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 subarcuate canal on CT images in the perspective of clinical basis.

OBJECTIVES: The aim of our study to contribute to the field of morphometrics by including measurements of the SAC and SAF and their distances from surrounding structures, particularly for surgeons involved in retrosigmoid approach for internal acoustic meatus tumor surgery and cerebellopontine angle surgery. Although there is limited information in the literature regarding the role of the subarcuate fossa (SAF) and subarcuate canal (SAC), it has been suggested that the SAC may be a potential pathway for infection from the middle ear to the posterior cranial fossa, and cerebellar abscesses may have this origin. METHODS: For the images of our study, computerized tomography images of 118 individuals (59 females and 59 males) between the ages of 18-65 who applied to Bayindir Health Group. RESULTS: The width of the cranial opening of the subarcuate canal was determined as 44 ± 0.54 mm, width of the labyrinth opening of the subarcuate canal was determined as 60 ± 0.42 mm, Length of the subarcuate canal was determined as 8.79 ± 2.31 mm, width of the subarcuate canal was determined as 5.54 ± 1.75 mm, and depth of subarcuate fossa was determined as 1.67 ± 0.69 mm. The distance of the cranial opening of the subarcuate canal to the superior semicircular canal (SSC-SAC/C) was measured as 5.33 ± 1.81 mm, The distance of the labyrinth opening of the subarcuate canal to the superior semicircular canal (SSC-SAC/L) was measured as 3.90 ± .98 mm, length of the petrous part of the temporal bone medial to the anterior semicircular canal measured from the apex to the SSCD (PLM) was measured as 33.56 ± 0.42 mm. No statistically significant differences were found between the right and left sides. CONCLUSIONS: The morphometric measurements obtained in this study can provide useful information for neurosurgeons, neurotologist and otolaryngologists involved in retrosigmoid approach for internal acoustic meatus tumor surgery and cerebellopontine angle surgery, and for patients undergoing cochlear implant planning with a retrofacial approach.

Evaluation of the Sigmoid Sinus Morphology by Cone Beam Computed Tomography; Touchstone of the Posterior Cranial Fossa.

OBJECTIVE: In this study, we aimed to analyze the relationship of the sigmoid sinus (SS) with the external auditory canal, facial nerve, and mastoid cells from an anatomic point of view, to define the position of the SS during transmastoid, translabyrinthine, retrosigmoid (lateral suboccipital) approaches, in tympanomastoidectomy and posterior cranial fossa surgery. METHODS: In this study, the morphologic structures associated with the sigmoid sinus were evaluated in cone beam computed tomography images taken between 2015 and 2022. The images of 68 men and 106 women, aged 18-65 years, obtained from the archive of Ankara University Faculty of Dentistry, Department of Oral and Maxillofacial Radiology were analyzed. RESULTS: The most common SS pattern was type II, with a rate of 60.8% (n = 209); the second was type III, with 20.6% (n = 71); and the least common was type I, with 18.6% (n = 64). Although the distance between the horizontal line passing through the external auditory canal and facial nerve and the anterior contour of the SS was highest in type I (right, 7.26 ± 1.62; left, 7.44 ± 0.97), it was lowest in type III (right, 4.40 ± 1.50; left, 4.84 ± 1.16) (P < 0.05). CONCLUSIONS: This study highlights the importance of the SS position in surgery, with special reference to otologic, neurotologic, and posterior cranial fossa surgery. To avoid intraoperative complications, each patient should be evaluated preoperatively by appropriate radiologic methods.

Operational Analysis of Trautman's Triangle in Petroclival Region Approaches: Cone-Beam Computed Tomography Study.

OBJECTIVE: This study was conducted to evaluate the anatomical and clinical features of Trautman's triangle (TT) and to better understand the possible surgical corridor for other surgical approaches involving the petroclival region, especially the presigmoid retrolabyrinthine approach. METHODS: In this study, morphological analysis of structures related to TT was performed from cone beam computed tomography images of 134 female and 206 male individuals aged 18-65 years. RESULTS: The TT area was observed as 5.6% (n = 19) type I, 63.2% (n = 215) type II, and 31.2% (n = 106) type III. It was determined that 87.6% of the sigmoid sinus (SS) was lateral to the posterior semicircular canal and 12.4% was medial. It was determined that the TT area showed a positive correlation with petrous slope and a negative correlation with mastoid aeration. In other words, as the TT area increased, the petrous inclination angle also increased, but the mastoid aeration decreased. It was also found that the TT area was associated with the location of the SS and the largest TT area (164.84 ± 42.29 mm2) was observed in the posteriorly located SS. CONCLUSIONS: The relationship between TT and SS, petroclival angle, mastoid aeration, and subarcuate fossa has a very dynamic structure. Understanding the variations and clinical significance of these structures in the petroclival region is critical in determining the surgical approaches to be applied and understanding the etiology of vestibular system diseases.

