The effect of different cleaning methods on the surface and temperature of failed titanium implants: an in vitro study.

The aims of this in vitro study are to compare the efficacy of different cleaning methods in removing debris of failed implants and to detect thermal changes of the implants treated by various scaling instruments. Twenty-seven failed implants and two unused implants as control were included to this study-group 1: plastic curette (P), group 2: titanium curette (T), group 3: carbon curette (C), group 4: titanium brush (TB), group 5: Er:YAG laser (laser 1 (L1) 100 mJ/pulse at 10 Hz), group 6: Er:YAG laser (laser 2 (L2) 150 mJ/pulse at 10 Hz), group 7: Er:YAG laser (laser 3 (L3) 200 mJ/pulse at 10 Hz), group 8: ultrasonic scaler appropriate for titanium (US), group 9: air abrasive method (AA) + citric acid, and group 10: implantoplasty (I). The changes on the treated/untreated titanium surfaces and remnant debris were observed by scanning electron microscopy (SEM). Temperature of the implants before and after treatment was detected using a thermocouple. The use of air abrasive and citric acid combination and Er:YAG laser groups was found as the best methods for the decontamination of titanium surfaces of failed implant. When the hand instruments were compared, titanium curette was found better than both the plastic and the carbon curettes which leave plastics and carbon remnants on the titanium surface. The temperature was higher after hand instrumentation when compared to other experimental groups (p < 0.05). Within the limitations of the present in vitro model, it can be concluded that the best method for decontamination of the implant surface is the use of air abrasives and Er:YAG laser.

Evaluation of Extraction Site Dimensions and Density Using Computed Tomography Treated With Different Graft Materials: A Preliminary Study.

PURPOSE: The preliminary human study was designed to evaluate extraction site changes using CT after socket preservation (SP) with different materials. MATERIALS AND METHODS: Fifty-two sockets from 17 Turkish individuals (8 women and 9 men; mean age 44.70 ± 9.99 years) localized at the maxillary anterior area were treated with demineralized bone matrix + collagen membrane (CM) (N = 14), hydroxyapatite bone substitute (HBS) + CM (N = 14), CM (N = 13), or left empty (N = 11). CT scans were taken 10 and 120 days after the procedure. Horizontal and vertical socket dimensions and Hounsfield unit (HU) values were evaluated. RESULTS: First 3 groups showed a significant horizontal decrease from day 10 to 120. No significant change was detected in vertical socket dimension. For both horizontal and vertical, no intergroup difference was detected at days 10 and 120. At days 10 and 120, HU values in HBS + CM group were significantly higher compared with others. Apical and coronal HU values were not different at any period. CONCLUSION: Even if it did not provide better socket dimensions, HBS + CM treatment brought higher tissue density and thus, can be recommended to increase the bone quality and implant success after SP in upper anterior area.

The importance of soft tissue examination in post-traumatic decision-making: a case report.

Dental and facial traumas involving teeth and supporting tissues are common sports-related injuries. In this case report treatment of a 23-year-old student who had been elbowed by an opponent player during a basketball game, which caused oblique fractures on both maxillary incisor teeth is presented. The patient presented 17 days following trauma having completed full recovery of soft tissues. A fragment of upper incisor tooth had been embedded in lower lip at the time of trauma, which was covered by healing tissues. At the 1 month control the patient complained of a hard structure in his lower lip. The elusive broken fragment was revealed by a radiograph and then removed surgically. This case report is a good example of the importance of the training of general dentists about sports-related traumatic injuries as well as emphasising the importance of the use of mouthguards during contact sports.

Correlation between clinical and magnetic resonance imaging findings in the treatment of anterior disc displacement.

PURPOSE: This study aimed to compare the agreement of clinical examination and magnetic resonance imaging (MRI) results before and after the treatment of nonreduction temporomandibular joint (TMJ) disc displacement. MATERIALS AND METHODS: The study group consisted of 22 patients, each with anterior disc displacement without reduction in at least one TMJ. Diagnosis was performed clinically and with MRI prior to treatment. All patients received the same treatment protocol, consisting of occlusal appliance therapy and exercise for a period of 24 weeks. By the end of treatment, clinical and imaging examinations were repeated and the results subjected to statistical analysis. RESULTS: Before treatment, MRI and clinical examinations matched in 35 of 44 joints (79.5%). On the basis of the kappa index, the agreement between clinical and imaging examinations was moderate (mean kappa index = 0.59, P = .0001). After treatment, these examinations matched in only 16 of 44 cases (36%) and the agreement was poor. CONCLUSION: Clinical criteria do not necessarily correlate with MRI findings in the postoperative period in patients treated for TMJ anterior disc displacement.

