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.

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.

Comparison of Different Kinesio Taping Techniques After Third Molar Surgery.

PURPOSE: Elastic therapeutic taping method has been shown to reduce pain and edema after surgery. The purpose of the present study was to compare the effects of 2 different Kinesio taping (KT) techniques on swelling, pain, and trismus after third molar surgery. PATIENTS AND METHODS: The study was designed as a split-mouth, single-blinded, and controlled randomized clinical trial. Patients undergoing lower impacted third molar extraction at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Izmir Katip Çelebi University, were included in the present study. Group I included 30 patients and was used to compare the classic KT technique (technique A) and the new KT technique (technique B). Group II included 15 patients and was used to compare the classic KT technique (technique A) and no KT (No-KT [control]). Group III included 15 patients and was used to compare the new KT technique (technique B) and No-KT (control). Swelling was assessed using the 3dMD Face System (3dMD, Atlanta, GA). The maximum interincisal distance was recorded using a digital caliper preoperatively (T0) and at postoperative days 2 (T1) and 7 (T2). The visual analog scale for pain scores were recorded postoperatively at 30 minutes, 1, 2, 3, 4, 5, 6, 8, 10, 12, and 24 hours, and 1, 2, 3, 4, 5, 6, and 7 days. The effects of operative time, patient age, and patient gender were also evaluated. RESULTS: The data from 60 patients (27 men and 33 women) with a mean age of 22.28 years (range, 18 to 31 years) were analyzed in the present study. The amount of swelling and the interincisal distance were less with technique B than with technique A and no KT (control group). CONCLUSIONS: KT is a useful method for reducing postoperative morbidity after impacted third molar extraction. In particular, the application of KT using the new technique described in the present study could be more effective than the classic methods.

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.

Reusing dental implants?: an experimental study for detecting the success rates of re-osseointegration.

BACKGROUND: The aim of this study was to histomorphometrically compare the implant-host integration between retrieved implants and new implants. METHODS: Jaws in 10 male beagle dogs were divided into four groups, and 36 dental implants were inserted into the jaws. In groups 1 and 2, experimental peri-implantitis was induced within 2 months after implant insertion. In group 1, surface decontamination of implants was achieved using air-flow and citric acid. In group 2, implants were sterilized with autoclave after air-flow and citric acid surface decontamination. Subsequently, these implants were inserted in contralateral jaws of the same dogs and a 3-month period was allowed for osseointegration. In group 3, the implants were removed from human jaws due to peri-implantitis and were inserted into dog jaws following surface cleaning protocol and sterilization with autoclave and a 3-month period was allowed for osseointegration. Group 4 was set as the control group. After the osseointegration period, all the animals were sacrificed. The degree of osseointegration in all groups was evaluated by evaluating the ISQ values and by using histomorphometric measurements. RESULTS: Histological findings showed that bone-implant contact (BIC) percentage (mean ± SD) was 83.39% ± 6.37 in group 1, 79.93% ± 11.83 in group 2, 75.45% ± 9.09 in group 3, and 80.53 ± 5.22 in group 4. Moreover, the resonance frequency analysis (RFA) and ISQ values were similar in all four groups both before and after the implantation. CONCLUSIONS: The results of this experimental study indicated that there is no significant difference between new dental implants and re-used dental implants with regards to osseointegration around the implant.

Comparative study of biomechanical stability of resorbable and titanium fixation systems after sagittal split ramus osteotomy with a novel designed in-vitro testing unit.

INTRODUCTION: Sagittal split ramus osteotomy (SSRO) is one of the most popular surgical procedures for correction of mandibular deformities. Several clinical and biomechanical studies exist in the literature which, comparing the stability of different osteosynthesis materials and techniques, were performed using two or three-point biomechanical test models. The aim of this study was to compare the stability of biodegradable and titanium materials for SSRO on one-piece polyurethane mandible samples which were fixed in a novel designed 6-point testing unit. MATERIALS AND METHODS: 16 polyurethane one piece replicas of human mandibles were used and bilateral SSRO were performed by the manufacturer according to Dal Pont modification. Mandibles were fixed with titanium and PLLA/PGA fixation materials. Displacement amounts were measured under loading forces using a non-contact extensometer, and strain values at the screws were recorded by strain gauges. RESULTS: Bicortical titanium screws (Group 2) showed significantly lower displacement values, while bicortical PLLA/PGA screws (group 4) showed significantly higher displacement values at 40-360 N forces. (p < 0.05). The highest strain value was measured on screws that were inserted upright in a proximal segment near the osteotomy line. CONCLUSION: To achieve more realistic results in biomechanical studies, test models should imitate jaw movements and test environments should be as similar as possible to physiological conditions. Newly designed six-point testing units will contribute to future biomechanical studies.

