Purpose: The purpose of this research was to evaluate the tensile strength of hypoallergenic acetal resin, heat-cured polymethylmethacrylate (PMMA) resin, to acrylic and silicone-based lining materials. Materials and methods: Heat-cured PMMA resins and acetal resins (pink) were used as denture base materials and samples were prepared with a dimension of 10 x 10 x 43 mm blocks (n = 16 each). Silicone-based liner (soft-liner tough) and acrylic resin-based liner (Visco-gel) specimens were processed between heat-cured PMMA resin blocks and acetal resin blocks (3 x 10 x 10 mm). The groups were denoted as HCAS—heat cure-soft-liner tough group, n = 8; HCAV—heat cure-Visco-gel group, n = 8; ACS—acetal resin-soft-liner tough group, n = 8; ACV—acetal resin-Visco-gel group, n = 8. On a universal testing machine with a crosshead speed of 1 mm/minute, the tensile bond strength was determined. Bonferroni HSD and one-way analysis of variance (ANOVA) test were used for data analysis (p < 0.05 was considered significant). Results:There were significant differences in bond strength across groups (p < 0.001). The acetal resin group exhibited lower bonding strength values than the heat cure PMMA resin group. The tensile bond strength of Visco-gel [0.88 ± 0.09 megapascals (MPa), HCAV group; 0.29 ± 0.04 MPa, ACV group] was higher than Soft-liner Tough (0.62 ± 0.38 Mpa, HCAS group; 0.19 ± 0.34 MPa, ACS group) in both resins. Mostly adhesive failures were seen in all groups. Intergroup comparison showed significant differences between all groups except for ACV vs ACS (p = 1.000). Conclusion: Regardless of the liner type, acetal resin demonstrated the lowest tensile strength values. Heat-cured acrylic with Visco-gel liners performed better than silicone-based liners and was preferred in patients who did not exhibit hypersensitivity.

Purpose: The purpose of this finite element analysis (FEA) was to evaluate and compare stresses generated in bone, with carbon fiber-reinforced polyetheretherketone (CFR-PEEK) and titanium ball and locator attachments, in CFR-PEEK and titanium implant-supported mandibular overdenture. Materials and methods: In this FEA study, two mandibular models were formed using three-dimensional (3D) scans. One model represented a completely edentulous mandible with two implants placed in the interforaminal region and loaded with an overdenture using ball attachment systems. Similarly, the second model consisted of locator attachment systems. Each model was divided into four subgroups according to the material (CFR-PEEK and titanium) used for the implant and attachment system. A 100 N vertical load and a 100 N oblique load (20° oblique) were applied in the canine region on the overdenture. The von Mises stresses and maximum and minimum principal stresses were analyzed using the analysis of systems software. Results: In ball attachment groups, a combination of CFR-PEEK implant and attachment showed the least stresses in bone (1.977 and 1.090 GPa) and implants (0.028 and 0.005 GPa) under vertical and oblique loading, respectively. Similarly, in locator attachment groups, combination of CFR-PEEK implant and attachment showed least stresses in bone (0.475 and 0.306 GPa) and implants (0.183 and 0.105 GPa) under vertical and oblique loading, respectively. When ball and locator attachment were compared, the minimum stresses in bone and implant were seen in the CFR-PEEK implant and CFR-PEEK locator attachment system. Conclusion: The use of locator attachment systems is better than the ball attachment system, as it increases the durability of the overdenture by decreasing the stresses in bone and implant systems. CFR-PEEK implant along with CFR-PEEK attachments can be used in overdenture cases, as it decreases the stresses in surrounding bone compared to titanium implant and attachments.

