Dental Restorations Research Articles

Comparing Properties of Urethane Dimethacrylate (UDMA) Based 3D Printing Resin Using N-Acryloylmorpholine (ACMO) and Triethylene Glycol Dimethacrylate (TEGDMA) Separately as Diluents

The purpose of our study reported here was to investigate the performance of urethane dimethacrylate (UDMA) based 3D printable resin systems when using N-acryloylmorpholine (ACMO) as a diluent. UDMA was mixed with ACMO with a series of mass ratios, and the viscosity, degree of double bond conversion (DC), volumetric shrinkage (VS), flexural strength (FS), and modulus (FM), water sorption (WS) and solubility (SL), hardness, wear resistance, and accuracy thereof the obtained resin systems were studied and compared with triethylene glycol dimethacrylate (TEGDMA) diluted resin systems. The results showed that the ACMO diluted resin systems had a higher viscosity than the TEGDMA diluted resin systems with the same diluent concertation. Replacing TEGDMA with ACMO showed improvement in DC, VS, FS and FM in dry conditions, and the accuracy of 3D printable resin systems. However, the reduction of water resistance and wear resistance would limit the application as dental restoration materials of ACMO diluted 3D printable resin systems. With the aim to improve the water resistance and wear resistance of ACMO diluted 3D printable resin systems, we suggest further research concerned about using a new base resin and optimizing resin composition should be undertaken.

Neurobehavioral, neurotransmitter and redox modifications in Nauphoeta cinerea under mixed heavy metal (silver and mercury) exposure

Heavy metals are encountered in nature, and are used in several human endeavors, including in dental fillings. It is well known that the safety of metals depends on their chemical form, as well as the dose and route through which biological systems are exposed to them. Here, we used the Nauphoeta cinerea model to examine the mechanism by which salts of the heavy metals used in dental fillings – silver and mercury – exert their neurotoxicity. Nymphs exposed to heavy metals presented with reduced motor and exploratory abilities as they spent more time immobile, especially in the periphery of a novel object, and covered less distance compared with control nymphs. Exposure to AgNO3 and HgCl2 also exacerbated levels of oxidative stress markers (MDA & ROS) and the neurotransmitter regulators – AChE and MAO, while reducing antioxidant activity markers, both in biochemical (thiol & GST) and RT-qPCR (TRX, GST, SOD, Catalase) examinations, in neural tissues of the cockroach. The observed disruptions in neurolocomotor control, synaptic transmission and redox balance explain how heavy metal salts may predispose organisms to neurological disorders.

Risk of thromboembolism after intraosseous implantation of metallic devices with extracellular vesicles derived from multipotent stromal cells: preliminary results

Background. New implantation methods are of great importance due to the development of endoprostheses in traumatology and orthopedics, restorative medicine and dentistry. Equally important is the early detection and description of the implant-associated complications. The aim of the study is to find and describe thrombi and emboli in the heart and lungs formed after experimental implantation of metallic devices in the peripheral part of limb using extracellular vesicles of mesenchymal stromal cells. Methods. Outbred rabbits of both genders at the age from 4 to 6 months and of weight from 3 to 4 kg underwent experimental implantation. The study enrolled 57 species in total. They were divided into two groups: 30 animals underwent implantation of metallic devices using extracellular vesicles of mesenchymal stromal cells (EV MSCs), 27 — without their use. The rabbits’ hearts and lungs were studied by light microscopy methods at different stages after integration of screw titanium implants into the proximal condyle of the tibia using EV MSCs. Results. After implantation of metallic devices into the proximal condyle of the tibia, we detected fibrin, detritus and even the red bone marrow structures (various blast forms of hematopoietic cells: megakaryocytes, cells of the erythroid and myeloid lineages) in the right cavities of the heart. In the pulmonary arteries, we also found thrombi and emboli, which either led to the obliteration of the involved vessel or to gradual lysis, not disappearing completely within 10 days of follow-up. Conclusions. After intraosseous implantation of the metallic devices, there is an embolism risk in the right atria and ventricle of the heart and the pulmonary arteries and veins due to the debris migration with the bloodstream from the surgery site. At the same time, one cannot exclude a thrombotic risk in the heart and pulmonary arteries as a reaction to the presence of detritus. It is advisable to take measures aimed at preventing both debris releasing into the bloodstream and pulmonary embolism during any implantations into the bone tissues, even of relatively small devices. Using EV MSCs to affect the implant engraftment processes has no significant effect on the severity and frequency of thromboembolic complications.

