The study aimed to assess the effect of mandibular advancement device (MAD) in patients with obstructive sleep apnea for reduction in 24-h mean blood pressure, sleep quality, Apnea Hypopnea Index (AHI), and patient compliance, compared to continuous positive airway pressure (CPAP), other interventions, or no treatment. Three different databases such as PubMed, EMBASE, and CENTRAL were searched using different search terms till July 2021 as per the inclusion and exclusion criteria. After inclusion of studies, data extraction including risk of bias assessment was done. For each study, we used odds ratio, mean difference, and 95% confidence interval to assess and synthesize the outcomes. The quality of evidence was evaluated as per the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). Twenty-one randomized controlled trials were included: 497 patients in the MAD group, 239 patients in the CPAP group, and 274 patients in the sham group. In MAD-CPAP comparison, the results favored CPAP in the reduction of AHI of 3.48 (1.76-5.19). However, unclear results were found for sleep quality measured as Epworth Sleepiness Scale (ESS), patient compliance, and 24-h mean blood pressure. In MAD-sham comparison, the results favored MAD in the reduction of AHI of − 8.39 (−10.90–−5.88] and ESS of − 0.91 (−1.70–−0.12) and favored sham in terms of patient compliance while, unclear results for 24-h mean blood pressure. The GRADE score indicated that the quality of evidence is very low, low, and moderate for different outcomes. CPAP in comparison to MAD and MAD in comparison to sham showed a significant AHI reduction. However, patient compliance and 24-h mean blood pressure were not significantly different in MAD-CPAP or MAD-sham. Quality of evidence is very low and low when MAD was compared with CPAP and sham, respectively, for AHI.

Aims: Silicone elastomers, chemically known as polydimethylsiloxane used in maxillofacial rehabilitation, over a period of time, undergo degradation and discoloration once aged, thereby reducing clinical longevity. Many previous studies reinforced the maxillofacial silicone material with stronger materials to increase its mechanical properties. However, no studies have been conducted to evaluate all the primary properties using single reinforcing agent. This study was conducted to evaluate and compare the tensile strength, tear strength, color stability, and Shore A hardness of conventional and 1% trisnorbornenylisobutyl polyhedralsilsesquioxanes (POSS) modified room temperature vulcanizing (RTV) maxillofacial silicone after a 6 - month artificial aging period. Setting and Design: In vitro comparative study. Materials and Methods: Eighty-eight silicone samples were fabricated. Therefore for each parameter of tensile strength, tear strength, color stability and hardness, twenty two samples comprising of 11 samples of conventional RTV silicone (Group 1) and 11 for POSS modified RTV silicone (Group 2) were fabricated in stainless steel molds using ASTM D 412–06, ASTM D 624, and ASTM D 2240–15 Standards. Baseline measurements for Shore A hardness and color values were recorded. Samples were then exposed to 6 months of natural weathering process and evaluated for tensile and tear strengths, color stability (ΔE), and hardness. Statistical Analysis Used: Paired and unpaired t-test. Results: Intragroup and intergroup comparison was done using unpaired and paired t-test. At the end of 6-month aging period, the tensile strength and tear strength of POSS-modified RTV silicone were significantly higher than conventional RTV silicone (P < 0.0001 and P = 0.00014, respectively). Intragroup comparison of conventional group showed highly statistically notable changes in L, a, and b values (P = 0.01631, > 0.0001, and = 0.0.0067, respectively), whereas the POSS-modified RTV silicone showed statistically nonsignificant results in L, a, and b values' (P = 0.91722, 0.15174, and 0.10847, respectively) comparisons after aging. Intergroup ΔE value comparisons showed an extremely statistically difference (P < 0.0001) within the groups. Intergroup comparisons postaging hardness showed a high statistical difference between both the groups, indicating a significant increase in hardness in the conventional group (P < 0.0001). However, intragroup comparison for hardness values showed a statistically highly significant difference for Group 1 (P < 0.0001) and a nonsignificant difference (P = 0.4831) for Group 2. Conclusion: After the simulated 6-month aging procedure, 1% NB 1070 trisnorbornenylisobutyl POSS-incorporated RTV maxillofacial silicone showed better tensile strength, tear strength, Shore A hardness and color stability as compared to conventional RTV silicone. Hence, trisnorbornenylisobutyl POSS is a potent cross-linking agent which enhances the primary mechanical properties of RTV silicone can result in in significant increase in the mean life expectancy of RTV silicone even after 6 months of weathering.