Implant-supported first molar restorations: correlation of finite element analysis with clinical outcomes.

PURPOSE: This study aimed to evaluate the effect of the placement of wide-diameter implants on bone stress concentrations and marginal bone loss in the first molar region. Study hypotheses held that increasing implant diameter would decrease peri-implant bone stress levels, but that statistically significant reductions in clinical bone loss would either (1) not be observed for any implant diameter or (2) be observed only for the widest implant diameter. MATERIALS AND METHODS: Three-dimensional finite element analysis (3D FEA) was used to analyze the relationship between implant diameter and peri-implant bone thickness, cortical bone thickness, occlusal load direction, and percentage of boneto-implant contact on bone stress levels in the first molar region. A retrospective review of patient records was also conducted in three private practices to assess clinical outcomes and bone level changes around one implant design in three diameters (3.7, 4.7, and 6.0 mm) placed in first molar locations. Categorical variable summaries and comparisons of 3D FEA and clinical findings were made using the FREQ procedure, t test procedures (Student t tests, folded F tests, Satterthwaite t tests), and the NONPAR1WAY procedure (Wilcoxon nonparametric test). RESULTS: Cumulative implant success was 98.4% and survival was 98% after a mean of 49.2 months. Although increasing implant diameter always reduced peri-implant stress concentrations in 3D FEA experiments, clinically, only 6.0-mm implants exhibited a statistically significant reduction in bone loss (0 mm) as compared to 3.7-mm and 4.7-mm implants. CONCLUSION: Only 6.0-mm implants were effective in reducing marginal bone loss in the first molar region. 3D FEA results supported previous clinical findings that maintaining approximately 1.8 mm of buccal plate thickness can help reduce bone stress concentrations and preserve buccal bone height. A history of periodontitis may adversely affect long-term marginal bone stability.

Effects of platelet-rich plasma and chitosan combination on bone regeneration in experimental rabbit cranial defects.

This study aimed to investigate and compare the effect of chitosan sponge and platelet-rich plasma (PRP) gel alone as well as their combination on bone regeneration in rabbit cranial defects. Four cranial defects with a 4.5-mm diameter were created in rabbit cranium and grafted with PRP, chitosan sponge alone, and chitosan sponge incorporated with PRP. The rabbits were killed by the fourth and eighth weeks, and the defects were analyzed histologically. Higher bone formation was observed in the PRP group when compared with the other groups at weeks 4 and 8. All parts of the defects were filled with thick trabecular new bone in the PRP group. The amount of new bone formation in the control groups was found to be less when compared with the PRP group and the least in the chitosan group. The defects that were filled with chitosan sponge showed a limited amount of new bone formation and an obvious fibrous demarcation line between chitosan particles and bone. Application of PRP showed a histological tendency toward increased bone formation. Other forms or derivatives of chitosan may have beneficial effects to achieve new bone regeneration.

ABM/P-15 modulates proliferation and mRNA synthesis of growth factors of periodontal ligament cells.

OBJECTIVE: Periodontal regeneration is histologically defined as regeneration of the tooth supporting structures, including alveolar bone, periodontal ligament, and cementum. Cells in the remaining periodontal tissues need optimal conditions if they are to perform their functions in the regeneration process. The present study is an investigation of the molecular effects of ABM/P-15 on human periodontal ligament cells (PDL) in vitro. MATERIAL AND METHODS: PDL cells obtained from healthy subjects were used for in vitro experiments. Cell proliferation, morphology, and mineralization using Von kossa staining were evaluated. mRNA expressions for transforming growth factor-beta (TGF-beta), insulin-like growth factor-I (IGF-I), basic fibroblast growth factor (b-FGF), vascular endothelial growth factor (VEGF), bone morphogenic protein-2 (BMP-2), platelet-derived growth factor (PDGF), and type 1 collagen (COL1) were assessed on days 3 and 7 using RT-PCR. RESULTS: ABM/P-15 enhanced proliferation of cultured PDL cells. It increased the mRNA expression of TGF-beta and BMP-2 in cultured PDL cells on days 3 and 7. IGF-I and b-FGF mRNA expressions showed a slight decrease, while PDGF expression was observed to have increased on day 3. VEGF and COL1 mRNA expressions were found not to be different on days 3 and 7. No differences were observed in the mineralization properties of cultured PDL cells treated with or without ABM/P-15. CONCLUSIONS: Based on the results of this in vitro study, it may be concluded that ABM/P-15 enhanced the regenerative capacity of PDL by regulating specific gene expressions of cells during early wound healing.

