Evaluation of Anatomical Variations of the Maxillary Sinus in Patients With and Without Mucous Retention Cyst.

Objectives: Mucous retention cyst (MRC) is a benign and self-limited lesion that can be caused by many risk factors, including anatomical variations of the sinonasal region. This study aims to investigate the relationship between anatomical variations and the presence of MRC. Materials and Methods: In total, 2109 sinonasal cone beam computed tomography images were evaluated for the presence of MRC, and the sinonasal anatomical regions such as the osteomeatal complex (OMC), infundibulum length, ostium height, the diameter of the ostium, the presence of accessory ostium, concha bullosa, and mucosal thickening of the maxillary sinuses. Shapiro-Wilk normality test, independent sample t-test, and chi-square test were used for statistical analysis, and P < .05 was considered significant. Results: The prevalence of MRC was 119 (5.6%) cases. The average diameter of the ostium in cases with and without MRC was 0.49 ± 0.41 mm and 0.99 ± 0.76 mm, respectively, which showed a significant inverse relationship(P < .001). A significant relationship was found between the septum deviation, the ostium height, the concha bullosa, and the accessory ostium with the presence of MRC (P < .001). Conclusions: Sinonasal anatomical variations such as ostium diameter, ostium height, septal deviation, the presence of accessory ostium, and concha bullosa can cause MRC development, and considering that surgery may be necessary in some cases; this could be of great importance to clinicians and surgeons for treatment and prevention of development or recurrence of these pseudocysts in patients.

Evaluation of the linear and volumetric measuring changes in different positions in CBCT.

OBJECTIVES: The effect of head position on reproducibility of volumetric measurements on Cone-beam computed tomography (CBCT) scans has not been evaluated before. Thus, this study aimed to assess the changes in linear and volumetric measurements on CBCT scans in different positions of the respective object. MATERIALS AND METHODS: In this experimental study, 16 balls were placed in containers and underwent CBCT in neutral position and 8 different altered positions. The horizontal and vertical diameters of each ball were measured by OnDemand software while the volume of each ball was quantified by ITK-Snap software. The reproducibility of linear and volumetric measurements in nine different positions was analyzed by the Cronbach's α. Paired t-test was applied to analyze the difference in volumetric and linear measurements of the balls in the anterior and posterior halves of the scans in neutral position versus the upward and downward tilts, and right and left halves of the scans in neutral position versus the right and left tilts. RESULTS: The Cronbach's α was found to be .982 and .933 for volumetric and linear measurements, respectively, indicating high reproducibility of the measurements. No significant difference was noted in the mean linear measurements on CBCT scans at different positions compared with neutral position. In volumetric measurements, maximum difference between neutral and the other positions was less than 1%. CONCLUSIONS: CBCT is a reliable modality for linear and volumetric measurements in different positions.

Prevalence and anatomical variations of maxillary sinus septa: A cone-beam computed tomography analysis.

Background: Detailed understanding the anatomy and variations of maxillary sinus septa is necessary. We aimed to investigate prevalence and various anatomical variations of maxillary sinus septa using cone-beam computed tomography (CBCT) images. Material and Methods: In this retrospective cross-sectional study, CBCT scans of 809 patients referred to a specialist dental and maxillofacial radiology clinic in Babol, northern Iran, during 2014-2020 were evaluated. Location, morphology, height, and direction of septa in different planes were recorded. Results: Sinus septa were observed in 37.9% (n=307) of the participants. There were 117 cases with septa only in left sinus, 83 cases with septa only in right sinus, and 107 cases with septa in both sinuses. Totally, 414 septa were seen in the subjects. Prevalence of partial septa was considerably higher than complete septa (77.5% versus 22.5%). Regarding septa location, middle area with a prevalence rate of 58.7% was found more prevalent than other sinus areas. The mean septum height on the left and right sinuses was 6.0±3.1 mm 5.7±3.9, respectively (p<0.001). Regarding left sinus, directions of vertical (63.8%), oblique (30.8%), and straight (63.8%) were the most prevalent compared with other directions in sagittal, frontal, and axial planes, respectively. In relation to right maxillary sinus, direction of vertical in sagittal and frontal planes (72.6% and 24.2%, respectively), and direction of straight in axial plane (58.4%) were the most prevalent directions compared with others in the same planes. Conclusions: Septa prevalence in maxillary sinus was relatively high, with various directions, locations, heights, and shapes. It is recommended to use CBCT for a careful evaluation of toothless area prior to surgeries on the sinus (especially sinus lift) in three plans, in order to take careful measures and prevent postoperative complications in case septa exist. Key words:Maxillary sinus septa, anatomical variation, cone-beam computed tomography, dental implant.

