Vanja Petrovic

Histological evaluation of platelet rich plasma and hydroxiapatite in apexogenesis: Study on experimental animals

BACKGROUND/AIM There are very few data about the effects of endogenous growth factors in vital pulp therapy, and still they are often controversial. The aim of the study was to evaluate the effects of platelet rich plasma (PRP) in conjugation with hydroxyapatite (HAP), as pulp capping materials, to root and periodontium formation. METHODS Eight young monkeys (Cercopithecus Aethiops) with permanent dentition and incomplete root formation were involved in this study. After pulpotomy, the pulp lesion was capped with calcium hydroxide (control), hydroxyapatite (experimental group I) or hydroxyapatite in conjugation with PRP (experimental group II). Six months later, the animals were sacrificed, the tissue was removed en block, and prepared for the histological analysis in a routine way. RESULTS The results of the histological analysis revealed that healing process was characterised by dentin bridge formation, maintained morphological and functional integrity of dental pulp and complete formation of dental root and surrounding periodontium. The inflammatory reaction was scored as mild to moderate, in almost all the samples in all groups, suggesting the biocompatibility of the used materials. CONCLUSION Materials used in this study are convenient as capping agents, contributing maintaining the integrity of the pulp tissue and facilitating root and periodontium forma tion. According to histological data it could be suggested that hydroxyapatite in conjugation with endogenous growth factors, represents superior alternative to other materials used in this study.

Effects of the platelet rich plasma on apexogenesis in young monkeys: Radiological and hystologycal evaluation

Platelet-reach plasma (PRP) is an attractive tool in regenerative medicine due to its ability to stimulate proliferation and differentiation of stem cells. Since dental pulp derived stem cells are recognized as central in apexogenesis, the aim of the study was to evaluate radiologically and histologically effects of PRP on apexogenesis in teeth with immature roots. The study included eight monkeys (Cercopithecus Aethiops) divided in two equal groups for evaluation 3 and 12 months after treatment. All participants obtained the same treatment including pulpotomy and after-treatment with: hydroxiapatite (HA)-incisor and HA+canine PRP. Radiological evaluation was performed using the long cone paralleling technique for recording of defined parameters and histological evaluation was performed using tissue removed en block for the observation of parameters related to apexogenesis. The results obtained radiologically and histologically have shown increase in bridge formation in HA+PRP (75%) group after 3 months comparing to HA group (50%). Contrary to that, after 12 months there were no significant differences between groups. The root delay was not registered in the HA+PRP group contrary to HA group where it was registered in 25% after 12 months. Results of the study suggest that PRP is a powerful tool for intensive and rapid apexogenesis since it offers clear and comprehensive results (mostly in the first three months) which are early radiologically visible without any failure in the proposed requests.

Radiological assessment of apex formation following use of hydroxyapatite

The treatment of pulp in teeth with incomplete apex formation is still a clinical challenge. In addition to the most widely used medication for this purpose, calcium hydroxide, other materials have also been tested. Following the use of synthetic biomaterials for restoring bone tissue, and considering their recognized biocompatibility and bioconductivity, our intention was to explore the possibility of using synthetic biomaterials in the endodontic treatment of permanent teeth with incomplete apex formation. The aim of this study was to observe the effectiveness of hydroxyapatite in apexogenesis of young permanent teeth. In this study a 100 µm synthetic hydroxyapatite material, Beohap (HAP) powder, was applied to 24 teeth in 3 dogs of 5.5 months of age, after incomplete root development was established on radiographs. The treated teeth were radiographed monthly and the radiographs compared with those of the corresponding teeth on the other side of the jaw until completion of apex growth. The tested teeth were divided into three groups according to the method of treatment: the first was direct pulp capping, the second was amputation of the pulp at the enamelcement junction and the third was high amputation at the radiographically identified point of root growth. On the basis of radiographic analysis, apex formation was successful in all test groups, with no significant differences between the three groups and the controls (Fishers and χ 2 test). Deformities of the root apex were observed in two teeth (25%) in the third group.

