Comparative Analysis of Periodontal Parameters and Patient Satisfaction Utilising Different Temporary Crown Fabrication Techniques: A Parallel-Group Randomised Controlled Trial.

Aim The study aims to evaluate the efficacy of different techniques for temporary crown fabrication in maintaining periodontal health and patient satisfaction, addressing a critical gap in the existing literature and informing evidence-based clinical practices. Materials and methods This study, conducted in accordance with CONSORT guidelines, was a parallel-group randomised trial conducted at a dental institute in India. In total, 36 participants aged 18-65 requiring anterior tooth region crowns were randomly assigned to three groups: direct (control), indirect (Test Group 1) and direct-indirect (Test Group 2) fabrication techniques. Participants were selected from outpatient departments based on eligibility criteria, and interventions were allocated using randomization tables. Outcome assessments included gingival health metrics and patient satisfaction levels, with statistical analyses performed using the Kruskal-Wallis test. Results Significant differences were observed in the pink esthetic score (PES) and patient satisfaction (P=0.029) among the three groups, with the direct-indirect technique group demonstrating the highest median PES (9 out of 10). However, no significant disparities were noted in the plaque index (PI) or probing depth (PD) among the groups. Conclusion The direct-indirect technique demonstrated superior PES and patient satisfaction, indicating potential benefits for periodontal health and patient experiences. Integration of virtual preparation workflows may optimise outcomes, but further research is needed for validation and guideline development.

Quantum mechanical analysis of yttrium-stabilized zirconia and alumina: implications for mechanical performance of esthetic crowns.

BACKGROUND: Yttrium-stabilized zirconia (YSZ) and alumina are the most commonly used dental esthetic crown materials. This study aimed to provide detailed information on the comparison between yttrium-stabilized zirconia (YSZ) and alumina, the two materials most often used for esthetic crowns in dentistry. METHODOLOGY: The ground-state energy of the materials was calculated using the Cambridge Serial Total Energy Package (CASTEP) code, which employs a first-principles method based on density functional theory (DFT). The electronic exchange-correlation energy was evaluated using the generalized gradient approximation (GGA) within the Perdew (Burke) Ernzerhof scheme. RESULTS: Optimization of the geometries and investigation of the optical properties, dynamic stability, band structures, refractive indices, and mechanical properties of these materials contribute to a holistic understanding of these materials. Geometric optimization of YSZ provides important insights into its dynamic stability based on observations of its crystal structure and polyhedral geometry, which show stable configurations. Alumina exhibits a distinctive charge, kinetic, and potential (CKP) geometry, which contributes to its interesting structural framework and molecular-level stability. The optical properties of alumina were evaluated using pseudo-atomic computations, demonstrating its responsiveness to external stimuli. The refractive indices, reflectance, and dielectric functions indicate that the transmission of light by alumina depends on numerous factors that are essential for the optical performance of alumina as a material for esthetic crowns. The band structures of both the materials were explored, and the band gap of alumina was determined to be 5.853 eV. In addition, the band structure describes electronic transitions that influence the conductivity and optical properties of a material. The stability of alumina can be deduced from its bandgap, an essential property that determines its use as a dental material. Refractive indices are vital optical properties of esthetic crown materials. Therefore, the ability to understand their refractive-index graphs explains their transparency and color distortion through how the material responds to light..The regulated absorption characteristics exhibited by YSZ render it a highly attractive option for the development of esthetic crowns, as it guarantees minimal color distortion. CONCLUSION: The acceptability of materials for esthetic crowns is strongly determined by mechanical properties such as elastic stiffness constants, Young's modulus, and shear modulus. YSZ is a highly durable material for dental applications, owing to its superior mechanical strength.

The "Central Tendency Bias" in the assessment of facial attractiveness in group-based and individual ratings-A survey-based study in 727 volunteers.

