Stress Distribution on Short Implants with Varying Crown Heights - An In vitro Study.

The aim of this study is to determine the stress in short implants loaded with varying crown heights using a 3D finite element analysis. A total of three mandibular sectional bone blocks depicting the mandibular left first molar region were modeled. Each block carried Bicon implants of the same size and was designated B1, B2, and B3. The implant- crown ratio is 1:1.5, 1:2.5, and 1:3 respectively. The loading protocol included axial and oblique loads. The von Misses' equivalent stresses at the implant-bone interface were evaluated. Intergroup comparison was determined using one-way ANOVA analysis, and P values were calculated. Under an axial load of 600N, the models B1, B2, and B3 do not show any statistically significant P-values at the crestal module of the implant, abutment, and bone, whereas in crowns, the P-values were highly significant. Under an oblique load of 225 N at 0°, 45°, and 90°, model B3 showed the highest values in the crestal module, abutment, and crown. Based on the intergroup comparison and P value the study concluded that the variance in the crown height does not affect the bone and therefore microfracture of the bone and failure of osseointergration is not likely.

Sapindus Mukurossi - An Effective Biocleanser for Removable Dental Prostheses? An In vitro Study.

This study aims to determine the efficient concentration of Sapindus mukorossi that can be used as a denture cleanser. 60 heat cure denture base resin specimens of dimensions 10*10*2 mm were fabricated. Among these, 30 were fabricated by compression moulding technique and the remaining 30 by an injection moulding technique. The samples inoculated with Candida albicans and Streptococcus mutans were subjected to denture cleansing protocols using a medicinal herbal extract from the Sapindus mukorossi, at various concentrations [15%, 20%, and 25%]. The colony-forming unit [CFU] values were evaluated using a microprocessor colony counter. The statistical analysis was performed. The intragroup comparison showed a statistically significant difference between all groups except the compression moulded samples inoculated with Streptococcus mutans. The intergroup comparison revealed no statistically significant differences between the compared groups. The reduction in CFU values is evident in the effective anti-microbial activity of Sapindus mukorossi. A concentration of 25% Sapindus mukorossi solution showed the greatest efficiency. The maximum anti-microbial activity was observed against Candida albicans in a 25% concentration of Sapindus mukorossi. Among all, injection moulded samples showed better results.

Green Synthesis of Ganoderma Lucidum-Mediated Silver Nanoparticles and its Microbial Activity against Oral Pathogenic Microbes: An In Vitro Study.

Nanotechnology is developing into a fast-expanding discipline with applications in science and technology, and nanostructures are a crucial research tool in many fields. Due to their remarkable electrical, optical, magnetic, catalytic, and pharmacological capabilities, metal and metal oxide nanoparticles (NPs) have drawn study interest. Natural elements (plants, microorganisms, fungi, etc.) are utilized in a chemical-free, environmentally benign way to synthesize metals and metal oxides. The optical, electrical, and antimicrobial qualities of silver nanoparticle (AgNP) make them a popular choice. More than 200 active ingredients, including water-soluble, organic-soluble, and volatile chemicals, are found in Ganoderma. The main components are polysaccharides, adenosine, and terpenoids, each of which has exceptional therapeutic properties. This article explains the synthesis of Ag NPs by Ganoderma lucidum and tests the antibacterial effectiveness for use in biological applications.

Comparative Analysis of Strength of Differently Activated Denture Base Materials Including Recent Acetal Resin-Based Biodentaplast.

