The effects of dental pulp stem cells on bone regeneration in rat calvarial defect model: micro-computed tomography and histomorphometric analysis.

OBJECTIVE: Stem cell therapies may be applicable to all fields of medicine, including craniomaxillofacial surgery. Dental pulp stem cells also have significant osteogenic properties. This study aimed to evaluate the influence of dental pulp stem cells on bone regeneration and to ascertain whether or not there was any superiority over traditional methods. DESIGN: In this study, 15 non-immunodeficient Wistar albino rats were used. The rats were divided into three groups: (1) untreated control group; (2) hydroxyapatite tri-calcium-phosphate (HA/TCP) paste; (3) human dental pulp derived stem cells (DPSC) mixed with HA/TCP paste (HA/TCP+DSPC group, n=10). Two symmetrical full-thickness cranial defects were created on each parietal region (10 defects for each group). The animals were sacrificed 8 weeks post-surgery and samples were analyzed by microcomputer tomography (µ-CT) and histomorphometry. RESULTS: The calcification rate and bone mineral density (BMD) values in Group 3 were found to be significantly higher than in the other two groups. Radiographically, bone regeneration was greater in Group 2 compared with the control group. However, there was no significant difference between Groups 2 and 1 in respect of histological analysis. CONCLUSIONS: According to the results of the present study, DPSCs may be a suitable factor for bone tissue engineering because they can be easily obtained and differentiate into bone cells.

Evaluation of "all-on-four" concept and alternative designs with 3D finite element analysis method.

PURPOSE: The aim of the present study was to evaluate the effect of the forces on the implant and supporting alveolar ridge in "all on four" concept and alternative designs using finite element analysis. MATERIALS AND METHODS: Different treatment alternatives with various implant designs were performed in an edentulous mandible. In Design 1, implants were placed according to "All-on-Four" concept; Design 2, two long (13 mm long, 4 mm diameter) and two short (7 mm long, 4 mm diameter) implants; Design 3, four long and two short implants; and Design 4, two long and four short implants were placed vertically. A force of 100 N for each tooth, a total of 300 N load was applied. Finite element analysis was used to evaluate and compare the different designs. RESULTS: The stress concentration within the cortical bone was significantly higher than the trabecular bone around the neck of the implants. The maximum stress values were located around the cortical bone of the distal implant for all designs. The reduction in the number of implants did not diminish the success of the design. CONCLUSIONS: In the presence of vertically resorbed posterior mandibula, although the "all on four" concept is a feasible approach clinically, short implants had decreased the amount of force transmitted to the supporting bone.

Comparative investigation of the effects of different materials used with a titanium barrier on new bone formation.

OBJECTIVES: In this study, we aimed to study the effects on new bone formation of autogenous blood, deproteinized bovine bone graft (DBBG), and biphasic calcium phosphate (BCP) bioceramic graft materials placed under titanium barriers. MATERIAL AND METHODS: Twenty-four adult male New Zealand white rabbits were used in this study. Two titanium barriers were fixed on each rabbit's calvarium. The study included four groups, one of which was a control group. The experiment groups, autogenous blood, DBBG (Bio-Oss(®) ; Geistlich Biomaterials, Wolhusen, Switzerland) and BCP (4Bone(TM) ; Biomatlante, Vigneux de Bretagne, France) were placed under titanium barriers; in the control group, no materials were used. Half of the animals were sacrificed after 1 month, and the rest were sacrificed after 3 months. After this, micro-computerized tomography images were taken, and a histomorphometric evaluation was carried out. RESULTS: The amounts of new bone formation were found to be higher at the third month than at the first month. The differences between the groups were examined with both a micro-computerized tomography and histomorphometric analysis, and no statistical significance was noted in the first month. In contrast, the increase in the amount of new bone formation at the third month was found to be statistically significant only between the DBBG and control groups (P < 0.05). CONCLUSION: Autogenous blood with titanium barriers in guided bone regeneration seems to be as successful as DBBG and BCP bioceramic graft material.