Clinical and Radiographic Evaluation of Applying Atorvastatin 1.2% Bio Adhesive with Plasma Rich in Growth Factor (PRGF) for Treatment of Mandibular Class II Furcation Defects: a Randomized Clinical Trial.

Statement of the Problem: Molar teeth with furcation involvement are one of the most common problems in patients with periodontal disease. Regeneration methods are of the most controversial treatment strategies for these lesions. Purpose: The purpose of this study was to determine the effect of plasma rich in growth factors (PRGF) with 1.2% Atorvastatin (ATV) in the treatment of furcation involvement of mandibular molars. Materials and Method: The present randomized clinical trial was conducted on 15 patients with moderate periodontitis and class II furcation involvements; 24 defects were located in four groups of six, including debridement, ATV1.2%, PRGF, PRGF with ATV1.2%. The parameters of vertical probing depth (VPD), vertical clinical attachment level (VCAL), gingival index (GI), horizontal probing depth (HPD) and gingival recession (GR) were measured at baseline (T0), immediately before surgery (T1), 3 (T2), and 6 (T3) months after surgery. Moreover, the bone conditions were evaluated by digital subtraction radiography before and six months after surgery. Data were analyzed using SPSS23 software. Results: No significant difference in radiographic parameters was observed among the groups (p= 0.08). There was no significant difference in the mean levels of VPD, VCAL and HPD among the groups at different times (p<0.05). Comparison of clinical parameters of VPD, VCAL and GI in the treatment groups compared to the baseline showed a significant improvement in each group (p< 0.05) but there was no significant difference among different groups (p< 0.05). Conclusion: The use of PRGF with ATV 1.2% in grade II furcation involvement in mandi-bular molars was effective in the improvement of clinical and radiographic parameters six months after treatment, but this effect revealed no difference in comparison with the other groups.

Evaluation of bone density by cone-beam computed tomography and its relationship with primary stability of dental implants.

Background: One of the critical factors determining the success of dental implants is primary stability. This study aimed to determine the density of jawbones in the implant candidate sites via cone-beam computed tomography (CBCT) and its correlation with the values obtained from resonance frequency analysis during surgery. Materials and Methods: In this descriptive-analytic study seventeen implant sites requiring implant placement were selected. Impressions were sent to the laboratory to construct a surgical guide via the stereolithographic method. An electronic surgery was performed on the chosen implant sites according to each patient's CBCT information entered into the Kaveh surgical guide software. The bone density of the target areas was calculated using the gray value (voxel value). After preparing the final osteotomy, an implant was installed in the area according to the manufacture's recommendation. The relevant Osstell® SmartPeg was selected and installed on the implant body to determine the primary stability. Kolmogorov-Smirnov test and the correlation pearson correlation statistical test. used for statistical analyze. P value amounts < 0.05 was considered significant. Results: The mean and standard deviation of the gray scale in this study were 563.7 ± 218.8 and 65.3 ± 7.7 implant stability quotient (ISQ) respectively. The correlation between gray scale and ISQ was evaluated by the Pearson correlation test, and the results indicated a strong correlation between the two variables. Conclusion: The voxel value and primary stability had a normal distribution and strong correlation. In other words, the gray scale determined by CBCT imaging techniques at the proposed implant site could be used to assess the bone density before the surgery.

