSA among medical and dental practitioners are crucial to the initial diagnosis and treatment. OBJECTIVE: This study aimed to identify the differences in knowledge and attitude toward OSA between medical and dental practitioners working in North-Eastern Peninsular Malaysia. METHODS: A comparative cross-sectional study was performed from February 2020 to February 2021. A total of fifty-two medical practitioners and fifty-two dental practitioners working at university-based outpatient clinics, government health clinics, and oral health clinics located in Kelantan State of Malaysia participated in the study, and data were collected by the structured questionnaire including sociodemographic inquiry and OSAKA questionnaire by non-probability stratified random sampling. The Mann-Whitney U test was used to compare knowledge and attitude scores between the two groups. RESULTS: The mean age of the respondents was 34.6 years. The current study shows that 92.3% of medical doctors and 96.1% of dental doctors were able to correctly answer the question "Most of the patients with OSA snore" a significant finding in our study. Only 1% of medical professionals could answer seventeen questions correctly with a median score of 11, and only 1% of dental professionals could answer sixteen questions correctly with a median score of 9. None of them could provide an accurate answer to all the knowledge questions. Medical and dental practitioners exhibited different knowledge levels on OSA (z- statistics=-4.39, U = 827.00 with p <  0.05, and effect size, r = 0.61). However, no significant differences were found in total knowledge score by gender (p-value>0.05), ethnicity (p-value>0.05), total service years (p-value>0.05), and training attended. In addition, significant differences in attitude levels between medical and dental practitioners have been observed (z-statistics=-3.42, U = 725.00 with p <  0.05, and effect size, r = 0.47). Nevertheless, no significant differences have been seen in total attitude score by ethnicity (p-value >  0.05), total service years (p-value >  0.05), attending training on OSA (p-value >  0.05), and professional status (p-value >  0.05) except gender (p-value <  0.05). CONCLUSION: A Significant difference is evident concerning knowledge and attitude toward OSA diagnosis and management between medical and dental practitioners working in North-Eastern Peninsular Malaysia. Medical practitioners in this study recorded a higher knowledge and attitude score compared to dental practitioners.

Prosthetic management of an ocular defect utilizing a novel threaded iris fabrication technique.

The conservative prosthodontic construction of an ocular prosthesis utilizing our novel threaded iris fabrication technique required high time and prosthodontic resource inputs and produced a lifelike aesthetic result. Abstract: Patients with ocular defects frequently present with significant local anatomical deficiencies and complex histories and require extensive time and resource inputs to treat. This case report describes the conservative management of an ocular defect completed in a postgraduate prosthodontics clinical residency program utilizing a novel threaded iris fabrication technique.

Effects of Riboflavin Collagen Crosslinker on Dentin Adhesive Bonding Efficiency: A Systematic Review and Meta-Analysis.

The aim of this study was to evaluate published data regarding riboflavin (RF) as a cross-linker for improved adhesive bond strength to dentin and to analyze previous studies for optimal concentration of riboflavin range suitable for dentin bond. Saliva and distilled water were used as storage media and aging time was 24 h and 6 months. Results of meta-analysis were synthesized using a statistical method of inverse variance in random effects with a 95% Confidence Interval (CI). Cochrane review manager 5.4.1 was used to determine results of the meta-analysis. In total, 3172 articles were found from search databases "PubMed", "Scopus", and "Google Scholar". Six of the fifteen studies were eligible for meta-analysis. Micro tensile strength shows significant improvement with the addition of riboflavin (p < 0.05) compared to without the addition of riboflavin from with 95% CI. A significant difference has been found in micro tensile bond strength between use of the riboflavin cross-linker and without use of the riboflavin crosslinker in the dentin adhesive system. With a 95% confidence interval (CI), the I2 for micro tensile strength was 89% with strong heterogeneity, Chi2 = 44.76, df = 5 (p < 0.00001), and overall effect size is Z = 2.22 (p = 0.03) after immediate aging. Chiang et al. 2013 shows maximum mean differences which is 38.50 [17.93-59.07]. After 6 months of aging in distilled water or artificial saliva micro tensile bond strength has been increased with the addition of riboflavin (p < 0.05). It can be clearly seen that pooled effect and 95% CI did not cross the line of no effect. With a 95% confidence interval (CI), the I2 for micro tensile strength was 96% with strong heterogeneity, Chi2 = 117.56, df = 5 (p < 0.00001), and overall effect size is Z = 2.30 (p = 0.02). Subgroup analysis proved a similar effect of distilled water and artificial saliva as storage media on micro tensile bond strength after incorporating riboflavin as a collagen crosslinker. An artificial saliva aged forest plot also showed considerable heterogeneity with I2 = 96%; Tau2 = 257.32; Chi2 = 94.37; df = 2 (p < 0.00001); test for overall effect, Z = 1.06 (p = 0.29). Riboflavin prior to or with bonding is recommended to improve the bonding of different adhesive systems.