BACKGROUND: The increasing number of esthetic procedures emphasizes the need for effective evaluation methods of outcomes. Current practices include the individual practitioners' judgment in conjunction with standardized scales, often relying on the comparison of before and after photographs. This study investigates whether comparative evaluations influence the perception of beauty and aims to enhance the accuracy of esthetic assessments in clinical and research settings. OBJECTIVE: To compare the evaluation of attractiveness and gender characteristics of faces in group-based versus individual ratings. METHODS: A sample of 727 volunteers (average age of 29.5 years) assessed 40 facial photographs (20 male, 20 female) for attractiveness, masculinity, and femininity using a 5-point Likert scale. Each face was digitally edited to display varying ratios in four lip-related proportions: vertical lip position, lip width, upper lip esthetics, and lower lip esthetics. Participants rated these images both in an image series (group-based) and individually. RESULTS: Differences in the perception of the most attractive/masculine/feminine ratios for each lip proportion were found in both the group-based and individual ratings. Group ratings exhibited a significant central tendency bias, with a preference for more average outcomes compared with individual ratings, with an average difference of 0.50 versus 1.00. (p = 0.033) CONCLUSION: A central tendency bias was noted in evaluations of attractiveness, masculinity, and femininity in group-based image presentation, indicating a bias toward more "average" features. Conversely, individual assessments displayed a preference for more pronounced, "non-average" appearances, thereby possibly pointing toward a malleable "intrinsic esthetic blueprint" shaped by comparative context.

Management of hyperplastic tissue response following connective tissue grafting.

OBJECTIVE: While connective tissue graft shrinkage is a well-documented post-transplantation reaction, there is a literature gap concerning hyperplastic tissue response. Despite its infrequent occurrence, investigation is warranted due to its capacity to compromise esthetics, disrupt lip dynamics, and promote food retention. Moreover, efforts to mitigate hyperplastic tissue response often prove challenging, and there is a potential risk of exacerbating gingival tissue rebound. CLINICAL CONSIDERATIONS: This report presents a potential solution to managing tissue overgrowth after connective tissue grafting in five clinical cases. The patients underwent corrective surgery involving internal excision of excessive tissue while preserving the overlying mucosa. The surgical approach was tailored to excise hyperplastic tissue with minimal trauma, aiming to optimize esthetic outcomes. Subsequent follow-up assessments spanning 1-5 years demonstrated stable results, with no indications of relapse or recurrence of tissue overgrowth. CONCLUSIONS: Within the limitations of this case series, surgical internal excision holds promise as a viable treatment modality for addressing post-transplantation hyperplastic tissue response. CLINICAL SIGNIFICANCE: This case series addresses the challenge of uncontrolled tissue overgrowth following connective tissue grafting, a concern for which previous attempts have proven unsuccessful. Internal in-toto excision emerges as a promising approach for effectively eliminating overgrown tissue, offering potential advancements in the clinical management of this complication.

Volumetric Analysis of Peri-implant Tissue Change Over Time: Validating an Innovative 3D Method.

PURPOSE: To validate an innovative 3D volumetric method of evaluating tissue changes proposed by Lee et al in 2020 by comparing the results of this method-in which the scanned peri-implant surfaces were transformed, visualized, and analyzed as 3D objects-to the results reported by an existing method based on calculation of the mean distance between measured surfaces. The null hypothesis was that there was no statistically significant difference between the two methods. Additionally, the present study evaluated peri-implant tissue changes 5 years after single implant placement in the esthetic zone. MATERIALS AND METHODS: Both methods were applied to 11 oral implant site casts (6 maxillary central incisor sites, 5 maxillary lateral incisor sites) taken from 11 patients at crown placement and at follow-up examinations 5 years later. The methods are based on digital workflows in which the reference and 5-year casts are scanned and the resulting STL files are superimposed and analyzed for three regions of interest (mesial papilla, central area, and distal papilla). The volumetric changes reported by the Lee et al method and the mean distance method were calculated and compared using the Spearman rank correlation coefficient (P < .01) and the Wilcoxon signed-rank test (P < .05). RESULTS: The correlation between the two sets of measurements was very high (Spearman rank correlation coefficient = 0.885). The new volumetric method indicated a mean volume loss of 2.82 mm3 (SD: 5.06), while the method based on the measurement of mean distance showed a mean volume loss of 2.92 mm3 (SD: 4.43; Wilcoxon signed-rank test result: P = .77). No statistically significant difference was found. The two methods gave equivalent results, and the null hypothesis was accepted. CONCLUSIONS: The new volumetric method was validated and can be considered a trustworthy tool.