Platelet-rich plasma and bone healing: a histologic study in titanium bone chambers.

The potential benefits of platelet-rich plasma in the healing of isolated defects are unclear. The purpose of this study was to evaluate the effects of PRP on bone healing in titanium bone chambers, which represented isolated defects. PRP was prepared from blood collected from six adult female albino New Zealand rabbits. Titanium bone chambers with a 4-mm inner diameter were implanted into the tibiae of each animal at baseline and 2 weeks later; chambers healed for 6 or 8 weeks, either with PRP (test) or without PRP (control). Bone chambers were harvested from each animal and processed for histologic evaluation. Bone formation in 8-week test samples was not significantly different from that of the 6-week test samples. In control samples, more bone formation was seen at 8 weeks than at 6 weeks. The fibrous tissue content in control samples was higher than that of the test group in superficial sections, revealing that the tissue differentiation rate was higher in the test chambers. Time-dependent bone tissue differentiation in bone chambers augmented with PRP is higher than in normal wound healing, and PRP seems to increase the rate of tissue differentiation in early healing.

Multidisciplinary approach for the treatment of an oblique root fracture: a case report.

This clinical case study describes a multidisciplinary modified technique for the treatment of an oblique root fracture. A-38-year old woman with a history of trauma and a broken tooth was referred to our clinic. There was an oblique crown fracture extending the coronal third of the root just underneath the cingulum of the crown. The patient was willing to keep her tooth in function by any means. Two weeks after root canal therapy the flap was raised. The coronal two third of the root canal was enlarged. An impression of the enlarged root canal and tooth surface with surrounding bone was taken. The flap was sutured and the impression was sent to the laboratory for the post-casting preparation. After 7 days, the flap was opened again and casting was cemented. The flap was sutured. Ten days after the second surgery, three anterior teeth were prepared and a final impression was taken for the preparation of porcelain crowns. Restoration was finished 15 days after the second operation. The patient is still under maintenance therapy and the 12 month results are presented in this report. Extraction may not be the only alternative for the root fractures. Even for fractures under the alveolar margin, alternative multidisciplinary approaches can be used to restore and allow the tooth to survive.

Intentional replantation of a hopeless tooth with the combination of platelet rich plasma, bioactive glass graft material and non-resorbable membrane: a case report.

Intentional replantation can be an alternative choice for periodontally involved hopeless tooth at least for a period of time. This technique may help to restore an original tooth to function in the mouth instead of replacing it with prosthesis. The combination of one or more techniques currently available for periodontal therapy may have the potential to enhance clinical results as compared to any of the techniques used alone. In this case report, intentional replantation was combined with regenerative techniques. A very popular agent, platelet rich plasma was used in combination with bioactive glass graft material and non-resorbable PTFE membrane. The technique and one year results of treatment were discussed radiographically and clinically.

Cells of the osteoclast lineage as mediators of the anabolic actions of parathyroid hormone in bone.

PTH is an anabolic agent used to treat osteoporosis, but its mechanisms of action are unclear. This study elucidated target cells and mechanisms for anabolic actions of PTH in mice during bone growth. Mice with c-fos ablation are osteopetrotic and lack an anabolic response to PTH. In this study, there were no alterations in PTH-regulated osteoblast differentiation or proliferation in vitro in cells from c-fos -/- mice compared with +/+; hence, the impact of osteoclastic cells was further investigated. A novel transplant model was used to rescue the osteopetrotic defect of c-fos ablation. Vertebral bodies (vossicles) from c-fos -/- and +/+ mice were implanted into athymic hosts, and the c-fos -/- osteoclast defect was rescued. PTH treatment to vossicle-bearing mice increased 5-bromo-2'-deoxyuridine (BrdU) positivity in the bone marrow and increased bone area regardless of the vossicle genotype. To inhibit recruitment of osteoclast precursors to wild-type vossicles, stromal derived factor-1 signaling was blocked, which blunted the PTH anabolic response. Treating mice with osteoprotegerin to inhibit osteoclast differentiation also blocked the anabolic action of PTH. In contrast, using c-src mutant mice with a late osteoclast differentiation defect did not hinder the anabolic action, suggesting key target cells reside in the intermediately differentiated osteoclast population in the bone marrow. These results indicate that c-fos in osteoblasts is not critical for PTH action but that cells of the osteoclast lineage are intermediate targets for the anabolic action of PTH.

