Evaluation of flexural strength and microhardness in Vaccinium macrocarpon (cranberry)-added self-cure polymethyl methacrylate dental resin: An in vitro study.

AIM: Occurrence of denture stomatitis and prosthesis breakage are common problems faced by elderly people wearing removable dentures. To overcome this, several attempts are made to improve the denture material by addition of antimicrobials without compromising original properties. The aim of the study was to evaluate flexural strength and microhardness of self-cured polymethyl methacrylate (PMMA) denture base resin after addition of Vaccinium macrocarpon (commonly called as cranberry), extract as antimicrobial, at varying proportions. STUDY SETTING AND DESIGN: Experimental in vitro study. MATERIALS AND METHODS: Frozen cranberry fruits were subjected to extraction process in the presence of aqueous solvents. Lyophilized extract was added in proportions of 0, 0.5, 1.0, 1.5, and 2.0 dry wt/wt % into polymer of self-cure PMMA denture base resin. Based on cranberry inclusion, the study comprised one control (0%) and four test groups (0.5%-2%) with total of 100 samples. A three-point bending test for flexural strength was done for fifty study samples (n = 10). Surface of fractured samples was analyzed using a scanning electron microscope (SEM). Microhardness was determined using Vickers hardness test. STATISTICAL ANALYSIS USED: One-way statistical ANOVA test was done to find the difference between groups, followed by Tukey's post hoc test for multiple pairwise comparison. RESULTS: Flexural strength ranged from 66.80 to 69.28 MPa, and a statistically insignificant difference was observed between groups (P > 0.05). SEM evaluation showed uniformly dispersed strands of cranberry extract in PMMA matrix. With higher concentration, less voids were seen. Vickers microhardness value significantly decreased from 15.96 in the control group to 14.57 with 2% cranberry addition (P < 0.05). CONCLUSION: Incorporation of cranberry extract into self-cure PMMA denture base resin, up to 2 dry wt %, did not decline the flexural strength. However, there was a significant decrease in Vickers microhardness values when compared against the control group (0% cranberry inclusion).

Retention and Patient Satisfaction of Conventional Over Simplified Non-Balanced Maxillary Removable Complete Dentures.

AIM: Insufficient evidence is available in quantifying the retention between simplified and conventional non-balanced dentures. The aim of the study was to quantify and compare the maxillary denture retention and patient satisfaction between conventional and simplified removable non-balanced complete dentures. METHOD: This randomized clinical trial recruited 44 patients (n=22) with definitive criteria. Simplified and conventional non-balanced complete dentures were fabricated for the intervention groups. The denture retention of maxillary complete dentures was assessed with a dynamometer and patient satisfaction with a visual analogue scale. The mean retention of maxillary denture and satisfaction were recorded at 0-,3-, and 6 - month intervals. The data were statistically analyzed. (α=.05). RESULTS: The mean ±SD of retention for conventional denture at 0, 3, and 6 months by dynamometer ranged from 122 ± 1.64 N to 121 ± 1.57 N and 111 ±1.45N to 110±1.97 N for the simplified denture. The mean ±SD of visual analogue score varied between 9.45±0.35 to 7.19± 0.69 for conventional dentures and 8.00 ±1.39 to 6.81±0.82 for simplified dentures. The repeated ANOVA, t-test and post-hoc Bonferroni revealed statistically significant differences between the two types of denture. (P⟨.05) Conclusion: Numerical retention and satisfaction were higher in conventional non-balanced dentures than simplified dentures.

Finite element analysis of displacement with single and two piece hollow bulb obturator prosthesis.

BACKGROUND: Rehabilitation of hemi-maxillectomy defects is difficult and challenging when there is displacement of obturator prosthesis. The literature lacks data on the displacement of different types of obturators. The intent of the study was to evaluate the differences in displacement between the single and two piece hollow bulb obturator prosthesis in Aramany Class I maxillectomy defect. METHODS: Finite element (FE) model of Aramany Class I maxillectomy defect restored with single and two piece closed bulb obturator was fabricated based on patient computed tomography (CT) scan. Finite element analysis (FEA) with three different load applications was done to measure the displacement of the obturator. Graphical and numerical values of displacement were obtained and the results were tabulated. RESULTS: The results were obtained as displacement colour images and the numerical displacement values. The displacement of two piece obturator was 4.779e-8, 6.372e-8, 7.965e-8 compared to single piece obturator 4.509e-8, 6.012e-8, and 7.5151e-8. There was marginal numerical increase in magnitude of displacement in two piece obturator compared to single piece obturator. CONCLUSION: The study observed no significant difference in displacement between the obturator. The numerical difference in displacement is more in two piece obturator compared to the single piece obturator.

