A Finite Element Analysis to Study the Stress Distribution on Distal Implants in All-on-Six Treatment Concepts as Affected Tilted and Short Implant.

The number of implants and their respective configurations for implant-supported treatment modalities have been studied for 4 implant-supported prostheses; however, it is not yet clear whether the use of tilting or short implants in rehabilitation would result in substantially improved bone/implant/prosthesis biomechanics in all-on-six concepts. This study compared the biomechanical behavior of tilted long implants and axially short implants to support fixed prostheses in an atrophic maxilla with all-on-six treatment concepts. Three different implant configurations were planned, and six models were obtained with posterior maxilla D3 and D4 bone densities in this study. Implants proper for the all-on-four concept were placed in all models. In models 1 and 2, the short implant was placed; in models 3 and 4, 30°, the mesial-angled implant was placed; and in models 5 and 6, 45°, the mesial-angled implant was placed to the molar region. In the models created, 200 N vertical and 150 N oblique (45° angled buccopalatal direction) forces were implemented to the bilateral tooth regions 4-5-6 on the rigid titanium-supported fixed hybrid prosthesis made on these models. When the stress values in the models were investigated, the oblique forces had higher stress values than the vertical forces did. When the stresses created by oblique forces were assessed, the highest values were observed in the models created with short implants, and the lowest stress values were observed in the models made with 30° angle to mesial. When bone densities were assessed, more stress values were noted in models with D4 bone density. It has been shown that mesial tilted long implants placed in the posterior molar region, in addition to all four implant treatment concepts, create less stress against undesirable oblique forces compared with short implants.

Comparison of Particulate, Block and Putty Forms of ß-tricalcium Phosphate-Based Synthetic Bone Grafts on Rat Calvarium Model.

Purpose: Bone augmentation is a necessity for atrophied alveolar ridge prior to dental implant placement. Various bone graft types and forms with different characteristics are available in the market for alveolar augmentation. Beta tricalcium phosphate (ß-TCP) is a synthetic biomaterial known as the oldest type of calcium phosphate. Studies comparing particulate, block or putty grafts are very limited. The aim of this study was to compare the particulate, block and putty forms of the same ß-TCP bone graft and analyze the efficiency in critical size calvarium defects. Material and Methods: Twenty male Wistar-Albino rats were employed for the study. Four bicortical bone defects with 5 mm diameter were created on each rat calvarium, and three defects were filled with particulate, block or putty ß-TCP graft and one defect was left empty. The animals were killed after 8 weeks. New bone formation, residual graft, loose connective tissue, condensed mesenchyme, alkaline phosphatase, proliferating cell nuclear antigen, osteocalcin were measured on the specimens. Results: Compared to block and putty forms, significantly higher new bone formation and least residual graft were observed in the particulate graft group. The residual graft was significantly higher in the block graft group than both the particulate and the putty groups. The cellular immunoreactivity of the samples in the particulate graft group was significantly higher. There was no significant difference between putty and block graft groups. Conclusion: Bone regeneration is significantly affected by the form of ß-TCP bone graft, and the particulate form was the most successful in our study.

Angiomyolipoma of the Hard Palate.

ABSTRACT: Angiomyolipoma (AML) is a tumor which commonly affects the kidney. Few authors have been reported AML in the oral cavity. In this clinical report, an AML of the hard palate will be presented in a 48-year-old patient. The AML contains mature adipose tissue, thick-walled blood vessels, and irregular bundle of smooth muscle. The AML is sometimes associated with tuberous sclerosis. Although the renal AMLs are often invasive, they involve regional nodes and may recur, extrarenal AMLs are commonly well demarcated, show no recurrence and may simply be removed. The AML usually behaves in a benign fashion.

Automated Bird Counting with Deep Learning for Regional Bird Distribution Mapping.

A challenging problem in the field of avian ecology is deriving information on bird population movement trends. This necessitates the regular counting of birds which is usually not an easily-achievable task. A promising attempt towards solving the bird counting problem in a more consistent and fast way is to predict the number of birds in different regions from their photos. For this purpose, we exploit the ability of computers to learn from past data through deep learning which has been a leading sub-field of AI for image understanding. Our data source is a collection of on-ground photos taken during our long run of birding activity. We employ several state-of-the-art generic object-detection algorithms to learn to detect birds, each being a member of one of the 38 identified species, in natural scenes. The experiments revealed that computer-aided counting outperformed the manual counting with respect to both accuracy and time. As a real-world application of image-based bird counting, we prepared the spatial bird order distribution and species diversity maps of Turkey by utilizing the geographic information system (GIS) technology. Our results suggested that deep learning can assist humans in bird monitoring activities and increase citizen scientists' participation in large-scale bird surveys.