Determining the widths of the maxillary anterior teeth for esthetics: comparison of the Mondelli and Albers formulas, esthetic proportion, and golden ratio.

The purpose of this study was to compare various formulas for idealized proportions of the maxillary incisors to the actual dimensions of natural teeth. The Mondelli formula 1 (MF1), Mondelli formula 2 (MF2), Albers formula (AF), esthetic proportion (EP) for width and height of anterior teeth, and golden ratio (GR) were calculated for a total of 50 dental students (30 women and 20 men) who participated in the study. The following measurements were obtained directly in the participant's mouth with a digital caliper: the mesiodistal and incisogingival dimensions of the maxillary central incisors, lateral incisors, and canines; the intercanine distance; and the smile width. The participants were photographed, and the smile width was also measured on the photographs. The MF1 and MF2 were each calculated twice, using both direct measurements and photographic measurements. The projected central incisor widths calculated using the MF1, MF2, and AF were compared among themselves and against the actual measurements using analysis of variance and Fisher test for multiple comparisons (α = 0.05). The EP and GR were analyzed using descriptive statistics. There was a statistically significant difference between all of the widths projected by the formulas and the actual widths of the central incisors (P < 0.05). Whether calculated from a direct or a photographic measurement, the incisor widths projected by the MF1 and MF2 were statistically similar to each other (P > 0.05). The EP values were similar to those reported in the literature. Only 2% of the participants had an incisor width ratio (central incisor/lateral incisor) that matched the GR of 1.618, while 86% fell within the range of 1.2 to 1.4. Overall, the proportions calculated with the MF1, MF2, AF, EP, and GR did not exactly match the actual dimensions of natural teeth. The formulas and the proportions available in the literature can assist in esthetic planning, but the individual characteristics of each patient and expertise of the dentist should guide treatment for each case.

3D facial mask for facial asymmetry diagnosis.

Objectives: Facial asymmetry is a common problem seen in orthodontic clinics that may affect patient esthetics. In some instances, severe asymmetry that affects patient esthetics may cause psychological issues. An objective method is therefore required to help orthodontists identify asymmetry issues. Materials and methods: We used three-dimensional (3D) facial images and landmark-based anthropometric analysis to construct a 3D facial mask to evaluate asymmetry. The landmark coordinates were transformed using a symmetric 3D face model to evaluate the efficacy of this method. Patients with facial asymmetry were recruited to conduct mirror and overlap analysis to form color maps, which were used to verify the utility of the novel soft tissue landmark-based method. Results: The preliminary results demonstrated that the asymmetry evaluation method had a similar response rate compared to diagnosis using mirror and overlap 3D images, and could therefore identify 3D asymmetry problems. Conclusions: By using 3D facial scans and 3D anthropometric analysis, we developed a preliminary evaluation method that provides objective parameters to clinically evaluate patient facial asymmetry and aid in the diagnosis of asymmetric areas. Clinical relevance: This study presents a novel facial asymmetry diagnostic method that has the potential to aid clinical decisions during problem identification, treatment planning, and efficacy evaluation.

Treatment of excessive gingival display using conventional esthetic crown lengthening versus computer guided esthetic crown lengthening: (a randomized clinical trial).

BACKGROUND: Surgical guides have been proposed in an attempt to reach more predictable outcomes for esthetic crown lengthening. The objective of the present study was to evaluate the effectiveness of esthetic crown lengthening using 3D-printed surgical guides in the management of excessive gingival display due to altered passive eruption type 1B. MATERIALS AND METHODS: Sixteen patients diagnosed with altered passive eruption type 1B, were divided into two groups. In the control group, the procedure was carried out conventionally, and in the study group, a dual surgical guide was used. The parameters of wound healing (swelling, color, probing depth, bleeding index, and plaque index), pain scores, gingival margin stability, and operating time were assessed at 1 week, 2 weeks, 3 months, and 6 months postoperatively. RESULTS: There was no statistically significant difference in terms of wound healing, pain scores, and gingival margin stability between both groups at different time intervals (P = 1), however, there was a statistical difference between both groups in terms of operating time with the study group being significantly lower (P < 0.001). CONCLUSION: Digitally assisted esthetic crown lengthening helps shorten the operating time and reduces the possibility of human errors during the measurements. This will be useful in helping practitioners achieve better results. PRACTICAL IMPLICATIONS: The conventional method remains to be the gold standard. However, shorter operating time and lower margins for errors will help reduce costs as the chair side time is reduced as well as the possibility for a second surgery is lower. This will improve patient satisfaction as well.