Purpose: The purpose of the present study was to evaluate and compare the crestal bone loss in surface-treated hydrophilic implants versus moderately rough hydrophobic implants. Materials and methods: A total of 20 implants were placed in patients, divided into two groups—group I—sandblasted, large grit, acid-etched implant surface (SLA) (sandblast, acid-etched hydrophobic, n = 10) and group II— SLA plus hydrophilic surface treatment (SLA-SH) (sandblast, acid etched hydrophilic, n = 10). Crestal bone loss was evaluated and compared radiographically with cone-beam computed tomography (CBCT) and intraoral periapical radiograph (IOPA). CBCT was done at baseline (time of insertion) and 24 weeks after insertion of implants. IOPA radiograph was taken at baseline, 10th and 24th week. The statistical analysis was done using paired t-test to evaluate the change from baseline to follow-up. The intergroup comparison was analyzed using an unpaired t-test to compare the mean crestal bone loss. Results: Crestal bone loss on mesial, distal, buccal, and lingual when compared using CBCT in both groups at baseline; no significant difference was observed. After 24 weeks of implant placement, a significant difference was observed on all sides in both groups (0.026, 0.008, 0.047, and 0.043, respectively). Intragroup comparison of group I and group II at 24 weeks using CBCT showed a significant difference in crestal bone loss when compared with baseline. On comparison of bone loss through IOPA, group I and II showed statistical differences on the distal side (0.001) at 10 weeks and mesial (0.046) and distal (0.006) sides at 24 weeks. Conclusion: The bone loss was evident in both groups when compared with the baseline. Surface-treated hydrophilic implants showed less bone loss as compared to moderately rough hydrophobic implants. Surface-treated implants seem to reduce crestal bone loss, so they can be preferred in cases where early loading is required.

Purpose: To evaluate the nasal volume and nasal area using acoustic rhinometry in patients with maxillectomy defects rehabilitated with obturator prosthesis. Materials and methods: A total of eight patients having maxillectomy defects rehabilitated with obturator prosthesis were assessed for nasal cross-sectional area (CSA) and nasal volume using Eccovision Acoustic Rhinometer system. The average nasal area and nasal volume in patients with maxillectomy defects were compared before and after rehabilitation with an obturator prosthesis. The statistical analysis was done using a paired t-test to compare nasal area and nasal volume before and after rehabilitation. Results: The mean ± standard deviation (SD) values of the nasal area and nasal volume showed statistically significant difference when compared with and without obturator prosthesis. The mean right nasal CSA before rehabilitation was 0.806 ± 0.158 mm² and it significantly reduced to 0.218 ± 0.039 mm² after the use of an obturator prosthesis (p < 0.0001). Similarly, the right nasal volume, which was 8.302 ± 1.229 cm³ significantly improved to 3.281 ± 0.44 cm³ after rehabilitation with obturator prosthesis (p < 0.0001). The average left nasal CSA and nasal volume were compared with and without prosthesis and they too showed a significant improvement from 0.677 ± 0.281 mm² to 0.215 ± 0.038 mm² and 8.81 ± 0.982 cm³ to 3.65 ±, 0.300 cm³, respectively (p < 0.0001). Conclusion: The assessment of pretreatment (postmaxillectomy) and posttreatment (postrehabilitation with obturator prosthesis) values of nasal volume and nasal area, when compared with standard values, clearly indicated that obturator prosthesis restored the nasal volume and area to the near normal.

Purpose: The purpose of this finite element analysis (FEA) was to comparatively assess implant stability, abutment stability, and screw passivity in dental implants with different internal connections and guide in their selection process. Materials and methods: Three widely accessible types of internal implant-abutment connections served as the study's foundation. Lengths of 9.5 and 11 mm and diameters of 3.5 and 4.1 mm were selected with three different internal abutment attachment crest module designs. The three designs studied were: hex with a 45° bevel, octagon with a reverse 82° bevel, and trilobe with a butt joint. Young's modulus and Poison's ratio were used to allocate the various structures employed in the FEA model to their respective materials. An axial load of 35 N was applied over the abutment, and a 70 N load was applied non-axially. Moreover, a 10 N horizontal load was also applied. Overall displacement and stresses in bone, implant, and screw were calculated using Analysis of Systems (ANSYS) software. Results: It was found that on the application of 35 N vertical load, almost all the models showed similar overall displacement. The oblique load of 70 N also showed not much difference in overall displacement in all models. However, the overall stress concentration was slightly higher (125.87 MPa) in model 3 with the trilobe butt joint design. Overall implant stress is lowest (121.3 MPa) in model 2 with an octagonal design. Octagonal type of internal connection showed better screw passivity and abutment stability under axial as well as nonaxial loading. Conclusion: Abutment stability, as well as implant stability, is more with octagonal internal connection design. Moreover, inner screw stress is lowest in the octagonal design as compared to the other two designs, with the highest stress in the trilobe butt joint connection.