Necrosis of gingiva and alveolar bone caused by acid etching and its treatment with subepithelial connective tissue graft.

The misuse of various chemicals in dentistry may cause damage to gingiva and alveolar bone. In this case report, we describe necrosis of the gingiva and alveolar bone caused by acid etching. A patient whose caries on the cervical third of the root of his mandibular right first molar were treated 2 days earlier presented to our clinic with severe pain and discomfort in the treated area. Intraoral examination revealed a spreading gingival ulceration and exposed alveolar bone. The patient was followed and a week later, when the gingival inflammation had decreased, periodontal surgery was performed. A full-thickness flap was raised and necrotic gingiva and bone were removed. As a result, only a narrow band of keratinized gingiva remained. To treat the gingival recession and protect the underlying bone, a subepithelial connective tissue graft was placed during the same session. After the operation, the patient"s complaints resolved. Subepithelial connective tissue graft can be an important treatment approach in cases of necrosis and gingival recession caused by the misuse of various chemicals.

Non-surgical treatment of sports-related temporomandibular joint disorders in basketball players.

In this study, 18 basketball players (11 female, seven male; age range 14-32 years) with temporomandibular joint (TMJ) problems who had a history of sport injuries related to head or jaw region were evaluated and the results of the treatment were presented. A standardized functional examination of the masticatory system was performed including measurement of maximal jaw movements, recording of joint sounds, pain on movement of the jaw as well as tenderness to palpation of the both TMJ or masticatory muscles. Patients were also evaluated periodontally. Diagnosis was made according the criteria, described by Okeson, and appropriate treatment was applied using different kind of splints. At the end of treatment only one patient continued with right TMJ reduction with slight pain. Except for that patient, none of the patients had pain after treatment. The maximum opening of the jaws and the maximal jaw movements were statistically increased after treatment. Patients with TMJ problems also showed periodontal problems, most likely due to inadequate oral hygiene because of the limited jaw movements and pain. Periodontal parameters including probing depth (PD), Plaque index (PI), and Sulcus Bleeding Index (SBI) improved after treatment. Sports-related TMJ injuries may result in complex problems such as pain, TMJ sounds, limitation in maximal jaw movements and maximum opening of the mouth, difficulty in chewing. With the appropriate diagnosis this could be treated non-surgically in 6-8 months. This study also showed that the TMJ disorders may cause periodontal problems, which may affect all teeth and also the general health of the athlete.

Treatment of periapical inflammatory lesion with the combination of platelet-rich plasma and tricalcium phosphate: a case report.

Periapical surgery is an important treatment alternative in the presence of a periapical inflammatory lesion. To achieve optimal healing and regeneration of the bone, different bone substitutes or barrier membranes can be used after degranulation of the lesion. Tricalcium phosphate (TCP) graft material is one of these substitutes. Platelet Rich Plasma (PRP) preparation is a new biotechnology and can be used in many different surgical procedures. It consists of thrombocyte concentrates and high amounts of growth factors (GFs), especially platelet derived growth factor (PDGF), insulin-like growth factor (IGF-I) and transforming growth factor (TGF-beta), which are important in wound healing and regeneration. In this case report, use of platelet gel in conjunction with TCP in the treatment of periapical inflammatory lesion and the results of 12 months has been reported.

Localized edentulous ridge augmentation with upside down osteotomy prior to implant placement.

