Comparative evaluation of simvastatin gel in enhancing peri-implant osteoblastic activity during the Osseo integrative phase using Bone scintigraphy: A prospective case-control double blinded study.

BACKGROUND: Simvastatin (SMV), a lipid lowering drug, can modulate the process of bone regeneration at the molecular and cellular levels. Its effect on the osseointegration of implants has been studied extensively on animals with assuring results with limited research on human subjects. AIM: To estimate the effect of simvastatin gel in the osseointegration of dental implants using bone scintigraphy, Materials and Methods: 20 participants with missing mandibular first molars and D2 type bone were assigned equally to Group A receiving 1.2% simvastatin and Group B receiving Placebo gels during the placement of implants. The participants were subjected to bone scintigraphy to determine the osteoblastic activity at baseline, 30th day and 90th day after implant placement. RESULTS: Group A revealed a significant increase in osteoblastic activity between baseline, day 30 and 90 (P<.05) with a higher mean of 100.06±21.644% on day 30. Group B revealed a significant increase in osteoblastic activity only between baseline and day 30, and baseline and day 90 (P<.05) whereas there was no difference between day 30 and 90 (P>.05) with a higher mean of 79.20±18.255% on day 30. Bivariate analysis at different time periods revealed a significant difference between groups A and B on day 30. CONCLUSION: Implants placed with 1.2% simvastatin gel showed enhanced osteoblastic activity on the fourth week of implant placement, indicating faster rate of osseointegration at an early stage.

Quality of Life with the Rehabilitation After Partial Mandibulectomy: a Systematic Review.

To evaluate the QoL before and after prosthetic rehabilitation of partial mandibulectomy patients based on the type of surgery, effects of radiation, the type of prosthesis, and to enlist their outcome on the rehabilitation. Literature search as per PICO format was carried out within a time range from January 2000 to June 2021. The review followed PRISMA guidelines and registered with the PROSPERO(CRD42021258472). The focus question was established as per the PICO format (Population, Intervention, Comparison, Outcome). The population involved partial mandibulectomy individuals with prosthetic rehabilitation as an intervention. The outcome, quality of life (QoL), was compared with the pre and post partial mandibulectomy patients rehabilitated with a prosthesis. The search yielded 367 articles and based on the search criteria only 7 articles were suitable for qualitative analysis. Marginal resection of the mandible is less aggressive than segmental resection which provided function, phonation, and esthetics at acceptable levels but the food mixing ability was reduced when resection is accompanied by glossectomy. However, the perceived chewing ability and OHRQoL were not accountable to the extent of surgical excision. An overall increase in the QoL on rehabilitation with acrylic prosthesis depicting satisfactory functionality with a considerable improvement in mastication, speech, and social life. QoL and Denture Satisfaction Index did not differ based on the number of implants in an implant overdenture prosthesis, but the chewing ability was improved. An increase in the number of remaining occlusal units improved the overall QoL. Restoration of the function, psychological comfort, and improvement in esthetics was significant in patients who underwent prosthetic rehabilitation. The QoL between conventional and implant prostheses was observed to be more similar, and the effect of remaining hard and soft tissue structures has a major influence on patient comfort signifying the influence of the extent of surgical excision. Supplementary Information: The online version contains supplementary material available at 10.1007/s13193-022-01664-x.

Comparative Effect of Rehabilitation with Three Different Treatment Modalities for a Single Missing Molar on Brain Activity-A Prospective Clinical Study.