Assessment of risk factors and preventive measures and their relations to work-related musculoskeletal pain among dentists

BACKGROUND Dentists have a high prevalence of musculoskeletal (MS) pain, which is the most common symptom associated with work-related musculoskeletal disorders (WMSDs). To overcome this problem, identification of the risk factors and preventive measures for MS pain are of paramount importance to dentists in order to improve their quality of life and work. OBJECTIVES The aims of this study were to recognize the risk factors for MS pain and their impact on dental work, as well as to identify preventive measures of MS pain among dentists. METHODS Self-reporting questionnaire consisting of 78 questions was exclusively developed for the study and sent to 500 working active dentists in Serbia. RESULTS Response rate was 71.2% (356 dentists). The prevalence of MS pain was 82.6% among dentists. The main risk factors for MS pain were advanced age, female dentists, presence of chronic diseases, long working hours, and high frequency of treated patients. The most effective preventive measures in preventing MS pain were massage treatments and physical activities. Followed by use of ergonomically designed equipment, correct and dynamic working positions, and an adequate workflow organization. CONCLUSION The risk factors for MS pain and their impact on dental work should widely be disseminated among dentists. Importantly, proper implementation in everyday life of adequate preventive measures is essential for preventing MS pain and development of WMSDs.

Posture in dentists: Sitting vs. standing positions during dentistry work - an EMG study

INTRODUCTION Adequate working posture is important for overall health. Inappropriate posture may increase fatigue, decrease efficiency, and eventually lead to injuries. OBJECTIVE The purpose was to examine posture positions used during dentistry work. METHODS In order to quantify different posture positions, we recorded muscle activity and positions of body segments. The position (inclination) data of the back was used to assess two postures: sitting and standing during standard dental interventions. RESULTS During standard interventions, whether sitting or standing, a tilt of less than 20 degrees was most prevalent in the forward and lateral flexion directions. Amplitude of electromyography signals corresponding to the level of muscle activity were higher in sitting compared with the electromyography in standing position for all muscle groups on the left and right side of the body. Significant difference between muscle activity in two working postures was evident in splenius capitis muscle on the left (p = 0.032), on the right side of the body (p = 0.049) and in muscle activity of mastoid muscle on the left side (p = 0.029). CONCLUSION These findings show that risk for increased fatigue and possible injures can be reduced by combining the sitting and standing occupational postures.

Different methods for subgingival application of chlorhexidine in the treatment of patients with chronic periodontitis

Abstract Objective: The aim of this study was to evaluate clinical efficacy of different chlorhexidine gluconate (CHX) preparations applied subgingivally as an adjunct to scaling and root planing (SRP). Material and methods: A total of 120 periodontal pockets was included in this randomized, controlled, split mouth designed study. According to protocols used in treatment, periodontal pockets were assigned to experimental and control groups as follows: CHX solution as an addition to SRP versus control SRP group; CHX gel as an addition to SRP versus control SRP; CHX chip as an addition to SRP versus control SRP group. Following clinical parameters were recorded at baseline, one and three months after the baseline: plaque index (PI), probing pocket depth (PPD), bleeding index (BI) and clinical attachment level (CAL). Results: The most significant improvements were found concerning PI in CHX solution with SRP and CHX gel with SRP groups over controls at one month recall, as well as concerning BI and PPD in CHX chip with SRP group over SRP alone at three-month recall. Conclusion: Results of this study favour combination therapy using CHX chip as an adjunct to SRP due to greater improvements in BI and PPD compared to those obtained by SRP alone in the treatment of chronic periodontitis.

Clinical study on the influence of hydroxyapatite on apexogenesis in monkeys.

Management of the affected pulp in teeth with incomplete root formation is still an issue. Calcium hydroxide and other materials have been employed for this purpose to a greater or lesser success. Bioceramic materials are in the last decades well established in a number of different medical fields. Having its constituents the same as those of the unorganic portion of bone tissue, hydroxiapatite (HAP), one of the two forms of calcium-phosphate ceramics, is already accepted in endodontic treatment of teeth with completed root formation. The aim of this study was to examine apexogenesis in teeth with immature roots, following the use of HAP on their affected pulp. Examination was performed on eight young monkeys (Cercopithecus Aethiops) with incomplete root development. The 100 _m synthetic HAP material was applied on 32 teeth divided into two groups of 16 teeth each. In one group teeth underwent pulpotomy, in the other high pulpotomy. Evaluation of root growth was recorded from radiographs (pre-treatment, 3 and 12 months following treatment) and by Demjrians scale for dental maturity and tooth age determination. On the basis of radiographic analysis, immature teeth with affected pulp treated with HAP, both with pulpotomy and high pulpotomy, reached the same stage of root development as control teeth in 50% of cases at 3-months radiographic assessment. After 12 months all tested teeth had the same rate of root development as control teeth, except for 1 of 8 with high pulpotomy. Dentinal bridge was radiographically visible in 50% and 87.5% of pulpotomized teeth after 3 and 12 months, respectively. Neither obliteration of the root canal, presence of denticles nor the presence of deformities in the periapical region were found in any of the observed teeth.