Biomonitoring Study of Toxic Metal(loid)s: Levels in Lung Adenocarcinoma Patients.

Lung cancer is a leading cause of cancer deaths worldwide. The aim of this study was to investigate heavy metal(loid)s (Cd, Pb, Hg, Cr, Mn, Mo, Ni, and As) in lung cancer patients in order to elucidate their role as lung cancer environmental risk factors. Sixty-three patients of both sexes with adenocarcinoma stage IIIB or IV were enrolled in this research. The heavy metal(loid) urine concentrations were measured using ICP-MS. Arsenic was quantified above 10 μg/L in 44.44% of the samples. Nickel urinary concentrations above the ToxGuide reference levels were found in 50.79% of the samples, while lead was quantified in 9.52% of the urine samples. The urinary chromium levels were above the mean ToxGuide levels in 41.27% of the patients and were significantly higher in men in comparison with women (p = 0.035). The chromium urinary concentrations were positively associated with the CRP serum levels (p = 0.037). Cadmium was quantified in 61.90% of the samples with levels significantly higher in females than in males (p = 0.023), which was associated with smoking habits. Mercury was measured above the limit of quantification in 63.49% of the samples and was not associated with amalgam dental fillings. However, the Hg urinary concentrations were correlated positively with the ALT (p = 0.02), AST (p < 0.001), and GGT (p < 0.001) serum levels. In 46.03% of the samples, the Mo concentrations were above 32 μg/L, the mean value for healthy adults according to the ToxGuide, and 9.52% of the patients had Mn levels higher than 8 μg/L, the reference value for healthy adults based on ToxGuide data. The obtained results are preliminary, and further studies are needed to have a deeper insight into metal(loid) exposure's association with lung cancer development, progression, and survival prediction.

Finite Element Analysis and Clinical Applications of Transverse Post for the Rehabilitation of Endodontically Treated Teeth.

Introduction The preservation of tooth structure during cavity preparation is crucial for maintaining tooth strength and longevity of restorations. The biomechanical behavior of teeth, especially those with mesio-occlusal-distal (MOD) cavity preparations, is significantly affected by the extent of cavity preparation and the type of restorative treatment employed. The aim of the current study was to evaluate and analyze the stress distribution seen in the mandibular molar with MOD cavity when restored with transverse post, using finite element analysis (FEA). Materials and methodology FEA was utilized to evaluate stress distribution in an endodontically treated mandibular first molar with MOD cavity preparation, restored using a transverse post and composite restoration. Three-dimensional models incorporating the tooth and the surrounding structures, along with the transverse post and composite restoration, were constructed based on known biomechanical properties. After meshing the models, loads were defined on the buccal and lingual cusps with a constant value of 600N and at an angle of 45 degrees. Preprocessing involved model preparation followed by postprocessing to obtain results representing the degree and type of stress distribution. Results FEA simulations revealed the distribution of stress within the tooth structure under functional occlusal forces. The transverse post system effectively reinforced the tooth by deflecting incident forces and providing uniform stress distribution. von Mises stresses were analyzed to assess the likelihood of material failure. The distribution of the stress in the restored tooth model was comparable to that seen in the intact model. Conclusion Transverse postalong with composite restoration provides a conservative and cost-effective alternative to fullcoverage crowns while providing a functional and aesthetic outcome. Further research and clinical studies are warranted to validate these findings and optimize the clinical application of transverse post systems in restorative dentistry.

Preserving the vital pulp in the permanent dentition: a simplified guide to indirect pulp capping

This article discusses vital pulp therapy in the adult dentition and describes two cases where a different strategy for caries removal has been used followed by dressing with a contemporary material and tooth restoration on the same visit. A simplified guide for best practice is given. CPD/Clinical Relevance: Vital pulp therapy is an important procedure that requires clinical skill and can be undertaken in general practice.