Computer-aided design and 3-dimensional artificial/convolutional neural network for digital partial dental crown synthesis and validation.

The current multiphase, invitro study developed and validated a 3-dimensional convolutional neural network (3D-CNN) to generate partial dental crowns (PDC) for use in restorative dentistry. The effectiveness of desktop laser and intraoral scanners in generating data for the purpose of 3D-CNN was first evaluated (phase 1). There were no significant differences in surface area [t-stat(df) = - 0.01 (10), mean difference = - 0.058, P > 0.99] and volume [t-stat(df) = 0.357(10)]. However, the intraoral scans were chosen for phase 2 as they produced a greater level of volumetric details (343.83 ± 43.52 mm3) compared to desktop laser scanning (322.70 ± 40.15 mm3). In phase 2, 120 tooth preparations were digitally synthesized from intraoral scans, and two clinicians designed the respective PDCs using computer-aided design (CAD) workflows on a personal computer setup. Statistical comparison by 3-factor ANOVA demonstrated significant differences in surface area (P < 0.001), volume (P < 0.001), and spatial overlap (P < 0.001), and therefore only the most accurate PDCs (n = 30) were picked to train the neural network (Phase 3). The current 3D-CNN produced a validation accuracy of 60%, validation loss of 0.68-0.87, sensitivity of 1.00, precision of 0.50-0.83, and serves as a proof-of-concept that 3D-CNN can predict and generate PDC prostheses in CAD for restorative dentistry.

Development of Artificial Neural Network-Based Prediction Model for Evaluation of Maxillary Arch Growth in Children with Complete Unilateral Cleft Lip and Palate.

INTRODUCTION: Cleft lip and palate (CLP) are the most common congenital craniofacial deformities that can cause a variety of dental abnormalities in children. The purpose of this study was to predict the maxillary arch growth and to develop a neural network logistic regression model for both UCLP and non-UCLP individuals. METHODS: This study utilizes a novel method incorporating many approaches, such as the bootstrap method, a multi-layer feed-forward neural network, and ordinal logistic regression. A dataset was created based on the following factors: socio-demographic characteristics such as age and gender, as well as cleft type and category of malocclusion associated with the cleft. Training data were used to create a model, whereas testing data were used to validate it. The study is separated into two phases: phase one involves the use of a multilayer neural network and phase two involves the use of an ordinal logistic regression model to analyze the underlying association between cleft and the factors chosen. RESULTS: The findings of the hybrid technique using ordinal logistic regression are discussed, where category acts as both a dependent variable and as the study's output. The ordinal logistic regression was used to classify the dependent variables into three categories. The suggested technique performs exceptionally well, as evidenced by a Predicted Mean Square Error (PMSE) of 2.03%. CONCLUSION: The outcome of the study suggests that there is a strong association between gender, age, and cleft. The difference in width and length of the maxillary arch in UCLP is mainly related to the severity of the cleft and facial growth pattern.

Modeling the Relationship Between Tooth Color and Skin Color in Equations to Predict Tooth Color.