A Cross-Sectional Study of Labial Bone and Covering Soft Tissue in Maxillary Anterior Segment: A Dilemma in Orthodontics.

PURPOSES: The thickness of the buccal bone and its covering gingiva is pivotal in determining the prognosis of implant therapy as well as fixed orthodontic appliances, especially nonextraction treatments. The purpose of this study was to evaluate the buccal bone thickness and covering soft tissue in the maxillary anterior segment. METHODS: This study measured the hard tissue thickness at 2 and 5 mm more apical from the crest and at the root apical apex, as well as the distance from the CEJ to the alveolar crest, using 80 CBCT images divided into three age groups. In addition, the distance from free gingiva to alveolar crest and from free gingiva to CEJ was measured. The acquired data then was analyzed using an ANOVA, t-test, and Pearson correlation to investigate any associations or statistically significant differences between parameters. RESULTS: The highest mean soft tissue thickness at the 5 mm level was for central incisors and the least for canine. The highest mean thickness of soft tissue at the crest level and its 2 mm apical level was related to central incisors and the lowest mean thickness at these levels was related to canine. Analysis of hard tissue variables showed the lower thickness of hard tissue at higher ages compared to the young patients group, but the thickness of the soft tissue increases with age. CONCLUSION: The highest mean thickness of the buccal hard tissue in the maxillary anterior segment was in lateral and central incisors. Also, the most prominent thickness of the labial soft tissue was in the central and lateral incisors at levels close to the crest.

Comparison of Bone Formation After Sinus Membrane Lifting Without Graft or Using Bone Substitute "Histologic and Radiographic Evaluation".

PURPOSE: Sinus floor elevation without using autogenous bone graft or bone substitute will eliminate donor site morbidity and reduce the cost and the risk of infection. We evaluated the bone gain after sinus membrane elevation without graft or using bone substitute in the same maxilla. Dental implants were inserted simultaneously as a 1-stage procedure. PATIENTS AND METHODS: In a split-mouth design, we conducted a randomized double-blinded clinical trial performing sinus lifts and simultaneous implant insertion in 10 healthy patients (n = 20). On the 1 site, we performed graft-less sinus lift (group 1) and on the other site Cerabone was used as bone substitute (group 2), respectively. The quantity and quality of bone gained in each sinus were evaluated and compared radiologically and histomorphometrically. RESULTS: After 6 months, the average gain of bone height was 6.21 and 9.58 mm in group 1 and 2, respectively, as measured radiologically (P < .001, P < .001). Histomorphometric examination showed significantly higher thickness of trabeculae and bone formation in group 1 (P = .003 and P = .002). However, the neovascularization was higher, but not significantly (P = .288). CONCLUSIONS: Radiological bone gain was similar in both groups. However, histomorphometric examination showed superior bone formation in graft-less group as compared to the Cerabone group. The blood clot seems to be an adequate filler and excellent medium for bone formation. More studies in split-mouth design are needed to compare different bone substitutes.

Clinical and Radiographic Evaluation of Chitosan Particles in Treatment of Intrabony Periodontal Defects: A Clinical Trial.

