Comparative study of decalcification versus nondecalcification for histological evaluation of one-wall periodontal intrabony defects in dogs.

Biological reactions between biomaterials and surrounding tissues, analyzed by histology, may be important predictors of clinical healing pattern and selection of slide preparation techniques requires a careful consideration regarding sample properties. In this study, we compared histology of bone specimens prepared with or without decalcification and performed histological and histomorphometrical assessments. For the histological evaluation, one-wall intrabony defects were created around the mandibular molars of six adult dogs, filled with biphasic calcium phosphate, synthetic bone graft material/recombinant human bone morphogenic protein-2, and healing pattern was histologically evaluated at 4 and 12 weeks. New bone formation in 5 x 4 x 4 mm defects and the length of new cementum, connective tissue attachments around the teeth and number of osteoclasts were measured by histomorphometric analysis. After decalcification, new cementum was easily observed and was significantly increased at week 4. In nondecalcified samples, significantly increased connective tissue attachments were seen at week 12. After 12 weeks, the number of countable multinucleated osteoclasts was significantly increased by 62% in nondecalcified versus calcified tissue sections (P = 0.030). Histomorphometric results may be significantly affected by histological preparation method and therefore, selecting the most appropriate histological preparation method is essential for reliable diagnosis and evaluation of bony samples in studies analyzing tissue regeneration.