Aim: Abutment screw loosening of implant-supported prosthesis causes a mismatch between the abutment and the implant. This screw loosening is influenced by the implant–abutment connection type, however, with contradictory results reported in different studies. The present study evaluates the stability of abutment–implant connections in three different systems before and after the fatigue test. Settings and Design: Thirty implants (4.3 mm in diameter and 12 mm in length) were divided into three groups of 10: Implantium, Zimmer, and straight internal hexagonal connection (SIC) implants. Materials and Methods: Two torques of 35 Ncm with an interval of 10 min were applied, followed by measuring removal torque value (RTV). The samples were re-torqued and then underwent a simulation of 1-year chewing clinical performance of dental implant under axial force of 400 N, with a frequency of 8 Hz (one million cycles). After fatigue test, the RTV was calculated and recorded. Statistical Analysis: The mean RTVs obtained before and after cyclic load were analyzed by SPSS version 22 software using multivariate analysis. Results: Significant differences in RTV and role of cyclic loading were found between SIC and Implantium groups (P = 0.006 and 0.021, respectively), as well as between Zimmer and SIC groups (P = 0.032 and 0.006, respectively), but not between Zimmer and Implantium groups (P = 0.771 and 0.248, respectively). Conclusion: The type of connection could affect the screw loosening, the preload loss, and the implant component stability. SIC group revealed the highest RTVs before and after cyclic loading.

Aim: Aim of this in vivo study was to assess the impact of two rehabilitation philosophies namely; Pankey Mann Schuyler (PMS) & Hobo Twin Stage (HOBO) on Oral Health-related Quality of life (OHRQoL) using Oral Health Impact Profile (OHIP 14). Settings and Design: This was a randomized clinical trial. Material and Methods: This study was designed based on the PICOT model. 40 patients were selected who need to undergo complete mouth rehabilitation. The intervention performed was complete mouth rehabilitation therapy and the results were compared with that of no intervention. The outcome was assessed in terms of improvement in mastication, phonetics, esthetics and overall OHRQoL (OHIP-14) over a period of 01 year at intervals of 48 hrs, 01 mon, 6 mon and 12 months. Patients were unaware of the treatment philosophy being used and were given a questionnaire (OHIP-14); at baseline (pre-treatment) and 48 hrs, 1, 6 and 12 months after completion of treatment (post-treatment) to evaluate OHRQoL. The data was collected by independent reviewers blinded to the regimen followed making the participants and the outcome assessors blinded to the procedure. Statistical Analysis: Independent Student's t-test and Chi-Square test were used for analysis Result: Analysis illustrated significant differences in scores obtained pre-treatment and post-treatment in both groups at 12 months (P < 0.05). At 12 months, OHIP-14 scores showed a mean percentage change of 51% in Group A (PMS); (P = 0.001) and a mean percentage change of 49% in group B (Hobo). Conclusion: Complete mouth rehabilitation therapy for management of generalized attrition or mutilated dentition is a viable and effective treatment option and brings about definitive improvement in Oral Health Related Quality of Life (OHRQoL) and overall health status of an individual.