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.

Synergistic Effect of Cold Plasma Treatment and RGD Peptide Coating on Cell Proliferation over Titanium Surfaces.

The aim of this study was to investigate the synergistic effect of cold atmospheric plasma (CAP) treatment and RGD peptide coating for enhancing cellular attachment and proliferation over titanium (Ti) surfaces. The surface structure of CAP-treated and RGD peptide-coated Ti discs were characterized by contact angle goniometer and atomic force microscopy. The effect of such surface modification on human bone marrow derived mesenchymal stem cells (hMSCs) adhesion and proliferation was assessed by cell proliferation and DNA content assays. Besides, hMSCs' adhesion and morphology on surface modified Ti discs were observed via fluorescent and scanning electron microscopy. RGD peptide coating following CAP treatment significantly enhanced cellular adhesion and proliferation among untreated, CAP-treated and RGD peptide-coated Ti discs. The treatment of Ti surfaces with CAP may contribute to improved RGD peptide coating, which enables increased cellular integrations with the Ti surfaces.

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.

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.

Cholesterol granuloma of the jaws: report of two cases.

Cholesterol granuloma (CG) is a foreign body reaction to the deposition and inadequate drainage of cholesterol crystals that are frequently found in association with chronic middle ear diseases but an uncommon entity in maxillary sinuses. The clinical symptoms are non-specific and depend on the localization and extent in each individual case. Bone erosion may be seen in cholesterol granuloma showing expansive growth. The differential diagnosis of CG includes cysts, mucocoeles and neoplasms. Radiological and histopathological findings are essential for diagnosis of CG. In this report it is aimed to introduce two new CG cases with its clinical, histopathological and radiological findings

Determination of lingual vascular canals in the interforaminal region before implant surgery to prevent life-threatening bleeding complications.

OBJECTIVES: Profuse hemorrhage and airway obstruction may occur during or after the implant surgery in the interforaminal region. The prevention from this complication requires identifying the location of the mandibular lingual vascular canals (MLVCs). The purpose of this study was to evaluate the anatomical variations of MLVCs and to determine the safety margins for implant placement in interforaminal region. MATERIALS AND METHODS: Computer tomography (CT) images of 200 consecutive patients were reexamined retrospectively by a radiologist and a maxillofacial surgeon to evaluate the presence of the MLVCs entering the mandible. The diameter and the number of the canals, the distance between the entrance of the canal and mandibular midline, and the height of the entrances of the canals from the inferior mandibular margin were measured. RESULTS: Two hundred and thirty-six median lingual canals (MLCs) and 159 lateral lingual canals (LLCs) were found in 200 patients. Significant differences were found between the number of lingual canals in the midline and canine regions (P < 0.001). CONCLUSION: There is a potential risk of complications due to the injuries of the vessels entering the lingual cortical bone through a number of bone canals during implant placement in the interforaminal region.

Vertical ridge augmentation using sandwich osteotomy: 2 case reports.

The placement of dental implants in atrophic jaws is a challenging procedure due to inadequate bone quantity. This anatomic limitation can be overcome by various treatment methods such as onlay bone graft, inlay bone graft (known as sandwich osteotomy), and distraction osteogenesis. Two female patients with complaints of atrophic mandible were included in this study. Both patients were treated with a segmental mandibular sandwich osteotomy with interpositional grafts. This is called a sandwich osteotomy technique because a section of the jaw bone is separated from the main part and a bone graft is inserted between the 2 parts. The postoperative period was uneventful, and sufficient bone gain was obtained in both patients. Sandwich osteotomy is an effective technique to gain vertical bone height in atrophic jaws.

Treatment of patient with Papillon-Lefevre syndrome with short dental implants: a case report.

Papillon-Lefevre syndrome (PLS) is an autosomal recessive disorder. Main features of PLS are hyperkeratosis of palms and soles concomitant with premature loss of primary and permanent dentition due to progressive periodontitis. Dental management of patients with PLS is usually challenging because of early excessive loss of alveolar bone support. We describe dental rehabilitation of a 34-year-old patient with PLS with severely atrophic mandible by means of 2 short (6 mm) dental implants between 2 mental foramina supporting an implant retained complete denture. After 1 year of follow-up period, the patient was doing well and there was no sign of bone resorption. In patients with PLS, dental osseointegrated implants (even with shorter lengths) can be safely used for atrophic mandibles instead of invasive preprosthetic applications such as bone augmentation, nerve lateralization, or alveolar distraction to avoid possible complications.