Objectives: Intrabony defects are among the most important signs of progression of periodontal disease. Complete tissue regeneration is the ideal goal of periodontal treatment, and regenerative methods aim to achieve this goal. New studies have reported the positive efficacy of chitosan to enhance the recovery of bony defects. This study aimed to clinically and radiographically assess the efficacy of chitosan particles for treatment of intrabony periodontal defects. Materials and Methods: In this clinical trial, 18 intrabony three-wall periodontal defects were randomly divided into three groups (n=6). The control group only received conventional flap surgery with a sulcular incision. In the second group, low molecular weight (100,000-300,000g/mol) chitosan was used in the three-wall intrabony defects during surgery while high molecular weight chitosan particles (600,000-800,000 g/mol) were used in the third group. The probing pocket depth (PPD), clinical attachment level (CAL) and radiographic defect depth (RDD) were measured at baseline and at 6 and 12 months later. Repeated measures ANOVA, and McNemar's test were used for statistical analysis. Results: In both the control (P<0.001) and coarse chitosan (P=0.035) groups, a significant difference was noted in PPD before and after surgery. CAL was not significantly different among the three groups (P>0.05). No significant difference was noted on radiographs between the groups regarding the regenerated bone density. Conclusion: Chitosan showed no positive efficacy for treatment of three-wall periodontal bone defects.

Evaluation of the Metal Artifact Caused by Dental Implants in Cone Beam Computed Tomography Images.

Statement of the problem: The presence of a metal object such as dental implants in the scan field may cause artifacts on the cone-beam computed tomography (CBCT) images, which can reduce the diagnostic quality and accuracy of images. Purpose: The aim of this in vitro study was to compare the severity of implant-induced metal artifacts on CBCT images. Materials and method: To this end, a dry human mandible and a maxilla were selected, then two Roxolid and two Zirconium fixtures with different diameters were placed in the central incisor and first molar sockets and fixed with dental wax. The mandible and maxilla were placed in the simulated phantom for soft tissue, and the occlusal plane was adjusted parallel to the horizon. Images were taken at standard and high resolutions using two CBCT units. The CBCT gray values were measured in three longitudinal sections of the fixture (cervical, middle and apical) and the contrast noise ratio (CNR) was calculated. The CNR values of images were analyzed based on the fixture material, resolution, jaw, unit parameters and fixture size by using the paired t-test and different fixture sections by one-way ANOVA. Results: Depending on the CBCT unit, the CNR values in Roxolid and Zirconium fixtures are completely different. Under higher exposure parameters, the CNR values of the Roxolid and Zirconium fixtures were significantly higher in the maxilla than mandible. However, the fixture size and longitudinal section type did not have a significant effect on the CNR values. Conclusion: In contrast to the fixture material, scanning parameters and jaw type, differences in the size and longitudinal section of the fixtures had no impact on artifact severity.

Effect of hydroalcoholic extract of flaxseed on bone mineral density in Wistar rats using digital radiography.

BACKGROUND: Given that the world's population is aging, the problems associated with osteoporosis and related fractures are increasing. The aim of the study was to evaluate the effect of flaxseed extract on bone mineral density (BMD) in Wistar rats using digital radiography. METHODS: In this experimental study, 25 male and 25 female Wistar rats were randomly divided into 5 groups: 1. Control, 2. Calcium and vitamin D (Ca/VitD), 3. 100 mg/kg flaxseed, 4. 200 mg/kg flaxseed, and 5. 400 mg/kg flaxseed. Then, the animals were kept for thirty days. Maxillary and mandibular BMD as well as serum levels of calcium, vitamin D and phosphorus were measured at baseline and after 30 days of keeping the rats. RESULTS: The results showed that serum levels of calcium and phosphorus were not significantly different in all five groups before and after 30 days. Serum levels of vitamin D were significantly higher in the group receiving Ca/vit D (with a mean of 61.6±15.8 in the male group and 85±12.9 in the female group) as compared with other groups (P<0.001). The highest level of change in maxillary and mandibular bone density was in 200 mg/kg flaxseed group with a mean difference of 24.5±6.1 and 26.5±3.1, respectively, which was significant in comparison with the control and Ca/vit D groups (p<0.001) . CONCLUSION: Flaxseed extract is more effective in increasing bone density than the group receiving Ca/vit D. The mandibular and maxillary BMD was higher in the group receiving 200 mg/kg flaxseed compared to the group receiving Ca/vit D (p<0.001).

Age estimation by pulp/tooth area ratio in anterior teeth using cone-beam computed tomography: comparison of four teeth.

