COMPARISON BETWEEN STRONTIUM RANELATE AND METAL SUBSTITUTED HYDROXYAPATITE AS GRAFTING MATERIALS IN TREATMENT OF PERI-IMPLANT BONY DEFECTS WITH IMMEDIATE IMPLANTS (CLINICAL AND EXPERIMENTAL STUDY)

Abstract

Objective:The aim of this study is to compare between both of strontium ranelate and metallic substitute of hydroxyapatite as grafting materials in the treatment of peri-implant bony defects with immediate placement of dental implant in type I extraction sites within maxillary esthetic zone among clinical and experimental levels. This assessment was based on clinical, radiographic and histological studies. Subjects and Methods: The present study was carried on two types of population among both experimental levels on experimental white albinus rabbits and on clinical level among human patients for replacement of non-restorable maxillaryanterior and/or premolar teeth within esthetic zone by immediate implant. A written informed consent was obtained from all patients before their participation in this study.Patients were classified into two groups: the first one was with five patients with non-restorable maxillary anterior or premolar tooth that was treated by an immediately placed implant in conjunction with metallic substituted hydroxyapatite while the second one was treated by an immediately placed implant in conjunction with strontium ranelate as grafting material.The second sample population of study was carried out among ten male white (newzland) experimental rabbits with average body weight between 2.5 and 3 KG and within suitable environmental conditions in Medical Experimental Research Center (MERC) in faculty of medicine, Mansoura University. All rabbits sample was also divided equally and randomly in two groups with five rabbits within each one by the same criteria as mentioned where the first group was composed of five rabbits that received dental implant within intentionally made defect in tibia by trephine bur in conjunction with metallic substituted hydroxyl apatite as grafting material within gap between implant and defect and the second group was with the same criteria and procedures with strontium ranelategafting material within the defect. Pre-oparative photographs and cone beam computed topography (CBCT) were taken for study sample population. Within clinical patients, immediately paced dental implant have been placed in anterior esthetic zone with bone grafting around dental implant according to each group, Immediate CBCT and implant stability measurements has been taken after surgery followed by six months follow-up period to evaluate marginal bone loss, bone density, papillary esthetic score, implant stability and probing depth around dental implants. While within experimental animals trephine bur was used to intentionally create the bony defect that will simulate defect around immediate dental implant with grafting material around according to each group with six months follow-up to evaluate marginal bone loss, implant stability,bone density and for histological examination around implant within grafted area. All data were collected and statistically analyzed. Results:Generally among both clinical and experimental levels within both of clinical patients and experimental rabbits, metal substituted hydroxyl apatite (MSHAP) showed better results with significant difference than that presented in other group that has received Strontium ranelate (Sr) as a grafting material to fill the bony marginal gap around immediate dental implant during six months follow-up study period. Results presented high difference of significance between two groups in experimental and clinical levels in concern with both implant stability, marginal bone loss and even in bone quality and denisty when measured after six months follow-up. On the other hand there was no significant difference in concern with soft tissue response after six months in relation with peri-implant probing depth and MSHAP showed slight better results than that of Sr in records of papillary esthetic scores among clinical patients. Histological results showed better response of surrounding bony tissues towards MSHAP than that of Sr with more affinity of osteoblasts and osteocytes to the site of the grafted area. Conclusions:Metallic substituted hydroxyl-apatite (MSHAP) with its additive magnetic molecules within hydroxyapatite structure has better bony response from surrounding bony tissues than that provided by Strontium Ranelate (Sr) according to bone filling and preservation with less marginal loss, more affinity of new osteoblasts and mature osteocytes, long term implant stability after grafting and better bone density and quality at the grafted area around immediate dental implants in anterior maxillary area.