Aim: The aim of this study was to compare the wear behavior of human tooth enamel opposing monolithic zirconia and layered zirconia after glazing and polishing by a two-body wear mechanism using a wear simulator. Settings and Design: This In-vitro study was done in Department of Prosthodontics, Sri Sai College of Dental Research, Vikarabad. Materials and Methods: Zirconia specimens were divided into four groups (n = 15), Group monolithic glazed zirconia (MG), Group monolithic polished zirconia (MP), Group zirconia layered with E. max ceram and glazed (LG), Group zirconia layered with E. max ceram and polished without glaze (LP). Sixty human premolar teeth were subjected to wear test against the zirconia specimens using a Pin on Disc wear tester under a constant load of 5 kg (49 N) at 30 rpm for 10,000 cycles. The loss of enamel was recorded before and after the wear test and mean loss of height of tooth enamel after 10,000 cycles of wear was measured with a profile projector. The surface characteristics of all the four group zirconia specimens were evaluated qualitatively with scanning electron microscope. Statistical Analysis Used: One way ANOVA, Tukey Post hoc. Results: One-way analysis of variance test revealed that the mean loss of enamel of four groups was statistically different with P < 0.001. A further Tukey post hoc test revealed that the MP group had lesser mean scores than group LP, MG, and LG. Conclusion: It was concluded that MP caused less wear to opposing natural teeth, and polished surfaces of both monolithic and layered zirconia showed less tooth wear compared to glazed surfaces of monolithic and layered zirconia.

Aim: Comparative evaluation of the fracture resistance of anterior provisional crowns fabricated by conventional and digital techniques. Settings and Design: Department of Prosthodontic, PGIDS, Rohtak, An in-vitro – Comparative study. Materials and Methods: Thirty recently extracted maxillary central incisors were handpicked. Tooth preparation was done according to the principles of tooth preparation. A single-step impression technique was used for impression making of the prepared tooth and stone models were poured. Extracted teeth were divided into 3 groups (n = 10 each) based on provisional crown fabrication technique. A bis-acryl-based (Protemp 4 3M ESPE) resin was used to fabricate the provisional crowns by the conventional indirect technique. The rest of the stone models (20) were scanned using lab scanner (Dentsply Sirona InLab EOS X5). CAD/CAM provisional material (Dentsply Sirona multilayer PolyMethyl Methacrylate) PMMA disc was used for fabrication of provisional restoration through milling technique. 3D printed temporary provisional material (NextDent C&B resin) was utilized for 3D printed provisional crowns. Cementation of provisional crowns was done using eugenol free temporary luting cement (Templute, Prime dental). All cemented provisional crowns were subjected to load under Universal Testing Machine. The maximum load to produce fracture for each specimen was recorded in Newton (N). Statistical Analysis Used: Shapiro–Wilk test was employed to test the normality of data. Kruskal- Wallis Test was used to compare the mean fracture resistance between all the groups. For intergroup comparison Mann-Whitney U Test was used. Results: The mean fracture resistance of group I (Conventional technique) was found to be 558.8459700 ± 22.33 N; for group II (CAD/CAM technique) 960.8427200 ± 37.49 N and for group III (3D Printed technique) 1243.1774000 ± 68.18 N. Group I had the least fracture resistance value while group III showed maximum value. Conclusion: Provisional crowns fabricated using 3-D printing technique showed higher fracture resistance followed by CAD/CAM technique and conventional technique. Additive manufacturing of provisional crowns using 3-D printing technique could be considered a reliable and conservative method for the fabrication of stronger provisional restorations.

Aim: Aim of this study was to evaluate the effect of silver nanoparticles incorporated injection molded heat-cured polymethylmethacrylate resin on wettability, anti-fungal effect, flexural strength and colour stability in human saliva. Settings and Design: An In-Vitro study with In -Vivo parameter Materials and Methods: Rectangular and circular stainless-steel dies were fabricated according to ISO standardization 20795-1:2018 and ADA specification number 12. A total of 144 samples were prepared and divided into 4 groups with thirty-six samples in each group. Each of the 4 groups were subdivided into 3 subgroups based on concentration of silver nanoparticles as 0% in subgroup A, 0.05% in subgroup B and 0.2% in subgroup C. Group 1 samples evaluated wettability, they were assessed at 0, 7, 90 and 180 days after immersing in human saliva using goniometer. Group 2 samples evaluated antifungal effect, they were assessed against Candida albicans in Muller hinton agar plate enriched with 2% glucose. Group 3 samples evaluated flexural strength, they were assessed by using universal testing machine. Group 4 samples evaluated colour stability, they were assessed using UV spectrophotometer at 0, 3 and 7 days after immersing in human saliva. Statistical Analysis Used: One-way ANOVA and Post- Hoc Tukey test were used to evaluate the significant differences in the mean values of the groups. Results: Subgroup C samples with 0.2% Ag nanoparticles had better wettability, maximum antifungal property, highest flexural strength and good colour stability followed by subgroup B and subgroup A samples. Conclusion: Injection molded denture base resin incorporated with 0.2% Ag nanoparticles could be used clinically as a denture base material for completely and partially edentulous patients.