Inequalities in children’s tooth decay requiring dental extraction under general anaesthetic: a longitudinal study using linked electronic health records

BackgroundDental extraction under general anaesthetic (DGA) is the most severe and irreversible dental treatment for childhood tooth decay. We investigated inequalities in DGA in an ethnically diverse, disadvantaged school-age population...

Optimization and ranking of dental restorative composites by ENTROPY‐VIKOR and VIKOR‐MATLAB

AbstractResin‐based composites, now the most prevalent material for restorative dental treatments, are available in a multitude of types. Next‐generation composites are designed to be bio interactive, solving issues such as secondary caries and mechanical failures, thus prolonging the restoration lifespan. To facilitate the discrimination of the bio interactive composite's performance and the identification of the optimal composition, we tested the VIKOR method for multi‐criteria decision‐making analysis. This study encompassed 12 performance parameters and 5 experimental dental composites. We measured density, void content, water sorption, water solubility, polymerization shrinkage, depth of cure, degree of conversion, hardness, compressive strength, and surface roughness as performance parameters, and we tested a conventional BisGMA‐TEGDMA resin blend filled with yttria‐stabilized zirconia (20 wt.%) and tricalcium phosphate. The alignment between computational methods and MATLAB‐based calculations validated the robustness of the assessment, verifying the significance of the conclusions drawn from this comprehensive analysis. Both methods (ENTROPY‐VIKOR and VIKOR‐MATLAB) ranked TZC0 as the top composite. This research provided a comprehensive understanding of the complex relationship between material composition, performance attributes, and optimization strategies in dental restorative composites, offering valuable insights for future advancements in restorative dentistry.

Mapping the Dental Applications of Nanosilver Fluoride: A Narrative Review.

The main objective of this paper is to discuss the current progress in the field of dentistry and highlight the aspects regarding silver nanoparticle incorporation, emphasizing the properties, applications, and advantages of nanosilver fluoride (NSF) that it brings to dentistry. An extensive electronic scientific search was conducted on published articles in various databases, such as Medline (PubMed), CENTRAL (Cochrane), Scopus, and Web of Science, using the search terms AgNPs, nano dentistry, caries prevention, and oral health. Further brief communications, randomized controlled trials (RCT), in vitro research, and animal studies written in English were also considered. Case reports, editorial reviews, and opinion letters were excluded from the first phase of our research. Pertaining to various kinds of literature reviews in journals, around 345 articles were retrieved. After screening, about 28 articles met all the selection criteria, focusing on NSF for the contemporary management of dental caries, emphasizing microinvasive therapeutic methods that can successfully halt the progression of caries at the initial level and minimize the loss of sound tooth structure. Due to its exceptional properties and wide range of clinical applications, AgNPs incorporated in fluoride may be employed as an effective, affordable, and improved anticaries agent that brings about superior enhancements in the fields of orthodontics, restorative dentistry, and pediatric and preventive dentistry. Thimmaiah C, Thomas NA, Baskaradoss JK, et al. Mapping the Dental Applications of Nanosilver Fluoride: A Narrative Review. Int J Clin Pediatr Dent 2024;17(7):833-837.

Clinical and Radiographic Evaluation of Diode and Er,Cr:YSGG Lasers as an Alternative to Formocresol and Sodium Hypochlorite for Pulpotomy Techniques in Primary Molars: A Randomized Controlled Clinical Trial.

