الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Implant-retained tissue-supported overdentures use different methods of retention approaches that include bars and clips, ball attachments, magnets, stress-breaker attachments, and resilient denture liners. Resilient denture liners have found increasing favor in several applications in prosthetic dentistry, including use with dental implants for retention. It allow the denture to move toward the implant heads and the edentulous areas, providing greater latitude of movement and comfort to the patient. Liners also absorb energy and dissipate masticatory forces more evenly to the implants and edentulous ridge. The major dental implant problem is the initial crestal alveolar bone loss. Implant crestal bone loss appear as a compound condition cre¬ated by bacteria and excessive stress at the crestal implant-bone interface. This consideration was the stimulus to plan this study to overcome the two major causative factors of crestal bone loss around implants especially with immediate loading approach. This study was planned to evaluate to what extent chitosan film coating would beneficially or adversely affect healing of surgical site around the implants and to what extent it would affect peri-implant tissue changes ? Ten male patients that had completely edentulous maxilla and mandible, complaining from poor mandibular denture retention and stability, having sufficient interarch space, free from any systemic diseases or chronic abnormal habits were selected from Out-Patient Clinic, Faculty of Dentistry, Mansoura University. For all patients in this study; the effect of chitosan film coating was divided into two phases. Firstly study the effect of chitosan film coating on implant surgical site healing. Secondly study the effect of chitosan film coating on peri-implant tissue changes with the ball abutment female housing soft liner. Evaluation the effect of chitosan film coating on implant surgical site healing around the dental implants, was done in terms of clinical and immunological evaluations. Evaluations were done after 1 week from chitosan film coating. Clinical evaluations of chitosan film coating on early wound healing were done using modified gingival index according to a the procedure described by Loe and silness (1963) and modified plaque index according to the procedure described by Mombelli et al.(1987). Immunological evaluation of chitosan film coating and its effect on implant surgical site wound healing was done by monitoring the pre-implant crevicular fluid collected from the newly formed pre-implant crevice using IL-1β biomarker. Evaluation the effect of chitosan film coating on peri-implant tissue changes was done in terms of clinical ,immunological and radiological evaluations. Evaluations were done at first six months (first observation period ) and after second six months (second observation period ). Clinical evaluations of chitosan film coating on peri-implant tissue changes were done in terms of modified gingival index according to a the procedure described by Löe and silness (1963), modified plaque index according to the procedure described by Mombelli et al.(1987), and peri-implant probing depth according to a procedure described by Eickholz et al .(2001). Immunological evaluation was done by monitoring the pre-implant crevicular fluid collected from pre-implant crevice . Radiological evaluation was done by monitoring the crestal alveolar bone changes along vertical and horizontal planes using periodic standardized long cone peri-apical radiographs as recommended by Heckmann et al.(2004). Results of this study indicate significant decrease in the mean difference of gingival index scoring, modified plaque index after 1-week in the group coated with chitosan film around implant surgical site, and after 1st and 2nd six months in the group coated with chitosan film with the ball abutment female housing soft liner, and significant increase in mean gingival, plaque indices and pocket depth measurement in the control group. These results indicate that chitosan produces buffering action, posses anti-bacterial activity when present in the oral cavity at concentration close to minimum inhibitory concentrations, and also its anti-adhesive effect due to tooth-surface coating. This explanation appeared supported by the levels of host tissue immune response represented by interleukin 1-β. Also results of this study indicate significant increase in the mean difference of the peri-implant pocket depth measurement with increase in the vertical and horizontal bone loss after 1st and 2nd six months in the control group non-coated with chitosan film with the ball abutment female housing soft liner than in the coated group. These results signify the role of chitosan film coating as an ideal candidate for tissue healing and potential bio-resorbable anti -bacterial barrier membrane. from results of this study ,it could be concluded that, 1- The importance of clinical evaluation of implant surgical site healing is the starting base time of implant marathon success. 2- The peri-implant crevicular fluid (PICF) basically become wound fluids and may be used to evaluate phases of healing. 3- Chitosan film coating as a biomaterial may enhance early wound healing without bacterial invasion due to its bactericidal and bacteriostatic characteristics. 4- Merits of using resilient soft liner for reducing stresses at the crestal –implant bone interface must be weighted against its adverse effect on peri-implant tissue health.