Prosthodontics

Visual analog scale in prosthodontics N Gopi Chander The Journal of Indian Prosthodontic Society 2019 19(2):99-100

The effect of incorporating various reinforcement materials on flexural strength and impact strength of polymethylmethacrylate: A meta-analysis Manali Vipul Somani, Meenakshi Khandelwal, Vikas Punia, Vivek Sharma The Journal of Indian Prosthodontic Society 2019 19(2):101-112 Polymethylmethacrylate (PMMA) is a widely used denture base material with a major drawback of inferior mechanical properties. In the existing published reports, most studies indicate the superiority of the incorporation of various reinforcement materials in PMMA in terms of the flexural strength (FS) and impact strength (IS), whereas none shows the compilation and comparison of all. The present meta-analysis aims at synthesizing all the available data. The purpose of this study was to systematically review the existing reports to compare and evaluate the effect of various reinforcement materials on FS and IS of heat-cured acrylic resin (PMMA) by combining the available evidence in a meta-analysis. A search strategy was adopted using PubMed, ScienceDirect, Ebscohost, Google Scholar, and Cochrane Central Register of Controlled Trials in February 2018 to screen research studies. These studies were screened against predetermined criteria for eligibility for meta-analysis. In the present meta-analysis, twenty articles were included. Out of 15 data available on reinforcement, 14 showed better results for IS of reinforced PMMA resin as compared to their respective control group. Out of the 25 available data, 11 showed better results for FS of reinforced PMMA resin when compared to their respective control group. The homogeneity test of meta-analysis confirmed acceptable heterogeneity among 15 reinforcement techniques of IS (i2 = 95.8%) and 25 reinforcement techniques of FS (i2 = 96.2%). A random-effects model and fixed-effects model were used for analysis. The present meta-analysis showed that reinforcement of PMMA can significantly increase FS and IS. Hence, it can be incorporated in clinical practice.

Comparative evaluation of condylar inclination in dentulous subjects as determined by two radiographic methods: Orthopantomograph and cone-beam computed tomography – An in vivo study Dipal Mawani, Byrasandra Channappa Muddugangadhar, Arindam Das, Arindam Mukhopadhyay The Journal of Indian Prosthodontic Society 2019 19(2):113-119 Aim: The aim of the study was to compare two radiographic techniques, orthopantomograph (OPG), and cone-beam computed tomography (CBCT) in determining the sagittal condylar guidance (SCG) and to find out if CBCT can serve as an alternative aid to program semi-adjustable and fully adjustable articulators. Materials and Methods: Following the inclusion and exclusion criteria, 40 individuals (20 males and 20 females) aged between 20 and 40 years were selected. An OPG and a CBCT radiograph were obtained for each individual. Using appropriate software, the SCG was measured for both the sides, for both the radiographic methods. The values for each individual were obtained by two investigators for both the methods using the respective software and the average value was taken. After performing the Shapiro–Wilk test, paired t-test was used to compare the mean difference pairwise (for both right and left side) while t-test was used to compare the mean difference between two groups. Results: Results showed that the right and left SCG values obtained from both, OPG and CBCT methods were comparable and there were no significant differences. Statistically significant difference was not found between the left and ride side condylar inclination values for both the sex obtained from both the methods. With increasing age, condylar inclination values obtained from both the radiographic methods tend to decrease. The values for SCG obtained from both the methods (CBCT and OPG) are thus comparable and correlated. Conclusion: The values for SCG obtained from both the methods (CBCT and OPG) are comparable and correlated. Thus, CBCT being a better radiographic technique can be used for obtaining the condylar inclination for programming the semi-adjustable and fully adjustable dental articulators.