Clinical and anatomical importance of foramen magnum and craniocervical junction structures in the perspective of surgical approaches.

This study was conducted to investigate the clinical and anatomical importance of the relevant region from the perspective of surgical approaches by determining the morphometric analysis of the craniocervical junction and foramen magnum (FM) region and determining their distances from important anatomical points. This research was carried out with 59 skulls found at the Anatomy Laboratories of Erciyes and Ankara Medipol University. Metric measurements of FM and condyle, FM shape, condyle-fossa relationship, and pharyngeal tubercle (PT) were made in mm-based dry bone samples of unknown age and sex. The distance between the anterior notches and the FM was 87.01±4.35, the distance between the anterior notches and the PT was 77.70±4.24, the distance between the PT-sphenooccipital junction was 13.23±2.42, and the FM index was 81.86±7.47. The anteroposterior and transverse lengths of FM were determined as 33.80±2.99 and 27.72±2.30, respectively. The morphometric and morphological data available regarding the craniocervical junction showed significant differences between populations. Comprehensive knowledge of this topic will provide a better approach to treat Arnold Chiari Malformation, FM meningiomas, and other posterior cranial fossa lesions. Therefore, we believe that FM and craniocervical junction morphology will be a guide not only for anatomists, but also for radiologists, neurosurgeons, ENT surgeons, and orthopedists.

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.

The Effect of Mobile Applied Anatomy Learning on Students' Academic Success, Cognitive Loads, and Attitudes.

Purpose/Objectives: Anatomy has always been one of the most important components of Health Science education. Worldwide, anatomy education is given in an environment based on cadaver, touch and 3D designs. However, this process has become quite difficult as the pandemic restricted use of laboratory procedures, models, and other learning materials. Therefore, education with mobile applications has become much more important. The aim of this study was to measure the effect of mobile applications used in anatomy course, which is one of the courses that form the basis of medical science, on the success levels of students, and to evaluate their perspectives on this method. Methods: In this study, a real experimental research model with pretest-posttest control group was used in order to determine the difference that may occur between academic achievement and cognitive load when anatomy course students use traditional method or mobile application technology learning method. Results: The findings of the study showed that the students in the experimental group, in which mobile applications were used in the anatomy course, had higher achievement levels and lower cognitive loads than the students in the control group. Another point that was determined was that the students in the experimental group were satisfied with the fact that the use of the mobile application facilitated learning, and they learned better as the ease of use in the mobile application increased.

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.

Clinical and variational evaluation of peroneus tertius muscle.

This research was conducted to define the typology of the peroneus tertius, which is considered to be a part of the musculus extensor digitorum muscle and plays a role in dorsiflexion and eversion of the foot. In addition, another aim of the study was to examine the relationship of the peroneus tertius with the extensor digitorum longus and to investigate the possible effects of the tendon/insertio properties of the peroneus tertius on the fifth metatarsal. In this study; classical anatomical dissection was performed on 30 lower limbs. In this study, various parameters related to muscle origin, insertion, tendon and muscle dimensions were measured. It has been found that PTM was absent in 26.6% of the specimens and in 23.3% (n = 7) of the cases PTM was directly originated from the EDL. In 56.7% of the specimens (n = 17), the PTM tendon was mutually inserted into the dorsomedial surface of the 5th metatarsal and dorsolateral of the 4th metatarsal, while in 10.0% of the specimens it has thin medial bands (2 × 1 mm) towards the 5th digit. At the end of the study, the PTM origin was categorized into three different types and PTM insertion was categorized into five different types. Variation of PTM, muscle morphology and tendon diameter are extremely important in terms of minimally invasive surgical technique. Since the accessory tendon must have the properties close to the tendon that will be replaced, we believe that the results of our research provide unique useful information to clinicians. This study is the cadaver research.

Can Lateral Offset Be Used as a Predictive Marker for Proximal Femur Disorders?

