Comparative Evaluation of Stress Distribution around Various Threaded Implants with and without Platform Switch: A 3-D Finite Element Analysis.

AIM: The purpose of this study was to compare the stress distribution around various thread design implants with or without platform switching in the maxillary posterior region. MATERIALS AND METHODS: Stress-based performances of four different thread design implants (single, double, triple, and asymmetric thread design each with or without platform switching) were analyzed by the three-dimensional finite element method under a static load of 100 N at 15° oblique direction buccolingually at the central portion of the abutment. A geometric model of the posterior maxillary segment (first molar region) with an implant and abutment was modeled using the CATIA V5R19 software. Type IV bone quality was approximated and complete osseous integration was assumed. RESULTS: The von Mises stresses recorded around the neck of the fourthread design implants without platform switching were greater than the platform switching variety. The single-threaded implant with platform switching showed the lowest amount of von Mises stress. Additionally, total displacement or micromovement of single, triple, and asymmetric thread implants with platform switching was found to be greater than the without platform switching variety. Further, the total displacement of the single-threaded implant without platform switching was lowest. CONCLUSION: Implant surface design, platform switching, and site of placement affect load transmission mechanisms. Due to low crestal resorption, single thread design with platform switching is preferred. The success of an implant in the maxillary molar region is more challenging in terms of the density of bone and the worst load transfer mechanism. With the right kind of implant surface design selection, this can be reduced to a great extent by the preservation of crest of the ridge. CLINICAL SIGNIFICANCE: Crestal bone resorption following implant placement is an important issue. An optimum implant design with a single thread having a platform switch could compensate for this issue to a great extent.

Intricate Estimation and Evaluation of Mandibular Movements in Geriatric Patients Suffering from Rheumatoid Arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disorder that usually affects joints and making them warm, painful, and swollen. The chief purpose of this study was to evaluate movements of mandible in geriatric patients suffering from RA with or without temporomandibular joint dysfunction. MATERIALS AND METHODS: A total of 45 people were included in this study with age of 60 years and above. Partially or completely edentulous patients were divided into experimental and control group. Experimental group consists of 20 people suffering from arthritis and control group consists of 25 people without arthritis. Movements were recorded with or without prosthesis while mastication in both experimental and control group. RESULTS: Statistical evaluation of two studied groups showed decrease opening angle (p < 0.05) during mastication; however, insertion of new prosthesis showd a significant increase in values in both groups, with an increase in opening and closing angles. CONCLUSION: Positive correlation was found between arthritis and movements of the mandible in older people suffering from RA. CLINICAL SIGNIFICANCE: Patients suffering from RA are having restricted mandibular movements thus imposing an overall negative impact however; presence of prosthesis has been shown to enforce a positive effect on mandibular movement.

Assessment of Influence of Contact Time between Alginate and Type III Dental Stone on Properties of Cast Model: An in vitro Study.

INTRODUCTION: Alginate is a versatile, irreversible hydrocolloid impression material, which is cost-effective and forms an essential component in dental practice. For elevating the hardness of the cast models, hardeners are combined with stone. Hence, we planned the present study to evaluate the impact of altering the time of contact between alginate and stone after various interim periods. MATERIALS AND METHODS: The present study included the assessment of impact of time of contact between alginate and stone by the construction of 90 casts using a cylinder model. Two bisecting lines were marked and were named as y and y'. These lines were used for testing the dimensional stability. Using chemically cured acrylic resin, the construction of ten special trays was done. All the impression casts were randomly divided into two study groups, with 45 casts in each group-group I: control group, casts were removed after 60 minutes; group II: study group, casts were removed after 9 hours. A digital caliper was used for measuring the dimensional stability of the cast. All the data were collected and analyzed. RESULTS: In the specimens of the control group (group I) and the study group (group II), the mean dimensions from y to y' were found to be 17.54 and 17.95 respectively. The mean reading of hardness in the control group and study group was found to be 0.59 and 0.20 respectively. In groups I and II, the number of specimens showing clarity of two lines (X and X") was 0 and 5 respectively. CONCLUSION: There was no change in the dimensional stability of the dental stone model when the contact time was increased. CLINICAL SIGNIFICANCE: Within certain limits, the contact time between alginate and stone can be altered without significantly altering the properties of the cast.

Comparison of Hypersensitivity in Metal Ceramic Crowns cemented with Zinc Phosphate and Self-adhesive Resin: A Prospective Study.