OBJECTIVES: Age estimation is one of the most important factors in forensic medicine. Measuring secondary dentin deposition using cone-beam computed tomography images is an easy and noninvasive method. The aim of this study was to evaluate cone-beam computed tomography images as a reliable method to estimate chronological age by pulp/teeth ratio in anterior teeth in Iranian population. METHODOLOGY: A total of 649 CBCT images from 377 Iranian patients aged between 20 and 69 years were evaluated. Pulp/teeth ratio (PTR) in maxillary and mandibular canine and central incisor teeth was measured in the axial and sagittal sections using OnDemand 3D Dental software. The Pearson correlation coefficient was determined to evaluate the correlation between the variables. Linear regression analysis, as well as age estimation formula, was used for each tooth separately. RESULTS: The regression analyses indicated that maxillary central incisors were more reliable for age estimation (R2=0.586 and standard error of estimate=7.045) compared with the other anterior teeth studied. Maxillary canine teeth had the lowest predictive power (R2=0.392 and standard error of estimate=8.387). Also, comparison of the axial and sagittal sections showed that the axial sections had a higher predictive power. (R2=0.48 for axial plans and R2=0.328 for sagittal plans). CONCLUSION: The use of cone-beam computed tomography in age estimation by pulp/teeth ratio of anterior teeth is useful and a reliable method for age estimation in Iranian population.

Effect of equisetum arvense extract on bone mineral density in Wistar rats via digital radiography.

BACKGROUND: Osteoporosis is a common disease of old age. The present study used digital radiography to determine the effects of equisetum arvense extract on the bone mineral density (BMD) of experimental rats. METHODS: In this experimental study, 25 male and 25 female Wistar rats, aged three weeks old and weighing 100 grams, were randomly divided into five groups: (1) control group, (2) calcium/vitamin D group, (3) 60 mg/kg equisetum arvense extract group, (4) 90 mg/kg equisetum arvense extract group and (5) 120 mg/kg equisetum arvense extract group. Rats received these diets for 30 days. The spongy bone density was measured in the maxilla and mandible using digital radiography and the serum levels of calcium, vitamin D and phosphorus were measured at baseline and after 30 days. The data were analyzed using ANOVA and Tukey test. RESULTS: There was no significant difference between serum calcium and phosphorus levels in the five groups before and after 30 days. The serum vitamin D in the group receiving calcium and vitamin D was significantly higher than in the other groups (with average values of 24.7, 61.7, 23.47, 23.95 and 39.16 in the male groups 1 to 5 and 29.0, 85.07, 31.58, 42.34 and 18.83 in the female groups 1 to 5, respectively (p<0.001). Moreover, the increased mandibular BMD in the 120 mg/kg equisetum arvense group was significantly higher than in the control group (p<0.01). CONCLUSION: A diet containing 120 mg/kg equisetum arvense extract resulted in increased mandibular bone mineral density.

Evaluation of the cone-beam computed tomography accuracy in measuring soft tissue thickness in different areas of the jaws.

PURPOSE: Due to the extensive use of cone-beam computed tomography (CBCT) in dentistry, especially in measuring thicknesses of hard and soft tissues, and the fact that CBCT has low contrast resolution, the aim of this study was to evaluate the accuracy of CBCT in measuring soft tissue thickness. MATERIALS AND METHODS: In this cross-sectional study, pink baseplate wax as a soft tissue simulation was overlaid in different areas of the jaws on the dry human skull, and the probe was used to determine the thicknesses of 1, 2, 3, and 5 mm. These thicknesses were then measured accurately with a digital caliper by one person four times at interval of a week. The skull was scanned using two CBCT scanners, and the different thicknesses of wax were measured by two observers four times with a week interval. The CBCT measurements were compared with digital caliper measurements as a reference. RESULTS: Statistical analysis showed no significant difference between CBCT and digital caliper measurements for thickness < 2 mm (P > 0.05). CONCLUSIONS: Statistically, the difference between digital caliper and CBCT measurements was < 0.1 mm, but this difference is not clinically important. The accuracy of CBCT in measuring soft tissue thickness was 0.1 mm.