Background Color selection for discolored teeth or for edentulous patients is a subjective process in dentistry. To the best of the authors' knowledge, there is no objective method for tooth color selection for edentulous patients. Several studies have investigated the relationship between tooth color and skin color and the ability to use skin color as a guide to select tooth color in dental rehabilitation cases. The objective of this study was to find and model the relationship between tooth color and skin color in equations to be able to predict tooth color by assessing skin color. Methodology This study was done on 150 participants with equal gender distribution. Digital photography with soft boxes and strobe lights were used to measure tooth and skin color. Digital photography was performed in a dark room with controlled and measured lighting sources and strength. A calibration board was used to create two calibration profiles in software. All photos were calibrated in Adobe Lightroom software. Then, color measurement was done using Adobe Photoshop software in the Commission International de I'Eclarirage (CIELab) system. Results There were positive significant relationships in color spaces L* and a* between tooth color and skin color, and an inverted significant relationship in color space b* between tooth and skin. Three equations with excellent reliability were formulated in this study to predict tooth color by assessing skin color. Conclusions The relationship between tooth color and skin color was modeled in three equations. For edentulous patients, this research might be useful in detecting the proper tooth color and transferring the CIELab color data to dental technicians for further processing. Computerized shade matching and prediction dental software may be designed using these equations.

The Analysis of Facio-Dental Proportions to Determine the Width of Maxillary Anterior Teeth: A Clinical Study.

The present study aimed to analyze mid horizontal facial third proportions, those being the interpupillary, inner intercanthal, and bizygomatic distance modified with golden proportion, The Preston proportion, golden percentage and 70% recurring esthetic dental proportion were used for determining maxillary anterior teeth width. A total of 230 participants took part in this study. The front dental and facial photographs along dental stone cast which were converted to three-dimensional (3D) models were used for evaluation. The mid horizontal facial third proportions showed no significant relationship with maxillary anterior teeth width without modification with dental proportions. Whereas, with modification, no statistically significant difference was found between inner-intercanthal distance by golden percentage and width of central incisors. The bizygomatic distance was greater than intercanine distance. While the interpupillary distance by golden proportion was found to be consistent with intercanine distance in female participants. The modified anterior teeth width was significantly different from measured values, when determined by using the three mid facial proportions with Preston and 70% recurring esthetic dental (RED) proportion. Furthermore, the measured width of maxillary anterior teeth showed no difference when plaster dental casts widths were compared with 3D models. The interpupillary, inner-intercanthal, and bizygomatic distance should not be directly used to determine maxillary anterior teeth width. While maxillary anterior teeth width can be determined by modifying the inner inter-canthal distance with golden percentage and interpupillary distance with golden proportion. Moreover, the midfacial third proportions modified with Preston and 70% recurrent esthetic dental proportion were found to be unreliable for the determination of maxillary anterior teeth widths.

The Potential of α-Mangostin from Garcinia mangostana as an Effective Antimicrobial Agent-A Systematic Review and Meta-Analysis.

This systematic review aims to evaluate the antimicrobial activity of α-mangostin derived from Garcinia mangostana against different microbes. A literature search was performed using PubMed and Science Direct until March 2022. The research question was developed based on a PICO (Population, Intervention, Control and Outcomes) model. In this study, the population of interest was microbes, α-mangostin extracted from Garcinia mangostana was used as exposure while antibiotics were used as control, followed by the outcome which is determined by the antimicrobial activity of α-mangostin against studied microbes. Two reviewers independently performed the comprehensive literature search following the predetermined inclusion and exclusion criteria. A methodological quality assessment was carried out using a scoring protocol and the risk of bias in the studies was analyzed. Reward screening was performed among the selected articles to perform a meta-analysis based on the pre-determined criteria. Case groups where α-mangostin extracted from Garcinia mangostana was incorporated were compared to groups using different antibiotics or antiseptic agents (control) to evaluate their effectiveness. A total of 30 studies were included; they were heterogeneous in their study design and the risk of bias was moderate. The results showed a reduction in microbial counts after the incorporation of α-mangostin, which resulted in better disinfection and effectiveness against multiple microbes. Additionally, the meta-analysis result revealed no significant difference (p > 0.05) in their effectiveness when α-mangostin was compared to commercially available antibiotics. α-mangostin worked effectively against the tested microbes and was shown to have inhibitory effects on microbes with antibiotic resistance.