The Effect of Atmospheric Pressure Cold Plasma Application on Titanium Barriers: A Vertical Bone Augmentation.

OBJECTIVE: The aim of the present, microcomputed tomographic (µCT) and histological study, was to evaluate the effect of surface modification by atmospheric pressure cold plasma (APCP) on vertical guided bone regeneration in a rabbit calvaria model. MATERIAL-METHODS: The experimental study was conducted on 12 male New Zealand rabbits with healing periods of 45 and 90 days. Following surgical exposure of the calvarium, 4 customized titanium cylindricalders were fixed. Surface modification was achieved by application of APCP on 2 of cylinders (P+) in each calvarium and other cylinders were set as control (P-). In both experimental and control groups, one of the cylinders was filled with bone graft (G+) while the other one was left empty (G-). To evaluate short term effects, randomly selected 6 animals were sacrificed at the end of 45 days and remaining 6 animals were left for observing long term effects. Histological and µCT evaluations were used to examine new bone formation. RESULTS: In µCT imaging; the bone volume was greater (P < 0.05) in grafted groups than nongrafted groups in both short and long term. The bone height values were significantly different in (P-G-) group than other groups (P < 0.05) in both evaluation periods. The histological evaluations revealed significant differences between P+G+ group and other groups but in long term both plasma treated groups revealed more bone formation than non plasma treated groups. CONCLUSION: Modification of the surfaces of titanium cylinders by APCP treatment, accelerated the bone regeneration either bone graft used or not in a rabbit calvaria model.

Vitamin E Promotes Bone Formation in a Distraction Osteogenesis Model.

The long consolidation period of distraction osteogenesis (DO) may lead to complications such as pain, infection, fracture, scar formation, malunion and delayed union. The aim of this study was to evaluate the effect of systemic Vitamin E application during mandibular DO on new bone regeneration in a rabbit model. 16 adult male 8 months old New Zealand rabbits underwent mandibular lengthening with a distractor for the study. After the latency period of 5 days, the distractor was activated at a rate of 0.5 mm/12 hours for 7 days. Experimental animals received 200 mg/kg injections of α-tocopherol intraperitoneally for 7 days starting with the operation. After the consolidation period of 30 days, rabbits were sacrificed. Lengthened mandibles were obtained and subjected to dual-energy X-ray absorptiometry (DXA), radiologic and histomorphometric analysis. Statistically, bone mineral density and bone mineral content values were found to be significantly higher in the experimental group than the control group during DXA analysis. Rabbits in the experimental group had statistically higher scores in terms of osteoblast, osteoclast, vessel numbers and newly formed bone area than the control group. Results of the present study showed that systemic Vitamin E application during DO may stimulate new bone formation in rabbits and thus results in shortened treatment time.

Bone Flap Technique With Piezosurgery for Impacted Teeth Extraction and Bone Cysts Removal Without Additional Fixation.

To explore a new surgical approach for impacted teeth extraction and cystectomy using piezosurgery that provides proper bone healing in normal anatomical structure without additional fixation and graft materials.In cases with intact and relatively thicker vestibular compact bone, a bone flap design was used with converging osteotomy lines made with piezosurgery tips which allow proper stabilization after enucleation or extraction.Procedure was performed in 10 patients with 9 to 36 months follow-up resulted in satisfactory healing without any complications.Comparing to traditional techniques, effective enucleation and accelerated bone regeneration are achieved, with reduced risk of complications, operation time, and costs.

Effects of boric acid on bone formation after maxillary sinus floor augmentation in rabbits.

PURPOSE: Augmentation of the maxillary sinus floor with bone grafting is commonly used for successful treatment of edentulous posterior maxilla with dental implants, and it is essential to maintain good bone volume and quality for long-term success of dental implants. The aim of this experimental study was to investigate the local and systemic effects of boric acid on new bone formation after maxillary sinus floor augmentation (MSFA). MATERIALS AND METHODS: Twenty-four male, New Zealand rabbits were randomly divided into three groups with eight rabbits each, and bilateral MSFA was performed in each animal. An autogenous bone/xenograft mixture was used to augment the maxillary sinuses in each group. Group 1 was determined as control with no additional materials, whereas 3 mg/kg boric acid (BA) was added to the mixture in group 2, and 3 mg/kg boric acid solution added to drinking water daily in group 3. RESULTS: The animals were sacrificed and also histologic, histomorphometric, and immunnohistochemical analyses were performed at weeks 4 and 8. At week 4, bone regeneration was better in the local BA group than in the control and systemic BA groups (p < 0.05). However, no significant difference was found among the groups in terms of bone regeneration at the end of week 8 (p > 0.05). CONCLUSION: Significant higher new bone formation was revealed by BA at early healing especially with local application. BA may be a therapeutic option for improving the bone regeneration.