Radiographic Evaluation of Dental Anomaly Prevalence in a Selected Iranian Population.

STATEMENT OF THE PROBLEM: Many studies have explored the prevalence of dental anomalies, with conflicting results, possibly attributed to differences in the ethnicities of the populations evaluated. PURPOSE: The aim of this study was to investigate the prevalence of dental anomalies, using panoramic images, in an Iranian population. MATERIALS AND METHOD: In this cross-sectional study, panoramic radiographs of patients aged 18 years or more, between 2015 and 2017 from three private clinics in Babol and Sari, were evaluated for presence or absence of anomalies (tooth shape, number, structure, and position). Data were analyzed using the chi square test, Student's t-test, and analyses of variance. In this study, p ≤ 0.05 was considered significant. RESULTS: Of 8018 cases examined, anomalies were found in 2250 cases (28.06%), with 95% confidence intervals of 27.08 - 29.0; one, two, and more than two types of anomalies were observed in 1968 (24.5%), 267 (3.3%), and 15 (0.2%) cases, respectively. Root dilaceration was the most prevalent anomaly (7.7%), followed by dens invaginatus (3.8%). Impaction was observed with a prevalence of 15.2%. Impaction, dens invaginatus, and missing teeth were significantly more prevalent in women than in men, whilst supernumerary teeth and hypercementosis were more common in men than in women (p< 0.05). CONCLUSION: Regarding the relatively high prevalence of dental anomalies such as root dilacerations and dens invaginatus, it is essential to consider these anomalies carefully in treatment decision-making.

Clinical and radiographic evaluation of applying 1% metformin biofilm with plasma rich in growth factor (PRGF) for treatment of two-wall intrabony periodontal defects: A randomized clinical trial.

Background . The ultimate aim of periodontal treatment is to regenerate periodontium and regenerative treatment after that. The aim of this study was to evaluate the effect of PRGF with 1% metformin biofilm in the treatment of two-wall intrabony periodontal defects. Methods . In this clinical trial, 8 patients with moderate chronic periodontitis and two-wall intrabony defect were selected. The defects were assigned to 4 groups: debridement, 1% metformin, PRGF, PRGF and metformin. The parameters of vertical probing depth, vertical clinical attachment level and gingival index were measured at baseline, immediately before surgery, and 3 and 6 months after surgery. In addition, the radiographic changes were evaluated with digital subtraction radiography before and 6 months after surgery. Analysis of the results was performed with repeated measurements, Friedman test and chisquared test. Results . All the groups exhibited improvements in all the clinical parameters after 6 months. Inter-group comparison of GI, CAL and PPD parameters revealed no statistically significant differences. Radiographic changes in the group of 1% metformin with PRGF revealed statistically significant differences compared with other groups; however, there were no statistically significant differences in other groups. Conclusion . Application of PRGF with 1% metformin in intrabony two-wall periodontal defects was effective in improving the clinical parameters but this effect revealed no difference compared with other groups; however, in terms of radiographic changes significant improvements were noted.

Age estimation by pulp/tooth area ratio in anterior teeth using cone-beam computed tomography: comparison of four teeth

