The micro CT evaluation of crown and root pulp volume versus dentin thickness in teeth in postmortem interval (PMI).

Determining the postmortem interval (PMI) is one of the main study subjects of forensic sciences. The main purpose of this prospective in vitro study that was the Micro-CT evaluation of teeth crown and root pulp volume versus dentin thickness in terms of PMI determination. The study involved 60 female Wistar rats, with weights ranging from 270 to 320 g. These rats were grouped into six different post-mortem period categories. Following the animals' sacrifice, they were subjected to a natural putrefaction period, with a control group, in the grounds of a sheltered garden. Hemi-mandible samples were then extracted and placed in glass tubes for Micro-CT evaluations, following the progression of putrefaction processes. The pulp volume and dentin thickness were assessed using Micro-CT, and the gathered data underwent statistical analysis. Micro-CT was employed to analyze sixty right mandibular second molar teeth in the hemi-mandible. The crown pulp volume exhibited a reduction in group 6, with a value of 0.239 mm3 after a three-month period of natural putrefaction (p < 0.001). There is statistically differences among groups in case of pairwise comparison (p < 0.05). However, the root pulp volume and dentin thickness variables did not display any statistically significant changes. Despite certain limitations associated with this study, the Micro-CT findings concerning teeth pulp volume can serve as an objective parameter, especially for late postmortem investigations and the estimation of time of death.

Evaluation of the anticarcinogenic effects of Rutin on brain tissue in mice with Ehrlich ascites carcinoma by micro-computed tomography and histological methods.

BACKGROUND: Studies for new treatment strategies on cancer continue, and new searches continue in the diagnosis and evaluation of cancer. This study examined the possible anticarcinogenic effect of Rutin on the brain tissues of male mice with Ehrlich ascites carcinoma (EAC). MATERIAL AND METHODS: We used micro-computed tomography (micro-CT) and histologically Hematoxylin&Eosin (H&E) staining methods for evaluation. RESULTS: In the evaluation results, we saw a significant decrease in the brain volume of the tumor group to the control group. The difference in volume between the Rutin treatment group and the control group was not significant. In the brain tissues of the tumor group, numerous degenerated neurons characterized by pericellular/perivascular space expansion, cell swelling, or expansion were detected in the cortex and hippocampus regions. We showed a reduction in the damage rate in the Rutin treated group. CONCLUSION: As a result, Rutin was found to have an anticarcinogenic effect. In addition to the classical histological evaluation, we used a newer method, micro-CT, in our study. We believe that this study has important results both in terms of its originality and adding new information to the literature.

Effects of design software program and manufacturing method on the marginal and internal adaptation of esthetic crowns for primary teeth: A microcomputed tomography evaluation.

STATEMENT OF PROBLEM: The adaptation of digitally produced crowns is affected by the design software program and manufacturing method. The effect of artificial intelligence (AI) software program design on the adaptation of the crowns is unclear and comparative evaluations should be documented. PURPOSE: The purpose of this study was to assess the marginal and internal gaps, the absolute marginal discrepancies, and the 3-dimensional (3D) discrepancy volumes of the resin-based milled and 3D printed crowns for primary teeth designed with computer-aided design (CAD) and AI software programs by using microcomputed tomography (µCT). MATERIAL AND METHODS: A total of 40 resin-based esthetic crowns were produced for a prepared typodont tooth (right mandibular primary second molar) according to the design software program (CAD and AI) and manufacturing method (milling and 3D printing) (n=10). Four experimental groups were generated as CAD-milled, CAD-3D printed, AI-milled, and AI-3D printed. The marginal, axial, and occlusal gap values, the absolute marginal discrepancies, and the 3D discrepancy volumes of the specimens were measured by using µCT. The data were analyzed by using 2-way ANOVA and the Tukey HSD tests (α=.05). RESULTS: The lowest value for the marginal gap (54 ±43 µm) was observed in the CAD-milled group and the marginal gap value of the AI-3D printed group was significantly lower than the AI-milled group (P<.05). The lowest value for the axial gap (63 ±7 µm) was observed in the AI-3D printed group, and the highest value (145 ±58 µm) was observed in the CAD-milled group; the result for the occlusal gap value was opposite. The highest absolute marginal discrepancy value was observed in the CAD-milled group. The 3D discrepancy volumes increased in the order of the CAD-3D printed, AI-milled, CAD-milled, and AI-3D printed groups. CONCLUSIONS: The marginal and internal gap values of the resin-based crowns were affected by the design software program and manufacturing method; however, tested groups showed clinically acceptable gap values.