The role of the combination of Moringa oleifera leaf extract and demineralized freeze-dried bovine bone xenograft (xenograft) as tooth extraction socket preservation materials on osteocalcin and transforming growth factor-beta 1 expressions in alveolar bone of Cavia cobaya Utari Kresnoadi, Primanda Nur Rahmania, Hera Utami Caesar, Eha Djulaeha, Bambang Agustono, Muhammad Dimas Aditya Ari The Journal of Indian Prosthodontic Society 2019 19(2):120-125 Aim: Alveolar bone resorption, often occurring after tooth extraction, can be minimized through socket preservation. This process uses a combination of Moringa leaf extract and demineralized freeze-dried bovine bone xenograft (DFDBBX) that is expected to generate both transforming growth factor-beta 1 (TGF-β1) expressions as a transcription factor associated with osteoblast differentiation and osteocalcin accelerating alveolar bone formation. This research aimed to analyze the role of the combination of Moringa leaf extract and DFDBBX induced in socket preservation when generating TGF-β1 and osteocalcin expressions. Materials and Methods: The left mandibular incisors of 56 Cavia cobaya were extracted and divided into four groups subjected to different socket preservation treatments. The first group treated with polyethylene glycol, the second group with DFDBBX, the third group with Moringa leaf extract, and the fourth group with a combination of DFDBBX and Moringa leaf extract. The C. cobaya were examined on days 7 and 30, after which the specimens were sacrificed and examined using an immunohistochemical technique. The resulting data were then analyzed using one-way ANOVA and Tukey's honestly significant difference tests. Results: There was a significant difference in TGF-β1 and osteocalcin expressions between the groups (P < 0.05). The highest mean amount of TGF-β1 and osteocalcin was found in the fourth group on both days 7 and 30. Conclusions: The combination of Moringa leaf extract and DFDBBX can effectively generate TGF-β1 and osteocalcin expressions during the preservation of tooth extraction sockets.

Evaluation of the effect of silicone residue after different surface treatments on shear bond strength of glass ionomer cement to the dentin surface R Anusha, M C Suresh Sajjan, A V Rama Raju, D Bheemalingeswararao, Nukalamarri Om Brahma Prasad Chary The Journal of Indian Prosthodontic Society 2019 19(2):126-133 Aim: Use of silicone fit-checking material during cementation of fixed restoration has shown to leave residual silicone film after peeling off of fit checker (FC). This residual film reduced bond strength of cement to the inner surface of restoration. Silicone residue effect on tooth surface needs to be studied. The aim of this study was to evaluate the effect of residual silicone film on shear bond strength (SBS) of glass ionomer cement (GIC) to dentin surface and the efficacy of different surface treatments (STs) on dentin in the removal of silicone residue. Materials and Methods: Fifty freshly extracted human molars were individually mounted on acrylic blocks and occlusal surfaces were ground flat until dentine surface was exposed. Specimens were divided into five groups as follows: Group I: without application of FC (n = 10) as control group; Group II: without any ST after peeling off FC (n = 10); Group III: ST using wet pumice after peeling off FC (n = 10); Group IV: ST with 37% phosphoric acid after peeling off FC (n = 10); and Group V: ST with 10% polyacrylic acid after peeling off FC (n = 10). GIC was placed on the dentinal surface using polyvinyl mold and subjected to SBS test using universal testing machine. The debonded specimens were observed under stereomicroscope for the mode of failure. Selected debonded dentinal surfaces from each group were examined under scanning electron microscope. One-way analysis of variance and Tukey's test. Results: Group II (1.083 MPa) showed significantly lower SBS. Among the STs, Group III (2.047 MPa) was comparable to the control group whereas Group IV (1.376 MPa) and Group V (1.63 MPa) were significantly lower. There was no significant association between failures and groups at P = 0.257. Conclusion: The residue of silicone was demonstrable on dentin surface after peeling off FC and caused a significant reduction in SBS between GIC and dentin. ST with wet pumice is found to be beneficial in removing silicone residue and improving SBS, followed by phosphoric acid and polyacrylic acid.