AIM AND OBJECTIVES: The aim of this study is to comparatively analyse the compressive and tensile strength of different types of record base materials made of different materials and processing techniques. MATERIALS AND METHODOLOGY: The compressive and tensile strength of 4 types of injection moulded materials were compared with a control of conventional compression moulded material. Twenty test specimens (10 tensile and 10 compressive) were fabricated from each material. A test was done using the Instron 3382 (Norwood, MA, USA) universal testing machine. RESULTS: Compressive and tensile test values showed significant differences between the record base resin groups tested for both compressive and tensile strength tests (p=0.00). The mean tensile strength value was greatest for Group V (66.0 MPa) and lowest for Group III (41.9MPa) and the mean compressive strength value was greatest for Group I (74.5 MPa) followed by Group V (70.2 MPa) and lowest for Group III (10.8 MPa). CONCLUSION: Injection moulded acetal resin showed the highest tensile strength value; it was comparable to that of conventional compression moulded polymethyl methacrylate (PMMA). Compression moulding is reported to have the highest compressive strength values followed by injection moulded acetal resin material. Injection moulded acetal resin material attributed to its advantages and superior strength value, can be used as a material of choice in various clinical scenarios.

Rehabilitation of a mid-facial defect using maxillary obturator with a maxillary expansion device and orbital prosthesis.

Midfacial defects are defined as congenital or acquired defects in the horizontal plane at the middle third of the face and communicate with intraoral maxillary defects. These defects lead to speaking difficulty, difficulty in saliva control and deglutition, mastication, and esthetics. Prosthetic rehabilitation of such defects with maxillofacial prosthesis is a challenging task. Maxillary defects with bilateral undercuts present are common. This case report explains to achieve retention by engaging the bilateral undercuts with the desired path of insertion and obtaining adequate retention of these prostheses. This clinical case report presents prosthetic rehabilitation of a mid-facial defect involving one orbit and the premaxilla region with the help of silicone orbital prostheses and magnets along with an expansion device. This dramatically improved the patient's speech, mastication, deglutition, esthetics, and self-confidence.

A comparative evaluation of shear bond strength between feldspathic porcelain and lithium di silicate ceramic layered to a zirconia core- An in vitro study.

BACKGROUND: The bond strength between the zirconia core and ceramic veneer is the weakest component in the layered structure. Delamination of veneering ceramic is reported as one of the most frequent problems associated with Veneered Zirconia restorations. The aim of this study is to compare the shear bond strength of lithium di silicate porcelain to that of feldspathic porcelain on a zirconia Substrate. MATERIAL AND METHODS: Two groups (group A and B) of zirconia blocks with each group having 20 samples were fabricated according to Schmitz Schulmeyer method. Group A (n =20 ) samples were veneered with feldspathic veneering porcelain and Group B (n=20) samples were veneered with heat pressed lithium disilicate ceramic. The fabricated samples were then evaluated for shear bond strength in Universal Testing Machine. The values were then statistically analyzed using independent sample t-test. RESULTS: Results of the current study showed that mean shear bond strength of feldspathic porcelain 11.40±1.29 MPa is comparatively lower than the mean shear bond strength of the lithium disilicate group 18.81±1.76 MPa. The statistical analysis indicated that (p value<0.01) there is a statistically significant difference in the shear bond strength between the two groups. CONCLUSIONS: The heat pressed lithium disilicate veneering materials has a better shear bond strength compared to feldspathic veneering ceramic material when layered to a zirconia core and it can be used as a viable alternative material to feldspathic porcelain layering material in bilayered zirconia restorations. Key words:Zirconia, bilayered ceramics, lithium disilicate , shear bond strength, ceramic chipping.

Implant supported prosthesis on edentulous mandible with multiple impacted teeth - a case report with 5 year follow up.

Multiple impacted teeth are quite often syndromically related, which could be hormonal or metabolic. It may be also due to infection, cyst, or trauma. A number of idiopathic multiple impacted teeth cases have been reported in the literature. In most of these situations, the impacted teeth are few in number. Here, we present a case with all mandibular teeth impacted. The number of reports in the literature of rehabilitation of such a clinical situation is very less. Impacted teeth can significantly complicate the rehabilitation of an otherwise straight forward case. When all teeth are impacted, the situation becomes even more complex. This case report illustrates prosthodontic rehabilitation of mandibular arch of a 24-year-old, asyndromic patient with implant-retained dentures following the surgical removal of impacted teeth. The objective of presenting this clinical report is primarily to increase the awareness, with which, the rehabilitation can be handled in a similar situation and also for the fact that such a report is a rarity.