Purpose: When the lateral offset (LO) changes, the forces acting on the head and neck of the femur change. Increase or decrease in LO can cause instability and possible dislocation of the implant. In addition, when the offset is reduced, more force is needed to balance the pelvis by the abductor muscles, and the force that occurs along the hip joint increases and causes wear and tear. In this study we aimed to investigate whether there is a correlation between LO and proximal femur morphology, and according to the results we aimed to investigate whether the LO can be used as a predictive marker for the risk of femoral neck fractures, osteoarthritis or femoroacetabular impingement. Methods: Femur length, femur neck length, femoral neck-shaft angle (NSA), anteroposterior (a-p) and superoinferior (s-i) diameters of femoral head and neck, and LO were measured on 82 dry adult femora of unknown age and gender from Turkish population. Results: There was no statistically significant correlation between the LO and a-p and s-i diameters of femoral head or neck. However, there was found statistically significant correlation between LO and femoral NSA (p < 0.01), femoral neck length (p < 0.05) and femur length (p < 0.01). Conclusion: High LO values can be used as an indicator for neck fractures, a negative marker for OA, but LO does not appear to be used as an indicator for FAI.

Morphologic Mapping of the Sublingual Microcirculation in Healthy Volunteers.

PURPOSE: Monitoring the sublingual and oral microcirculation (SM-OM) using hand-held vital microscopes (HVMs) has provided valuable insight into the (patho)physiology of diseases. However, the microvascular anatomy in a healthy population has not been adequately described yet. METHODS: Incident dark field-based HVM imaging was used to visualize the SM-OM. First, the SM was divided into four different fields; Field-a (between incisors-lingua), Field-b (between the canine-first premolar-lingua), Field-c (between the first-second premolar-lingua), Field-d (between the second molar-wisdom teeth-lingua). Second, we investigated the buccal area, lower and upper lip. Total/functional vessel density (TVD/FCD), focus depth (FD), small vessel mean diameters (SVMDs), and capillary tortuosity score (CTS) were compared between the areas. RESULTS: Fifteen volunteers with a mean age of 29 ± 6 years were enrolled. No statistical difference was found between the sublingual fields in terms of TVD (p = 0.30), FCD (p = 0.38), and FD (p = 0.09). SVMD was similar in Field-a, Field-b, and Field-c (p = 0.20-0.30), and larger in Field-d (p < 0.01, p = 0.015). The CTS of the buccal area was higher than in the lips. CONCLUSION: The sublingual area has a homogenous distribution in TVD, FCD, FD, and SVMD. This study can be a description of the normal microvascular anatomy for future researches regarding microcirculatory assessment.

Examination of inner ear structures: a micro-CT study.

BACKGROUND: We investigated the inner ear anatomy accurately in detail by microcomputed tomography (micro-CT) to contribute to the data related to the inner ear anatomy and the potential clinical contribution of these data in the treatment of the inner ear's pathologies. AIMS/OBJECTIVES: This study aimed to define a range for normal measurements of the VA, vestibule, lateral semicircular canal, and cochlea. We scanned temporal dry bone samples at high resolution using micro-CT. MATERIAL AND METHODS: Forty dry temporal bones used in anatomy student education were included in this study with a micro-CT device. All measurements were made on sections in the axial plane with micro-CT programs. RESULTS: The operculum and the vestibular aqueduct middle diameters median values were 0.487 mm and 0.294 mm, respectively. The median value of middle diameters for the nonampullated section of lateral semicircular canal was 1.103 mm. The mean height of the cochlea was 3.417 mm and the width of the cochlea was 5.615 mm. The mean length of the vestibule was 6.085 mm and the width of the vestibule was 3.002 mm. CONCLUSIONS AND SIGNIFICANCE: We present a database that clinicians can consider in their studies by creating normal anatomical values measured with high precision for the bone labyrinth.

Micro-CT evaluation of 'danger zone' and microcrack formation in mesial root canals of primary teeth with single-file rotary and reciprocating systems.

BACKGROUND: Although single-file rotary systems are accepted in the field of paediatric dentistry in terms of providing time advantage, research works continue due to the variable anatomical structure of the root canal. AIM: This study aimed to evaluate rotary systems in different kinematics in terms of microcracks and the shaping of the danger zone in primary molars by micro-CT. DESIGN: The mesial canals of primary molars (n = 30) were used. Root canals in each group (n = 10) were prepared with single-file rotary systems (One Shape®, OS; XP-endo® Shaper, XP-ES; WaveOne Gold, WOG). The images were evaluated for dentin thickness in the danger zone and microcrack formation. RESULTS: WOG caused the highest dentin reduction in the danger zone area. OS led to significantly less dentin reduction than XP-ES and WOG (P < .05). The XP-ES showed the highest number of microcracks (P < .05). No statistically significant difference was found between WOG and OS (P > .05). In all systems, more microcracks were observed in the middle third than coronal and apical. CONCLUSION: Within the limitations of this study, the rotary systems were superior to reciprocating in terms of shaping ability in the danger zone. It is thought that further studies with different systems should be designed considering the anatomical variations and chemical composition of primary teeth.