Micro-CT evaluation of the removal of root fillings using rotary and reciprocating systems supplemented by XP-Endo Finisher, the Self-Adjusting File, or Er,Cr:YSGG laser.

Objectives: This study aimed to compare the effectiveness of a single-file reciprocating system (WaveOne Gold, WOG) and a multi-file rotary system (ProTaper Universal Retreatment, PTUR) in removing canal filling from severely curved canals and to evaluate the possible adjunctive effects of XP-Endo Finisher (XPF), the Self-Adjusting File (SAF), and an erbium, chromium: yttrium, scandium, gallium garnet (Er,Cr:YSGG) laser using micro-computed tomography (µCT). Materials and Methods: Sixty-six curved mandibular molars were divided into 2 groups based on the retreatment technique and then into 3 based on the supplementary method. The residual filling volumes and root canals were evaluated with µCT before and after retreatment, and after the supplementary steps. The data were statistically analyzed with the t-test, Mann-Whitney U test, analysis of covariance, and factorial analysis of variance (p < 0.05). Results: PTUR and WOG showed no significant difference in removing filling materials (p > 0.05). The supplementary techniques were significantly more effective than reciprocating or rotary systems only (p < 0.01). The supplementary steps showed no significant differences in canal filling removal effectiveness (p > 0.05), but XPF showed less dentin reduction than the SAF and Er,Cr:YSGG laser (p < 0.01). Conclusions: The supplementary methods significantly decreased the volume of residual filling materials. XPF caused minimal changes in root canal volume and might be preferred for retreatment in curved root canals. Supplementary approaches after retreatment procedures may improve root canal cleanliness.

Effects of Stabilization of the Sinus Membrane by Dental Implant Insertion and Membrane Suturing on Endo-Sinus Bone Gain in Cases of Lateral Sinus Lift Performed Without Graft Material.

PURPOSE: The aim of this study was to investigate the effects of membrane stabilization by suturing the sinus membrane and dental implant insertion on endo-sinus bone formation in lateral sinus lifting performed without grafting. MATERIALS AND METHODS: Maxillary sinus lift surgery using the lateral approach was performed bilaterally in 30 New Zealand white rabbits. The maxillary sinus areas were divided into control and test groups. In the control group, a titanium screw was placed after sinus membrane elevation, while in the test group, the sinus membrane was sutured to the lateral walls and a titanium screw was placed in the center of the alveolar crest. The animals were sacrificed at 4 and 8 weeks. Samples were collected, and micro-computed tomography (micro-CT) analysis was performed. The volume of newly formed bone, percentage of osseointegration, sinus volume, residual bone height, and protrusion length of the implants were measured using micro-CT analysis. RESULTS: The sinus volume, volume of newly formed bone, and percentage of osseointegration in the test group were significantly higher than those in the control group at 4 weeks (p = 0.01, p = 0.04, p = 0.02, respectively) While the volume of newly formed bone was 17.1 ± 3.08 mm3 in the control group, it was 26.9 ± 14.26 mm3 in the test group at 4 weeks. The volume of newly formed bone was significantly decreased from 26.9 ± 14.26 mm3 to 17 ± 3.66 mm3 at 8 weeks (p = 0.02). No significant difference in residual bone height was found at 4 and 8 weeks (p = 0.07). No significant difference in implant protrusion length was found between the control and test groups (p = 0.18). Protrusion length and new bone formation in the sinus showed a negative relationship (p = 0.01). CONCLUSION: Suturing the sinus membrane to the lateral sinus wall is an effective approach for increasing osseointegration, bone volume, and sinus volume in the short-term. A slow-absorbing suture material can be used to maintain sinus and bone volumes in the long-term.