The effect of a zirconia primer on the shear bond strength of Y-TZP ceramic to three different core materials by using a self-adhesive resin cement Rashin Giti, Reza Zarkari The Journal of Indian Prosthodontic Society 2019 19(2):134-140 Aim: Considering the importance of bond strength of zirconia ceramic to different core materials, this study aimed to evaluate the effect of a new zirconia primer, a mixture of organophosphate and carboxylic acid monomers, on the bond strength of zirconia to three core materials cemented with a self-adhesive resin cement. Materials and Methods: The study was done on 36 disk-shaped zirconia specimens in the case (receiving new zirconia primer) and control groups (n = 18) and three core material subgroups (n = 6) (amalgam, nickel–chromium [Ni-Cr], and composite resin). A self-adhesive resin-based luting agent bonded the two parts together. The shear bond strength was tested and the facture modes were determined. Two-way ANOVA and Tukey's honestly significant difference tests were used for data analyses (α = 0.05). Results: Zirconia primer could not significantly increase the bond strength of zirconia ceramic to different core materials (P = 0.754). Composite resin and amalgam cores showed significantly higher bond strength than Ni-Cr core (P = 0.001). On using zirconia primer, 100% of failures of composite resin cores were cohesive inside the core material, 75% in amalgam core and 100% in Ni-Cr core were adhesive. Conclusions: The use of new zirconia primer based on organophosphate/carboxylic acid monomers could not enhance the bond strength of zirconia ceramic to different core materials. The bond strength of zirconia to amalgam and composite resin cores was higher than that to Ni-Cr core material.

Evaluation of the effect of dentin surface treatment by air abrasion and Er:YAG laser on the retention of metal crowns luted with glass ionomer cement in teeth with reduced crown height: An in vitro study Sameer Chauhan, Neerja Mahajan, Rajesh Sethuraman, YG Naveen The Journal of Indian Prosthodontic Society 2019 19(2):141-148 Aim and Objectives: The purpose of this study was to investigate the effect of dentin surface treatment with aluminum oxide air abrasion and Er:YAG laser on tensile bond strength of metal crowns. Metal crowns were luted with conventional glass ionomer cement (GIC) in the teeth with reduced crown height, where preparation geometry did not provide optimal retention form. Materials and Methods: Forty-eight human premolars were prepared to receive metal crowns and were randomly divided into four groups for tensile bond strength testing. Group A: Untreated dentin luted with self-adhesive composite resin cement as positive control; Group B: Untreated dentin luted with GIC as negative control; Group C: Surface treatment with 50 μm aluminum oxide air abrasion and luted with GIC; Group D: Surface treatment with Er:YAG laser (λ =2.94 mm) with a total energy 84.88 J/cm2 of (60 mJ/pulse, 10 Hz, 60 pulses, and 100 μs pulse width) and luted with GIC. The cemented specimens were thermocycled and later subjected to axial load in a universal testing machine at 0.5 mm/min cross-head speed for tensile testing. Scanning electron microscopic evaluation of dentin surface treatment and cement–dentin interface was also done in representative specimens. Results: One-way analysis of variance showed statistically significant difference among/within the groups (P < 0.001). Tukey's post hoc test presented significant increased tensile bond strength of Er:YAG laser group. Air abrasion group showed no significant increase in tensile bond strength values (P = 0.033). Conclusion: Dentin surface treatment with Er:YAG laser significantly improved the tensile bond strength of luting GIC compared to air-abraded and untreated dentin.

Evaluation of the effect of implant angulations and impression techniques on implant cast accuracy – An in vitro study Aman Arora, Viram Upadhyaya, Kirti R Parashar, Divya Malik The Journal of Indian Prosthodontic Society 2019 19(2):149-158 Aim: The purpose of this study was to evaluate the accuracy of implant casts generated with splinted and nonsplinted impression techniques with multiple parallel and nonparallel implants. Materials and Methods: In this experimental study, two edentulous maxillary stainless steel models with seven implant analogs in the central incisor, canine, premolar, and first molar region simulating clinical condition were used (control groups). In one master model, implant analogs were placed parallel to each other, whereas in another model, analogs were placed with a tilt-to-longitudinal axis. Forty stone casts were made from each model using splined and nonsplinted technique using polyether with open-tray technique. Then, the difference in the distance between the master cast and experimental cast in three dimensions was measured by coordinate-measuring machine. One-way ANOVA, post hoc Bonferroni test, and unpaired t-test were used for data analysis. Results: Statistical comparisons were made using ANOVA test, post hoc test, and unpaired t-test. Splinted technique with parallel implants generated interimplant distance values closest to the master model, followed by nonsplinted technique with parallel implants, splinted technique with angulated implants, and nonsplinted technique with angulated implants. Conclusions: Splinted impression technique exhibited higher accuracy than the other technique studies in both parallel and angulated implants.