Aim: The aim of this study was to assess surface roughness and marginal adaptation of Stereolithographic versus Digital Light Processed three-dimensional (3D) printed provisional resins. Materials and Methods: A 3-unit fixed partial denture (FPD) preparation was done on ideal model irrespective to 44–46. The Model was scanned and a 3-unit FPD was designed using 3-shape software. The STL file was transferred to two different 3D printers – Sprintray digital light processing (DLP) and Formlabs stereolithography (SLA). Eight samples were printed per group (total of 16 samples) using C and B temporary tooth-colored resin and cured according to the manufacturer's instructions. Marginal adaptation was checked for six surfaces per tooth for all the samples using a stereomicroscope. Surface roughness was also calculated for four samples from each group before and after polishing (pumice slurry + rouge and cotton buff) using a contact profilometer. Results: The mean maximum marginal gap overall, was seen for the DLP group on the mesiobuccal surface of the first premolar, i.e., 178.8 ± 8.35 μm, while the minimal marginal gap was seen for the SLA group on the mesiolingual surface of first molar − 32.5 ± 7.07 μm. Furthermore, all the DLP samples showed a statistically significant higher mean marginal gap as compared to SLA samples (P < 0.005). All the samples showed surface roughness within the acceptable range. There was a statistically significant difference noted in Rz (roughness depth) before and after polishing (P < 0.05). Conclusion: 3D printed temporary resin FPD via SLA showed a much better marginal adaptation (49.6 μm mean marginal gap for 46 and 106.8 μm for 44) as compared to those printed via DLP (101.8 μm mean marginal gap for 46 and 157.5 μm for 44). All the samples showed an acceptable surface roughness. Clinical Relevance: 3D printed temporaries have shown good marginal fit and adaptation and are a viable choice in patients where temporaries has to be given for long term before a final prosthesis can be fabricated (especially for full mouth rehabilitations).

Aim: To compare the effect of complete denture fabricated using selective pressure impression and functional impression technique on masticatory efficiency and oral health-related quality of life (OHRQoL) in patients with resorbed ridges. Settings and Design: A randomized two arm, parallel group study. Materials and Methods: Forty-eight participants with set inclusion and exclusion criteria were randomly allocated into two groups. Complete denture was fabricated in Group A and Group B using selective pressure and functional impression technique, respectively. The follow-up was done at 3 months. Masticatory efficiency was measured by color-changing chewing gum, and OHRQoL was assessed using the Geriatric Oral Health Assessment Index (GOHAI) Hindi Version. Statistical Analysis Used: The Wilcoxon signed-rank test was applied to check the intergroup analysis for the GOHAI scores of both impression techniques. The Mann–Whitney U test was applied to compare intragroup analysis for masticatory efficiency and the GOHAI scores of both the techniques. Results: A total of 45 participants completed the follow-up. The mean age of the total participants was 62.7 ± 3.8. No statistically significant difference (P > 0.05) was observed between the masticatory efficiency and post-GOHAI scores of both the impression techniques. Conclusion: Selective pressure and functional impression techniques may be successfully used to fabricate complete dentures for patients with resorbed ridges.