A Custom Made Intrinsic Silicone Shade Guide for Indian Population.

INTRODUCTION: Replication of natural skin colour in maxillofacial prosthesis has been traditionally done using trial and error method, as concrete shade guides are unavailable till date. Hence a novel custom made intrinsic silicone shade guide has been attempted for Indian population. AIM: Reconstruction of maxillofacial defects is challenging, as achieving an aesthetic result is not always easy. A concoction of a novel intrinsic silicone shade guide was contemplated for the study and its reproducibility in clinical practice was analysed. MATERIALS AND METHODS: Medical grade room temperature vulcanising silicone was used for the fabrication of shade tabs. The shade guide consisted of three main groups I, II and III which were divided based upon the hues yellow, red and blue respectively. Five distinct intrinsic pigments were added in definite proportions to subdivide each group of different values from lighter to darker shades. A total number of 15 circular shade tabs comprised the guide. To validate the usage of the guide, visual assessment of colour matching was done by four investigators to investigate the consent of perfect colour correspondence. Data was statistically analysed using kappa coefficients. RESULTS: The kappa values were found to be 0.47 to 0.78 for yellow based group I, 0.13 to 0.65 for red based group II, and 0.07 to 0.36 for blue based group III. This revealed that the shade tabs of yellow and red based hues matched well and showed a statistically good colour matching. CONCLUSION: This intrinsic silicone shade guide can be effectively utilised for fabrication of maxillofacial prosthesis with silicone in Indian population. A transparent colour formula with definite proportioning of intrinsic pigments is provided for obtaining an aesthetic match to skin tone.

Comparison of the Effect of Different Ceramic Alloys and Porcelain Systems upon the Color of Metal-Ceramic Restorations: An In Vitro Study.

UNLABELLED: The exact replication of natural tooth color in a metal ceramic restoration is a challenging fact as its affected by enumerable factors. Research revealing the influence of base metal alloys with different porcelain systems on the color of the restorations have shown minimal interest. The aim of the study was to evaluate the optical influence of different alloys (mainly base metal) and ceramic systems affecting the final color of metal-ceramic restorations. Four commercial ceramic alloys, two Ni-Cr, one Co-Cr and a high-noble alloy were combined with two porcelains in metal-ceramic specimens with a standardized thickness of layers. Ten disc-shaped specimens were prepared for each alloy/porcelain combination. High-noble was used as control group. Only opaque and dentin layers were applied. The specimens were analysed with Spectrophotometer, and data were obtained in the CIELAB color system. The recorded data were analysed with a one-way ANOVA and multiple range test by tukey-HSD procedure to identify the significant groups at 5 % level. The final color of the metal-ceramic specimens were significantly affected by both type of the alloy and the porcelain systems used (P < 0.0001). The Co-Cr alloy-porcelain combination produced least color difference when compared with the high-noble control group. There was significant difference (P < 0.0001) between both the brands of Ni-Cr alloy-porcelain systems. For all the alloy-porcelain combinations VMK 95 porcelain showed minimum color difference compared to the d-SIGN porcelain group. CONCLUSION: The final color of metal ceramic specimens was influenced both from the type of base metal alloy substructure and from the type of overlying porcelain.

Comparison of obturator design for acquired maxillary defect in completely edentulous patients.

The most challenging and appreciated area in the field of Prosthodontics is the rehabilitation of maxillary defects. Tumors of the head and neck are the common cause for acquired maxillofacial defects. Surgical consequences predispose the patient to hypernasal speech, fluid leakage into nasal cavity, impaired masticatory function, and cosmetic deformity. The Prosthodontists play a significant role in the intervention and improve the quality of life of such patients. The current article describes two clinical case reports of completely edentulous patients with acquired maxillary defects.