Localized bone defects may be seen following the extraction of teeth with periapical lesion or advanced periodontal disease, or as a result of trauma. When these regions are considered for treatment with implants, localized ridge augmentation will be necessary. Autogenous bone grafts are used exclusively for ridge augmentation. This case report represents the treatment of a localized edentulous ridge with an upside down osteotomy technique at the symphysis region prior to implant placement. Systemically healthy 21-year-old female patient, who was missing a lower right incisor tooth, was scheduled for an implant treatment. However, the crestal width was only 1 mm. The augmentation was planned and the region was treated with an upside down osteotomy technique. Nine months after the augmentation procedure, the computed tomography (CT) examination of the area revealed that the width of the crest was 7 mm, and the height of the crest was in good relation with the cementoenamel junction of the adjacent teeth. Flipping a bone block graft, which was harvested from the edentulous area, upside down may provide a successful result in partially edentulous ridges, in both maxilla and mandible.

Platelet-rich plasma: a promising innovation in dentistry.

The goal of periodontal therapy is to protect and maintain the patient's natural dentition for his or her lifetime. More specifically, after periodontal regenerative surgery, the aim is to achieve complete wound healing and regeneration of the periodontal unit. A recent innovation in dentistry is the preparation and use of platelet-rich plasma (PRP), a concentrated suspension of the growth factors found in platelets. These growth factors are involved in wound healing and are postulated as promoters of tissue regeneration. This clinical update outlines the specific effects of these growth factors, both in vitro and in vivo, on periodontal wound healing. The review focuses on current animal and human trials using PRP to promote tissue regeneration and alveolar bone repair. The article goes on to describe the clinical benefits of PRP and the step-by-step preparation of PRP in the dental office.

Intentional replantation for periodontally involved hopeless teeth.

The aim of this study was to evaluate the clinical and radiographic results of intentional replantation of periodontally involved teeth after conditioning of root surfaces with tetracycline-HCl. Thirteen patients (seven female, six male; age range: 35-52 years) with 15 periodontally involved hopeless teeth were included in this study. During the replantation procedure, the affected teeth were gently extracted, then the granulation tissues, calculus, remaining periodontal ligament and necrotic cementum on the root surfaces were removed. Tetracycline-HCl, at a concentration of 100 mg ml(-1), was applied for 5 min to the root surfaces. The teeth were then replaced into the socket and splinted. Patients were clinically and radiographically evaluated at baseline (time of surgery) and 6 months after the surgery. The following measurements were recorded: probing depth (PD), gingival recession (R), the amount of bone loss (BL) and bone gain (BG). Results indicated a reduction in PD and in the amount of bone loss and healthy gingiva. Mean PD was decreased from 5.25 to 2.36 mm, gingival recession was increased from 3.73 to 4.0 mm, and BL was reduced from 73.20 to 56.86%. At the end of 6 months, no root resorption or ankylosis was observed radiographically. Even during the short period of evaluation, it may be suggested that intentional replantation can be an alternative approach to extraction in cases where advanced periodontal destruction is present and no other treatments could be considered.

Anabolic actions of parathyroid hormone during bone growth are dependent on c-fos.

PTH has anabolic and catabolic actions in bone that are not clearly understood. The protooncogene c-fos and other activating protein 1 family members are critical transcriptional mediators in bone, and c-fos is up-regulated by PTH. The purpose of this study was to examine the mechanisms of PTH and the role of c-fos in PTH-mediated anabolic actions in bone. Mice with ablation of c-fos (-/-) and their wild-type (+/+) and heterozygous (+/-) littermates were administered PTH for 17 d. The +/+ mice had increased femoral bone mineral density (BMD), whereas -/- mice had reduced BMD after PTH treatment. PTH increased the ash weight of +/+ and +/-, but not -/-, femurs and decreased the calcium content of -/-, but not +/+ or +/-, femurs. Histomorphometric analysis showed that PTH increased trabecular bone volume in c-fos +/+, +/- vertebrae, but, in contrast, decreased trabecular bone in -/- vertebrae. Serum calcium levels in +/+ mice were greater than those in -/- mice, and PTH increased calcium in -/- mice. Histologically, PTH resulted in an exacerbation of the already widened growth plate and zone of hypertrophic chondrocytes but not the proliferating zone in -/- mice. PTH also increased calvarial thickness in +/+ mice, but not -/- mice. The c-fos -/- mice had lower bone sialoprotein and osteocalcin (OCN), but unaltered PTH-1 receptor mRNA expression in calvaria, suggesting an alteration in extracellular matrix. Acute PTH injection (8 h) resulted in a decrease in osteocalcin mRNA expression in wild-type, but unaltered expression in -/-, calvaria. These data indicate that c-fos plays a critical role in the anabolic actions of PTH during endochondral bone growth.