Background Pulpotomy treatment is one of the vital pulp therapies that can play a major role in the preservation of primary teeth until their natural exfoliation. The objective of this current clinical trial was to assess the clinical and radiographical success of diode and Er,Cr:YSGG lasers as a viable alternative to formocresol (FC) and sodium hypochlorite in the primary molar pulpotomies. Materials and methods Sixty primary molars were selected and randomly allocated to four groups. All treatment groups followed the same clinical protocol, except for the techniques used for hemostasis of the pulpotomy sites. In group A, hemostasis was achieved by applying a 1:5 dilution of FC solution, whereas in group B, 3% sodium hypochlorite was applied to achieve hemostasis. In group C, exposure to a diode laser of 940 nm was performed, whereas for group D, erbium laser irradiation with Er,Cr:YSGG laser of 2,780 nm was employed to achieve hemostasis. Radicular pulp stamps were covered with a 2 mm layer of mineral trioxide aggregate (MTA) paste. Stainless steel crowns were utilized for the final restorations of the primary teeth. The clinical and radiographic outcomes were evaluated at the six- and 12-month follow-up intervals. The investigation was registered with the ClinicalTrials.gov Protocol and Registration System (ID: NCT06002646). Results The overall clinical and radiographic success rates of pulpotomy were 92.3% for FC, 89% for sodium hypochlorite, 98.3% for a diode laser, and 98.7% for Er,Cr:YSGG lasers. There were no statistically significant differences among the four groups (p > 0.05). Conclusions Both the diode and Er,Cr:YSGG lasers showed outcomes comparable to those of FC and sodium hypochlorite. Therefore, they could be promising alternatives to primary tooth pulpotomies.

Hall technique in children: A cross-sectional survey among Indian pedodontists

Background: Stainless steel crowns are considered to be a practicable alternative in the restoration of carious primary tooth. This study was done to assess Indian pediatric dentists’ knowledge, attitude, and practice of this technique and related factors with the use of the Hall technique (HT). Methods: A well-structured preused online questionnaire was sent to pedodontists practicing in India through various social media groups and emails. Descriptive statistics were used to characterize survey responses. A Chi-square test was employed to check the distribution of responders using the HT. Statistically P &lt; 0.05 or less was considered statistically significant. Results: A total of 210 pedodontists participated in this survey. 66.20% of the participants have &lt;10 years’ experience; majority of the participants are in private clinical practice in urban areas. 97.14% of Indian pedodontists are aware of HT, and 22.54% regularly practice HT. 37% of the participants has apprehension of change in vertical dimension due to ooclusal changes and 35% of the participants fear of pulpal damage due to Hall technique. A significant number of pedodontists who have passed master of dental surgery (MDS) in pediatric and preventive dentistry &lt;10 years ago (P = 0.034*), those from academic institutions (P = 0.048*), and those from urban areas (P = 0.045*) practice HT. Conclusion: A substantial proportion of the respondents were familiar with the HT, but considerably less number of participants use it regularly in clinical practice. There is a scope for increased practice of this technique so that the children in need of treatment of multisurface carious lesions can benefit.

Evaluation of Different Materials used in Prosthetic of Dental Implants: A Comparitive Study

ABSTRACT Background: Implant-supported prostheses have become a cornerstone of restorative dentistry, offering patients an effective solution for missing teeth. However, the choice of material for these prostheses can significantly impact their maintenance requirements and long-term success. Methods: Patient records of individuals who received implant-supported prostheses over a 2-year period were reviewed. Data on maintenance interventions, including adjustments, repairs, and replacements were collected and analyzed for metal alloys, ceramics, and composites. Results: Metal alloys exhibited slightly higher average numbers of adjustments compared to ceramics and composites. Ceramics required a higher mean number of repairs and replacements compared to other materials. Statistical analysis revealed significant differences in adjustment frequency between metal alloys and ceramics (P = 0.047), but no significant differences were observed for repairs or replacements. Conclusion: The outcomes imply that material choice plays a significant role in the maintenance requirements of implant dental prostheses. While metal alloys may require more frequent adjustments, ceramics and composites may necessitate more repairs and replacements over time. Clinicians should consider these factors when selecting materials for implant prostheses and develop tailored maintenance protocols to optimize treatment outcomes.