Aim: Screw loosening is a very common cause of failures in implant prosthodontics. In order to avoid screw fracture, it is imperative to understand the mechanical behavior of the screw and the dynamics it is subjected to intraorally. The present study was conducted to qualitatively evaluate and compare the morphological changes, surface defects, and cracks observed under a scanning electron microscope (SEM) in the prosthetic screw. Settings and Design: Two Stainless steel edentulous mandible models were fabricated on the basis of all on four and all on six concepts by using CAD design. Screw retained prosthesis were fabricated for both the models and total number of 80 prosthetic screws were made up of Ti6Al4V. Materials and Methods: Eighty prosthetic screws (N = 80) used in four- and six-unit implant-retained cast hybrid denture were subjected to cyclic loading of 1.5 million cycles and 3 million cycles, simulating a 5 and 10 years of usage, respectively. Once the simulated cycles had been completed in all subgroups, each prosthetic screw was inspected under SEM (×150–×1000) for any changes. Statistical Analysis: The data thus obtained were statistically analyzed using SPSS 12.0 software and P < 0.005 was considered statistically significant. Results: The study revealed statistically significant (P < 0.005) changes (like morphological changes, surface defects, crack initiation, and propagation) in the prosthetic screws after exposing them to predefined test conditions (P < 0.001). Conclusion: It can be concluded that the prosthetic screws need to be changed after a period of clinical use of 5 years irrespective of the number of implants used for rehabilitation. Further, the tilt of the abutment and numbers of implants also contribute to the stresses on the implant-supported prostheses.

Aim: The purpose of this study was to compare the accuracy of conventional implant impressions with digital impression techniques made using two different intraoral scanners. Setting and Design: In-Vitro study. Material and Methods: A scan of master cast containing four implants was made using two intraoral scanners: CEREC Primescan (Dentsply Sirona, USA) and 3Shape Trios (Copenhagen, Denmark) with PEEK scan bodies attached to the implants. Model was scanned ten times using different scanners. The accuracy of the chairside scanners was compared with highly accurate laboratory scanner. The scans were transferred into the software (Geomagic Control X 20, 3D Systems, Rock Hill, SC, USA) for analysis. The linear deviations and the angular deviations between the scans (scan of each model made using high-definition scanner and the master model scan) were calculated to determine the accuracy. Trueness was used as a parameter to compare the accuracy of different scanners (comparing test and reference). Statistical Analysis: Analysis of variance was performed with Bonferroni's post hoc test for multiple group comparisons. Results: Distribution of the mean overall absolute linear deviation was significantly lower in the conventional impression group compared to the CEREC Primescan scanner group and 3Shape Trios group (P < 0.05 for both). Distribution of the mean overall absolute linear deviation was significantly lower in the CEREC Primescan scanner group compared to the 3Shape Trios group (P < 0.05). Distribution of the mean overall absolute angular deviation did not differ between the three groups (P > 0.05 for all). Conclusion: Conventional impressions showed significantly greater accuracy compared to the digital impressions made with both the above intraoral scanners for implant-supported restoration of an edentulous arch. In addition, the digital impressions with the CEREC Primescan scanner showed greater accuracy as compared to the 3Shape Trios scanner.

While dealing with a grave second wave of ongoing pandemic COVID-19, India also saw a surge in cases of COVID-19-associated mucormycosis, a systematic fungal infection caused by the Mucorales species. Mucormycosis is a highly angioinvasive, rapidly spreading fungal infection. In numerous cases of mucormycosis, bilateral subtotal maxillectomy was performed due to unpredictable and indefinable advancement of fungus clinically. Effective obturation of bilateral maxillectomy defect is a difficult task and as this is a relatively uncommon surgical problem, insufficient data are available on the construction of delayed surgical obturator for such cases. The aim of this article is to discuss the design of Z-spring-retained delayed surgical obturator which is easy to fabricate, easy to rectify, cost-effective, and comfortable for the patients compared to previous spring-retained obturators. This surgical obturator is retained through Z-spring made of 1.02 mm thick wire. Due to the thick gauge, this spring counters postsurgery trismus and develops the seal between the acrylic plate and dorsum of the tongue during deglutition thus helps the patient in taking a soft diet initially. Novelty in this case is the design of the spring, which makes it beneficial for both patient and prosthodontist.