The biomaterial-mediated healing of critical size bone defects in the ovariectomized rat.

UNLABELLED: This study demonstrated an impaired biomaterial-mediated bone regeneration in a critical sized calvarial defect established within an ovariectomized rat model. Histological and microtomographic evidences were supported by an impaired osteoblastic gene expression and altered expression of estrogen receptors and adipogenic markers. INTRODUCTION: This work aims to address the bone regeneration process in the ovariectomized rat model, by assessing a calvarial critical size defect implanted with a biocompatible bovine bone mineral graft. METHODS: Animals were randomly divided into two groups: Ovx (bilateral ovariectomy) and Sham (control surgery). Following 8 weeks, all animals were submitted to a surgical bicortical craniotomy (5-mm circular critical size defect), which was filled with a biocompatible mineral graft. Animals were euthanized at 1, 3, and 6 months following graft implantation (n = 10), and results on the orthotopic bone regeneration process were blindly evaluated by radiographic, microtomographic, histological, histomorphometric, and gene expression techniques. RESULTS: In the attained model, in both Sham and Ovx groups, the bone regenerative process was found to occur in a slow-paced manner. Likewise, a qualitative evaluation of the microtomographic and histological analysis, as well as quantitative data from histomorphometric indexes, revealed reduced bone regeneration in Ovx animals, at the assayed time points. Significant differences were attained at the 3 and 6 months. Gene expression analysis revealed a reduced expression of osteoblastic-related genes and an altered expression of estrogen receptors and adipogenic markers, within the regenerating bone of Ovx animals. CONCLUSIONS: Due to the similarities between the osteoporotic animal model and the human condition of postmenopausal osteoporosis, it might be relevant to consider the potential clinical implication of the osteoporotic condition in the biomaterial-mediated bone tissue healing/regeneration process.

Periodontal inflammation in renal transplant recipients receiving everolimus or tacrolimus - preliminary results.

OBJECTIVE: To compare oral health status between renal transplant recipients (RTRs) receiving tacrolimus (Tac) or everolimus (ERL) as immunosuppressive therapy. DESIGN: This study is a cross-sectional study. METHODS: Thirty-six RTRs receiving Tac and 22 RTRs receiving ERL were included in the study. Age, gender, time since transplant and pharmacological data were recorded for both groups. Oral health status was assessed through the evaluation of teeth, periodontal parameters as well as saliva flow rate and pH. RESULTS: RTRs receiving ERL were older than those receiving Tac. No differences were found between groups concerning oral hygiene habits, oral symptoms, smoking habits, unstimulated and stimulated saliva flow rate and pH, clinical attachment level or the number of decayed, missing and filled teeth. However, RTRs receiving ERL presented lower visible plaque index and lower values for bleeding on probing when compared to RTRs receiving Tac. In addition, RTRs receiving ERL presented a gingival index varying from normal to moderate inflammation whereas RTRs receiving Tac presented a gingival index varying from mild to severe inflammation. CONCLUSIONS: RTRs receiving ERL have lower periodontal inflammation when compared to RTRs receiving Tac.

IL1 gene polymorphisms and unsuccessful dental implants.

OBJECTIVES: This study aimed to analyse the association between polymorphisms in the IL1 gene cluster and failure of dental implants in a Portuguese population. MATERIAL AND METHODS: A total of 155 Caucasian Portuguese subjects were divided into two groups: 100 with successful dental implants and 55 with unsuccessful dental implants. DNA was obtained through an oral mucosa scraping. PCR was used to identify the polymorphisms: single nucleotide changes in positions -889 of IL1A gene and +3953 of IL1B gene. RESULTS: The prevalence of the polymorphisms -889IL1A gene and +3953IL1B gene, determined by the positive result of TGP (Genetic Test for Periodontitis; CGC, Genetics, Portugal), in the studied population rehabilitated with dental implants was of 33.50%. Allele 1 of the IL1B gene was the most prevalent (62.20%), followed by allele 1 of the IL1A gene (54.80%) and the least frequent was allele 2 of IL1B gene (37.40%). Success of dental implants was mainly associated with a negative TGP result, whereas no success was found to be related to a positive result. There were no statistically significant differences between the alleles 1 and 2 of the genes IL1A and IL1B and the tobacco and alcohol consumption for the success or no success of the dental implants. CONCLUSIONS: The alleles 1 and 2 of IL1A gene and the alleles 1 and 2 of IL1B gene were statistically associated with the success or no success of the dental implants. Tobacco habit and alcohol consumption showed no statistically significant association with success or no success of the dental implants.