Demographic review of aesthetic surgery for patients with facial palsy.

BACKGROUND: This study analyzed the demographic characteristics of patients with facial palsy who were treated using either dynamic or static procedures. This study aimed to compare the frequency of procedure implementation and age distribution between the two groups. METHODS: This study retrospectively analyzed the medical records of patients treated for facial palsy at a single institution from 2014 to 2022. Among cases included in our study, dynamic procedures involved cross-facial nerve graft and latissimus dorsi or gracilis muscle flap transfer. Static procedures included gold weight insertion, canthopexy, browlift, and thread lift/static slings. RESULTS: Among the 31 patients included in our study, eight (25.8%) incorporated dynamic techniques, and the average age of patients was 44.75 years (range, 24-68 years) with a male to female ratio of 1:4. The remaining 23 patients (74.2%) underwent a static procedure, of which the average age was 59.17 years (range, 23-81 years) which was statistically significantly higher than the average age of 44.75 of dynamic patients (p= 0.013). Regarding the timing of treatment after diagnosis, no patient underwent dynamic procedures more than 20 years after initial diagnosis. A greater diversity in the timing of treatment was observed in the static group. All patients who underwent dynamic procedures were treated using static procedures during the study period. CONCLUSION: Because aesthetics-based static techniques are typically quick outpatient procedures that can be performed under local anesthesia, our study shows that these are often preferred treatments for all age groups, especially for debilitated or older patients. Further research is required to investigate the long-term functional outcomes of these surgical techniques in a wider population of patients.

Enjoying art: an evolutionary perspective on the esthetic experience from emotion elicitors.

The ubiquity of human art prompted evolutionary psychologists to explore its origins as a potential adaptation to the environment. Here we focus on emotionally charged art and posit that affective affordances embedded into some artworks play a pivotal role in explaining why these artworks are enjoyed from an evolutionary perspective. Such features, recurring in various art forms, are interpreted as cues to the emotional state of others, enabling art consumers to engage in empathetic experiences and vicarious emotions. We explore the adaptive value of deriving pleasure from vicarious emotions, while also addressing the seemingly counterintuitive enjoyment of artworks that evoke negative emotions. We discuss the appreciation of vicarious emotions irrespective of their valence and maintain this appreciation to hold adaptive significance for three key reasons. Firstly, it aids art consumers in refining their interpretational schemes of internal states, potentially enhancing emotional regulation skills. Secondly, it contributes to a deeper understanding of the emotions of others, thereby fostering emotional intelligence and empathy. Lastly, the enjoyment of affectively charged artworks reinforces social cohesion by harmonizing the emotions of group members. This perspective provides a comprehensive framework for understanding the evolutionary underpinnings of the human capacity for art appreciation and emotional engagement.

Artificial Intelligence in Plastic Surgery: Analysis of Applications, Perspectives, and Psychological Impact.

Artificial intelligence (AI) is emerging as a promising tool in the field of plastic surgery, offering a wide array of applications that enhance surgical outcomes, patient satisfaction, and overall efficiency. This paper explores the utilization of AI, highlighting its various advantages and potential drawbacks. AI-driven technologies such as computer vision, machine learning algorithms, and robotic assistance facilitate preoperative planning, intraoperative guidance, and postoperative monitoring. These advancements enable precise anatomical measurements, personalized treatment plans, and real-time feedback during surgery, leading to improved accuracy and safety. Furthermore, AI-powered image analysis aids in facial recognition, skin texture assessment, and simulation of surgical outcomes, enabling enhanced patient consultations and predictive modeling. However, the integration of AI in plastic surgery also presents challenges, including ethical concerns, data privacy, algorithm biases, and the need for comprehensive training among healthcare professionals. Additionally, the reliance on AI systems may potentially lead to over-reliance or reduced surgeon autonomy, necessitating careful validation and continuous refinement of these technologies. Despite these challenges, the synergistic collaboration between AI and plastic surgery holds great promise in advancing clinical practice, fostering innovation, and ultimately benefiting patients through optimized esthetic and reconstructive outcomes.Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266 .