BACKGROUND: Luting agents used to fix artificial prostheses, such as fixed partial denture (FPD) to tooth are basically viscous in nature and show chemical reaction for fixation. Postcementation hypersensitivity is a frequent complaint of patients. The present study was conducted to compare postcementation hypersensitivity with zinc phosphate and self-adhesive resin in complete coverage crown. MATERIALS AND METHODS: This study included 30 patients in which 60 porcelein fused to metal crowns was placed. Two metal crowns were placed in each patient in nonantagonis-tic contralateral quadrants. First crown was cemented with zinc phosphate cement, while the other was cemented with self-adhesive resin. Hypersensitivity was evaluated by visual analog scale (VAS) score and by clinical test. For clinical evaluation of sensitivity, hot and cold water was applied to the cervical margin of restoration for 5 seconds and response was recorded. RESULTS: This study consisted of 30 patients in which 60 crowns were given. There was no statistical difference in VAS score of mastication in zinc phosphate cement recorded at baseline, 1 week, 4 weeks, 6 months, 1 year, and 2 years (p > 0.05). Cold response also did not show a significant difference at six time points. Warm response showed slight decrease in subsequent time points but was nonsignificant (p > 0.05). Similarly, with self-adhesive resin cement, VAS score during mastication, hot and cold response was statistically nonsignificant (p > 0.05). CONCLUSION: Postcementation hypersensitivity is a frequent complaint that patient may experience. However, we found no statistically significant difference in both cements tested. CLINICAL SIGNIFICANCE: Postcementation hypersensitivity is an unpleasant sensation experienced by patients. This may affect the success of any prosthesis. Thus, selection of luting agent for cementation plays an important role to eliminate this symptom.

A Comparative Analysis of Bacterial Adhesion on Different Long-Term Provisional Fixed Prostheses Fabricated by CAD/CAM Milling, 3D Printing, and Heat Cure Technique: An In Vivo Study.

Objectives: This study compares the bacterial susceptibility to three different provisional restorations manufactured with different laboratory techniques, i.e., heat cure, CAD/CAM, and 3D printing. Materials and Methods: Totally, 45 health patients with age group of 30-60 years undergoing complete veneer crown treatment were selected for the study and divided into three groups with 15 samples in each as Group I: the crowns were made from polymethyl methacrylate polymer fabricated by the conventional heat cure method, Group 2: the crowns were made from polymethyl methacrylate fabricated by subtractive manufacturing CAD/CAM method, and Group 3: the crowns were made from oligomers fabricated by additive manufacturing 3D printing. The samples were examined for bacterial adherence at scanning electron microscope. The colony-forming units (CFUs) were calculated, and statistically analyzed. Results: It has been determined that the digitally fabricated provisional restorations prove to be superior in terms of surface topography than to the conventionally fabricated provisional restorations. Conclusion: The study concludes that 3D-printed provisional restorations are more precise with reduced bacterial susceptibility than milled ones.

Clinical and CBCT Assessment of Role of Bisphosphonate on Osteotomy Site and Implant Surface.

Objectives: To assess the role of bisphosphonate on osteotomy site and implant surface. Materials and Methods: Twenty patients with adequate width and height of edentulous space and a single missing posterior tooth between the ages of 25 and 55 were incorporated in this research. Ten participants received implant therapy alone; the other ten patients received implant therapy and bisphosphonate application to osteotomy site and the implant surface. Result: Changes in the crestal bone level were seen in both the study and control groups. At 1 year, crestal bone loss was less in the bisphosphonate-treated group than in the control group. Conclusion: The quantity of crestal bone loss was reduced when bisphosphonate (sodium alendronate) was applied locally near the implant and osteotomy site.

Assessment of Role of Bisphosphonates on Dental Implant Treatment in Post-menopausal Ladies.

Objectives: To examine the impact of bisphosphonates (BPs) on dental implant treatment and alveolar bone in post-menopausal ladies. Materials and Methods: Twenty post-menopausal ladies who had at least one dental implant within the previous 5 years participated in the current study. Ten subjects were categorized into two groups: Group A had BP medication for 1.5 years, and group B received parathyroid hormone (PTH). Both groups' bone thickness and bone mineral density (BMD) were measured. Result: Group A had 5%, and group B had 5% of dental implants failures. BMD of cortical bone was 1468 ± 136 mg/mL and 1008 ± 84 mg/mL in groups A and B, correspondingly. The cortical and cancellous bone densities in both the groups were statically significant. Cortical bone thickness was insignificant in comparison. Conclusion: Both cortical and cancellous bones' bone mineral density decreased in both groups. With continued usage of BPs, the cortical bone thickness increased.

Efficacy of Ozone, UV Radiation, Herbal and Glutaraldehyde Method for Sterilisation of Elastomeric Impression Materials for Orthodontic and Prosthodontic procedures.

Objectives: The objectives of the current study was to evaluate the disinfection efficacy of ozone, ultraviolet (UV) radiation, herbal and glutaraldehyde method for sterilization of elastomeric impression materials. Materials and Methods: Disinfection of elastomeric impression material was performed with each of the disinfection methods: ozone, UV radiation, herbal, and glutaraldehyde. Later microbiological analysis was performed and the colony-forming units were evaluated and compared. Results: The highest disinfection efficacy was found with glutaraldehyde, followed by ozone and UV radiation, and the least with neem herbal rinse. Intergroup comparison was highly significant. Conclusion: Dry gaseous ozone and UV radiation can be used effectively for the disinfection of impressions.

Influence of pH on wet-synthesis of silver decorated hydroxyapatite nanopowder.

