Statement of the problem: Designing of removable partial denture (RPD) present numerous biomechanical problems regarding the principles of reciprocation. However, extra coronal resilient attachment does not always supply suitable support and bracing because of their resilient nature. Therefore, they require specially designed bracing arms on surveyed crowns that require deeper tooth preparation lingually to prevent over contouring of the abutment teeth crown. Purpose of the study: The aim of this study was to evaluate clinically and radiographically the extra coronal semi precision attachments incorporated in metallic (RPD) with two different designs of reciprocation; parallel interlock and integrated interlock. Materials and methods:Six patients were selected for this study having maxillary completely dentulous arch against mandibular bilateral distal extension ridges posterior to second premolar. All attachment clinical and laboratory steps were performed for both designs using Split-mouth experimental method. Abutment teeth were examined clinically using; Plaque Index, Gingival Index, Periodontal Probing Pocket Depth and Clinical Attachment Level and radiographically immediately at time of RPD insertion then 3, 6 months of denture use. Results:Clinical results showed statistically significant increase in all parameters around parallel interlock design than integrated interlock design after six months. There was statistically significant increase in total mesial and distal bone loss associated with parallel interlock design in relation to integrated interlock design at six months follow up period. Conclusions: Absence of lingual bracing arm with integrated interlock design decreased the opportunity for plaque accumulation and enhanced the oral health of the premolar abutment teeth. Clinical implications:This study recommends the use of integrated interlock design for reciprocation as a common design of extracoronal semiprecision attachment for distal extension RPD for its favorable intraoral health parameters.

INTRODUCTION:Computer-assisted design, computer-assisted manufacture (CAD/CAM) can be successfully applied to the fabrication of removable partial denture (RPD) alloy frameworks and replace laboratory crafting techniques. The CAD/CAM techniques have been widely used for a long time to manufacture dental prostheses. Computer-aided technologies allow more precise and systematic modeling, and could therefore reduce the burdensome steps of both chair-side and laboratory work, saving vital time. OBJECTIVES: This study was aimed to compare between the accuracy of chrome-cobalt removable partial denture frameworks designed and fabricated using CAD/CAM technique with that fabricated using conventional technique MATERIALS AND METHODS: Seven maxillary bilateral partially edentulous patients having Class III modification 1 Kennedy classification were selected from those attended to the prosthodontic department, Faculty of Dentistry, Alexandria University. For each patient, two different cobalt chromium removable partial frameworks were constructed; the first one was fabricated using CAD CAM technique (group A)and the other framework was fabricated using conventional manufacturing technique(group B) and were compared through evaluation of: (1) Guiding plane/plate relation. (2) Accuracy of fit of occlusal rests and major connector. RESULTS: all removable partial dentures fabricated by CAD/CAM technology showed increased improvement of accurate adaptation of the palatal strap major connector, guiding plane\plate relation and fit of occlusal rest, also it was less time consuming and economic need compared to conventional technique. CONCLUSIONS: The use of CAD/CAM technology for fabrication of removable partial denture frameworks should be widely applied because of its favorable clinical accuracy.

INTRODUCTION:Recent researches had shown that, in principle, computer-assisted design, computer-assisted manufacture and rapid prototype technologies (CAD/CAM) can be successfully applied to the fabrication of removable partial denture (RPD) alloy frameworks and replace laboratory crafting techniques. The (CAD/CAM) techniques have been widely used for a long time to manufacture dental prostheses. Polyoxymethylene (POM) also known as acetal resin has been used as an alternative tooth-colored denture base and denture clasps material since 1986 and was promoted primarily for superior esthetic. OBJECTIVES: To evaluate clinically the use of Polyoxymethylene partial dentures designed and fabricated by using CAD/CAM technology compared to conventional cobalt chromium partial denture through both the masticatory efficiency and patient satisfaction. MATERIALS AND METHODS: This clinical trial was conducted on twenty mandibular partially edentulous patients (Kennedy class I) who received two types of RPD. Type I was Polyoxymethylene partial denture designed and fabricated by using CAD/CAM Technology and Type II was cobalt chromium partial denture fabricated using the conventional technique .At time of denture insertion, the masticatory efficiency of both types of dentures was evaluated for each patient .After 3 months of denture use, each patient was clinically evaluated through both the masticatory efficiency and patient satisfaction. RESULTS: Type I RPD showed better masticatory efficiency than Type II RPD but without statistical significant values at different follow up periods. Patients showed more satisfaction with type I RPD than with type II RPD with a significant value. CONCLUSIONS: Polyoxymethylene partial denture designed and fabricated by using CAD/CAM Technology is a favorable treatment for partially edentulous patients showing improvement of masticatory efficiency and favorable patient satisfaction.