Abstract Objectives Age estimation is one of the most important factors in forensic medicine. Measuring secondary dentin deposition using cone-beam computed tomography images is an easy and noninvasive method. The aim of this study was to evaluate cone-beam computed tomography images as a reliable method to estimate chronological age by pulp/teeth ratio in anterior teeth in Iranian population. Methodology A total of 649 CBCT images from 377 Iranian patients aged between 20 and 69 years were evaluated. Pulp/teeth ratio (PTR) in maxillary and mandibular canine and central incisor teeth was measured in the axial and sagittal sections using OnDemand 3D Dental software. The Pearson correlation coefficient was determined to evaluate the correlation between the variables. Linear regression analysis, as well as age estimation formula, was used for each tooth separately. Results The regression analyses indicated that maxillary central incisors were more reliable for age estimation (R2=0.586 and standard error of estimate=7.045) compared with the other anterior teeth studied. Maxillary canine teeth had the lowest predictive power (R2=0.392 and standard error of estimate=8.387). Also, comparison of the axial and sagittal sections showed that the axial sections had a higher predictive power. (R2=0.48 for axial plans and R2=0.328 for sagittal plans) Conclusion The use of cone-beam computed tomography in age estimation by pulp/teeth ratio of anterior teeth is useful and a reliable method for age estimation in Iranian population.

Comparison of apical transportation and centering ability of Mtwo and Reciproc R25 in severely curved canals using cone-beam computed tomography.

BACKGROUND: Apical transportation (AT) of the root canal moves the physiologic canal terminus to a new location on the external root surface and results in the accumulation of debris and residual microorganisms due to inadequate cleaning and shaping of the canal end. This study aimed to assess the prevalence of AT following canal preparation with Mtwo and Reciproc R25 using cone-beam computed tomographic (CBCT). MATERIALS AND METHODS: In this in vitro study, 40 mesiobuccal root canals of the maxillary molars with 19-22 mm length and (>40°) taper were prepared in two groups using Mtwo and Reciproc R25 rotary systems along with irrigation with 2.5% NaOCl. CBCT scans were obtained of the canals before and after preparation under similar conditions, and the values were measured using the device software. The amount of AT was measured according to Gambill et al. Data were analyzed using SPSS 17 and Chi-square and t-tests. P < 0.05 was considered significant. RESULTS: Both systems caused some degrees of AT. No significant difference was found between the two systems in terms of the amount and direction of AT (P > 0.05); overall, the frequency of AT toward the mesial wall was greater than that toward the distal direction. However, this difference was not statistically significant. CONCLUSION: The mean amount of AT and the ability to keep the instruments in severely curved canals were not significantly different in canals prepared by Mtwo and Reciproc rotary systems. Thus, these systems can be used in the clinical setting with the lowest risk of AT.

Histopathological, histomorphometrical, and radiological evaluations of hydroxyapatite/bioactive glass and fluorapatite/bioactive glass nanocomposite foams as cell scaffolds in rat tibia: an in vivo study.

Bone defects are common and persistent problems in clinical orthopedics and dentistry. The development of synthetic reconstruction materials is essential owing to the restricted access to natural bone grafts, disease transmission risks, surgical costs, donor-site morbidity, infections, and immune response-related complications. The present study was done to evaluate the histopathological, histomorphometrical, and radiological characteristics of composite foams containing hydroxyapatite/bioactive glass (HA/BG) and fluorapatite/bioactive glass (FA/BG) as cell scaffolds in rat tibia reconstruction. A total of 60 rats were divided into four equal groups, of which three groups were implanted with HA/BG, FA/BG, and CenoBone® biomaterials, and the fourth group served as the implant-free controls. Five rats from each group were sacrificed at 15, 30, or 60 days after implantation, and radiological, histopathological, and histomorphometrical assessments were carried out. Based on the findings, no foreign body reaction was present in the rats. Additionally, bone-biomaterial contact occurred directly without the involvement of connective tissues. The number of osteoblasts was reduced in the implant groups, whereas the trabecular thickness and rate of new bone formation were increased in all groups, where the increase in the FA/BG group was the most prominent. The mean percentage difference in bone density between the implant site and the host bone was greater in the FA/BG group at all three time points of the study. Based on the results of the present study and the positive characteristics of these nanocomposite foams, they can be suitable options for implantation in damaged tissues in tissue engineering.

Evaluation of the Prevalence of Complete Isthmii in Permanent Teeth Using Cone-Beam Computed Tomography.

