A comparative evaluation of internal and marginal fits of custom post and core fabricated using conventional and two digital techniques: An in vitro study.

AIM: The purpose of this in vitro study was to comparatively evaluate the marginal and internal fits of cobalt-chromium metal custom post and core fabricated using a conventional technique with two digital techniques. SETTINGS AND DESIGN: The study was designed in an in-vitro study setting. MATERIALS AND METHODS: Five sets of custom post and core restorations were fabricated using the conventional (Group 1) and two semi digital methods (digital scanning of the resin pattern and computer aided additive manufacturing, and digital scanning of the silicone impression and subsequent computer aided designing [CAD] computer aided manufacturing fabrication) (Group 2 and 3). Marginal and internal fits of the posts were evaluated using a micro computed tomography scan at various points. STATISTICAL ANALYSIS USED: A one way ANOVA test of the scores was made to evaluate the effect of different methods of custom post and core fabrication on marginal and internal fits. Bonferroni adjusted post hoc tests were conducted for intergroup comparison. RESULTS: Least marginal gap was reported in Group 3 (82.5 ± 14.36 µm) followed by Group 1 (110 ± 25.19 µm) and Group 2 (112.5 ± 26.75 µm). Least internal gap at cervical, middle and apical as well as overall values were observed in Group 3 (78 ± 9.25 µm, 72 ± 7.79 µm, 160 ± 15.81 µm, 103.3 ± 4.43 µm) followed by Group 1 (113.5 ± 25.35 µm, 132.5 ± 19.92 µm, 502 ± 74.63 µm, 249.3 ± 25.44 µm) and Group 2 (114.5 ± 21.68 µm, 133.5 ± 19.57 µm, 598 ± 87.86 µm, 282 ± 28.91 µm) respectively. The results of one-way ANOVA and Bonferroni adjusted post hoc tests for marginal gap did not show any statistically significant difference between the three groups (P > 0.05) but revealed statistically significant difference (P = 0.02) in internal gap values at the cervical, middle, and apical regions as well as overall internal gap region between the three groups. CONCLUSIONS: Better marginal and internal fits were observed in custom post and core fabricated by digital scanning of the silicone impression and subsequent CAD as compared to those fabricated by the other two groups.

Validation of Digital Impressions' Accuracy Obtained Using Intraoral and Extraoral Scanners: A Systematic Review.

BACKGROUND: At present, the evidence regarding digital impressions' accuracy recorded by using digital scanners is lacking. This systematic review aimed to evaluate whether the type of scanning (intraoral/extraoral) affects the Accuracy of Digital Impressions. METHOD: Two independent reviewers performed a systematic search in the database both electronically and manually (PubMed, Ebsco HOST, the Cochrane Library, and Google Scholar) for articles published from 1 January 2010 to 1 December 2022. This study was registered with the International Prospective Register of Systematic Reviews (PROSPERO CRD42020188765) and followed the PRISMA statement. The question in focus was as follows: Does the type of scanning (intraoral or extraoral) affect the accuracy of digital impression? RESULTS: A total of 449 papers were obtained by searching electronically and manually. In total, 15 complete-text papers qualified for assessment based on eligibility criteria. After reading the full-text articles, five studies were excluded. Ten studies were selected for the qualitative analysis. The qualitative data reported that the accuracy of both types of scanners (intraoral and extraoral) lies within the range of clinical acceptability. Nevertheless, the intraoral scanners seem to be more accurate when compared to the extraoral scanners for a partial arch situation. CONCLUSIONS: Scanning type affects the accuracy of the digital impression. Various factors influence the scanning ability. Intraoral scanners seem to be more accurate compared to extraoral scanners for a partial arch situation. More studies comparing the accuracy of the intraoral scanner and extraoral scanner for a complete arch scan and in an in vivo study setting are needed.

A Retrospective Analysis of the Need for the Root Canal Therapy for the Full Crown Restorations: An Original Study.

Introduction: There are numerous chances for pulpal irritation during the placement of a crown on a tooth. This study's goal was to find and examine the variables that influence the prevalence of routine root canal therapy after the teeth were restored with full coverage crowns. Methods: The hospital records were retrospectively evaluated from 2000 to 2010 for a decade. The demographics as well as the various variables that caused for the intervention with the root canal therapy for the teeth with the full crowns were evaluated. The values were compared for the significance. Results: The total number of the teeth that were finalized in the study was 4308. Of the total teeth that were treated with full coverage crowns, 50% were metal ceramic, 42% were full ceramic, and 9% were full metal crowns. After 10 years, possibility that every tooth with a crown would survive was 91%. The most frequent adverse incident was the intervention with the RCT. Metal ceramic crowns had poor survival rates and needed the maximum intervention. Younger age-group had least survival rate than the older age-groups. Conclusions: Endodontic therapy is unlikely to be necessary after crown installation. As the patient's age declines and all-ceramic or PFM crowns are used, this risk rises.

A Retrospective Study on the Fracture Toughness of the Coronal Restorations in Endodontically Restored Teeth. An Original Research.

