Relation of Biological Factors with Failure of Osseointegration of Dental Implants

Osseointegration, a term explained by Branemark and co-workers in the early 1960s, represents a direct connection betweenbone and implant without interposed soft tissue layers. The purpose of the present topic is to discuss various factors responsiblefor the loss of implants. The factors influencing the failure of osseointegration have been identified as the medical status ofthe patient, smoking, bone quality, bone grafting, irradiation of bone, bacterial contamination, lack of pre-operative antibiotics,degree of surgical trauma, and operator experience. Furthermore, it appears that implant surface properties, roughness, andpremature loading influence the failure rate. Dental implantology is the science associated with the diagnosis, design, insertion,restoration, and/or management of alloplastic or autogenous oral structure to restore the loss of contour, comfort, function,esthetic, speech, and/or health of the partially or completely edentulous patient.

Comparison of Bone grafts for Alveolar ridge dimensional preservation

Introduction: The aim of this study was to assess the prevalence of suicidal ideation, suicidal attempts, andloneliness among dental and medical students in the western region of Saudi Arabia. Materials and Methods:This cross-sectional study investigated 607 dental and medical students and interns in private colleges in SaudiArabia. A self-administrated questionnaire was based on the Revised UCLA Loneliness Scale. Suicidal ideationand attempts were measured by a questionnaire adopted from previous research. The data was collected at theend of the year at examination time. Results: The loneliness mean was M= 45.14 (SD 8.66). Among theparticipants, 37.7% had experienced suicidal ideation throughout their lives, 33.4% had experienced suicidalideation during the previous 12 months, and 23.2% had attempted suicide. Loneliness was significantly relatedwith suicidal ideation during the previous 12 months (p <0.001) and with suicidal attempts (p = 0.005). Theresults showed that the following subgroups had higher risk for suicidal ideation and suicidal attempts: female,low family income, married, and dental students. Conclusion: The high levels of suicidal ideation and attemptsamong dental and medical students in the western region of Saudi Arabia call for the implementation ofprofessional counselling and health promotion programs.

Calcium phosphate cement as an alternative for formocresol in primary teeth pulpotomies.

Background: Formocresol remains to be the preferred medicament in pulpotomy, despite the concerns regarding tissue devitalization and systemic toxicity. Several materials were used as alternatives, but none proved significantly advantageous. Of recent, calcium phosphate cement (CPC) has been projected as an ideal pulpotomy material considering its tissue compatibility and dentinogenic properties. This study explores the suitability of a CPC formulation for pulpotomy, in comparison with formocresol. Materials and Methods: This comparative case study included 10 children (8-12 age group) having a pair of non-carious primary canines (both maxillary and mandibular) posted for extraction. Pulpotomy was performed with CPC in the right canines and formocresol in the left and sealed with IRM® (Dentsply). The teeth were extracted at 70 ± 5 days and sectioned and stained for the histopathological evaluation. Parameters such as pulpal inflammation, tissue reaction to material, dentine bridge formation, location of dentine bridge, quality of dentine formation in bridge, and connective tissue in bridge etc. were evaluated. Results: The histological assessment after 70 days showed no statistically significant difference between the two groups in any of the parameters. However, CPC gave more favorable results in pulpal inflammation, with a lower score of 1.6 against 2.6 for formocresol. CPC samples showed better formation of dentine bridge in quantity and quality. The mean scores for CPC for the extent of dentine bridge formation, quality of dentine bridge and connective tissue in the bridge, were 2.0, 1.4, and 1.2 respectively, whereas the corresponding values for formocresol were 0.8, 0.2, and 1.0. Conclusion: CPC is more compatible to pulp tissues than formocresol and it shows good healing potential. CPC is capable of inducing dentine formation without an area of necrosis.

Evaluation of the relative efficacy of autologous platelet-rich plasma in combination with β-tricalcium phosphate alloplast versus an alloplast alone in the treatment of human periodontal infrabony defects: A clinical and radiological study.

Background: Platelet-rich plasma (PRP) contains high levels of polypeptide growth factors that may enhance periodontal regeneration when combined with graft materials. Aim: The purpose of this study was to compare the efficacy of autologous PRP in combination with β-tricalcium phosphate (β-TCP) versus β-TCP alone in the treatment of human infrabony defects. Materials and Methods: Using a split-mouth design, 20 patients showing clinical evidence of almost identical bilateral infrabony defects were randomly selected. The right infrabony defects of the patient were designated as Group A and treated by the placement of β-TCP alone. The left infrabony defects of the same patient were designated as Group B and treated by the placement of PRP mixed with β-TCP. Clinical assessment of probing pocket depth and attachment level and radiographic evaluation of the defect depth were done preoperatively and at 12, 24 and 36 weeks postoperatively. The relative efficacy of two treatment modalities was evaluated using paired Student's t-test and the comparative evaluation between the two groups was done using independent Student's t-test. Results: Both the groups exhibited a highly significant reduction in probing pocket depth, gain in clinical attachment level and linear bone fill at the end of 36 weeks postoperatively. Comparative evaluation between the two study groups revealed a significant reduction in probing pocket depth (P = 0.036*), mean gain in clinical attachment level (P = 0.042*) and linear bone fill (P = 0.014*) in Group B as compared to Group A. Conclusions: Combination of PRP and β-TCP led to a significantly more favorable clinical and radiographic improvement in infrabony periodontal defects.