Purpose: The purpose of this study was to compare the masticatory efficiency and bite force of patients wearing complete mandibular dentures with and without a soft acrylic liner, having no previous denture-wearing experience. Materials and methods: A total of 24 healthy, completely edentulous patients aged 45–65 years with no previous history of complete denture wear were included. Participants were provided with a conventional maxillary denture against either a conventional mandibular denture [conventional complete denture (CCD)] followed by a new mandibular denture lined with acrylic soft liner [acrylic soft liner complete denture (ASLCD)] or in the reverse sequence as per the randomization chart. The masticatory efficiency was measured using a spectrophotometer, and the bite force was measured using a piezoelectric quartz sensor-based bite force-measuring device. The outcome variables were evaluated at 3 and 6 weeks after the insertion of each mandibular denture in all patients using repeated measures analysis of variance (ANOVA) and intergroup comparison was done with paired t-test. The p < 0.05 was considered to be statistically significant. Results: Mean difference in masticatory efficiency showed a significant difference among the two groups, 0.233 ± 0.037 and 0.443 ± 0.164 (optical density at λ_max = 530 nm) at 3 and 6 weeks, respectively (p < 0.001). Bite force increased with time in both groups and the significant difference in mean difference was found as 15.48 ± 2.72 at 3 weeks and 17.35 ± 3.87 N at 6 weeks (p < 0.001). Conclusion: Masticatory efficiency and bite force improved significantly over time for first-time complete denture wearers. A better outcome was observed with acrylic soft-lined mandibular dentures compared to when the same patients wore the denture without a liner.

Purpose: To evaluate the effect of the location of implants, radiation therapy, and soft tissue reactions on survival rates of dental implants in the extraoral maxillofacial prosthesis. Materials and methods: An electronic search was conducted for articles published in English, listed with Medline (PubMed) and Embase from 2000 to till date. The focused question was “Is there any effect of location, radiation, and soft tissue reactions on survival rates of dental implants in extraoral maxillofacial prosthesis?” The selection of articles was done according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines. The risk of bias was checked using the Newcastle–Ottawa scale. Results: The investigation identified a total of 10,800 titles of studies with extraoral maxillofacial prostheses, out of which 17 studies were included in this review based on the selection criteria. It was seen that there was an increase in the failure rate of dental implants in the extraoral maxillofacial prosthesis in presence of radiation. The mean survival rate of implants in nonirradiated areas was 82.6% whereas that of irradiated areas was 77.72%, suggesting a lower survival rate in irradiated areas. Conclusion: Radiation therapy does affect the survival rates of implants, but they are not a contraindication. Implant placement in such cases must be calculated and planned carefully, with special emphasis on the quality of bone, location of implants and their characteristics, compliance, and manual abilities of the patients, and their health status.

Management of swallowed dentures involves a multidisciplinary approach. The diagnosis of ingested dentures can be challenging, requiring awareness of different specialists including dentists, gastroenterologists, surgeons, otolaryngologists, anesthesiologists, etc. This case series presents three cases of swallowed removable partial dentures. The first case is a 65-year-old female with a denture transversely impacted between the walls of the esophagus. The second and third case is accidental ingestion of removable prosthesis during swallowing. The dentures were retrieved with the help of a multidisciplinary team approach. The case series aims to spread awareness among the geriatric and general population on the safety aspect of the usage of dentures.

Prosthetic rehabilitation of rhinectomy defects with a custom-made silicone prosthesis can provide excellent results for patients. However, prosthesis stability, retention, and time to full rehabilitation remain a concern for many patients. The aim of this clinical report is to describe the early prosthetic rehabilitation of a rhinectomy defect with a zygomatic implant-supported nasal prosthesis. Bilateral horizontal zygomatic implant placement, performed at the time of tumor resection in this Brown class VI nasomaxillary resection, provided predictable remote anchorage for a subsequent prosthesis, with the initial implant-retained prosthesis being provided just 2 weeks following surgery. High implant stability was achieved, which allowed early loading of the implants and facilitated early rehabilitation for the patient through the engagement of high-quality bone in the zygomatic body. The technique has offered an accelerated restoration of facial cosmesis following rhinectomy, allowing early recovery for the patient even prior to postoperative (post-OP) radiotherapy.