Introduction: The best treatment for the deeply carious tooth that cannot be restored is by the root canal therapy. This method has saved many patients from the loss of tooth. The common practice is either to deliver a full crown or close the access cavity with restoration. Hence in this study, the clinical longevity of the routine practice is tested for by analyzing the fracture toughness and the survival of the teeth that were restored endodontically with various materials. Materials and Methods: The hospital records were retrospectively evaluated from 2000 to 2010 for a decade. The demographics as well as the survival and the failure rates noted and compared for the various types of the restorations. The number of the walls of the teeth was also compared. Results: Thousand teeth were considered in the study. Less than 7% of teeth had coronal fractures. Of the 93% teeth that had survived, the most common restoration was Individual post (+ crown) followed by GIC, amalgams, and crowns. The mean survival of the crown+ bridge & gold restoration was highest. The mean survival was 10 ± 2 years for the restored teeth without any fractures at the coronal level. The failure was greatest for the GIC followed by amalgam, and the variations when compared with other restorations were significant. There was no significant difference for the number of the walls on the crown; however, the number of walls present was proportional to the survival rate. Conclusion: The teeth that were covered with a crown were comparatively fracture resistant and had a better survival rate compared to other restorations. GIC showed highest fracture, and the post core with crown had the best survival. Restoration of the lost crown architecture and the reinforcement are the best methods that can be followed for the survivals.

Fracture toughness of 3D printed denture teeth.

BACKGROUND: Advances in digital dentistry lead to use of three-dimensional (3D) printed resin denture teeth. Fracture toughness of these teeth must be assessed. OBJECTIVE: This study aimed to compare the chipping and indirect tensile fracture resistance of denture teeth fabricated by 3D printing technique with traditionally fabricated resin denture teeth. METHOD: Four groups (Gr) were made (n= 50/group): Gr-1 3D printed denture teeth (denture teeth; Formlabs Inc., Somerville, MA, USA), Gr-2 SR-Orthosit-PE (Ivoclar Vivadent AG), Gr-3 Portrait IPN (Dentsply Sirona), Gr-4 Pala Premium 8 (Heraeus Kulzer GmbH). Stereolithography 3D printing was used to create the methacrylate-based photopolymerized resin teeth models and remaining group teeth were collected commercially. A 1 mm/min chipping and indirect tensile fracture speed tests were carried out till fracture occurred. The data so obtained were statistically analysed using one-way analysis of variance with Tukey's honestly significant difference multiple comparisons test (p< 0.05). At the end of the test, the fractured areas of the specimens were evaluated by the chief researcher to assess the fracture pattern of the teeth. RESULTS: The indirect tensile fracture values of the 3D printed teeth were more than that of Pala Premium-8 and SR-Orthosit-PE but it was lower than that of Portrait IPN teeth. In chipping test, buccal chipping of the loaded cusp was seen in 3D printed resin without distortion and in indirect tensile test in 3D printed resin teeth, line of fracture emerges near the loading point propagates from the inner incline of both cusps and extends cervically, unlike in other groups where first deformation occurs then fracture. CONCLUSION: Prosthetic teeth fabricated by the 3D printing technique using printable resin material provide adequate fracture resistance as denture teeth.

Acupuncture ( zhen jiǔ) - an emerging adjunct in routine oral care.

Acupuncture ( Zhen Jiǔ) ('acus' (needle) + 'punctura' (to puncture)) is the stimulation of specific points along the skin of the body involving various methods such as penetration by thin needles or the application of heat, pressure, or laser light. Acupuncture ( Zhen Jiǔ) aims to treat a range of medical and dental ailments, though is most commonly used for pain relief. This article reviews about the various possible roles of acupuncture ( Zhen Jiǔ) in clinical dental practice. Acupuncture ( Zhen Jiǔ) has potential in supplementing conventional treatment procedures by its diverse applicability outreach. Role of acupuncture ( Zhen Jiǔ) in dental practice has been well supported by clinical trials. Its role in alleviating facial pain, pre-operative and post-operative dental pain has led to its widespread application. Its role as sole analgesic for treatment procedure has to be tested. It's It is a thought that acupuncture ( Zhen Jiǔ) may prove an indispensible supplement to conventional treatment modalities and more of clinical trials and studies are required to prove the efficacy. Acupuncture ( Zhen Jiǔ) is not a miracle cure and is not going to replace the drill. However, the technique can be a supplement to conventional treatments in TMDs, facial pain, pain management Sjoegrens syndrome, and in phobias and anxiety. The application and use of Acupuncture ( Zhen Jiǔ) comes with some side effects. Proper training needs to be obtained before commencement of any procedure related to acupuncture ( Zhen Jiǔ). Various training programs are offered to train clinical practitioners the apt method to use acupuncture ( Zhen Jiǔ).

Comparative Evaluation of the Complementary and Alternative Medicine Therapy and Conventional Therapy Use for Musculoskeletal Disorders Management and Its Association with Job Satisfaction among Dentists of West India.

Musculoskeletal problems have become a significant issue in the profession of dentistry. There are currently no recommended effective disease-preventing and modifying remedies. High prevalence rates for musculoskeletal disorders (MSDs) among dentists have been reported in the literature. Complementary and alternative medicine can be helpful in managing and preventing the MSDs. The purpose of this study was to determine if dentists in the western part of India are using complementary and alternative medicine therapies for MSDs, and also to find if those who use complementary and alternative medicine therapies have greater job/career satisfaction compared to conventional therapy (CT) users. Dentists of western India registered under the Dental Council of India (N = 2166) were recruited for the study. Data were analyzed using univariate and bivariate analyses and logistic regression. A response rate of 73% (n = 1581) was obtained, of which 79% (n = 1249) was suffering from MSDs. The use of complementary and alternative medicine or CT was reported by 90% (n = 1124) of dentists with MSDs. Dentists using complementary and alternative medicine reported greater health (P < 0.001) and carrier satisfaction (P < 0.001) and were able to work as many hours they wanted (P < 0.001) compared to CT users. Complementary and alternative medicine therapies may improve the quality of life and enhance job satisfaction for a dentist who suffers from MSDs.