PURPOSE: To evaluate and compare the changes in brain activity for individuals with a single missing mandibular molar replaced with a removable dental prosthesis (RPD) and a fixed tooth-supported implant prosthesis in the static and postmasticatory phases. MATERIALS AND METHODS: In total, 24 patients with a unilateral missing mandibular first molar were rehabilitated with a removable dental prosthesis and divided into two groups of 12 each; Group A was rehabilitated with implants and Group B with 3-unit tooth-supported fixed partial dentures (FPDs). An electroencephalogram (EEG) was taken during the three phases of assessment: (1) before insertion of any prosthesis (N0), (2) after insertion of an RPD (N1), and (3) after cementation of an FPD or implant crown (F2). The effect of bite force with RPD (N1M) and FPD or implant prosthesis (F2M) on alpha waves was evaluated by recording EEG immediately after chewing gum for 30 seconds. RESULTS: The improvement of the amplitude of alpha waves before and after prosthesis insertion showed a significant difference between Group As and B (P < .05) with the highest mean values of 158.3 µV, 147.9 µV, and 182.1 µV occurring in pairs F2-N0, F2-N1, and F2M-N1M, respectively, for Group A. Similarly, for the power of alpha waves between group A and B, a statistically significant difference (P < .05) with the highest mean values of 30.3 dB, 28.9 dB, 36.9 dB, and 11.2 dB in pairs F2-N0, F2-N1, F2M-N1M, and F2M-F2 ,respectively, was observed for Group A. There was no statistically significant increase in pair N0-N1 (P > .05). CONCLUSIONS: Replacement of a single missing tooth enhanced brain activity and was highest with an implant-supported crown. Int J Prosthodont 2023;36:563-569.

The Right Leg that Troubled the Left Leg.

INTRODUCTION: Oncogenic osteomalacia or tumor induced osteomalacia (TIO) is a rare acquired paraneoplastic syndrome characterized by defective bone mineralization secondary to release of Fibroblast Growth Factor-23 (FGF-23), a phosphaturic protein - released from small, slow-growing mesenchymal tumors. Here, we report such a case and how it was investigated. MATERIALS: A 31 year old female presented with history of left leg pain and difficulty in walking since 1 year. General and systemic examination were found to be within normal limits and initial diagnostic workup revealed elevated alkaline phosphatase. X-ray bilateral hip and legs showed pseudo fractures of femur and tibia. Hence a probable diagnosis of metabolic bone disease was considered and further workup showed isolated hypophosphatemia. Patient was worked up for hypophosphatemic osteomalacia and further investigations showed low Tmp-GFR with a high FGF23 level. Hence a diagnosis of oncogenic osteomalacia was considered and a whole body PET scan was done which showed evidence of mesenchymal tumor in the right lower limb. Removal of the tumor resulted in resolution of symptoms and hence the diagnosis of oncogenic osteomalacia was confirmed. RESULT: Hypophosphatemia Normal S. Calcium and S. Vitamin D3 levels Conclusion: Oncogenic osteomalcia is a rare paraneoplastic form of renal phosphate wasting that results in severe hypophosphatemia and has excellent prognosis as surgical removal of the causative tumor results in dramatic improvement. High index of suspicion combined with prompt investigations can result in early diagnosis of the causative tumor and proper surgical treatment which will improve outcomes. Reference Chong WH, Molinolo AA, Chen CC, et al. Tumor-induced osteomalacia. Endocr Relat Cancer 2011;18(3):R53-R77.

Impact of Complete Denture and Mandibular Advancement Device in the Management of Completely Edentulous Obstructive Sleep Apneic Individuals: A Systematic Review with Meta-Analysis.

Statement of the Problem: Obstructive sleep apnea (OSA) is an underdiagnosed and potentially serious disorder that is accentuated by edentulism. The overclosure of the mandible and a potential upper airway collapse during sleep creates challenges in treating edentulous sleep apneic patients. Purpose: To evaluate complete dentures and mandibular advancement devices as potential oral appliances in the management of sleep apnea in completely edentulous patients. Materials and Method: The study design was a systematic review with meta-analysis. The search criteria complied with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines and the keywords in population, intervention, control, and outcomes (PICO) format was systematically searched for relevant research articles published till August 2021 in an electronic database (PubMed, Cochrane, Science Direct, Ovid). Randomized controlled trials and cohort studies were included that compared the effectiveness of oral appliances on apnea-hypopnea index (AHI), airway space, and quality of sleep in edentulous sleep apneic patients. Results: 1785 articles were derived from the initial search and based on inclusion criteria, 10 articles were systematically filtered for qualitative analysis and assessed for risk of bias using the Cochrane risk of bias tool and ROBINS-I tool. Out of the 10 articles, 5 articles were taken for quantitative analysis. The use of a mandibular advancement device (MAD) showed a decrease in AHI score, but the available data was heterogeneous to conduct a meta-analysis. The mean difference of AHI for the random effect model between the non-complete denture and complete denture wearers at sleep was -0.49[95% CI (-1.47,0.48)] events per hour, but the change was non-significant (p>.05). Conclusion: The complete dentures as an oral appliance had reduced apneic episodes in completely edentulous sleep apneic patients, but the effectiveness cannot be solely attributed to the prosthesis in the treatment of OSA. MAD showed greater improvement in reducing AHI, however, the level of evidence was inadequate to provide a conclusive statement.