INTRODUCTION: Obstructive sleep apnea (OSA) is a condition in which there is repetitive and intermittent occlusion of the upper airway (UA) during sleep. OSA can be treated through; continuous positive airway pressure (CPAP), surgery, or oral appliances. Mandibular Advancement Appliance (MAA) is considered a valid alternative, which can be the first choice in simple snorers and mild-moderate OSA. MAA can be either custom-made or non-custom-made, one-piece or two-piece, titratable or non-titratable. While Monoblock designs permit no mouth opening, two-piece appliances vary in permissible lateral jaw movement and in the coupling mechanisms which attach the two plates together. OBJECTIVES: measuring the change in UA volume after the use of two different designs of MAA (Monoblock and Biblock) MATERIALS AND METHODS: Twenty patients with diagnosed OSA were divided randomly into two equal groups: Monoblock group ; received Monoblock MAA fabricated using CAD/CAM technique at different advancement levels; 50% then 75% of maximum advancement, Biblock group; received Biblock MAA fabricated using CAD/CAM technique at different advancement levels; 50% then 75% of maximum advancement. UA volume of all patients were evaluated after three months of acclimatization of each stage of advancement through Cone-Beam Computed Tomography (CBCT). RESULTS: Biblock group showed statistically significant increase in UA volume at 75% mandibular advancement level, compared to Monoblock group (p=.001). There was statistically significant increase in UA volume percentage change from baseline to 50% advancement (p=.016), and also from baseline to 75% advancement (p=.001) in favor to Biblock MAA. CONCLUSIONS: Both Monoblock and Biblock MAA produced statistically significant increase in UA volume of OSA patients. Biblock MAA with elastics presented statistically significant favorable increase in UA volume in relation to Monoblock MAA.

INTRODUCTION:Maxillary implant overdenture has improved the quality of life for edentulous patients especially patients with atrophic maxilla. Sub-nasal lifting was introduced to solve the problem of severely atrophic anterior edentulous maxilla to allow insertion of dental implants. The type of attachment may influence the retention and stability of the prosthesis and thus, masticatory efficiency. Especially locator attachment is used with great success for improvement of implant-assisted over denture OBJECTIVES:To evaluate clinically and radiographically the effect of wearing implant-retained over denture in patients with atrophic anterior maxilla which was reconstructed by nasal lifting. Patient satisfaction was also evaluated. MATERIALS AND METHODS:This clinical trial was conducted on seven patients with edentulous atrophic anterior maxilla rehabilitated by Sub-Nasal Lifting, restored with bilateral two implants and grafted with Platelet-Rich Fibrin. For each patient an implant-retained over denture with locator attachments was constructed. Patient assessment was done using different three method including clinical, radiographic evaluation and patient satisfaction at three intervals: at time of over denture insertion, 3months and 6 months of denture use. RESULTS: All patients showed increased bone density around dental implants with slight decrease in marginal bone height, no mobility of each implant was detected .All patient showed increased well satisfaction throughout the follow up periods. CONCLUSIONS Two implant-assisted maxillary over denture is an acceptable treatment for patients with atrophic anterior maxilla and it showed increased patient satisfaction and favorable clinical and radiographic findings.