Effect of different resin removal methods on enamel after metal and ceramic bracket debonding : An in vitro micro-computed tomography study.

PURPOSE: The aim of this study was to conduct an in vitro evaluation of the effects of different adhesive debonding and polishing techniques performed after metal and ceramic bracket removal on enamel using micro-computed tomography (micro-CT). METHODS: This study was performed on 42 extracted maxillary first premolars divided into 2 main groups and 6 subgroups as follows: metal (group 1) or ceramic (group 2) brackets were bonded to the teeth, then, after debonding, one of three different methods was used to remove the residual adhesive: tungsten carbide burs with pumice (A), fiber-reinforced composite burs and polishing paste (B), or Sof-Lex discs (C; 3M Dental, St Paul, MN, USA). The samples were evaluated by micro-CT before bracket bonding (T0) and after resin removal (T1). Demineralization area, demineralization depth, demineralization volume, mineral density, and mineral volume were measured. RESULTS: At T1, demineralization area was significantly larger in groups 1A and 2A compared to groups 1B, 1C, 2B, and 2C (P = 0.001). Group 2A (ceramic bracket/tungsten carbide-pumice) had the highest demineralization volume (P = 0.001). When the groups were compared in terms of change from T0 to T1, groups 1A and 2A showed significantly larger changes in demineralization area compared to the other 4 groups (P = 0.001). The increase in demineralization volume was larger in group 2A compared to all other groups (P = 0.001). CONCLUSION: All resin removal methods damaged the enamel surface to varying degrees. Regardless of bracket type, the use of tungsten carbide and pumice should be avoided when cleaning the tooth surface after debonding. Use of composite burs and Sof-Lex discs in particular after the debonding of ceramic brackets will help minimize damage.

Evaluation of the detectability of early mandible fracture healing findings in terms of vitality aspect by using micro-CT technology in postmortem interval.

The purpose of the present study was to investigate the vitality aspect of mandibular fractures using micro-CT in the analysis of bone mineral density and other bone microstructure trabecular parameters in the postmortem interval. This study included 72 female Wistar rats. In the study groups, the rats' mandibles were first fractured and after three days of living, the rats were sacrificed. In the control groups, the rats were sacrificed first and then the mandibles were fractured. All rats were left for a natural putrefaction period according to their group's time as week-0, week-1, week-2, week-4, week-8, and week-12. All fractured hemi-mandibles were scanned by micro-CT and analyzed in terms of BMD and other bone trabecular microstructures. BMD and the other bone trabecular microstructures, such as bone volume, percent bone volume, trabecular separation, and trabecular pattern factor, showed statistically significant differences in both the study and control groups (p ≤ 0.05). There were statistically significant differences between the study and control groups in comparisons of BMD in groups 1, 2, 3, 4 and 5, bone volume and percent bone volume in groups 1 and 3, bone surface and bone surface density in group 6, trabecular separation in group 1, and trabecular number, trabecular pattern factor, and structural model index in group 6. Micro-CT scanning and analysis of BMD and other bone trabecular microstructure parameters for evaluation of vitality aspects of mandible fractures in the PMI has various valuable results that should provide guidance for possible studies in the future.

Investigation of the effect of ghrelin on bone fracture healing in rats.

Ghrelin is known to have effects on proliferation and differentiation of osteoblasts and improvement of bone mineral density in rats. However, no experimental research on ghrelin's effects on fracture healing has been reported. In this context, the effect of ghrelin on the union of femoral shaft fractures was examined in this study by evaluating whether ghrelin will directly contribute to fracture healing. Forty male Wistar-Albino rats were divided into two groups as control and experimental (ghrelin treated) and standard closed shaft fractures were created in the left femurs of all rats. Daily ghrelin injections were applied to the experimental groups and equal numbers of rats were killed after 14 and 28 days following fracture formation. Tissue samples were examined with radiological, biomechanical, biochemical and histological analyses. Densitometry study showed that bone mineral density was improved after 28 days of ghrelin treatment compared to control. On histological examination, at the end of the 14 and 28 days of recovery, significant union was observed in the ghrelin-treated group. The ghrelin-treated group had higher breaking strength and stiffness at the end of 28 days of recovery. Biochemically, ALP levels were found to be higher in the ghrelin-treated group at the end of 28 days of recovery. Results showed that ghrelin directly contributes to fracture healing and it is promising to consider the effect of ghrelin on fracture healing in human studies with pharmacological applications.