Comparison of Osteoblastic Activity Around Endosseous Implants Placed with Osseodensification and Adaptive Osteotomy Techniques--A Split-Mouth Prospective Case-Control Study.

Purpose: To compare the osteoblastic activity around dental implants placed via adaptive osteotomy and osseodensification techniques using bone scintigraphy in human subjects. Materials and Methods: A single-blinded, split-mouth design was conducted on two sites in each of the 10 subjects, with the adaptive osteotomy (n = 10) and osseodensification (n = 10) techniques for implant placement performed on either side of the D3-type bone in the posterior mandible. All participants were subjected to a multiphase bone scintigraphy test on the 15th, 45th, and 90th days after implant placement to evaluate the osteoblastic activity. Results: The mean values obtained on the 15th, 45th, and 90th days in the adaptive osteotomy group were 51.14% ± 3.93%, 51.40% ± 3.41%, and 50.73% ± 1.51%, respectively, while the osseodensification group values were 48.88% ± 3.94%, 48.78% ± 3.38%, and 49.29% ± 1.56%, respectively. The intragroup and intergroup analyses revealed no significant difference between the mean values of the adaptive osteotomy and osseodensification groups on the tested days (P > .05). Conclusions: Osseodensification and adaptive osteotomy techniques improved primary stability of D3-type bone and accelerated the osteoblastic activity after implant placement, with no superiority of one method over the other.

Early Implant Bone Loss in the Preprosthetic Phase: A Retrospective Study.

Initiation of the inflammatory response begins with the surgical placement of an implant that stimulates bone remodeling. The occurrence of crestal bone loss during submerged healing affects the prognosis of an implant. Hence, this study was conducted to estimate the early implant bone loss during the preprosthetic phase on bone level implants placed equicrestally. This retrospective observational study included evaluation of crestal bone loss around 271 two-piece implants placed in 149 patients from the archived postsurgical (P1) and preprosthetic (P2) digital orthopantomographic records using MicroDicom software. The outcome was categorized based on (1) sex (male or female), (2) time of implant placement (immediate [I] vs conventional [D]), (3) duration of healing period before loading (conventional [T1] vs delayed [T2]), (4) region of implant placement (maxilla [M1] vs mandible [M2]), and (5) site of implant placement (anterior [A] vs posterior [P]). To find the significant difference between the bivariate samples in the independent groups, an unpaired sample t test was used. The average marginal bone loss during the healing phase was 0.56 ± 0.573 mm in the mesial region and 0.44 ± 0.549 mm in the distal region of the implant, with a statistically significant difference (P < .01). There was no statistically significant difference in crestal bone level with the (1) sex of the patient (male or female), (2) type of implant placement (I or D), (3) time of implant loading (T1 or T2), (4) region of implant placement (M1 or M2), or (5) site of implant in the arch (A or P) (P > .05). An average of 0.50 mm crestal bone loss occurred in the peri-implant region during the preprosthetic phase. We found that the delayed placement of an implant and a delay in the healing period would further increase the early implant bone loss. The difference in the healing period did not alter the outcome of the study.

Microbiome and the inflammatory pathway in peri-implant health and disease with an updated review on treatment strategies.