Stabilization of autotransplanted teeth using thermoplastic retainers

Objective: Different fixation techniques have been used for stabilization of autotransplanted teeth. Because rigidor extended fixation periods can cause complications such as ankylosis and disturbances of pulpal revascularization,our aim was to evaluate an alternative technique, a removable splint, for improving the success rate of autotransplantedmolar teeth.Study Design: In 44 patients, (20 male and 24 female patients), 45 transplanted teeth were analyzed. These caseswere followed for 31 to 47 months after operation. Transplanted teeth were evaluated after use of a thermoplasticretainer for 1 month, in terms of success rate and dissatisfaction with this apparatus. The primary stability, ankylosis,and root resorption were also analyzed.Results: To date, 1 transplant was extracted after 6 months due to unpreventable periapical root inflammation,and 2 transplants were extracted after one year due to external root resorption. Although 2 ankylosed transplantswere still functional after an average follow-up period of three years, with no dissatisfaction by the patients, thesecases were treated as failures because of the probable risk for external root resorption. The remaining 40 (88.8 %success rate) transplants remained asymptomatic and functioning for a mean follow-up period of 37 months. In theassessment of dissatisfaction with the thermoplastic retainer, 36 (81.8 %) patients had no or little dissatisfaction, 4(9 %) patients had very appreciable or excessive dissatisfaction, and 4 (9 %) patients had moderate dissatisfaction.Conclusions: A thermoplastic retainer for use after autotransplantation of third molar teeth is a reasonable anduseful method and a good alternative to conventional rigid or semi-rigid splints. This technique was especiallyuseful in autotransplanted teeth that had poor stability, i.e., in cases in which it is conventionally advised to uselong-term rigid or semi-rigid splints (AU)

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Stabilization of autotransplanted teeth using thermoplastic retainers.

OBJECTIVE: Different fixation techniques have been used for stabilization of autotransplanted teeth. Because rigid or extended fixation periods can cause complications such as ankylosis and disturbances of pulpal revascularization, our aim was to evaluate an alternative technique, a removable splint, for improving the success rate of autotransplanted molar teeth. STUDY DESIGN: In 44 patients, (20 male and 24 female patients), 45 transplanted teeth were analyzed. These cases were followed for 31 to 47 months after operation. Transplanted teeth were evaluated after use of a thermoplastic retainer for 1 month, in terms of success rate and dissatisfaction with this apparatus. The primary stability, ankylosis, and root resorption were also analyzed. RESULTS: To date, 1 transplant was extracted after 6 months due to unpreventable periapical root inflammation, and 2 transplants were extracted after one year due to external root resorption. Although 2 ankylosed transplants were still functional after an average follow-up period of three years, with no dissatisfaction by the patients, these cases were treated as failures because of the probable risk for external root resorption. The remaining 40 (88.8 % success rate) transplants remained asymptomatic and functioning for a mean follow-up period of 37 months. In the assessment of dissatisfaction with the thermoplastic retainer, 36 (81.8 %) patients had no or little dissatisfaction, 4 (9 %) patients had very appreciable or excessive dissatisfaction, and 4 (9 %) patients had moderate dissatisfaction. CONCLUSIONS: A thermoplastic retainer for use after autotransplantation of third molar teeth is a reasonable and useful method and a good alternative to conventional rigid or semi-rigid splints. This technique was especially useful in autotransplanted teeth that had poor stability, i.e., in cases in which it is conventionally advised to use long-term rigid or semi-rigid splints.

Neoplasms of the salivary glands in a Turkish adult population

Objective: This retrospective study aimed to investigate the types and distribution of neoplasm of salivary glandsin a Turkish population.Study Design: The histological diagnosis records of the Department of Pathology at Cumhuriyet University were reevaluated for 125 patients who were treated for salivary gland tumors from 1987 to 2008. The neoplasms were analyzed for histological diagnosis, age, sex, and site. The histological diagnoses were analyzed according to the2005 WHO classification.Results: A total of 125 primary salivary gland neoplasms, consisting of 95 (76%) benign and 30 (24%) malignant groups were recorded. The most common major and minor salivary gland sites were the parotid (61.6%) and palatalglands (9.6%), respectively. Pleomorphic adenoma was the most frequent benign tumor followed by Warthin’stumor. Among the malignant group, adenoid cystic carcinoma was the most prevalent. Age for all cases rangedfrom 16-80 years; mean age was 41.97 years, with a female to male ratio of 1:1.15.Conclusions: Although there were some discrepancies, the characteristics of salivary gland tumors of Turkish patients are in line with those of patients from other countries according to tumor type, tumor site distribution,and age and sex of patients (AU)

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Neoplasms of the salivary glands in a Turkish adult population.

