Influence of thyroid hormanes on bone heading around titanium implants : a histometric study in rats / Influencia dos hormonios tireoidianos no reparo osseo ao redor de implantes de titanio : estudo histometrico em ratos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The aim of this study was to evaluate, by histometric analysis, the influence of thyroid dysfunctions, hyper and hypothyroidism, on bone healing around titanium implants inserted in rats. Forty-two male Wistar rats were randomly assigned to one of three groups: group 1 (n=15) - hyperthyroidism (800 mcg of sodium Lthyroxine and 180 mcg of sodium triiodothyronine / 1000 ml of water); group 2 (n=14) - control; group 3 (n=13) - hypothyroidism (1000 mg propyllthiouracil / 1000ml of water). Ninety eight days after solutions administration, serum analyses confirmed hormone levels differences and single screw-shaped titanium implants were placed in rat tibiae. Bone healing was evaluated sixty days after surgical procedure. The animals were sacrificed and undecalcified sections from tibiaes with implants were obtained. Percentage of bone in a 500mm-wide zone lateral to the implant (BA), percentage of bone filling within the limits of the implant threads (BF) and percentage of bone-to-implant contact (BIC) were obtained and arranged separately for the cortical (Zone A) and cancellous bone (Zone B). The data were statistically analysed using one-way ANOVA and Tukey?s test (alpha=5%). In Zone A, intergroup analyses revealed a tendency for reduction in bone repair while hormone levels decreased. There was a statistical reduction in BA in group 3 (93.74±2.70) compared to group 2 (95.93±1.90). T3 and T4 significantly affected BF, showing 78.72±3.88, 71.92±5.12 and 65.60±8.76, for groups 1, 2 e 3, respectively. Differences were also found in BIC, between groups 1(20.76±9.3) and 3 (12.28±9.04). In addition, no differences were observed with respect to Zone B, in any parameter. Therefore, within the limits of the present investigation, thyroid dysfunctions may influence cortical bone repair around titanium implants placed in rats.

ASSUNTO(S)

thyroid titanium periodontics periodontia tireoide titanio

ACESSO AO ARTIGO

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