Complete diagnosis in dentistry needs more detail and accurate quantitative as well as qualitative jawbone trabeculation evaluation. This requires modern diagnostic radiography that in Indonesia are still very limited. One form of the periodontitis that demands more attention and detailed information due to the great efforts to overcome, is Rapidly Progressive Periodontitis, and thus this disease has chosen as a model in this study. The objective of this study to get more detail and accurate radiometric of Direct Digital Intraoral value from grading Conventional value. This method expected to be a model of studies on jawbone quality in dentistry. The healting RPP patients as a subjects of this study. The methods trabeculation density from mandibular DDIR and conventional periapical radiographs of 116 healthy subjects and 41 RPP patients were evaluated and correlated to obtain transformation formula in the form of regression function. This study was performed Clinic of Dental Radiology and Periodontology, Faculty of Dentistry, University of Indonesia function were then used as a method to obtain quantitative data from conventional radiographs available. The results were indicated a significant independent variables were included in the regression function (p<0.05). Therefore even no DDIR equipment available, this transformation enable dentists all over Indonesia with only conventional radiographs available, to obtain more detail quantitative trabeculation density data. The conclusion is apart from getting a methode to transform conventional radiographic data into radiometric data equal to data obtained from DDR that more detail and accurate, this study also provides the normal radiographic trabeculation density value of peron 20 – 40 years as data base for further studies.