OBJECTIVE: This retrospective study aimed to investigate the types and distribution of neoplasm of salivary glands in a Turkish population. STUDY DESIGN: The histological diagnosis records of the Department of Pathology at Cumhuriyet University were reevaluated for 125 patients who were treated for salivary gland tumors from 1987 to 2008. The neoplasms were analyzed for histological diagnosis, age, sex, and site. The histological diagnoses were analyzed according to the 2005 WHO classification. RESULTS: A total of 125 primary salivary gland neoplasms, consisting of 95 (76%) benign and 30 (24%) malignant groups were recorded. The most common major and minor salivary gland sites were the parotid (61.6%) and palatal glands (9.6%), respectively. Pleomorphic adenoma was the most frequent benign tumor followed by Warthin's tumor. Among the malignant group, adenoid cystic carcinoma was the most prevalent. Age for all cases ranged from 16-80 years; mean age was 41.97 years, with a female to male ratio of 1:1.15. CONCLUSIONS: Although there were some discrepancies, the characteristics of salivary gland tumors of Turkish patients are in line with those of patients from other countries according to tumor type, tumor site distribution, and age and sex of patients.

Experience of maxillary sinus floor augmentation in the presence of antral pseudocysts.

Sinus floor elevation is increasingly being used with implant placement procedures. However, certain surgical difficulties can develop, such as sinus membrane perforation, bleeding, anatomic variations, or some pathologies of the maxillary sinus. Maxillary antral pseudocysts are one of the most common benign pathologies of the maxillary sinus. Although some investigators have described the presence of this pathology as a contraindication, recent reports have demonstrated that pseudocysts of the maxillary sinus are not a contraindication for sinus augmentation. In these reports, maxillary sinus augmentations related to antral pseudocyst experiences are presented.

Analgesic and anti-inflammatory effects of oxaprozin and naproxen sodium after removal of impacted lower third molars: a randomized, double-blind, placebo-controlled crossover study.

PURPOSE: In this study, oxaprozin, a long-acting nonsteroidal anti-inflammatory drug, and naproxen sodium were compared in terms of their effects on edema, pain, and trismus after surgery for impacted mandibular third molars. MATERIALS AND METHODS: Thirty healthy patients with bilaterally impacted mandibular third molars were included in this randomized, cross-over, double-blind, placebo-controlled study. Patients were assigned randomly to 1 of 3 surgery groups and received postoperatively 1,200 mg oxaprozin, 550 mg naproxen sodium, or a placebo. Postoperative edema was measured with ultrasonography performed before and after surgery. Trismus was measured by comparison of preoperative and postoperative maximum interincisal mouth opening measurements by caliper. Pain was assessed by a visual analog scale (VAS) and by recording the number of rescue analgesic pills taken. RESULTS: After removal of impacted third molars, the patients administered oxaprozin and naproxen showed superior results over those given placebo in terms of pain parameters (P < .05), but these treatments had no statistically significant effect on facial swelling. Comparing the oxaprozin and naproxen groups, there were no differences in the mouth opening measurements, but naproxen showed a statistically superior effect over the placebo (P < .05). Although not statistically significant, oxaprozin showed a more pronounced effect in reducing trismus than did the placebo (P = .07). CONCLUSIONS: Administration of either oxaprozin or naproxen sodium during the postoperative period is effective and has similar effects in reducing pain but questionable benefit for the management of trismus. However, neither agent has clinical benefit in terms of reducing edema.

Prevalence study of signs and symptoms of temporomandibular disorders in a Turkish population.

AIM: The aim of this study was to evaluate the prevalence of signs and symptoms of temporomandibular disorders (TMD) in a population of 792 Turkish adults ranging in age from 15- to 72-years-old. METHODS AND MATERIALS: Subjects were examined objectively and subjectively for signs and symptoms of TMD through the distribution of frequency of the data obtained from a questionnaire and a physical examination using a similar methodology of previous studies. RESULTS: This study determined the prevalence of signs and symptoms of TMDs in subjects from male and female subgroups in a Turkish adult population. Both signs and symptoms of TMDs were generally more prevalent in females than in males. CONCLUSION: The prevalence of signs and symptoms were generally greater than in previous studies of other populations.

Penetration depth of laser Doppler flowmetry beam in teeth.