Can locally applied risedronate be an effective agent when combined with xenografts? An animal study.

BACKGROUND: To examine the effects of local risedronate application with xenografts on healing of rabbit skull defects using histological, histomorphometric, immunohistochemical, and three-dimensional radiological methods. METHODS: Two critical-sized defects with a diameter of 10 mm were created in 16 rabbits and filled with xenogenic bone graft and xenogenic bone graft + 5 mg risedronate in the control I and risedronate (RIS) groups, respectively. Residual graft, new bone, soft tissue areas, and bone volume were evaluated in the 4- and 8-week study groups. RESULTS: In both the 4- and 8-week samples, the RIS group samples had significantly higher mean new bone area values than the C group (p < 0.05). In both groups, the values for the new bone area were significantly higher in the 8-week-old samples than in the 4-week-old samples (p < 0.05). The h scores obtained for sialoprotein and osteopontin did not differ significantly between the groups at either time point (p > 0.05). The results of radiological evaluation showed that the bone density value was significantly higher in the C group than in the RIS group at either time point (p < 0.05). CONCLUSIONS: Although this study aimed to demonstrate the effect of risedronate on the osteoconductive properties of xenografts when applied locally, targeted results could not be achieved.

Comparison of three different biomaterials used in in vitro molar apexification models.

OBJECTIVES: New biomaterials had some advantages such as mixing and easier application as compared to traditional MTA in single step apexification method. This study aimed to compare the three biomaterials used in the apexification treatment of immature molar teeth in terms of the time spent, the quality of the canal filling and the number of x-rays taken to complete the process. METHODS: The root canals of the extracted thirty molar teeth were shaped with rotary tools. To obtain the apexification model, ProTaper F3 was used retrograde. The teeth were randomly assigned into three groups based on the material used to seal the apex; Group 1: Pro Root MTA, Group 2: MTA Flow, Group 3: Biodentine. The amounts of the filling, the number of radiographs taken until treatment completion and the treatment duration were recorded. Then teeth were fixed for micro computed tomography imaging for quality evaluation of canal filling. RESULTS: Biodentine was superior to the other filling materials according to time. MTA Flow provided greater filling volume than the other filling materials in the rank comparison for the mesiobuccal canals. MTA Flow had greater filling volume than ProRoot MTA in the palatinal/distal canals(p = 0.039). Biodentine had greater filling volume more than MTA Flow in the mesiolingual/distobuccal canals (p = 0.049). CONCLUSIONS: MTA Flow was found as a suitable biomaterial according to the treatment time and quality of root canal fillings.

Micro-CT evaluation of the effect of various ScRp instrumentation methods on cement loss, porosity and micro-crack formation.

OBJECTIVES: The purpose of this study was to compare the effectiveness of three different instruments on cement loss, porosity and micro-crack formation, which was not evaluated before, following scaling and root planning (SRP) using micro-computed tomography (micro-CT). METHODS: In this experimental study, 30 single-rooted extracted human teeth were used and divided into three groups. All the teeth were scanned with micro-CT before and after SRP. Group 1: SRP was performed with Gracey curettes, Group 2: SRP was performed by using an ultrasonic device, and Group 3: SRP was performed by using diamond burs. Cement loss from the root surface, porosity, and micro-crack formation in the root dentine were analysed. Micro-CT is used for qualitative and quantitative analysis of samples. The obtained data were analysed statistically (p < 0.05). RESULTS: Minimum cement loss following SRP was detected with ultrasonic scaler (26.98 mm3 ), whereas the highest was created by diamond burs (96.20 mm3 ) (p < 0.05). The total porosity values after SRP were 0.278%, 0.334% and 0.252% for Groups 1, 2 and 3, respectively. Although Group 3 had the least porosity values, there was no statistically significant difference between the groups. The highest micro-crack formation was seen in Group 2 and the lowest was in Group 1 with a significant difference (p < 0.05). CONCLUSIONS: More cement loss was observed with diamond burs. Ultrasonic devices appear to be a viable alternative to instrumentation with curettes. However, ultrasonic devices should be used carefully because of micro-crack formation since the micro-crack resulting from instrumentation with hand instruments is the least of all.