Comparison of Different Implant Systems by Stress and Resistance of Prosthetic Screws: An Original Research

ABSTRACT Introduction: For the best possible clinical results, dental implant systems must have their biomechanical characteristics thoroughly evaluated. These systems are essential to restorative dentistry. The purpose of this study was to analyze the resistance and stress distribution of prosthetic screws across five distinct implant systems. Methods: The stress distribution on prosthesis screws was evaluated, and loading conditions were simulated using finite element analysis (FEA). To assess the screws’ resistance to torque forces, mechanical testing was done. Findings: Among the implant systems, there were notable differences in torque resistance and stress distribution. System A had the least amount of stress and the most torque resistance, whereas System E displayed the most stress and the least torque resistance. Conclusion: The results emphasize the significance of taking biomechanical characteristics into account when choosing implant systems for clinical usage, which has ramifications for patient care and treatment planning. Additional investigation concentrating on thorough clinical assessments is necessary to confirm these results and enhance treatment plans.

Fish scale-derived hydroxyapatite for alveolar ridge preservation.

Alveolar ridge resorption following tooth extraction poses significant challenges for future dental restorations. This study investigated the efficacy of fish scale-derived hydroxyapatite (FSHA) as a socket preservation graft material to maintain alveolar bone volume and architecture. FSHA was extracted from *Labeo rohita* fish scales and characterized using Fourier transform infrared (FTIR) analysis. In vitro, biocompatibility and osteogenic potential were assessed using Saos-2 human osteosarcoma cells. Cell viability, migration, and proliferation were evaluated using MTT and scratch assays. In vivo performance was assessed in a rat model, and FSHA was compared to a commercial xenograft (Osseograft) and ungrafted controls. Histological analysis was performed at 8-week post-implantation to quantify new bone formation. FTIR confirmed the purity and homogeneity of FSHA. In vitro, FSHA enhanced Saos-2 viability, migration, and proliferation compared to controls. In vivo, FSHA demonstrated superior bone regeneration compared to Osseograft and ungrafted sites, with balanced graft resorption and new bone formation. Histological analysis revealed an active incorporation of FSHA into new bone, with minimal gaps and ongoing remodeling. Approximately 50%-60% of FSHA was resorbed by 8 weeks, closely matching the rate of new bone deposition. FSHA stimulated more bone formation in the apical socket region than in coronal areas. In conclusion, FSHA is a promising biomaterial for alveolar ridge preservation, exhibiting excellent biocompatibility, osteogenic potential, and balanced resorption. Its ability to promote robust bone regeneration highlights its potential as an effective alternative to currently used graft materials in socket preservation procedures.

Mechanical properties and formulation of hydrophilic fiber and shrimp shell combination as a novel eco-friendly dental restoration material

This study evaluates the mechanical properties and formulation of dental restoration material comprised of cellulose acetate (CA) from water hyacinth and chitosan (C) from white shrimp shells. The research phases included extraction, formulation, functional group testing, antibacterial, toxicity, water absorption and solubility, compressive, shear, tensile, hardness, microleakage, thermal expansion, and shrinkage. The experimental data were analyzed using probit regression, one-way ANOVA, and Kruskal-Wallis test. The data showed that CA and C had microxyl and amine groups, could inhibit S. mutans, and were non-toxic. Composite resins were divided into nine formulations with different concentrations: F1 (1 % CA + 3 % C), F2 (1 % CA + 5 % C), F3 (1 % CA + 7 % C), F4 (3 % CA + 3 % C), F5 (3 % CA + 5 % C), F6 (3 % CA + 7 % C), F7 (5 % CA + 3 % C), F8 (5 % CA + 5 % C), and F9 (5 % CA + 7 % C). The F9 has mechanical strength close to the control group, with 113.33 μg/mm3 absorption, 80 μg/mm3 solubility, 32.67 Mpa compressive strength, 17.18 Mpa tensile strength, and no shrinkage. It shows that F9 has potential as an eco-friendly dental filling material. The present study completed the development of a formulation for a restoration material by combining water hyacinth fiber and shrimp skin chitosan. The outcomes of a comparative analysis of the mechanical properties of synthetic composite resins and water hyacinth fiber composites containing shrimp skin chitosan revealed that the F9 formulation (CA 5 % + C 7 %) exhibited the following fiber: absorption, compressive strength, tensile strength, hardness, and thermal expansion.