Crestal bone preservation around the dental implant for aesthetic and functional success is widely researched and documented over a decade. Several etiological factors were put forth for crestal bone loss; of which biofilm plays a major role. Biofilm is formed by the colonization of wide spectra of bacteria inhabited around dental implants. Bacterial adherence affects the regulators of bone growth and an early intervention preserves the peri-implant bone. Primary modes of therapy stated in early literature were either prevention or treatment of infection caused by biofilm. This narrative review overviews the microbiome during different stages of peri-implant health, the mechanism of bone destruction, and the expression of the biomarkers at each stage. Microbial contamination and the associated biomarkers varied depending on the stage of peri-implant infection. The comprehensive review helps in formulating a research plan, both in diagnostics and treatment aspects in improving peri-implant health.

Evaluation of Changes in the Mechanical Properties of O-Ring in One Piece and Two Piece Ball Retained Implant Supported Overdentures: A Three-Year Retrospective Study.

The O-rings in ball retained overdentures deteriorate with time and need replacement to restore the retentive quality. We evaluated retrospectively the mechanical properties of O-rings after 3 years in function in 1 and 2-piece implant-supported overdentures. The O-rings were retrieved from one-piece (Myriad snap, Equinox-Straumann, 3.3 × 13 mm) and 2-piece (Neo Biotech, 3.3 × 13 mm) implant-supported overdenture patients. A total of 16 pairs of matrices were tested for wear, type of damage, and elasticity using Pin on Disc method, USB Digital Camera in 30× zoom and Universal Tensile Machine, respectively. The statistical analysis for independent groups were done with the Mann-Whitney U test. Assessment of used O-rings showed 84% more wear in the 2-piece system with an abrasive type of damage while 46% wear in the 1-piece system with a compressive type of damage. The O-rings in 1-piece system showed increase in elongation and maximum displacement to 2% and 7%, respectively, whereas the 2-piece system showed decrease in elongation and maximum displacement by 13% and 6%, respectively. In 1-piece system, the loss of retention was more with slow wear rate, and in 2-piece system, the wear resistance of O-rings decreased due to increased stiffness. Further studies to evaluate the changes in O-ring with increased sample size and at interval 1 year will pave way for insight into the progressive changes in the mechanical properties of an O-ring.

Comparison of the effect of conventional and implant-retained overdentures on brain activity and cognition in a geriatric population - A functional MRI study.

PURPOSE: This study aims to evaluate the effect of rehabilitation with complete dentures versus implant-retained overdenture on activity in various parts of the brain cognition in a geriatric edentulous population via Functional MRI (fMRI) studies and the Mini-Mental State Examination (MMSE). METHODS: Ten completely edentulous patients were rehabilitated with both complete dentures and two-implant retained overdentures for three months each. fMRI studies were performed for each modality during chewing and recall tasks at three time periods: T0: Completely Edentulous (CE) T1: after three months of wearing Conventional Complete Dentures (CD) and T2: after three months of wearing Implant-retained Overdentures (IOD). The Z scores obtained from the fMRI at these phases of examination were tabulated and correlated with MMSE scores obtained at the corresponding time periods. RESULTS: Z scores obtained during the memory recall tasks at T2 were the greatest (Prefrontal Cortex (p=0.059) and Hippocampus (p=0.036). The MMSE scores obtained were significantly higher for the IODs when compared to the CDs and Baseline values (p < 0.05). CONCLUSION: IODs may potentially result in superior sensory feedback in edentulous patients and lead to improved cognitive performance when compared to conventional complete dentures.

Custom-Made Dual-Functional Oral Appliance for Management of Obstructive Sleep Apneic Completely Edentulous Patient.

Continuous positive airway pressure (CPAP) being a gold standard treatment to open the upper airway by application of controlled compressed air is still not a widely accepted mode of treatment among obstructive sleep apnea (OSA) individuals. To improve patency of upper airway space and reduce the risk of sleep apnoea, it is essential to provide mandibular advancement devices (MADs) that could provide non-continuous positive airway pressure (non-CPAP) for patients with OSA. Availability of prefabricated oral appliances (OAs) like MADs, tongue holding devices reduced the chair-side fabrication time but has poor adaptation, excessive salivation, and deprivation of sleep. Customized OAs can overcome these challenges, but their fabrication for an edentulous individual is challenging due to the absence of teeth and the encroachment of tongue space by the device. This clinical report gives an insight into the clinical and technical aspect of fabrication of MAD with tongue retaining space for an edentulous individual with OSA.