How can excess residual cement be reduced in implant-supported restorations?: An in vitro study.

OBJECTIVE: The aim of this study was to investigate the effect of different cements and cementation techniques used in implant-supported restorations and the application of various vent modifications and extraoral replica techniques on the amount of overflowing cement in cemented systems. MATERIALS AND METHODS: In this study, three different abutment designs were used as fully closed, occlusal vented, and occlusal + proximal vented. An extraoral replica was produced by milling the CAD/CAM ceramic block. The number of groups with and without replicas was determined as six (n = 10). For the cementation procedures, three different cements were tested: dual-cure resin, eugenol-free zinc oxide, and polycarboxylate cements. Cobalt-chromium superstructures to be cemented to the implant analog-abutment complex were produced by direct metal laser sintering method. Twenty-four hours after the cementation process, residual cement were measered with Micro-CT. In comparisons between groups, ANOVA test was used for normally distributed variables and Kruskall-Wallis H test was used for non-normally distributed variables at a significance level of p < 0.05. RESULTS: The difference in residual cement volumes between the groups in terms of both cementation techniques (whether or not to use an extraoral replica and different vent desings) and cement types was found to be statistically significant (p < 0.05). There was significantly less residual cement in all groups that used extraoral replicas than those that did not. As for the cement types, the most residual cement occurred in the resin cement. CONCLUSION: The use of extraoral replicas and vent designs on the abutment significantly reduces the amount of residual cement. Regardless of the cementation technique, the type of cement used affects the amount of excess cement. CLINICAL RELEVANCE: To reduce residual cement, both the type of cement and the cementation technique used must be considered.

Resveratrol prevents ovariectomy-induced bone quality deterioration by improving the microarchitectural and biophysicochemical properties of bone.

INTRODUCTION: Osteoporosis is a major health problem that is very common worldwide and is characterized by both low bone density and deterioration in bone quality. New treatment options without side effects have become an active area of research in recent years. This study was designed to investigate the preventive effects of resveratrol on bone quality deterioration caused by ovariectomy. MATERIALS AND METHODS: Sixty rats were randomly divided into five groups (12 animals per group): Control, Sham-operated (SHAM), ovariectomized (OVX), OVX + Resveratrol-40 mg/kg/day (OVX + Res40), OVX + Resveratrol-80 mg/kg/day (OVX + Res80). Resveratrol was administered by oral gavage (40 and 80 mg/kg/day) for ten weeks. Micro-CT measurements, biomechanical testing, Raman spectroscopy analysis, and RT-PCR analysis were performed. ALP, OCN, TAS, and TOS levels were also measured from blood serum. RESULTS: Bone strength, bone volume/total volume, trabecular volume, and trabecular thickness were higher in the OVX + RES-80 group than in the OVX group. Resveratrol increased osteogenic differentiation, as the expression of osteogenic markers ALP, Col1A1, Runx2, OPG, OCN increased in both OVX + RES-80 and OVX + RES-40 groups compared to the OVX group. 80 mg/kg/day resveratrol administration decreased the levels of ALP, OCN and TOS in ovariectomized rats. Raman spectroscopy findings showed a preventive effect of resveratrol administration against ovariectomy-induced deterioration in biophysiochemical properties of bone tissue. CONCLUSION: This study revealed that administration of different doses of 80 mg/kg/day and 40 mg/kg/day of resveratrol had protective effects on bone quality deterioration caused by ovariectomy.

Investigation of taurine and aqueous garlic extract diet supplementation effect on the healing of rat osteoporotic fractures.