Three-Dimensional Evaluation of the Effects of Kinesio Taping on Postoperative Swelling and Pain after Surgically Assisted Rapid Palatal Expansion.

OBJECTIVES: The purpose of the present study was to evaluate the effects of kinesio taping on pain and swelling after surgically assisted rapid palatal expansion. MATERIAL AND METHODS: A total of 21 (12 male and 9 female) patients with transverse maxillary deficiency were enrolled in the study. Kinesio taping (KT) was applied unilaterally in each patient, whereby sides of the face with KT application were included into the (a) KT group and the other sides were included into the (b) non-KT group. Changes in facial volume were evaluated on digital images using the 3dMD Face System. Pain scores were assessed at postoperative days 1, 2, 3, 4, 5, 6, and 7 using the visual analog scale (VAS). Two-way repeated measures analysis of variance and Mann Whitney U test were used for statistical analyses. RESULTS: Swelling was significantly lower in the KT group compared to the non-KT group from T0 to T1 (36.42 [SD 19.71] mm3 vs. 183.84 [SD 49.33] mm3) and was significantly greater in the non-KT group compared to the KT group from T0 to T2 (70.88 [SD 15.73] mm3 vs. 21.46 [SD 13.39] mm3) (P < 0.001 for both). The VAS scores were significantly lower in the KT group compared to the non-KT group at all time points (P < 0.05). CONCLUSIONS: The application of kinesio taping after maxillofacial surgery reduced the pain and swelling in the postoperative period. Kinesio taping can be used as an alternative to other methods that are used for the reduction of postoperative complaints.

Benign Paroxysmal Positional Vertigo Following Sinus Floor Elevation in Patient with Antecedents of Vertigo.

Benign paroxysmal positional vertigo (BPPV) is an unfamiliar and rare complication occurring following osteotome sinus floor elevation (OSFE) and simultaneous implant placement. Etiology of this disorder is commonly displacement of otoliths by vibratory forces transmitted by osteotomes and mallet along with the hyperextension of the head during the operation, causing them to float around in the endolymph. This report presents a case of protracted BPPV following OSFE and simultaneous implant placement. A 43-year-old female suffered intense vertigo and nausea immediately after implant placement using an OSFE procedure. Upon further questioning after the procedure she gave an account of two times vertigo history within the last 9 years. Despite nootropic drug medication and canalith repositioning procedure applied by a specialist at operation night, the condition did not improve. Patient did not totally recover and was admitted again after 1 month. After repeated maneuvers, nine dosage intravenous serous fluid and piracetam administration the patient recovered. Duration of these procedures took 10 days and the patient was successfully treated with no recurrence of dizziness. Prevention and management of OSFE related BPPV are reviewed especially in patients having prior vertigo history in this report.

Evaluation of the bond strength of root-end placed mineral trioxide aggregate and Biodentine in the absence/presence of blood contamination.

OBJECTIVE: Mineral trioxide aggregate (MTA) has been accepted as an appropriate root-end filling material in endodontic microsurgery because of setting ability in the wet environment. The aim of this study was to assess the bond strength of root-end placed MTA and Biodentine (Septodont, Saint Maur des Fossés, France) in the absence/presence of blood contamination. MATERIALS AND METHODS: Forty-eight single-rooted maxillary incisors were used. subsequent to root-end resection and apical preparation using ultrasonic retro-tips, the specimens were randomly separated into two groups according to the root-end filling materials: MTA (Cerkamed Medical Company, Stalowa, Poland) or Biodentine. The specimens were then separated into two subgroups according to storage condition (absence/presence of blood) (n = 12). After obtaining 2.0 ± 0.1 mm slices, push-out tests were performed. Each slice was examined under a stereomicroscope to evaluate the failure mode. The data were analyzed using two-way analysis of variance and Tukey's post hoc test for multiple comparisons. The failure modes were analyzed using the Chi-square test (P = 0.05). RESULTS: The bond strength was significantly affected by the presence of blood contamination and root-end filling material type (P < 0.001). Biodentine had better bond strength than MTA (P < 0.001). The most common failure type was adhesive failure. According to the Chi-square test, there were no statistically significant differences among the groups (P = 0.394). CONCLUSIONS: Biodentine had better bond strength values compared to MTA, and the bond strength of both MTA and Biodentine as root-end filling materials was negatively affected by the presence of blood.

Unilateral Absence of Mental Foramen with Surgical Exploration in a Living Human Subject.