Establishment of a 3D esthetic analysis workflow on 3D virtual patient and preliminary evaluation.

BACKGROUND: In esthetic dentistry, a thorough esthetic analysis holds significant role in both diagnosing diseases and designing treatment plans. This study established a 3D esthetic analysis workflow based on 3D facial and dental models, and aimed to provide an imperative foundation for the artificial intelligent 3D analysis in future esthetic dentistry. METHODS: The established 3D esthetic analysis workflow includes the following steps: 1) key point detection, 2) coordinate system redetermination and 3) esthetic parameter calculation. The accuracy and reproducibility of this established workflow were evaluated by a self-controlled experiment (n = 15) in which 2D esthetic analysis and direct measurement were taken as control. Measurement differences between 3D and 2D analysis were evaluated with paired t-tests. RESULTS: 3D esthetic analysis demonstrated high consistency and reliability (0.973 < ICC < 1.000). Compared with 2D measurements, the results from 3D esthetic measurements were closer to direct measurements regarding tooth-related esthetic parameters (P<0.05). CONCLUSIONS: The 3D esthetic analysis workflow established for 3D virtual patients demonstrated a high level of consistency and reliability, better than 2D measurements in the precision of tooth-related parameter analysis. These findings indicate a highly promising outlook for achieving an objective, precise, and efficient esthetic analysis in the future, which is expected to result in a more streamlined and user-friendly digital design process. This study was registered with the Ethics Committee of Peking University School of Stomatology in September 2021 with the registration number PKUSSIRB-202168136.

Evaluation of the External Soft Tissue Changes Following the Correction of Class II Skeletal Malocclusion in the Adolescence Period Using Removable and Fixed Functional Appliances: A Systematic Review and Meta-Analysis.

In this systematic review, we aimed to assess the current evidence regarding the effectiveness of functional treatment with both removable and fixed appliances to normalize the external soft tissue for skeletal class II adolescent individuals. We performed a broad electronic search to retrieve relevant studies from nine databases to identify randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that investigated soft tissue changes following functional treatment and evaluated the changes using 2D lateral cephalometric radiographs and 3D-optical surface laser scanning. A total of three RCTs and eight CCTs were included. Ages ranged from 11 to 16 years with the fixed functional appliances, and from eight to 12 years with the removable ones, including 689 skeletal class II patients. Version 2 of Cochran's risk-of-bias (RoB2), and the risk of bias in non-randomized studies of interventions (ROBIN-I) were used to assess the risk of bias for the included papers. Of the 11 eligible studies, three studies were included in the meta-analysis to assess the upper and lower lip position in relation to the E-line (Ricketts's aesthetic line) in addition to the nasolabial angle. The meta-analysis showed that the upper lip retracted after functional treatment with Twin-block in relation to E-line (mean difference (MD) = -1.93; 95% CI: -2.37, -1.50; p < 0.00001; χ² = 5.43; p = 0.07; I2 = 63%), while the lower lip position did not change after functional treatment with Twin-block in relation to E-line (MD = 0.03; 95% CI: -0.56, 0.61; p = 0.92; χ² = 1.74; p = 0.42; I2 = 0%). The nasolabial angle increased after Twin-block treatment (MD = 5.75; 95% CI: 4.57, 6.93; p < 0.00001; χ² = 6.77; p = 0.03; I2 = 70%). The mentolabial angle and Z-angle also increased after functional therapy, where the facial convexity angle decreased, regardless of the functional devices used. On the other hand, using the 3D-optical surface laser scanning showed that the upper lip length and the commissural width did not change following therapy, but the lower lip increased in length, as well as the total face height. More high-quality RCTs are required to obtain accurate evidence in this field.

Dental implant placement with simultaneous localized ridge augmentation using L-shaped titanium mesh in the esthetic zone: a case report.