BACKGROUND: We have evaluated the effects of taurine and aqueous garlic extract (AGE) as a dietary supplement on osteoporotic fracture (OPF) healing in the ovariectomized rat femur fracture model. METHODS: In this experimental animal study,twenty-four osteoporosis-remodeled female Wistar albino rats were randomly divided into 3 groups (n: 8) according to their supplemented diet; control, taurine, and AGE groups. Unilateral femur middiaphysis mini-open osteotomy was stabilized with Kirschner wires. Six weeks after osteotomy, the rats were sacrificed before the femurs were harvested and OPF healing was evaluated with biochemical, histologic, microcomputed-tomography, and scintigraphic methods. RESULTS: As an indicator of the antiosteoporotic effect, the calcium levels of the taurine group were significantly lower than the AGE and control groups in biochemical analyzes (p < 0.01). In histological studies, the new bone diameter and new bone volume values of the taurine group were significantly higher than the control group (p = 0.002 and p = 0.032, respectively), while higher trabecular-compact callus was observed in the taurine and AGE groups, respectively, compared to the control group. In morphological analyses, taurine and AGE groups had significantly higher bone volume/tissue volume, trabecular number, bone surface density, and lower trabecular separation than the control group (p < 0.05). The scintigraphic imaging showed a significant increase in osteoblastic activity of the taurine group compared to the control group (p = 0.005). DISCUSSION: Taurine and AGE have positive anabolic effects, respectively, on the healing of OPFs, demonstrated by biochemical, histological, morphological, and scintigraphic methods.

Effects of a locally administered risedronate/autogenous bone graft combination on bone healing in a critical-size rabbit defect model.

BACKGROUND: Risedronate is a bisphosphonate with poor oral absorption. An extremely hydrophilic molecule that has a high affinity for bone, risedronate also inhibits the farnesyl diphosphate synthase enzyme, inhibiting osteoclastic activity and reducing bone turnover and resorption. Autogenous bone grafts contain osteogenic cells and osteoinductive factors that are essential for bone regeneration and are therefore considered the gold standard. Thus, this study aimed to investigate the impact of local risedronate administered with autogenous bone grafts on the healing of defects in rabbit skulls using histological, histomorphometric, immunohistochemical, and three-dimensional radiological methods. METHODS: Two 10-mm-diameter critical-size defects were created in 16 rabbits and filled with autogenous bone graft and autogenous bone graft + 5 mg risedronate in the control (C) and risedronate (RIS) groups, respectively. Residual graft, new bone, soft tissue areas, and bone volume were evaluated in the 4- and 8-week study groups. RESULTS: There were no statistically significant differences in bone graft, new bone, or soft tissue area between the groups at 4 weeks (p > 0.05). At 8 weeks, the new bone area was significantly higher in the RIS group than in the C group (p < 0.05). The h scores obtained from sialoprotein and osteopontin did not differ significantly between the groups (p > 0.05). The radiologically measured total bone volume was significantly higher in the RIS group than in the C group at both time points (p < 0.05). CONCLUSIONS: In this study, risedronate enhanced the osteoconductive properties of autogenous bone grafts and rapidly created better-quality bone. This could improve future patient outcomes.

Examination of sinus tympani, subtympanic sinus, and facial sinus with MicroCT.

This study aimed to determine sinus tympani, subtympanic sinus (STS), facial sinus (FS) morphologies, and type distributions. Type distributions were based on their relations with the facial nerve (FN). A total of 20 right and 20 left temporal dry bones without physical deformation were scanned with a MicroCT device. All measurements were made using MicroCT programs from sections in the axial plane. For the FS, the average depth was measured as 3.485 mm without any classification, and 29 of the 40 bones had Type C radiological morphology. The mean depth for all sinus tympanicus was 2.646 mm, and 22 of the 40 bones had Type B morphology. For the STS, 29 out of 40 samples had no contact with the FN; regardless of the classification, the average depth was measured as 2.376 mm. We reveal the depths of the tympanic cavities and their relationship with the FN. The results of this study may benefit clinicians performing retrotympanum surgeries.

Effect of different preparation finishing procedures on the marginal and internal fit of CAD-CAM-produced restorations: A microcomputed tomography evaluation.