The mental foramen (MF) is an important anatomic landmark of the mandible, in which the somatic afferent sensory nerve of the mandibular nerve emerges as mental nerve and blood vessels. The identification and actual location of MF are important in order to avoid sensory dysfunction or paresthesia due to mental nerve injury. In the literature there are some rare reports on the anatomical variations of the MF such as its location or presence of accessory foramina. The present report describes the absence of mental foramina on the left side of the mandible, as detected by cone-beam computed tomography before impacted tooth removal and observed directly during surgery.

Multidisciplinary Management of Complicated Crown-Root Fracture of an Anterior Tooth Undergoing Apexification.

The purpose of this case report was to present the multidisciplinary management of a subgingival crown-root fracture of a patient undergoing apexification treatment. A 12-year-old male patient was referred to the pediatric dentistry clinic with an extensive tooth fracture of the right permanent maxillary lateral incisor. Clinical and radiographic examinations revealed the presence of a complicated crown-root fracture, which had elongated to the buccal subgingival area. The dental history disclosed that the apexification procedure had been started to be performed after his first trauma experience and he had neglected his appointment. The coronal fragment was gently extracted; endodontic treatment was performed; flap surgery was performed to make the fracture line visible. The coronal fragment was reattached to the root fragment with a dual-cure luting composite. A fiber post was stabilized and the access cavity of the tooth was restored with composite resin. At the end of the 24th month, the tooth was asymptomatic, functionally, esthetically acceptable and had no periapical pathology. It is important for the patients undergoing apexification treatment to keep their appointments because of the fracture risk. Restoration of the fractured tooth by preparing retention grooves and a bonding fiber-reinforced post are effective and necessary approaches for successful management.

Total antioxidant capacity and total oxidant status of synovial fluids in patients with temporomandibular joint pain and dysfunction.

OBJECTIVES: The objective of this study was to investigate whether a relationship exists between total antioxidant capacity (TAC) and total oxidant status (TOS) of synovial fluids (SFs) of temporomandibular joint (TMJ) pain patients with pain and dysfunction. MATERIALS AND METHODS: Forty-two patients with TMJ pain were included in this study. TAC and TOS values of SFs were measured with a novel colorimetric method. Independent t test and correlations were used to analyze the data. RESULTS: TAC of SFs in patients with TMJ pain and limited mouth opening (LMO; n = 21) were significantly lower (P = 0.03) than patients without LMO (n = 21). TOS of SF was negatively correlated with duration of the disease. There was no correlation between TAC, TOS, and VAS scores of the patients as well as age and maximum mouth opening values. CONCLUSIONS: Antioxidant response to oxidative changes (TAC and TOS) in SF decreased as the stage of dysfunction increased. CLINICAL RELEVANCE: Local administration of antioxidant agents might be considered in management of TMJ pain and dysfunction to prevent possible increased oxidative stress.

Resonance frequency analysis of orthodontic miniscrews subjected to light-emitting diode photobiomodulation therapy.

The aim of this prospective experimental study was to evaluate the effect of light-emitting diode (LED) photobiomodulation therapy (LPT) on the stability of immediately loaded miniscrews under different force levels, as assessed by resonance frequency analysis (RFA). Sixty titanium orthodontic miniscrews with a length of 8 mm and a diameter of 1.4 mm were implanted into cortical bone by closed flap technique in each proximal tibia of 15 New Zealand white adult male rabbits (n = 30). The animals were randomly divided into irradiated and control groups under different force levels (0, 150, and 300 cN). OsseoPulse® LED device (Biolux Research Ltd.) 618 nm wavelength and 20 mW/cm(2) output power irradiation (20 minutes/day) was applied to the miniscrews for 10 days. The RFA records were performed at miniscrew insertion session (T1) and 21 days after surgery (T2). Wilcoxon and Mann-Whitney U-tests were used for statistical evaluation at P < 0.005 level. It was found that initial primer stability of all miniscrews was similar in all groups at the start of the experimental procedure. Statistically significant differences were found for changes in implant stability quotient (ISQ) values between LED-photobiomodulated group and the control (0 cN, P = 0.001; 150 cN, P < 0.001; and 300 cN, P < 0.001). Significant increase was found in ISQ values of LPT applied miniscrews under 0 cN (+11.63 ISQ), 150 cN (+10.50 ISQ), and 300 cN (+7.00 ISQ) force during observation period. By the increase of force levels, it was determined that ISQ values decreased in non-irradiated control miniscrews. Within the limits of this in vivo study, the present RFA findings suggest that LPT might have a favourable effect on healing and attachment of titanium orthodontic miniscrews.