The aim of this case report is to illustrate a successful technique for dental implant placement in the esthetic zone using simultaneous localized ridge augmentation with L-shaped titanium mesh. A 35-year-old patient presented with a single missing tooth in the esthetic zone requiring dental implant placement. The treatment plan was made to place a dental implant in conjunction with a guided bone regeneration procedure using a prefabricated L-shaped titanium mesh. The procedure achieved successful reconstruction of the deficient ridge, providing ample volume and contour for implant placement. Implant osteointegration was achieved, resulting in a satisfactory functional and esthetically pleasing outcome. The use of L-shaped titanium mesh offers superior stability and biocompatibility, ensuring optimal support and containment of graft material. This case report highlights the feasibility and clinical effectiveness of dental implant placement with simultaneous localized ridge augmentation using L-shaped titanium mesh in the esthetic zone. Further studies are warranted to assess the long-term success and esthetic outcomes of this technique.

Comparative Evaluation of Horizontal Lip Position With Ricketts Esthetic Plane in Preschool and School-Going Children of Bankura, West Bengal: A Craniofacial Anthropometric Study.

Introduction The horizontal lip position and esthetic plane are two important parameters to define facial beauty, and these factors are always given importance in children undergoing fixed orthodontic therapy. The purpose of this study was to evaluate horizontal lip position in primary and mixed dentition children with class I occlusion and to analyze its association with gender among preschool and schoolchildren of villages in the Bankura district in West Bengal. Materials and methods Researchers screened 437 children for the study and selected those who met the inclusion criteria. A total of 407 children were segregated: 201 children aged three to five years with the flush terminal plane and mesial step in primary teeth and 206 children aged seven to eleven years with class I occlusion in mixed dentition were selected from schools in villages in Bankura district, West Bengal, India. The subjects were instructed to hold the head in the natural head position by looking straight, and points were marked on the nose and chin tip, respectively. A metallic ruler was placed from nose to chin, representing Rickett's esthetic line. The horizontal lip distance to the esthetic plane of both upper and lower lips was measured as a linear distance from the most anterior part of the lip to the metallic ruler. The data were recorded, compared with gender, and statistically analyzed using the Chi-square test using the Statistical Package of Social Sciences software (SPSS version 19.0, 2015, IBM Corp., Armonk, NY). Results The most prevalent horizontal lip distance for both upper and lower lips to the esthetic line for primary and mixed dentition in the Bankura region of West Bengal was category I, where the lip is seen beyond the E plane, followed by category II, where lips are at a horizontal distance in the range of 0-1.5 mm from the esthetic line. A significant correlation of lip position with Rickets aesthetic plane was also illustrious with gender in primary dentition, but a non-significant association with gender was noted in mixed dentition. Conclusion Children with class I occlusion from the Bankura district of West Bengal showed a higher percentage of lip position beyond the esthetic plane in both primary and mixed dentition, which is not in line with the inference of Ricketts's studies on the Caucasian population. There is a definite association between gender and horizontal lip distance in Ricketts esthetic plane. Protrusive upper lips were seen more in males, and retrusive lips were seen more in females. Clinical significance  The horizontal lip position with reference to Ricketts esthetic plane has been documented in the literature for adults and teens undergoing fixed orthodontic treatment. However, there is no study done to define these measurements in preschool and school-going children, which can assist in determining future esthetic profiles and in preparing a protocol for early age interceptive orthodontics along with aesthetic rehabilitation of the anterior area of the mouth.

SEM Evaluation of the Marginal Gap of Zirconia-Reinforced Lithium Silicate Full Crowns and the Effect of Post Crystallization: An In Vitro Study.

BACKGROUND: This study compared the influence of crystallization on marginal gap adaptation by using computer-aided design and manufacturing (CAD-CAM) for producing monolithic zirconia-reinforced lithium silicate (ZLS) ceramic crowns. METHODS: A total of 25 plastic teeth were scanned using a Primescan intra-oral scanner (IOS), and ZLS crowns were ground. For each unit (abutment and crown), the marginal gap was evaluated pre crystallization and post crystallization at four regions of interest through the use of a scanning electron microscope (SEM). To compare the marginal gap between the two groups, a Kolmogorov-Smirnov test performed on the study variables indicated a normal distribution (p > 0.05) followed by paired samples T-tests (α = 0.0005). RESULTS: After crystallization, there were significantly higher circumferential marginal gaps (CMGs) for all four surfaces (distal (p = 0.0005), mesial (p = 0.0005), palatal (p = 0.0005), and buccal (p = 0.0005)). The total mean marginal gap (MMG) revealed a significantly higher result for the post-crystallization group (79.82 ± 7.86 µm) compared to the pre-crystallization group (24.25 ± 5.49 µm). CONCLUSIONS: The post-crystallization group showed a significantly higher marginal gap compared to the pre-crystallization group in all parameters, but both groups were in the clinically accepted threshold (<120 microns). In terms of the marginal gap, it is arguable whether to carry out post-crystallization for CELTRA® DUO crowns and achieve better mechanical properties but significantly increase the marginal gap.

