Comparison between subtraction radiography and conventional radiographic interpretation during long-term evaluation of periodontal therapy in Class II furcation defects.

BACKGROUND: Limited information comparing digital subtraction radiographic assessment with conventional radiographic interpretation is available from longitudinal clinical trials. The aim of this study was to evaluate the ability to detect periodontal bone changes during the long-term maintenance of Class II furcation defects by conventional radiographic interpretation compared to interpretation of digital subtraction images. METHODS: Standardized radiographs of 18 Class II furcation defects in mandibular molars were taken at baseline and at 6, 12, 18, and 24 months after non-resective periodontal surgery. Conventional radiographic and digital subtraction interpretations were performed masked, respectively, by two and three experienced examiners, according to the following categories: bone gain; bone loss; unchanged appearance; and impossible to visualize. Percent concordance and the kappa statistic value (kappa) were computed. RESULTS: Conventional radiographic and digital subtraction interpretation images resulted in 72 decisions for each examiner. The visual interpretation of digital subtraction images by two examiners revealed the same results. The interpretation of conventional radiographic images showed a low concordance between examiners (kappa < 0.40) at all examinations. The concordance between subtraction radiography and conventional radiographic interpretation was also low for all examiners (kappa < 0.36) at all examinations. Using subtraction radiography as a reference, bone changed and bone unchanged were diagnosed correctly in 47.2% of cases by examiner A, in 43.1% by examiner B, and in 38.9% by examiner C. CONCLUSION: It can be concluded that conventional radiographic interpretation is a more subjective and inaccurate method of detecting periodontal bone changes in Class II furcation defects in mandibular molars when compared with subtraction radiography.

The relationship between radiographic and clinical parameters in periodontal maintenance in class II furcation defects.

The goal of the present study was to investigate the relationship between probing and radiographic parameters, and the reliability of repeated longitudinal periodontal probing measurements for early diagnosis of periodontal breakdown in class II furcation defects. Eighteen class II furcation defects in lower molars were included in this study. Standardized radiographs and clinical measurements, relative vertical clinical attachment level (CAL-v) and probing depth (PD) were obtained immediately before periodontal surgeries and at 6, 12, 18, and 24 months after surgery. A total of 72 pairs of radiographs were subtracted following correction for contrast and planar geometric discrepancies, and the bone loss/gain (in mm) was measured. There was no statistically significant correlation between CAL-v and bone height (BH) measurements. A statistically significant correlation for PD reduction at 24 months and BH increase at 18 months was found (r = 0.5, p < 0.05). These results suggest that clinical measurements and radiographic bone height reflect different features of periodontal destruction and periodontal healing, and repeated longitudinal measurements of vertical clinical attachment level are not reliable for early diagnosis of periodontal breakdown in class II furcation defects.

The relationship between radiographic and clinical parameters in periodontal maintenance in class II furcation defects

O objetivo deste estudo foi investigar a relação entre medidas clínicas e radiográficas durante a terapia de manutenção periodontal e a confiabilidade de medidas clínicas periodontais repetidas para o diagnóstico precoce de destruição periodontal de lesões de furca classe II. Dezoito lesões de furca classe II em molares inferiores foram incluídas neste estudo. Radiografias padronizadas e medidas do nível clínico de inserção vertical (NCI-v) e da profundidade de sondagem (PS) foram obtidas imediatamente antes do tratamento cirúrgico e aos 6, 12, 18 e 24 meses após a cirurgia. Um total de 72 pares de radiografias foram subtraídos após correção das distorções geométricas e de contraste, e a altura de ganho/perda óssea (AO) (em mm) foi medida. Não houve correlação estatisticamente significante entre NCI-v e AO. Houve uma correlação estatisticamente significante entre redução na PS aos 24 meses e aumento na AO aos 18 meses (r = 0,5, p < 0,05). Os resultados deste estudo sugerem que medidas clínicas e radiográficas refletem diferentes características da reparação e destruição periodontais e medidas clínicas longitudinais repetidas do NCI-v não são confiáveis para o diagnóstico precoce de destruição periodontal em lesões de furca classe II.