Abstract:

This study aimed to compare the amount of stress generated on two versus four implants with equator attachments in maxillary implant overdentures with palatal coverage and palateless designs. Four standardized educational edentulous maxillary models simulating bone type II were used. The models were divided into two main groups according to palatal design (palatal coverage and palateless), and each group was further subdivided based on the number of implants (two or four implants). In the two-implant subgroup, implants were placed bilaterally in the canine regions perpendicular to the residual ridge using a surgical stent, whereas in the four-implant subgroup, implants were installed bilaterally in the canine and second premolar regions. Equator attachments with appropriate cuff heights were selected, and framework patterns were constructed. Four strain gauges were cemented to each fixture using strain gauge cement. A LLOYD digital loading device was used to apply compressive loads to measure the resulting stresses around the implants for each attachment configuration. The results demonstrated a statistically significant difference between stresses on two implants with equator attachments (74.53 ± 35.9 N/m × 10²) and four implants with equator attachments (10.85 ± 10.81 N/m × 10²) within the same palatal coverage design. Similarly, a statistically significant difference was found between stresses on two implants with equator attachments (123.75 ± 44.60 N/m × 10²) and four implants with equator attachments (14.51 ± 14.60 N/m × 10²) within the same palateless design. It was concluded that stress on two implants with equator attachments was markedly greater in the palateless design compared with the palatal coverage design, whereas stress on four implants with equator attachments was slightly greater in the palateless design than in the palatal coverage design, with no statistically significant difference.

This study compared the retention of polyamide clasps engaging porcelain-fused-to-metal and zirconia retainers with identical 0.50 mm undercuts in posterior free-end saddle maxillary removable partial dentures. Four standardized acrylic resin models simulating maxillary bilateral posterior edentulous with first premolar abutments were prepared to receive either porcelain-fused-to-metal or zirconia crowns incorporating mesial occlusal rest seats. Polyamide RPA clasps were fabricated using an injection molding technique and tested for retention using a universal testing machine at a crosshead speed of 5 mm/min. The mean retention force of polyamide clasps was 6.68 ± 2.59 N for zirconia crowns and 5.47 ± 2.27 N for porcelain-fused-to-metal crowns. The results demonstrated minimal loss of retention for polyamide clasps against both ceramic materials, with no significant difference in retention related to the type of ceramic retainer.

Abstract:

This study aimed to evaluate stress distribution around two and four implants supporting maxillary implant overdentures retained by locator attachments, comparing full and partial palatal coverage designs. Four identical acrylic models representing completely edentulous maxillary arches were fabricated and covered with polyvinyl siloxane impression material to simulate the oral mucosa overlying the residual ridge. The models were divided into two main groups according to the number of installed implants (two or four), and each group was further subdivided based on palatal design (full or partial palatal coverage). Locator abutments (female components) were secured to the implants using an abutment driver, after which the prosthetic frameworks were constructed. Four strain gauges were bonded to each implant fixture using strain gauge cement to record strain values. A LLOYD digital loading device was employed to apply controlled compressive loads, and the resulting stresses around the implants were measured for each configuration.

Statistical analysis revealed a significant difference in stress values between two-implant overdentures with full palatal coverage (30.64 ± 17.47 N/m × 10²) and those with partial palatal coverage (49.72 ± 23.17 N/m × 10²), with higher stresses observed in the partial coverage design. In contrast, although four-implant overdentures with partial palatal coverage (8.77 ± 4.54 N/m × 10²) demonstrated higher mean stress values than those with full palatal coverage (5.51 ± 3.83 N/m × 10²), this difference was not statistically significant.

Within the limitations of this in vitro study, full palatal coverage design resulted in lower stress values compared to partial palatal coverage in two-implant-supported maxillary overdentures. For four-implant-supported overdentures, full palatal coverage also showed lower stress values; however, the difference was not statistically significant.

Abstract

Complete dentures remain an essential treatment option for edentulous patients, especially in regions where implant-supported prostheses are limited. Successful prosthodontic outcomes require systematic execution of clinical steps, including patient examination, impression taking, custom tray fabrication, jaw relation recording, try-in, and post-insertion management. This study aimed to assess the knowledge of complete denture fabrication among fourth-year dental students. A descriptive cross-sectional design was employed among 37 students (94.9% response rate) enrolled in 2024 at the Department of Prosthodontics, Faculty of Oral and Dental Medicine, Gharyan University. Data were collected using a validated, self-administered questionnaire covering patient assessment, primary and final impressions, custom tray design, jaw relation records, occlusal plane orientation, articulator use, try-in procedures, and post-insertion care, and analyzed descriptively.