Precise tooth design using deep learning-based templates.

OBJECTIVES: In prosthodontic procedures, traditional computer-aided design (CAD) is often time-consuming and lacks accuracy in shape restoration. In this study, we combined implicit template and deep learning (DL) to construct a precise neural network for personalized tooth defect restoration. METHODS: Ninety models of right maxillary central incisor (80 for training, 10 for validation) were collected. A DL model named ToothDIT was trained to establish an implicit template and a neural network capable of predicting unique identifications. In the validation stage, teeth in validation set were processed into corner, incisive, and medium defects. The defective teeth were inputted into ToothDIT to predict the unique identification, which actuated the deformation of the implicit template to generate the highly customized template (DIT) for the target tooth. Morphological restorations were executed with templates from template shape library (TSL), average tooth template (ATT), and DIT in Exocad (GmbH, Germany). RMSestimate, width, length, aspect ratio, incisal edge curvature, incisive end retraction, and guiding inclination were introduced to assess the restorative accuracy. Statistical analysis was conducted using two-way ANOVA and paired t-test for overall and detailed differences. RESULTS: DIT displayed significantly smaller RMSestimate than TSL and ATT. In 2D detailed analysis, DIT exhibited significantly less deviations from the natural teeth compared to TSL and ATT. CONCLUSION: The proposed DL model successfully reconstructed the morphology of anterior teeth with various degrees of defects and achieved satisfactory accuracy. This approach provides a more reliable reference for prostheses design, resulting in enhanced accuracy in morphological restoration. CLINICAL SIGNIFICANCE: This DL model holds promise in assisting dentists and technicians in obtaining morphology templates that closely resemble the original shape of the defective teeth. These customized templates serve as a foundation for enhancing the efficiency and precision of digital restorative design for defective teeth.

The association between Dental Fluorosis and COL1A2 gene polymorphism among a Tunisian Population.

Dental fluorosis (DF) is a prevalent developmental defect of tooth enamel caused by exposure to excessive fluoride, with the severity dependent on various factors. This study aimed to investigate the association between DF and a specific genetic polymorphism (rs412777) in the COL1A2 gene among a Tunisian population. A case-control study was conducted from July to November 2022, involving a total of 95 participants including 51 cases and 44 controls. Dental examinations and genetic analysis were performed to assess the relationship between the COL1A2 gene polymorphism and DF.The results of allelic distribution revealed that A allele carriers were significantly protected against (DF) when compared to those with the C allele (C vs. A, p = 0.001; OR = 0.375 (0.207-0.672)). This suggests a strong correlation between the presence of the C allele and the risk of developing DF. Additionally, significant association between the CC genotype of rs412777 and an increased risk of DF was found under both codominant and dominant genetic models (P = 0.002 and P < 0.001 respectively).The findings suggest that genetic predisposition plays a relevant role in the development of DF. Further research is needed to explore the potential use of genetic markers for DF and their implications for public health. This study provides the first insights into the genetic factors associated with DF in the Tunisian population, contributing to our understanding of this prevalent dental condition.

Enhancing root coverage and esthetic outcomes in isolated gingival recession using orthodontic intervention and lateral closed tunnel technique: An interdisciplinary prospective case series.