INTRODUCTION: The current study aimed at determining the prevalence of complete isthmii in permanent teeth, using cone-beam computed tomography (CBCT) in a selected Iranian community. METHODS AND MATERIALS: In this cross sectional study, 100 CBCT images (from 58 female and 42 male patients) including 1654 teeth (809 maxillary and 845 mandibular teeth) were evaluated. Each tooth root was evaluated in axial plane (interval, 0.1 mm; thickness, 0.1 mm) from the orifice to the apex and from the apex to the orifice to detect the presence of complete isthmus. Scans of teeth with complete isthmii were reevaluated in axial, sagittal, and coronal planes with the thickness, 0.1 mm. Presence and absence of complete isthmii in each tooth was reported. The root canal was divided into 3 equal parts (cervical, middle and apical thirds), and isthmii were classified with respect to the start and end points. Findings were classified into 6 categories with respect to the start and end points of the isthmii: 1) the beginning and end in the cervical third; 2) the beginning in the cervical third and end in the middle third ; 3) the beginning in the cervical third and end in the apical third ; 4) the beginning and end in the middle third ; 5) the beginning in the middle third and end in the apical third and 5) the beginning and end in the apical third. RESULTS: The prevalence of complete isthmus in permanent teeth was 8.6%, and the highest prevalence was reported in mesial roots of the mandibular first molars. In maxilla, the highest prevalence of complete isthmus was found in mesiobuccal roots of the maxillary first molars, whereas in canines and central incisors, no isthmii were detected. In the mandible, the lowest prevalence of isthmus was found in second premolars. In maxillary molars, isthmii starting and ending in the middle third of the root had the highest prevalence. On the other hand, isthmii in mandibular molars, from apical or middle third of the root beginning to the end of the apical third, had the highest prevalence. CONCLUSION: As the prevalence of complete isthmii was the highest in molars, endodontists should pay particular attention to accomplish a successful surgical or nonsurgical root canal therapy.

Guided tissue regeneration and platelet rich growth factor for the treatment of Grade II furcation defects: A randomized double-blinded clinical trial - A pilot study.

BACKGROUND: The treatment of furcation area defects remained as a challenging issue in periodontal treatments. Regeneration treatment of furcation defects is the most discussed periodontal treatment. Although not completely hopeless in prognosis, the presence of the furcation involvement significantly increases the chance of tooth loss. The current research was conductedeto compare theeadditive effect of combined guided tissue regeneration (GTR) and platelet-rich growth factor (PRGF) on the treatment of furcation bony defects. MATERIALS AND METHODS: A randomized, triple-blinded, split-mouth study was designed. It included patients with a moderate to severe chronic periodontitis with bilateral Grade II furcation involvement of first or second mandibular molars. Each side of mouth was randomly allocated for the treatment with either Bio-Gide American Society of Anesthesiologists GTR or a PRGF or PRGF by itself. Plaque index, gingival index, vertical clinical attachment level, vertical probing depth, recession depth (REC), horizontal probing depth, fornix to alveolar crest (FAC), fornix to base of defect (FBD), furcation vertical component and furcation horizontal component (FHC) were recorded. The current research was conducted to compare the additive effect of combined GTR and PRGF on treatment of furcation bony defects. Altman's nomogram, Kolmogorov-Smirnov test, Friedman test, general linear model, repeated measures, and paired t-test were used as statistical analysis in this research. P < 0.05 was considered statistically significant. RESULTS: Eight patients were finally enrolled for this study. Overly, general and specific clinical and furcation parameters were improved except REC that was deteriorated insignificantly and FAC improved not significantly. Intergroup comparison revealed better improvement of FHC in GTR/PRGF group (P = 0.02). CONCLUSION: A significant improvement in the Grade II furcation defects treated with either GTR or PRGF/GTR was noticed. Further large-scale trials are needed to reveal differences of mentioned treatment in more details.