OBJECTIVE: The aim of this study was to determine the penetration depth of laser light in teeth for contact and noncontact probe tip. STUDY DESIGN: Fifty-one freshly extracted human mature maxillary and mandibular single rooted teeth were selected for the study. A laser Doppler flowmeter was used as a laser source. A digital camera was used to take pictures (with "night shot" mode in total darkness). When probe tip was in contact and when it was 1 mm away from the tooth, the depths of the areas illuminated in high and low density were measured. RESULTS: In contact probe, root was illuminated to 4.28 +/- 0.14 mm depth with high density and 13.27 +/- 0.27 mm depth with low density. In noncontact probe, 4.36 +/- 0.16 mm with high density and 13.28 +/- 0.30 mm with low density of illumination were seen on the root. Between contact and noncontact probe situations the difference was not statistically significant in the depth of illumination. On the other hand, in both groups the difference between areas illuminated in high and low density was statistically significant (P < .05). CONCLUSION: Contact or noncontact of the probe on tooth surface did not show any significant difference in light penetration. Besides, we think that, for the present, it is impossible to eliminate the contamination from periodontal tissues completely even if the necessary precautions (periodontal paste etc.) are taken.

Effect of gingiva on laser doppler pulpal blood flow measurements.

The purpose of this study was to evaluate the effect of labial and palatinal gingiva on laser Doppler pulpal blood flow measurements. Twenty upper central incisor teeth determined to be vital from 20 volunteers were included into the study. To stabilize the probe, a laboratory-made acrylic splint positioned the probe labially on the cervical third of the tooth crown. We collected measurements without any gingival covering, and under three conditions: after application of an opaque paste on the labial gingiva, the palatal gingiva, or both the labial and palatal gingiva. The measurement values decreased 46% when there was opaque paste on labial gingiva, 10% on palatinal gingiva, and 63% on both. The decrease in the values when there was an opaque paste on palatinal gingiva was not statistically significant (p > 0.05). The differences between all other groups were statistically significant (p < 0.05). In these measurements, the contribution of labial gingiva to laser Doppler pulpal blood flow measurements is more than that of palatinal gingiva.

The sources of laser Doppler blood-flow signals recorded from vital and root canal treated teeth.

OBJECTIVES: The aim was to determine the strength of signals derived from the dental pulp and those from the surrounding tissues in human teeth using the laser Doppler flowmetry (LDF). METHODS: Twenty-six vital teeth (13 experimental and 13 controls) from 12 patients were used. Experimental teeth had root canal treatment in a single visit and their healthy antimeres were controls. Blood flow measurements were made before and after local anaesthesia, after root canal preparation, following root canal filling and coronal restoration. RESULTS: Perfusion unit (PU) values recorded from empty pulp chamber were determined to be only 30% lower than the values recorded before anaesthesia from the experimental intact teeth. When the measurements in the group were compared with each other the values of variation in the both groups were not statistically significant. The variation between the groups when the measurement values before anaesthesia, 10min after anaesthesia and after coronal restoration were compared, it was not statistically significant (P>0.05). The variation between the groups after preparation and root canal filling in their values of measurements was important statistically (P<0.05). The measurement values of the study group were lower than that of the control group. CONCLUSIONS: In pulpal, LDF a major portion of the signal comes from tissues other than pulp. Without taking precautions (such as rubber-dam application) in pulp blood flow measurements, the results may be inconsistent.

Pulpal blood flow: effects of corticotomy and midline osteotomy in surgically assisted rapid palatal expansion.

INTRODUCTION/PURPOSE: Surgically assisted rapid palatal expansion is used for the management of transverse maxillary deficiency in the early permanent dentition. The success depends on the maintenance of an adequate blood supply to the mobilized segments. The aim of this study was to assess the effects of corticotomy and midline osteotomy on the tooth pulpal blood flow. MATERIAL: Laser Doppler flowmetry was applied as a non-invasive and reliable technique for the assessment of pulpal blood flow in the maxillary centrals, canines and first molars. The blood flow was investigated pre- and postoperatively, on the first, third, and seventh postoperative days bilaterally in 13 cases. RESULTS: The results of this study indicate that ischaemia of the pulp can occur following osteotomy at the Le Fort I level. CONCLUSION: Corticotomy 5mm above the dental apices and separating the midpalatal suture did not have any serious effect on pulpal blood flow in this study.