BACKGROUND: Gingival recession (GR) in malposed tooth in association with bone dehiscence and/or fenestration poses a challenge for successful root coverage treatment. Lateral closed tunnel (LCT) technique is particularly useful in isolated GR in mandibular anterior region, where the shallow vestibular depth prevents tension-free coronal mobilization of tissues. METHODS: Twenty patients with GR associated with tooth malposition were treated using a combined orthodontic-periodontic approach with a torquing auxiliary spring followed by LCT technique. RESULTS: The two techniques resulted in a combined recession depth reduction from 3.75 ± 1.14 mm to 0.40 ± 0.50 mm at the end of 6-month study period. The orthodontic intervention led to an increase in labial marginal bone levels, as assessed through cone beam computed tomography (CBCT), while the LCT achieved closure of residual recession defect. Also, an increase of keratinized tissue width from 0.81 ± 0.88 mm at baseline to 3.30 ± 0.67 mm at 6 months was achieved. Mean root coverage percentage (MRC%) of 91.40% + 10.25% was seen, with 11 out of 20 sites (55%) showing complete root coverage (CRC). CONCLUSIONS: Single tooth orthodontic repositioning followed by LCT technique proved effective in successfully managing isolated recession defects in the mandibular anterior gingival region, which often presents challenging mucogingival conditions. The precise single tooth repositioning resulted in labial marginal bone augmentation, while the LCT surgical approach allowed residual defect closure. KEY FINDINGS: Why are these cases new information? Correction of single tooth malposition is achieved before recession coverage treatment to achieve a favorable environment for graft uptake. The reduction in denuded root surface along with the bone remodeling results in increasing the ratio of vascular to avascular region, thus improving the overall prognosis of the treatment. What are the keys to successful management of these cases? The lateral closed tunnel technique involves creating a mucoperiosteal tunnel to close the recession site. Precision is crucial to avoid damage to surrounding tissues. The recipient site should be wider than the width of recession to improve graft vascularity. What are the primary limitations to success in these cases? Limitations may arise when dealing with complex cases, such as multiple teeth involvement or teeth with significant vertical or horizontal bone loss.

Comparative Assessment of Marginal Micro Leakage of Different Esthetic Restorative Materials Used on Primary Teeth: An In-vitro Study.

AIM: The aim of the current investigation was to evaluate the marginal microleakage of various esthetic restorative materials applied to primary teeth. MATERIALS AND METHODS: A total of 75 noncarious primary molars that were removed for orthodontic intervention and teeth nearing exfoliation were chosen. One millimeter (mm) above the cementoenamel junction, on the buccal surface of the teeth, Class V cavities were prepared. William's graded periodontal probe was used to standardize cavity preparation on all teeth. 3 mm was the cavity's length, 2 mm in width, and 2 mm in depth. The teeth were then divided into three groups (25 samples in each group) according to the type of esthetic restorative material used. Group I: Resin-modified glass ionomer cement, Group II: Ormocer, Group III: Giomer. The samples underwent 500 cycles of thermocycling, with an immersion time of 60 seconds and a well time of 15 seconds, between 5 and 55°C. The samples were submerged in methylene blue dye for 24 hours at room temperature and dried. The samples were then divided into sections and examined with a stereomicroscope. Data was recorded and statistically analyzed. RESULTS: The least marginal microleakage was found in the ormocer group (1.22 ± 0.01) followed by resin-modified glass ionomer cement group (1.31 ± 0.07) and the giomer group (1.78 ± 0.03). There was a highly statistically significant difference found between resin-modified glass ionomer cement group and the ormocer group, resin-modified glass ionomer cement group and giomer group. And no significant difference was found between the ormocer group and the giomer group. CONCLUSION: The present study concluded that there was some amount of microleakage in primary teeth in all restorative materials examined in this in-vitro investigation. However, the marginal sealing ability of ormocer was found highest compared to resin-modified glass ionomer cement and Giomer materials. CLINICAL SIGNIFICANCE: The primary reason dental restorations fail, particularly in Class V cavities, is microleakage since the margins of these restorations are typically found in the dentin or cementum. Assessing microleakage is a crucial step in determining the marginal integrity of restorative materials. Developing methods and resources that reduce the adverse effects caused by the restorative marginal seal failing would benefit from this. How to cite this article: Al Ghwainem A, Alqarni AS. Comparative Assessment of Marginal Micro Leakage of Different Esthetic Restorative Materials Used on Primary Teeth: An In-vitro Study. J Contemp Dent Pract 2024;25(1):58-61.