In a healthy organism outer and inner walls of the tooth root are protected by the thin antiresorptive barrier. A layer of precementum protects the outer wall meanwhile predentine and odontoblasts protect the inner wall of root dentine. A number of mechanical, chemical, thermal factors have been proved to cause premature mineralization of the protective barrier and stimulate resorptive process. Resorption is defined as a condition associated with either physiological or pathological processes resulting in loss of dentine, cementum and bone.
Andreasen has classified tooth resorption as internal (inflammatory, replacement) and external (surface, inflammatory and replacement) types. Resorption is more common in men than in women .Clinical diagnosis of tooth root resorption is often made accidentally during X-ray examination. Discoloration of the crown with pink spot and gray shade is sometimes the only clinical manifestation, while other signs occur at the stage of complications. Thus, roentgenographic interpretation of resorption is crucial for differential diagnosis, treatment and outcome prognosis [2,3]. Traumatized teeth are clinical challenge from the point of view of the diagnosis, treatment planning and outcome prognosis.
Tree-dimensional images allow to assess the needed area without overlay of adjacent structure . Unlike conventional computed tomography, cone beam computed tomography under the conditions of low-dose X-ray radiation provides accurate information . Covering small or restricted area, cone beam computed tomography allows for 3D high resolution images of the teeth and adjacent dentoalveolar structures. CBCT images assess resorptive process in submillimeter layers of different root areas, avoiding the overlay of anatomical structures .Regardless X-ray film projection defect, roentgenographic characteristics of inner resorption in the X-ray image are the occurrence of round symmetric lesion within root cavity, similar to enlarged pulp cavity or root canal lumen. Pulp cavity or root canal inside the lesion are marked by slight shadow. In contrast, external resorption roentgenographically occurs in typical pathological lesion with rough, asymmetric edges. The lesion location is different in case of image projection change, it looks like area separate from the root surface. The healthy and resorptive areas are clearly demarcated [6,7]. The treatment of resorption varies, depending on its type, location, lesion size and clinical manifestations [8,9,10]. Materials and methods To make the results of the study comparative, two patients of the same gender, under the age of 25, with no accompanying severe somatic diseases on examination as well as in the past medical history, with no harmful habits (smoking, drug addiction, alcoholism) were chosen. Both patients had the history previous trauma to their anterior incisors. Cone beam computed tomography, determination of gingival crevicular fluid volume and pH were carried out within the study. Taking into consideration the fact that vestibule and oral side changes of the root are not visible in the two-dimensional images due to shadow overlay, jaw scanning was performed by means of cone beam computed tomography (Planmeca ProMax 3D Max, Planmeca, Finland). The images were analyzed by Planmeca Romexis computer program (Planmeca, Finland).The material for the gingival crevicular fluid volume determination was taken 3 hours after breakfast. The study area was isolated with cotton rolls and was dried off by weak air jet. Gingival crevicular fluid was collected by PERIOPAPER (Gingival Fluid Collection Strips, Oralflow, Smithtown, NY 11787, USA) paper strip. The latter was thoroughly inserted into the gingival sulcus before reaching the slightest resistance and was left there for 30 seconds. Normally absorbent surface with gingival fluid is 0-5 mm2. In order to determine the pH of gingival crevicular fluid a special indicator Plastic pH Indicator Strips (Hydrion, USA) was used, which was into gingival sulcus. Gingival fluid pH can vary ranging from 6.30 to 7.93.ResultsCone beam computed tomography confirmed tentative clinical diagnosis. The results of the study were as follows: in case of tooth root external resorption paper strip absorbent surface made up 5mm2 which corresponds to the upper limit of normal. Gingival crevicular fluid pH was 6,5 which is known as slightly acidic environment typical of inflammatory processes. In case of internal resorption complicated with root canal perforation the volume of gingival crevicular fluid exceeded the normal limit, making up 6mm2 and gingival crevicular fluid pH was 6,5. Obtained slightly acidic pH and gingival crevicular fluid excess of norm indicated the presence of inflammatory process in periodontium. DiscussionIn tooth root external and perforating internal resorption periodontium is also involved in the process, which is indicated by roentgenographic changes, gingival crevicular fluid volume increase and pH reduction. Peculiarity and significance of the study is the fact that the condition of periodontal complex in young people with different types of tooth root resorption, developed years after trauma was first assessed by means of gingival crevicular fluid study. In contrast to periapical roentgenogram, the new X-ray extraoral imaging systems can be beneficial for the early diagnosis of different resorption types, while the actual size, character and location of periapical and resorptive lesions can be more precisely assessed, which allows for the due treatment, averting further complications and tooth loss at a young age. Thus, we consider regular dental check-up among the population, at least once a year to be of a great importance, while those with past maxillofacial traumas should undergo regular outpatient follow-up since post-traumatic complications can manifest months and even years after the traumatic event. The fact is conditioned by asymptomatic resorption process and occurrence of clinical signs when resorption lesion involves the most part of the tooth root and conservative treatment is no longer possible.