STATEMENT OF PROBLEM: Accurate fit is an important factor for the longevity of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramic restorations. Few studies have compared how restoration finishing procedures affect the marginal and internal fit of these restorations by using microcomputed tomography (µCT). PURPOSE: The purpose of this in vitro study was to evaluate the preparations with different surface finishing procedures for the fit of CAD-CAM restorations by using µCT. MATERIAL AND METHODS: A total of 28 anatomic contour monolithic feldspathic ceramic crowns were produced for 4 typodont teeth prepared according to the different surface finishing procedures (n=7). The generated experimental groups were finishing with extra-coarse (181 µm) diamond rotary instruments (EC), finishing with fine (40 µm) diamond rotary instruments after extra-coarse diamond rotary instruments (F), finishing with very fine (20 µm) diamond rotary instruments after extra-coarse and fine diamond rotary instruments (VF), and finishing with extra-coarse, fine, and very fine diamond rotary instruments followed by polishing rubber points (P). µCT scans were obtained to measure the gaps between the typodont teeth and the crowns. Reference points such as the margin, chamfer (the deepest point), cusp tips, and central fossa were determined, and 196 measurements were made. Data were analyzed by using 2-way analyses of variance and the Tukey HSD test (α=.05). RESULTS: The highest gap values in all sections were observed in the finishing with extra-coarse (181 µm) diamond rotary instruments group. The lowest gap value in the marginal point was observed in the P group (P<.05). In total, the gap values of the reference points were in the order of margin, chamfer, cusp, and central fossa. CONCLUSIONS: µCT evaluation showed that tooth preparation finishing procedure with finer grit rotary instruments yielded better marginal fit for monolithic feldspathic CAD-CAM restorations. The internal gap values of all groups were also in the range of clinically acceptable values, important for mechanical properties.

Inhibition of Ehrlich ascites carcinoma growth by melatonin: Studies with micro-CT.

Melatonin is a versatile indolamine synthesized and secreted by the pineal gland in response to the photoperiodic information received by the retinohypothalamic signaling pathway. Melatonin has many benefits, such as organizing circadian rhythms and acting as a powerful hormone. We aimed to show the antitumor effects of melatonin in both in vivo and in vitro models through the mammalian target of rapamycin (mTOR) signaling pathway and the Argyrophilic Nucleolar Regulatory Region (AgNOR), using the Microcomputed Tomography (Micro CT). Ehrlich ascites carcinoma (EAC) cells were administered into the mice by subcutaneous injection. Animals with solid tumors were injected intraperitoneally with 50 and 100 mg/kg melatonin for 14 days. Volumetric measurements for the taken tumors were made with micro-CT imaging, immunohistochemistry (IHC), real-time polymerase chain reaction (PCR) and AgNOR. Statistically, the tumor tissue volume in the Tumor+100 mg/kg melatonin group was significantly lower than that in the other groups in the data obtained from micro-CT images. In the IHC analysis, the groups treated with Tumor+100 mg/kg melatonin were compared when the mTOR signaling pathway and factor 8 (F8) expression were compared with the control group. It was determined that there was a significant decrease (p < 0.05). Significant differences were found in the total AgNOR area/nuclear area (TAA/NA) ratio in the treatment groups (p < 0.05). Furthermore, there were significant differences between the amount of mTOR mRNA for the phosphatidylinositol 3-kinase (PI3K), AKT Serine/Threonine Kinase (PKB/AKT) genes (p < 0.05). Cell apoptosis was evaluated with Annexin V in an in vitro study with different doses of melatonin; It was observed that 100 µg/mL melatonin dose caused an increase in the apoptotic cell death. In this study, we have reported anti-tumor effects of melatonin in cell culture studies as well as in mice models. Comprehensive characterization of the melatonin-mediated cancer inhibitory effects will be valuable in advancing our fundamental molecular understanding and translatability of pre-clinical findings to earlier phases of clinical trials.

Effect of Locally Administered Denosumab on Bone Graft Healing in Rabbit Critical-Size Calvarial Defects.