Calcium phosphate cement as a "barrier-graft" for the treatment of human periodontal intraosseous defects.

Background : Calcium phosphate cements (CPC) are apparently good candidates for periodontal treatment by virtue of their biocompatibility, mouldability and osteoconductivity. However, the clinical efficacy in this regard has not been established. This study is aimed at the evaluation of the efficacy of a formulation of CPC in healing human periodontal intraosseous defects in comparison with hydroxyapatite ceramic granules. Materials and Methods : In this clinical study, 60 patients with periodontal defects were divided into 2 test groups and 1 control group. The defect sites in the test groups were repaired with CPC and hydroxyapatite ceramic granules (HAG). Debridement alone was given in the control group. The progress was assessed at 3, 6, 9 and 12 months observation intervals through soft tissue parameters (probing depth, attachment level and gingival recession). Results: CPC showed significantly better outcome. Probing depth reduction values of CPC, HAG and Control at 6 months were 5.40 ± 1.43, 3.75 ± 1.71 and 2.90 ± 1.48, and those at 12 months were 6.20 ± 1.80, 4.5 ± 1.91 and 2.95 ± 1.73. Clinical attachment gain values of CPC, HAG and Control at 6 months were 5.15 ± 1.50, 3.45 ± 1.96 and 2.25 ± 1.52, and those at 12 months were 5.80 ± 2.02, 3.55 ± 2.06 and 2.30 ± 1.78, In both cases the P value was <0.001 showing high significance. The gingival recession over 12 months, for the CPC group is lesser than that in the HAG group and the value for the control group is marginally higher than both. Soft-tissue measurements were appended by postoperative radiographs and surgical re-entry in selected cases. Conclusions: Calcium phosphate cement is found to be significantly better than hydroxyapatite ceramic granules. The material could be considered as a "barrier-graft".

Bone healing capacity of the new fluoridated hydroxyapatite in the rabbit cranium defect

The bone graft materials are grossly divided into autogenous bone, allogenic bone, xenogenic bone, and alloplastic material. Among the various allogenic graft materials, hydroxyapatite(Ca10(PO4)6(OH)2, HA), the main inorganic phase of human hard tissue, is widely used as a repair material for bones. When HA applied to bony defect, however, it may be encapsulated with fibrous tissue and floated in the implanted area by the lack of consolidation. Fluoridated hydroxyapatite(Ca10(PO4)6(OH)2, FHA), where F- partially replaces the OH- in the hydroxyapatite, is considered as an alternative material for bone repair due to its solubility and biocompatibility. This study was designed to find out the bone healing capacity of FHA newly produced as a nanoscale fiber in the laboratory. We implanted HA and FHA in the rabbit cranium defect and histologically analysed the specimen. The results were as follows. 1. In the 4 weeks, fibrous connective tissue and little bone formation around materials of the experimental group I implanted HA were observed. In the experimental group II implanted FHA, newly formed bone around materials were observed. 2. In the 8 weeks, the amount of newly formed and matured bone of the experimental group II was more than the experimental group I and control group. From the results obtained, we suggest that FHA, newly synthesized, is relatively favorable bone substitute with bioconpatibility and has better bone healing capacity than pure HA.

Maxillary Sinus Augmentation Using Macroporous Biphasic Calcium Phosphate (MBCP(TM)): Three Case Report With Histologic Evaluation / 대한치주과학회지

BACKGROUND: Several bone grafting materials have been used in sinus augmentation procedures. Macroporous Biphasic Calcium Phosphate(MBCP(TM)) consists of the mixture of 60% HA and 40% beta-TCP. Therefore, it can provide good scaffold for the new bone to grow owing to HA, in the other hand, it can have bioactivity for bone remodeling owing to beta-TCP. The purpose of this study was to evaluate bone formation following maxillary sinus augmentation using MBCP(TM) by means of histologic analysis. MATERIAL AND METHOD: MBCP(TM) was placed as a primary bone substitute for maxillary sinus augmentation. Three patients were selected after evalaution of their medical dental examination. MBCP(TM) only, MBCP(TM) combined with Irradicated cancellous bone and MBCP(TM) combined with autogenous bone were used for each patient. After about eight months, bone biopsies were harvested for histologic evaluation and fixtures installed. RESULTS: Eight months after surgery we observed new vital bone surrounding MBCP(TM) particle and the amount of new bone was about 30% even though there were discrepancies between specimens. This case report documents that MBCP(TM) when used as a grafting material for sinus floor augmentation whether combined other bone graft material or not, may lead to the predictable results for dental implants on posterior maxillary area with insufficient vertical height for fixture installation.