Influence of the Fly Ash Material Inoculants on the Tensile and Impact Characteristics of the Aluminum AA 5083/7.5SiC Composites.

The choice of suitable inoculants in the grain refinement process and subsequent enhancement of the characteristics of the composites developed is an important materials research topic, having wide scope. In this regard, the present work is aimed at finding the appropriate composition and size of fly ash as inoculants for grain refinement of the aluminum AA 5083 composites. Fly ash particles, which are by products of the combustion process in thermal power plants, contributing to the large-scale pollution and landfills can be effectively utilized as inoculants and interatomic lubricants in the composite matrix-reinforcement subspaces synthesized in the inert atmosphere using ultrasonic assisted stir casting setup. Thus, the work involves the study of the influence of percentage and size of the fly ash dispersions on the tensile and impact strength characteristics of the aluminum AA 5083/7.5SiC composites. The C type of fly ash with the particle size in the series of 40-75 µm, 76-100 µm, and 101-125 µm and weight % in the series of 0.5, 1, 1.5, 2, and 2.5 are selected for the work. The influence of fly ash as distinct material inoculants for the grain refinement has worked out well with the increase in the ultimate tensile strength, yield strength, and impact strength of the composites, with the fly ash as material inoculants up to 2 wt. % beyond which the tensile and impact characteristics decrease due to the micro coring and segregation. This is evident from the microstructural observations for the composite specimens. Moreover, the role of fly ash as material inoculants is distinctly identified with the X-Ray Diffraction (XRD) for the phase and grain growth epitaxy and the Energy Dispersive Spectroscopy (EDS) for analyzing the characteristic X-Rays of the fly ash particles as inoculant agents in the energy spectrum.

Assessment of a smartphone-based software application as a potential digital tool in tooth shade selection: a prospective clinical study.

OBJECTIVE: To determine the reliability of a newly developed software application (Shadent) in natural tooth shade selection. METHOD AND MATERIALS: A smartphone device with the self-developed Shadent software (patent no. 201841046815, Intellectual Property of India) recorded tooth shades of the maxillary right central incisor and canine for 250 volunteers. A prospective, clinical, double-blind trial was conducted. The shade match obtained under the standardized condition from Shadent software was compared with the visual method and spectrophotometer. The digital recordings were captured by two master's candidates, while the visual shade match was evaluated by four master's candidates and one faculty member from the Department of Prosthodontics. Crosstab analysis assessed the relationship between the visual method of shade selection, a spectrophotometer, and the Shadent software. Cohen kappa was used to measure the agreement between the methods. RESULTS: A kappa coefficient of 0.59 was observed between the visual assessment and the Shadent software, with an agreement percentage of 64.6%. A kappa coefficient of 0.65 was observed between the spectrophotometer and the Shadent software with an agreement of 69.3%. The software also had a better Cohen kappa agreement with the maxillary central incisor than the maxillary canine. CONCLUSIONS: Shadent's reliability was comparable with the visual and spectrophotometric methods and offered repeatability with standardized light intensity.

Body image perception and its psychological influence on prosthesis satisfaction.

AIM: To identify the body image perception of an individual utilising figure rating scale and assess its psychological influence in altering the prosthetic satisfaction. METHODS: One hundred five of 140 participants were categorised into Groups I, II and III according to their body image satisfaction. Pre- and posttreatment denture satisfaction questionnaires, and pretreatment Big Five personality, Life Satisfaction questionnaires were given to the participants in each group. Analysis of variance (ANOVA) and Tukey post hoc tests assessed the significant relation between the groups. RESULTS: Body image satisfied group (I) was highly contented with the prosthetic treatment (46.90), while body image dissatisfied groups (II and III) had lower denture satisfaction scores (36.80 and 29.70). Neurotic score was significantly different in pairs; Groups I and III, and Groups II and III (P < .001), with high mean for Group III (75.30). The agreeable score was significantly different in Groups I and II (P < .05), with a high mean for Group I (83.60). Life Satisfaction score was significantly different in pairs; Groups I and III, and Groups I and II (P < .001), with a high mean for Group I (30.60). CONCLUSION: The individual's perception of body image had an effect on their denture satisfaction level, and figure rating scale would help in identifying the psychological profile of the patient.