All students (100%) reported performing histories, oral examinations, primary impressions with alginate, and centric relation registration. Knowledge gaps were observed in advanced procedures: 75.7% selected light-cure acrylic for custom trays, awareness of spacers, stops, and relief holes was limited, polyvinylsiloxane was the most frequently used final impression material (62.2%), yet 59.5% disinfected impressions improperly with water alone. None used a face bow or semi-adjustable articulators, relying solely on non-adjustable types. Students demonstrated solid foundational knowledge of basic procedures; however, deficiencies in custom tray design, post-palatal seal determination, impression disinfection, and articulator use indicate a need for enhanced clinical teaching and practical training to meet current prosthodontic standards.

Keywords. Complete Denture, Dental Students, Prosthodontics, Impression Technique.

Abstract The aim of this study was to estimate the levels of TNF-α in serum and gingival crevicular fluid, in patients with chronic periodontitis (CP), before and after phase I therapy with subgingival delivery of Hyaluronic acid (Gengigel Gel). A total of thirty subjects were included in this study; 20 CP patients as a study group (group I) and 10 systemically healthy subjects with clinically healthy gingiva as a control group (group II). The nonsurgical periodontal therapy (SRP) + HA gel were done in group I. Periodontal parameters, including PI, GI, BOP, PD and the CAL, were recorded. GCF and serum were collected from all individuals included in the study; the first sample was collected from all groups (study and control) before treatment. The second sample was collected 4 weeks after subgingival delivery of Hyaluronic acid & phase I therapy from group I. Levels of TNF-α in GCF and serum were quantified using ELISA. The results showed a statistically significant reduction in total levels of TNF-α in serum and TNF-α in GCF in study group after application of Hyaluronic acid with phase I therapy. Results also showed all clinical parameters were significantly improved after application of Hyaluronic acid with phase I therapy in groups I (p<0.001). Scaling and root planing (SRP) is the mainstay of treatment of periodontal diseases, furthermore subgingival application of Hyaluronic acid gel with SRP were effective in improving clinical parameters in CP patients. TNF-α level in serum and GCF are reduced after phase I therapy with application of Hyaluronic acid.

لدراسة كانت مقارنة بين نسبة الفلورايد في عينات عشوائيه لمياه طبيعية و مياه معلبة و ذلك لأهمية الفلورايد في تكوين الأسنان و حمايتها من التسوس

The researchers in this study set out to do just that by investigating what goes wrong with people's permanent dental prostheses in Libya. One hundred patients from the clinic in Gharyan, Libya, who had come in complaining of problems with their fixed dental prostheses were included in the study, and the reasons for their failure were categorized using Manappallil's system. Failures in Class 3 accounted for 30% of all failures, Class 4 for 24%, Classes, 2, and 4 for 8%, Classes 5 and 6 for 15%, and Class 6 for 11%. Class 1 for 8%, Class 2 for 12%, Class 4 for 24% Class 5 for 15 % and Class 6 for 11%. Unserviceable restorations due to poor margins were indicated as the most common cause of failure in class 3 failures in the current study. Keywords: Rehabilitation, Fixed partial dentures, Failure classification, success

Abstract

Purpose: The purpose of this study was to evaluate the fitness of mandibular Kennedy class I PEEK removable partial dentures fabricated with various techniques.

Materials and Methods: Six patients were selected for this study with maxillary completely edentulous arch against mandibular distal extension ridges posterior to canine teeth. each patient was randomly given the following frameworks in a crossover design; Group I: All patients were received PEEK frameworks fabricated by milling via CAD-CAM technique (PEEK disc were used). Group II: All patients were received PEEK frameworks fabricated by injection molding technique (Granular form of medical grade PEEK). For each framework (milled & injected), the fitness evaluation were done by measuring the gap between the framework and oral structures by evaluation the thickness of light body poly vinyl- siloxane impression material.

Results: The mean overall and site specific values of Gap distance beneath frameworks fabricated by CAD-CAM technique was significantly higher than the mean values of Gap distance in frameworks fabricated by injection technique.

Conclusion: Within the limitations of this short-term clinical study it was concluded that: 1) The fitness of both techniques of the RPD PEEK BioHPP frameworks manufacture were clinically accepted by the participants. 2) The RPD PEEK BioHPP frameworks manufactured by CAD / CAM was less fitness values than BioHPP frameworks constructed by Injection molding technique.

placing anterior dental implant is a challenging procedure for dental professional

T he conclusion from this present review would indicate that there were insufficient RCTs to adequately address the original research question, although a number of suggestions may be recommended. There was no doubt from the evidence presented in the published literature that in the the accumulation of the plaque which may in turn lead to gingival inflammation. Furthermore, there also appears to be a higher risk of dental caries (particularly root caries) in RPD wearers in the absence of good oral hygiene measures The importance of an integrated prosthodontics maintenance programme with regular recall visits to include both oral and denture hygiene care of a RPD cannot be under-estimated and should be adopted as a gold standard in general dental practice.absence of good oral hygiene measures a RPD may promote