Background/Aim: Denosumab is a human monoclonal immunoglobulin G2 antibody developed from the ovarian cells of Chinese hamsters. We aimed to histomorphometrically and radiologically evaluate the effects of xenografts used with local denosumab on the healing of defect sites using rabbit skulls. Materials and Methods: Two 10-mm diameter critical-size defects were created in 16 rabbits. The defect areas were filled with xenografts and xenograft + 3 mg denosumab in the control and denosumab groups (DEN), respectively. We evaluated new bone, residual graft, soft tissue areas, and bone volume in 4- and 8-week study groups. Results: Histomorphometrically, there were no statistically significant differences between groups at both 4 and 8 weeks regarding residual graft, new bone, and soft tissue area (p > 0.05). The 4-week residual graft control group values were significantly higher than the 8-week values (p < 0.05). The soft tissue area was significantly greater in the 4-week compared with the 8-week DEN group (p < 0.05). The radiologically measured total bone volume was significantly greater in the 8-week specimens than in the 4-week specimens (p < 0.05). Conclusion: In this study, denosumab used locally with bone grafts, showed no direct effect on new and total bone volume.

Effect of different voxel sizes on the accuracy of CBCT measurements of trabecular bone microstructure: A comparative micro-CT study.

Purpose: The aim of this study was to assess the accuracy of cone-beam computed tomographic (CBCT) images obtained using different voxel sizes in measuring trabecular bone microstructure in comparison to micro-CT. Materials and Methods: Twelve human skull bones containing posterior-mandibular alveolar bone regions were analyzed. CBCT images were obtained at voxel sizes of 0.075 mm (high: HI) and 0.2 mm (standard: Std), while micro-CT imaging used voxel sizes of 0.06 mm (HI) and 0.12 mm (Std). Analyses were performed using CTAn software with the standardized automatic global threshold method. Intraclass correlation coefficients were used to evaluate the consistency and agreement of paired measurements for bone volume (BV), percent bone volume (BV/TV), bone surface (BS), trabecular thickness (TbTh), trabecular separation (TbSp), trabecular number (TbN), trabecular pattern factor (TbPf), and structure model index (SMI). Results: When compared to micro-CT, CBCT images had higher BV, BV/TV, and TbTh values, while micro-CT images had lower BS, TbSp, TbN, TbPf, and SMI values (P<0.05). The BV, BV/BT, TbTh, and TbSp variables were higher with Std voxels, whereas the BS, TbPf, and SMI variables were higher with HI voxels for both imaging methods. For each imaging modality and voxel size evaluated, BV, BS, and TbTh were significantly different (P<0.05). TbN, TbPf, and SMI showed statistically significant differences between imaging methods (P<0.05). The consistency and absolute agreement between micro-CT and CBCT were excellent for all variables. Conclusion: This study demonstrated the potential of high-resolution CBCT imaging for quantitative bone morphometry assessment.

Evaluation of the Efficiency of the Graft Material Combined with Ozonized Blood in Maxillary Sinus Lifting Applications in Rabbits.