The Consequence of Complete Dentures on Quality of Life of Edentulous Patients in the South-Indian Population Based on Educational and Socioeconomic Grades.

Purpose The purpose of this study was to establish the level of denture satisfaction with socio-demographic variables and educational status of the patients rehabilitated with complete denture. Materials and method A total number of 250 completely edentulous patients were selected who fulfilled the inclusion and exclusion criteria. The patients had no past medical history which affects the oral condition; they were first-time denture wearers with period of edentulousness altering between six months to one year and were in the age group of 40-50 years, and were willingly involved in the study. The subjects were grouped according to their socioeconomic status such as employment, education and income level. The correlations were statistically determined using regression analysis. Results Statistical analysis was done using Statistical Package for Social Sciences (SPSS, Chicago, Illinois, USA), version 16.0. The significance of percentage error of the two groups was tested by Student t test and p value denoted level of significance (p<.05). Based on the education level, 30.47% of the population were under primary level of education, 57.82% completed higher secondary education and 11.72% of the population were graduates. Based on employment status, 53.12% of the population was unemployed, 32.03% were employed while 14.84% of the population were pensioners. Based on income per month, the population was classified as 6.25%, 31.25%, 21.09%, 22.66%, 18.75% for no income, less than 3000, 5000, 8000 and more than 10000 respectively. Psychological comfort, social ability, and functional improvement was better with higher secondary education level, employed and lower income individuals. Conclusion Rehabilitation of an elderly individual not only includes clinician skills but also the personal perception by the patient. The study concludes that the though there was no statistically significant difference, the individual with secondary level of education and with employed low socioeconomic status had better denture satisfaction than the other category.

Comparison of Colour Stability Between Various Denture Base Resins on Staining and Denture Cleansing Using Commercially Available Denture Cleansers.

Statement of problem Discoloration of denture base materials on routine usage has been one of the common esthetic problems encountered by patients. Aim To determine the color stability of three different denture base materials upon staining with beverages and denture cleansing using commercially available denture cleansers. Materials and method Three denture base materials were used for the study, processed according to the manufacturer's recommendation, and cut into 40 study samples measuring approximately 1 cm x 1 cm with 1 mm thickness. The samples were divided into two groups, Group A and Group B, and spectrophotometric analysis of all samples was done to evaluate the base value of the color for comparative analysis. Group A was immersed in coffee and Group B was immersed in cola and color change was noted after 12 hours and then after 24 hours. The samples were then cleansed using a denture cleanser and analyzed again. All values were tabulated and statistically analyzed. Result On descriptive statistical analysis, polymethylmethacrylate (PMMA) had higher ∆E values at 12 hrs after immersion in coffee and cola; after 24 hrs, high impact PMMA had higher ∆E values in coffee and PMMA in cola. Two-way analysis of variance (ANOVA) analysis showed no statistically significant difference for the samples immersed in coffee, whereas samples immersed in cola at the end of 24 hrs showed a significant statistical difference. Conclusion Thermoplastic resin was the least staining denture base material when compared to conventional PMMA and high-impact PMMA when immersed in coffee and cola. There was no significant difference in the cleanability of all three-denture base materials.

Single Implant Retained Overdenture Treatment Protocol: A Systematic Review and Meta-Analysis.