Here, effect of solution pH on precipitation of silver decorated hydroxyapatite (Ag-HAp) nano powder during its wet-synthesis was systematically studied. XRD pattern of Ag-HAp nano powder synthesised at pH ranging from 5 to 10 shows that calcium hydrogen phosphate was formed as dominating phase when the solution pH was between 5 and 9 and this phase was gradually transformed into a stable HAp above pH 9. A quantitative analysis of silver amount in Ag-HAp nano powder synthesised at different pH showed that silver can be precipitated to its maximum amount at pH 8 and the further addition of ammonia leads to the formation of a silver-ammonium complex, thereby remaining in the solution. HR-TEM and XPS analysis further confirmed the presence of silver in HAp nanocrystals, synthesised at an optimum pH 9. This trace amount of silver in HAp nano powder showed effective antibacterial activity against Staphylococcus aureus and Escherichia coli. In addition, the cytocompatibility studies carried out on MG63 cells further confirmed the present optimised silver concentration of the Ag-HAp nano powder is well within the toxic limit to be useful in various biomedical applications.

Orientation of Dental Professionals in India towards Integrative Medicine: A Cross-Sectional Survey.

INTRODUCTION: There is a growing demand on our health care system, including Dentistry, to shift from a bio-medical approach to Integrative model of care. The attitudes of health professionals towards Integrative Medicine (IM) are an important factor that influences this transition. AIM: The aim of this study was to evaluate and compare the orientation of the dental professionals in India towards the principles and practice of Integrative Medicine. MATERIALS AND METHODS: A cross-sectional survey was conducted on 286 dental faculty and postgraduate students from three dental schools in India. The participants voluntarily and anonymously completed the "Integrative Medicine-30' questionnaire, a 30 item self-report instrument that measures the health care provider's orientation towards Integrative Medicine in five subscales. Data analysis included summary statistics and intergroup comparisons by gender and professional status with independent samples Mann-Whitney U test. RESULTS: The overall orientation of the dental professionals towards IM was almost neutral. While the use of learning resources on Complementary and Alternative Medicine was lower, they showed a more positive orientation towards patient-centred care. Compared to postgraduate students of Dentistry, the dental faculty were more oriented towards IM (median score of 82 vs. 79.5, p<0.01), especially in terms of learning from alternate paradigms (14 vs. 12, p<0.01) and safety of Complementary and Alternative Medicine (13 vs. 12, p<0.01). Females scored better than males both in terms of overall orientation (82 vs. 78, p<0.01) and towards patient-centred care (12 vs. 11, p<0.001). CONCLUSION: The results highlight the impending need to improve the orientation of dental professionals in India towards the principles and practice of IM.

Prosthodontic Management in Conjunction with Speech Therapy in Cleft Lip and Palate: A Review and Case Report.

Cleft lip and palate (CLP), a congenital disturbance needs a lot of attention with respect to its rehabilitation as a person suffering from this defect can lead a normal life given with the right type of treatment at the right time. However, if a patient cannot get surgical treatment at the appropriate time either due to availability or economic constraints, it is still possible to improve their social and psychological well-being with prosthodontic rehabilitation. The literature search was carried out through PubMed and Google scholar and manual search. The articles related to prosthodontic treatment in congestion with speech therapy and some articles on psychological assessment were considered The available prosthodontic treatment options for improvement of speech is discussed and highlighted the importance of prosthetic management of such patients along with a speech therapist. Also, a review of the available prosthetic treatment options is discussed in detail. Finally, a case report of a CLP patient treated prosthodontically with the assistance of speech pathologist is presented.

Prosthodontic management of flat mandibular ridge by mini implant supported over denture.

Loosening of lower denture has always been a common complaint of denture wearer, particularly in case of severe bone resorption. Various treatment modalities including preprosthetic surgery or ridge augmentation therapy to improve the ridge height and conventional implant treatments are available. But many patients are not willing to undergo through such extensive surgical procedure or conventional twin stage implant therapy owing to the chronic old age ailment and cost factor. So mini implant (SENDAX MDI) supported over denture is a boon for them who want a quick and minimally invasive solution, with a much lower cost. In this article we shall discuss the case report of a 60-year-old female patient with atropic mandibular ridge rehabilitated with MDI, (mini dental implant), Sendax mini implant.

A Comparative Study of the Stress Distribution in Different EndodonticPost-RetainedTeeth with and without Ferrule Design-A Finite Element Analysis.

Purpose. To analyze the stress distribution in an endodontically treated maxillary central incisor restored with various post-core systems and assess the benefit of ferrule using finite element analysis. Material and Methods. Twelve models with metal ceramic crown were created based on the combination of three types of post-core systems (titanium post-composite resin core, nickel-chromium post-core, and fiber reinforced composite resin post-composite resin core), two varieties of posts (tapered, parallel), and with or without ferrule. 100 N load was applied in three directions and the von Mises stress was compared. Results. Ferrule made no difference in stress distribution for the titanium and nickel-chromium posts, though it showed some stress reduction in fiber-reinforced composite resin posts. Nickel-chromium cast post-core transmitted the least amount of stresses to the dentin despite producing the maximum stress. Conclusion. Incorporation of ferrule offered some degree of stress reduction in nonmetal post, and it increased the stresses within cervical dentin.