Effects of various thicknesses and levels of mineral trioxide aggregate coronal plugs on nanoleakage and fracture resistance in revascularization: An in vitro study.

The aim of this study was to evaluate the effects of mineral trioxide aggregate (MTA) applied at varying levels and thickness in the cervical region of the root on the leakage and fracture resistance of the simulated immature teeth. 3 study groups (n = 16) (Group 1: 2 mm MTA, Group 2: 4 mm MTA, Group 3: 2 mm MTA+2 mm RMGIC below cementoenamel junction) and 2 control groups (Group 4: Complete canal obturation, Group 5: No coronal plug) were used for the study. Nanoleakage was measured using a micro-computed tomography system. For the fracture resistance test, a universal testing machine was used. The amount of silver nitrate penetration decreased while MTA thicknesses increased (P < 0.001). However, the placement of MTA as a thicker layer did not make any additional contribution on the fracture resistance (P > 0.05). The 4-mm coronal MTA plug can be suggested in RETs for its superior sealing and reinforcement abilities.

Micro-CT Evaluation of the Marginal and Internal Fit of Crown and Inlay Restorations Fabricated Via Different Digital Scanners belonging to the Same CAD-CAM System.

PURPOSE: To evaluate the marginal and internal adaptation of all-ceramic crowns and inlays fabricated by different scanners of the same CAD/CAM system. MATERIALS AND METHODS: All-ceramic crown preparations were performed on typodont maxillary first premolars, and mandibular first molars were prepared for ceramic Class II mesio-occlusal inlays. Two intraoral scanners (CEREC Bluecam and Omnicam, Dentsply Sirona) and one model scanner (CEREC inEos X5, Dentsply Sirona) were used to scan the preparations. All restorations were fabricated by milling single-feldspathic ceramic blocks (CEREC Blocks). The marginal and internal discrepancies of restorations were evaluated via micro-CT analyses. RESULTS: For linear crown measurements, the marginal gaps were 63.75 µm, 88.24 µm, and 90.89 µm for Bluecam, Omnicam, and inEos X5, respectively. For crowns at central groove areas, the maximum values for Bluecam, Omnicam, and inEos X5 were found to be 144.78 µm, 165.19 µm, and 129.49 µm, respectively. For inlays, the highest range at the midpoint of the axiopulpal line angle for Bluecam, Omnicam, and inEos X5 were determined as 138.57 µm, 184.33 µm, and 179.71 µm, respectively. In volumetric measurements, inEos X5 showed lower gap for both crowns (11.47 mm3) and inlays (5.65 mm3) compared to both intraoral scanners. These results are within a clinically acceptable range. CONCLUSION: When all-ceramic crowns were evaluated, there were generally no significant differences found between scanners for the regional linear measurements, but more gaps occurred in restorations obtained with intraoral scanners for volumetric measurements. On the other hand, when the inlay restorations were evaluated, significant differences were found between groups except for the midpoint of the axio-pulpal line angle and the midpoint of the mesio-gingival margin. However, marginal and internal gaps of both crowns and inlays presented mean values less than 150 µm in many surfaces, which could be considered clinically acceptable.

Can the Combination of Simvastatin and Melatonin Create a Synergistic Effect on Bone Regeneration?

PURPOSE: The present study evaluated the potential bone regeneration capacity of combining melatonin and simvastatin, with a goal of producing more osteogenic bone substitutes. MATERIALS AND METHODS: A total of 48 male Wistar rats were randomly divided into 4 groups. The following were administered into critical-sized calvarial defects of the rats: Group I-human allograft; Group II-human allograft + 10 mg melatonin; Group III-human allograft + 0.1 mg simvastatin; and Group IV-human allograft + 10 mg melatonin + 0.1 mg simvastatin. Histopathologic, histomorphometric, and microcomputed tomographic evaluations were performed postprocedurally at 4 and 8 weeks. A P value < .05 was considered significant for all evaluations. RESULTS: Groups II and III had significantly superior regeneration compared to Group I at weeks 4 and 8. Group III had significantly superior regeneration compared to Group II, particularly in week 4. Group IV had significantly superior regeneration compared to all groups at week 8. CONCLUSIONS: The local administration of melatonin and simvastatin resulted in increased new bone mass and quality of bone microstructure than was seen in the control group. Simvastatin shortened the defect regeneration time more effectively than melatonin did. The combined use of melatonin and simvastatin provided a synergic effect on bone regeneration, particularly in the late phase of healing.