PURPOSE: This systematic review was undertaken to establish the most favourable protocol to treat an edentulous mandible with a single implant-retained overdenture. The formulated PICO question was: "Which surgical and prosthetic protocols result in the highest survival and complication rates of implants and prostheses employed in a single implant retained overdenture for the rehabilitation of a completely edentulous mandibular ridge?" MATERIALS AND METHODS: A structured literature search was conducted using the following databases; PubMed, ScienceDirect, COCHRANE, LILACS, IndeMED, OVID, EMBASE, NIH Clinical Trials for reports related to the single implant-retained overdenture treatment. Only English articles were included. Publications with a minimum follow up time of 1 year and above were included for meta-analysis. A Poisson regression model was applied to estimate the survival rates of the implant and prosthesis employed. RESULTS: The electronic database search yielded 2083 titles and abstracts; and a total of 17 were selected for the systematic review, of which 11 studies were subjected to meta-analysis. The implants showed high estimated five and 10-year survival rates of 91.93% and 84.62%, respectively. Implants that were delayed loaded showed the greatest survival rates, while immediately loaded implants presented with higher survival rates at five (p = 0.849) and 10 years (p = 0.464) when compared to early loaded implants. The greatest number of fractures were associated with ball abutments with an event rate of 10.8 (95% CI: 10.5-11.09) per 100 prosthesis years, while locator abutments showed a greater number of maintenance events with an event rate of 16.84(95% CI:16.01-17.66) per 100 prosthesis years. CONCLUSION: Single implant-retained overdenture treatment is a cost-effective, minimally invasive and simple treatment that can be used to restore function and aesthetics to edentulous patients, with relatively high implant and prosthesis success rates and minimal complications.

A three-dimensional finite element analysis to evaluate stress distribution tooth in tooth implant-supported prosthesis with variations in non-rigid connector design and location.

BACKGROUND: The physiologically mobile natural tooth and rigidly fixed dental implant causes different distribution of stress when connected in prosthesis and nonrigid connector compensates this. Understanding of biomechanical behavior is necessary for an adequate choice and construction of this type of rehabilitation. However, there has been insufficient research focusing on different location and type of the nonrigid connector related with the prognosis of both implant and the tooth. AIM OF THE STUDY: The purpose of this finite element (FE) analysis was to evaluate the stress distribution around bone, implant, and tooth in tooth implant fixed prosthesis under static load with variations in design and location of nonrigid connectors under simulated functional loads. MATERIALS AND METHOD: Three, 3-dimensional FE models connecting tooth and implant were constructed with different location and type of nonrigid connector. Simulated occlusal load was applied on the restorations and stresses developed in the supporting structures were monitored. RESULTS: The highest stresses were found around the implant in model with nonrigid connector placed between the tooth and implant and model with modified nonrigid connector. On the other hand, less stress was noted around the implant where nonrigid connector was placed between the implant and pontic. CONCLUSION: It is advisable to place the nonrigid connector between the implant and the pontic to protect the implant from torque effects in a tooth implant fixed prosthesis.

Antifungal Efficacy and the Mechanical Properties of Soft Liners against Candida albicans after the Incorporation of Garlic and Neem: An In vitro Study.

OBJECTIVES: To evaluate the in vitro growth inhibition of Candida albicans, in the soft-liner material and Shore A hardness from resin-based denture soft lining materials modified by neem or garlic incorporation. MATERIALS AND METHODS: Resin discs were prepared with poly methyl methacrylate (PMMA) and soft liners incorporated with varying concentrations of neem or garlic. For antifungal activity, resin discs were placed on agar plates inoculated with C. albicans and were evaluated after 2, 4, and 7 days using the streaking method. The hardness of the PMMA was evaluated with the use of Shore A at 2, 4, and 7 days. Data were statistically processed by SPSS software (IBM Company, Chicago, USA) using Kruskal-Wallis test, and post hoc comparisons were done using Dunn's test. P <0.05 was considered statistically significant. RESULTS: Neem and garlic added to PMMA soft liner had an inhibitory effect on C. albicans. Both the neem and garlic when added showed positive results against C. albicans when compared to the control group. The soft liner hardness increased statistically by time but not for the different plant extract concentrations. CONCLUSIONS: Within the limitations of this in vitro study, it was found that neem and garlic can be used as an additive to tissue conditioner to reduce the adherence of C. albicans without significantly affecting the hardness of the heat-polymerized acrylic resin.