Image-based Bone Density Classification Using Fractal Dimensions and Histological Analysis of Implant Recipient Site

Abstract

Background: Success of dental implants is affected by the quality and density of the alveolar bone. These parameters are essential for implant stability and influence its load-bearing capacity. Their assessment is usually based on preoperative radiographs used as a tool prior to implant procedures. Objective: The aim of the study was to compare the bone density of surgically harvested bone specimens at implant recipient sites in the maxillary and mandibular posterior region using histological analysis to the radiographic bone density using fractal dimension for reliability and determining an image based classification of bone density prior surgery. Methods: Fifty implants were placed in the posterior region of male patients, (twenty five implants in the maxilla and twenty five in the mandible). The edentulous regions were presurgically assessed using Photo Stimulable Phosphor Plate (PSP) intra-oral radiographs and the fractal dimension box counting of region of interest was calculated at the implant recipient site. During surgery, bone core specimens were trephined, and bone densities and minerals parameters were evaluated based on histological analysis using SEM (Scanning Electron Microscopy), and atomic absorption spectrometry. Results: Fractal dimensions (FD) values for the same region of interest (ROI) selected on the radiographs of bone blocks and edentulous sites were different but showed a proportional variation in molar and premolar region of the maxilla and mandible. Bone density results, calculated by the ratio of bone mass (BM) to the bone volume (BV) of the bone core specimen (D=M/V), increased in the mandibular bone blocks, and decreased in the maxilla specimens. Moreover, fractal dimension values of preoperative radiographs at implant recipient sites and bone density of trephined showed a statistically similar distribution. However, no significant difference was shown in the percentage of minerals contents and mass of calcium phosphate of each bone specimen between maxilla and mandible based on scanning electron microscopy analysis. Four types of bone densities were classified according to the distribution of FD values based on preoperative radiographs and on the densities of bone cores calculations. Conclusion: Radiographic estimation of bone quality calculated with fractal dimension could be a useful, non-invasive tool when using preoperative intra-oral radiographs to predict bone density at implant recipient sites with caution and limits concerning the kind of digital radiographs and size of region of interest, especially when these results were based with bone specimens harvested from implant site as an absolute reference.

Use of mineralized dentin graft in augmentation of different indication areas in the jaw bones

“…In the period after 3 months, a control digital panoramic X-ray was made, where with the help of a special Software -Image J (version 1.36b issued by the American National Institutes of Health) the density of newly formed bone with numerical values from 0-255 grey in 1 pixel of an image was measured. A value of 0 refered to the black color of the X-ray image (brightness), while 255 refers to the white color, complete x-ray absorption (shading) [7]. In our specific case, augmented osseous defect showed a solid bone density of 178 gray, which indicated faster process of osteointegration and regeneration of new bone tissue, while the non-augmented osseous defect shows higher luminosity of 77 grey (Figure 14).…”

“…This grafted site preserved the alveolar ridge both functionally and esthetically. It can be utilized for implant insertion after 3 months in the maxillary posterior region, changing it from D3 bone into D1 bone [7].…”

“…Kontrolni digitalni panoramski snimak urađen je posle tri meseca i uz pomoć specijalnog softvera -Image J (verzija 1,36b, izdata od strane Američkog nacionalnog instituta za zdravlje) sa numeričkim vrednostima 0-255 greja u jednom pikselu slike meri se denzitet novoformirane kosti. 0-vrednost odgovara crnoj boji na RTG snimku (prosvetljenje), dok 255 odgovara beloj boji, potpuna x-ray apsorpcija (senke) [7].…”

“…Ovaj graft štiti alveolarni greben kako u funkcionalnom tako i u estetskom smislu. Može se koristiti posle tri meseca za inserciju implantata u posteriornoj maksilarnoj regiji, menjajući D3 kost u D1 [7].…”

Application of Texture and Fractal Dimension Analysis to Evaluate Subgingival Cement Surfaces in Terms of Biocompatibility

“…Hayek et al tested radiographic estimation of bone quality using FDA. They noticed that it was a useful and non-invasive tool for examining bone density before the implantation, and proposed an image-based classification of bone density in the posterior regions of each jaw [ 57 ]. FDA can also be used as an objective method for detecting bone destruction induced by periodontitis.…”