Effects of external staining on mechanical, optical, and biocompatibility properties of additively manufactured 3Y-TZP ceramic for dental applications

Three mole percent yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) ceramics are exemplary materials for dental restoration due to their high mechanical strength, fracture toughness, chemical endurance, and biocompatibility. Nevertheless, 3Y-TZP ceramics are opaque and their CAD/CAM manufacturing process may cause micro-cracks in conventional clinical practice. In this study, 3Y-TZP ceramic samples were prepared using vat photopolymerization, pre-sintering, external staining, and final high-temperature sintering. The microstructures, mechanical properties, optical properties, and cytotoxicity of the 3Y-TZP ceramic samples were investigated. The results indicate that with increasing Fe3+ concentration of staining solution from 0.1 mol/L to 0.3 mol/L and increasing staining time from 5 s to 30 min, the 3Y-TZP ceramic samples showed a tetragonal crystal structure of zirconia with densely packed grains and a slight increase in grain size. The flexural strength, Vickers hardness, and fracture toughness of 3Y-TZP ceramic samples stained in 0.1–0.3 mol/L Fe3+ solution for 5 s to 3 min were all greater than 665 MPa, 11.9 GPa, and 5 MPa m1/2, respectively, meeting the mechanical requirements for clinical application. Colorimetric analysis revealed a decrease in L* (black-white index) from 90.4 to 81.3, an increase in a* (green-red index) from −1.5 to 3.2, and an increase in b* (blue-yellow index) from 11.6 to 20.3, approximating the commercial VITA 3D-Master Shade Guide chromaticity. Furthermore, the 3Y-TZP ceramic samples exhibited a cell viability of 90% or higher toward L929 cells.

Comparative Evaluation of Disinfection Protocols for Dental Impressions in Prosthodontics.

In prosthodontics, dental impressions are essential for creating precise dental restorations. However, these impressions are susceptible to microbial contamination, which can pose a risk of infection to patients. Consequently, effective disinfection methods are crucial to prevent postoperative infections. This study aims to evaluate the effectiveness of various disinfection techniques for dental impressions used in prosthodontics. A total of 148 poured dental impressions were randomized into three disinfection groups: immersed in 0.5% sodium hypochlorite, 2% glutaraldehyde, or 0.2% chlorhexidine solution. The bacterial contamination was evaluated by direct colony-forming unit (CFU) counting, while the dimensional accuracy and surface detail duplication of each resin sample were determined as physical properties. Data were analyzed using SPSSversion 23.0 (IBM Corp., Armonk, NY). Either analysis of variance (ANOVA) with the option for post-hoc or non-parametric tests was used to investigate and compare the efficacy of the better disinfection protocols where the p-value was considered significant if less than 0.05. Glutaraldehyde showed the lowest mean CFU count (2.5 log10 CFUs), followed by sodium hypochlorite (3.2 log10 CFUs) and chlorhexidine (3.5 log10 CFUs). All disinfection protocols were able to significantly reduce microbial contamination when compared with the control group (p < 0.05). The results of the physical property assessment demonstrated acceptable dimensional accuracy in all tested protocols, with slight differences recorded between them regarding the reproduction of surface detail. More specifically, the mean dimensional deviation was in the range between 0.02 and 0.04 mm, while scores for surface detail reproduction ranged from 2 to 4. The ANOVA results revealed significant differences in microbial contamination levels (F(2, 145) = 5.72, p = 0.007) and dimensional accuracy (F(2, 145) = 3.45, p = 0.032) between the various disinfection protocols. This study enlightens the effective sterilization protocol to be adopted in prosthodontics for dental impressions. Glutaraldehyde was most effective in microbial reduction, while sodium hypochlorite and chlorhexidine were equally effective. Therefore, clinicians must be vigilant in assessing the type of microbial flora that can be encountered during prosthodontic procedures while choosing disinfection protocols for patient safety and quality of impressions.