Objectives: The aim of this study is to investigate the effect of the graft material combined with ozonized blood on bone healing in rabbit in maxillary sinus lifting applications histomorphometrically, immunohistochemically and microtomographically. Materials and Methods: Twenty-eight New Zealand rabbits were randomly divided into 2 groups as experimental (n = 14) and control (n = 14). In experimental group, 5 ml (milliliter) blood obtained from the ear vein of each rabbit was ozonized by 80 µl (µl)/ml concentration ozone-oxygen mixture. Graft material was combined with this ozonized blood. In control group, the graft was combined with saline solution at 0.9% concentration. A 5 mm (millimeter) in diameter window was created on right maxillary sinus window in each rabbit under general anesthesia by local anesthesia support. Sinus membrane was elevated and the space was augmented by 1 cc (cubic centimeter) graft material. One rabbit from the control group which was planned to sacrifice at the end of 8 weeks could not participate in the evaluation because of the extensive inflammation at the operation site. Newly formed bone area and bone density were measured using by image analysis program. Bone morphogenetic protein-2 (BMP-2), vascular endothelial growth factor (VEGF) and collagen-1 (COL-1) analyses were carried out immunohistochemically. The amount of the newly generated bone and the amount of the total augmented space were calculated volumetrically by microtomography. Results: According to histomorphometrical analysis, although newly formed bone area has increased in both experimental and control group with time, statistically significant results were obtained when only O-8 (ozone-treated experimental group planned to be sacrificed after 8 weeks) and O-4 (ozone-treated experimental group planned to be sacrificed after 4 weeks) groups were compared (p = 0,037). The increase in new bone density was seen in both experimental and control groups with time and the results were statistically significant when O-8 group compared to O-4 and C-4 group (ozone-free control group planned to be sacrificed after 4 weeks) (p = 0,07 and p = 0,04, respectively) and C-8 (ozone-free control group planned to be sacrificed after 8 weeks) group compared to C-4 group (p = 0,023). According to immunohistochemical analysis, the intensity and the severity of field staining with anti-BMP-2 have increased in experimental group whereas it has decreased in control group but despite that there was no statistically significance among all groups compared to each other. The number of new vessels stained with anti-VEGF has increased in both experimental and control group with time and multiple comparison results were statistically significant when O-8 group compared with O-4 and C-4 (p = 0,000, p = 0,000, respectively), O-4 group compared with C-8 (p = 0,000) and C-8 group compared with C-4 (p = 0,000). Although the intensity and the severity of field staining with anti-COL-1 have increased in both experimental and control group with time, there was no statistically significance among all groups compared to each other. According to microtomographical analysis, the percentage of the volume of the newly generated bone in the total augmented space volume has decreased with time in both experimental and control groups. Conclusions: Considering the results of this study, the graft material combined with the ozonized blood increased the density of the newly generated bone and the number of new vessels in maxillary sinus lifting applications in rabbits. Clinical Relevance: We suggest further studies should be done combining the graft with ozone by different methods, dosages and exposure times.

Micro-CT comparative evaluation of porosity and dentin adaptation of root end filling materials applied with incremental, bulk, and ultrasonic activation techniques.

The purpose of this study is to investigate the effect of different application methods on the adaptation to dentin and porosity properties of calcium silicate based materials. This study included 72 maxillary canine teeth that had been extracted for various reasons. Following the root canal treatment, root, end resections were performed on the specimens. After the apicectomy, 3 mm deep cavities were created. All materials were mixed according to the manufacturer's instructions. Retrograde cavities were filled with RetroMTA [Group 1a-1c], Biodentine [Group 2a-2c] and BioAggregate [Group 3a-3c]. Placement techniques were applied for each material by using incremental, bulk technique and ultrasonic activation, respectively. The samples were scanned with the SkyScan 1272 µCT system. Porosity values were higher in bulk fill and incremental placement techniques than ultrasonic technique when using MTA and BioAggregate (p < 0.05), but Biodentine showed no statistically significant difference (p > 0.05) on using different placement techniques. The ultrasonic activation technique is beneficial to improve the condensation quality of MTA and BioAggregate. Biodentine showed better results regardless of different application techniques.

Micro-computed tomography assessment of triple antibiotic paste removal using different irrigation methods.

Purpose: The study aimed to compare four irrigation methods for triple antibiotic paste (TAP) removal using micro-computed tomography (micro-CT) analysis. Materials and methods: Forty bovine central incisor teeth were selected, and the root canals were prepared up to #6 Peeso reamer drills. Equal portions of metronidazole, ciprofloxacin, and minocycline were used for the TAP preparation. The TAP was prepared by mixing the powder with distilled water (with a powder to liquid ratio of 1 mg/1 mL). The TAP was introduced to the canals with a lentulo spiral; then, the access cavities were temporarily sealed. After 21 days of storage, the teeth were randomly divided into four equal groups according to irrigation techniques: open-ended, side-vented, double side-vented needle irrigations and EndoActivator irrigation device. The TAP was removed using 17% EDTA (20 mL) and distilled water (5 mL) for all of the groups. The volume of the intracanal medicament before and after the irrigation procedure was recorded by scanning the samples with micro-CT, and the TAP percentage was calculated. The percentages obtained from each group were compared using ANOVA. The significance level was set at p<0.05. Results: The results showed that there was no statistically significant difference among the TAP percentage volumes removed by the different irrigation techniques. Conclusion: The irrigation techniques used in this study showed similar TAP removal efficiency, however, they could not completely remove the TAP from the root canal systems.