Validity and reliability of intraoral conventional tracer and intraoral digital tracer in different positions for recording horizontal jaw relation in edentulous patients Nikhil Bharat Abbad, Rajeev Srivastava, Vivek Choukse, Vandana Sharma The Journal of Indian Prosthodontic Society 2019 19(2):159-165 Aim: The purpose of the study is to evaluate and compare the horizontal mandibular positions recorded between intraoral conventional tracer and intraoral digital tracer in upright and supine position. Materials and Methods: Twenty-four edentulous patients with well-formed ridge and adequate interarch distance space were selected. MATLAB software was assimilated with intraoral digital tracer and was utilized in the study for recording the horizontal movements of the mandible, i.e., gothic arch tracing by intraoral digital tracer and was observed on a laptop with the help of MATLAB Software. For each subject, multiple mandibular readings were recorded and analyzed through software, and similar readings were recorded with conventional intraoral tracers. The comparison between intraoral conventional tracer and intraoral digital tracer was done to assess the reliability. Moreover, the consistency of recording horizontal mandibular position was also compared between upright and supine position. Results: The data were procured and utilized in comparison for different positions revealed statistically significant difference by using Student's Paired t-test. The test resulted in supine position better compared to upright position (P = 0.0001). The association between supine position with upright position was calculated using Fischer's exact test, and it was also found to be statistically significant (P = 0.002). The Pearson's Correlation analysis was performed to check the agreement between upright and supine position and very weak downhill correlation (r2= −0.130) was observed between the two variables. Conclusion: On evaluation and comparison of horizontal mandibular position, it was found that the intraoral digital tracing technique is more valid compared to conventional intraoral tracer technique. It was also observed that the consistency of reproducibility in recording horizontal mandibular position in supine position is significantly higher than upright position.

An in vitro study to compare the influence of newer luting cements on retention of cement-retained implant-supported prosthesis Hasan Sarfaraz, Arifa Hassan, K Kamalakanth Shenoy, Mallika Shetty The Journal of Indian Prosthodontic Society 2019 19(2):166-172 Purpose: The study was conducted to evaluate the retentiveness of specifically formulated implant cements and compare its retentiveness with a commonly used noneugenol zinc oxide luting cement and also to assess the influence of abutment height on the retentiveness of these cements. Materials and Methods: A master stainless steel mold was used to mount snappy abutment-implant analog complex in acrylic resin. A total of six snappy abutments (Nobel Biocare®) of 4 mm and 5.5 mm height with their analogs were used. A total of 66 ceramill® Sintron metal copings fabricated using computer-aided design/computer-aided manufacturing system and divided into six groups (n = 11) according to the height (three 4 mm abutment and three 5.5 mm abutment). The cements that were compared were a Noneugenol zinc oxide provisional cement (Temp-BondTM NE), a Noneugenol temporary resin cement (Premier® Implant Cement) and a resin based acrylic urethane cement (Implalute® Implant Cement). After cementation samples were immersed in artificial saliva for 7 days and subjected to a pull-out test using a universal testing machine at a crosshead speed of 1 mm/min. The load required to de-cement each coping was recorded and analyzed using one-way ANOVA, post hoc multiple comparison, and independent t-test. Results: Noneugenol temporary resin cement had the highest tensile strength followed by noneugenol zinc oxide cement and the least retentive strength was observed in resin-based acrylic urethane cement. Conclusion: The results suggest that noneugenol temporary resin cement may be considered as a better choice for cementation of implant prosthesis, as it has shown to have better mechanical properties.