Comparison of the Efficacy of Artificial Intelligence-Powered Software in Crown Design: An In Vitro Study

Introduction and aimsArtificial intelligence (AI) has been adopted in the field of dental restoration. This study aimed to evaluate the time efficiency and morphological accuracy of crowns designed by two AI-powered software programs in comparison with conventional computer-aided design software. MethodsA total of 33 clinically adapted posterior crowns were involved in the standard group. AI Automate (AA) and AI Dentbird Crown (AD) used two AI-powered design software programs, while the computer-aided experienced and computer-aided novice employed the Exocad DentalCAD software. Time efficiency between the AI-powered groups and computer-aided groups was evaluated by assessing the elapsed time. Morphological accuracy was assessed by means of three-dimensional geometric calculations, with the root-mean-square error compared against the standard group. Statistical analysis was conducted via the Kruskal–Wallis test (α = 0.05). ResultsThe time efficiency of the AI-powered groups was significantly higher than that of the computer-aided groups (P < .01). Moreover, the working time for both AA and AD groups was only one-quarter of that for the computer-aided novice group. Four groups significantly differed in morphological accuracy for occlusal and distal surfaces (P < .05). The AD group performed lower accuracy than the other three groups on the occlusal surfaces (P < .001) and the computer-aided experienced group was superior to the AA group in terms of accuracy on the distal surfaces (P = .029). However, morphological accuracy showed no significant difference among the four groups for mesial surfaces and margin lines (P > .05). ConclusionAI-powered software enhanced the efficiency of crown design but failed to excel at morphological accuracy compared with experienced technicians using computer-aided software. AI-powered software requires further research and extensive deep learning to improve the morphological accuracy and stability of the crown design.

The Effectiveness of Zirconia Crowns Versus Metal Crowns in Anterior Teeth: In vitro Study.

The selection between Zirconia crowns and metal crowns for anterior teeth restorations is pivotal in prosthodontics due to their distinct properties. However, a comprehensive investigation into their effectiveness in anterior tooth restorations is warranted. This in vitro study aimed to compare the effectiveness of Zirconia crowns and metal crowns in anterior teeth restorations. A total of thirty extracted human maxillary central incisors were prepared to receive crowns and randomly allocated into two groups: group A, zirconia crowns; and group B, metal crowns. The crowns were fabricated following standardized protocols and cemented onto the prepared teeth. Various tests, including fracture resistance, marginal adaptation, and color-matching assessment, were conducted on the samples. The mean fracture resistance of Zirconia crowns (Group A) was determined to be 320 N (SD ± 25), whereas it was 280 N (SD ± 30) for metal crowns (Group B). Marginal adaptation assessment revealed a mean gap width of 50 microns (SD ± 10) for Zirconia crowns and 70 microns (SD ± 15) for metal crowns. Evaluation of color matching showed a higher percentage of acceptable matches for Zirconia crowns compared to metal crowns. Zirconia crowns exhibited superior fracture resistance, marginal adaptation, and color matching in comparison to metal crowns for anterior teeth restorations. These findings advocate for Zirconia crowns as a more effective choice for restoring anterior teeth, offering both strength and esthetic appeal.

Antimicrobial activity of laser assisted endodontic therapy in disinfecting root canals.

Light Amplified Stimulated Emission of Radiation (LASER) is nowadays widely studied regarding their use in endodontics and restorative dentistry. Therefore, it is of interest to evaluate the antibacterial activity of three types of LASERs namely CO2 LASER.Er, Cr:YSGG LASER and Diode LASER in disinfection of root canals. 70 patients (105 single rooted teeth) were included in the study. There was application of 2% Sodium Hypochlorite (NaOCl), 2780 nm Er,Cr:YSGG LASER, 900 nm Diode LASER and CO2 LASER. Microbial samples were collected from root canals both before and after the interventions through paper points. These parameters were evaluated in microbiology laboratory to obtain Log10 Colony Forming Units (CFUs). There was significant reduction in CFUs of microorganisms inside root canal in all three LASERs evaluated and NaOCl. The reduction in CFUs in LASERs was comparable to NaOCl. Then secondly we applied each LASER in combination with NaOCl. It was observed that reduction in CFU was greater when combination of LASER with NaOCl was applied as compared when applied alone. It can be inferred that LASER when applied with NaOCl can have significant role in disinfection of root canals.