Risk of Bleeding during Implant Surgery in Patients Taking Antithrombotics: A Systematic Review.

The objective of this systematic review is to assess the risk of postoperative bleeding in oral surgery for implant placement in individuals taking antithrombotics (i.e., anticoagulants and/or antiplatelet agents). A literature search was performed in PubMed (MEDLINE), Web of Science, Scopus, and EMBASE databases for articles published until August 2020, with no date restriction, and manually completed. We included prospective clinical studies that provided information regarding the presence of an experimental group (i.e., implant placement), a control group (patients not under treatment with antithrombotics), and a well-established protocol for evaluating bleeding. Meta-analysis determined the risk of bleeding during the placement of implants in antithrombotic-treated patients. Of the 756 potentially eligible articles, 5 were included in the analysis with 4 ranked as high and 1 as medium quality. Antithrombotic treatment comprised the following drug classes: (1) anticoagulants: vitamin K antagonists, (2) nonvitamin K antagonist oral anticoagulants, (3) low-molecular-weight heparin, and (4) antiplatelet agents (not specified). The results suggest that the risk of bleeding is not substantially higher in antithrombotic-treated patients (odds ratio = 2.19; 95% confidence interval: 0.88-5.44, p = 0.09) compared with nontreated patients. This systematic review suggests that the absolute risk is low and there is no need to discontinue or alter the dose of the antithrombotic treatment for implant placement surgery.

Evaluation of the efficacy of the use of violet LED light in the bleaching of damaged primary incisors darkened by trauma.

BACKGROUND: The aim of this study was to evaluate efficacy of violet LED light for the bleaching treatment of primary incisors darkened by trauma. METHODS: Twenty deciduous incisors with color change were selected, divided into two groups: control - no bleaching protocol was applied, and VL- treated with violet LED. The change color analysis was taken in each tooth, by spectrophotometer. In three different time: baseline - before treatment, after 4 treatment sessions and after 8 treatment sessions. RESULTS: The color change data were analyzed using ANOVA and a post- hoc Tukey tests (α=0.05). After 4 and 8 sessions no differences were observed between the groups (p<0.05). CONCLUSIONS: Thus, it can be concluded that violet LED light was not effective in bleaching primary incisors darkened by trauma after 8 sessions.

Fresh-frozen human bone allograft in vertical ridge augmentation: clinical and tomographic evaluation of bone formation and resorption.

The aim of the current study is to evaluate fresh-frozen human bone allografts (FHBAs) used in vertical ridge augmentation clinically and by computed tomography, and to analyze the resulting bone formation and graft resorption. Sixteen FHBAs were grafted in the maxillae and mandibles of 9 patients. The FHBAs, which were provided by the Musculoskeletal Tissue Bank of Marilia Hospital (Unioss), were frozen at -80°C. After 7 months, dental implants were placed and bone parameters were evaluated. Vertical bone formation was measured by computerized tomography before (T0) and at 7 months (T1) after the surgical procedure. Bone graft resorption was measured clinically from a landmark screw head using a periodontal probe. The results were analyzed by Student's t-test. Significant differences existed in the bone formation values at T0 and T1, with an average change of 4.03 ± 1.69 mm. Bone graft resorption values were 1.0 ± 0.82 mm (20%). Implants were placed with varying insertion torque values (35-45 Ncm), and achieved primary stability. This study demonstrates that FHBAs promote satisfactory vertical bone formation with a low resorption rates, good density, and primary implant stability.

The comparative analysis of homologous fresh frozen bone and autogenous bone graft, associated or not with autogenous bone marrow, in rabbit calvaria: a clinical and histomorphometric study.

The aim of this study was to evaluate the potential of fresh frozen homologous and autogenous grafts, associated or not with autogenous bone marrow, to form bone. Sixty titanium cylinders were used, and were fixed to the skulls of 30 rabbits. These cylinders were filled with (A) autogenous bone (AM) autogenous bone associated with the bone marrow (H) fresh frozen homologous bone (HM) fresh frozen homologous bone associated with the bone marrow (M) pure autogenous bone marrow and (C) blood clot. The animals were sacrificed after 02 and 03 months. After clinical evaluation, the samples were stained with hematoxylin, eosin and Mallory Trichrome dyes for optical microscopy analysis and histomorphometric analysis. Experimental groups that received mineralized materials (A, AM, H, HM) showed the best bone formation results, presenting no statistical difference between them (P > 0.05). Groups that did not receive mineralized materials (M and C) showed the worst results (P < 0.05), but the M group showed better results than the C group. Most of the autogenous and homologous bone particles were resorbed and there was a larger amount of residual particles in the homologous graft (H, HM) when compared with the autogenous graft (A, AM; P < 0.05). These findings suggest that fresh frozen homologous grafts produced similar amounts of new bone when compared with the autogenous grafts. However, the amount of residual bone particles was larger in the homogenous groups, which may indicate a slower remodeling process. The homologous fresh frozen bone seems to be a good osteoconductive material. The use of only autogenous bone marrow showed better results when compared to the bood clot. However, this research indicates that association with mineralized materials is required.

Antimicrobial photodynamic therapy using optical fiber for oral fistula resulting from mandibular osteoradionecrosis.

Osteoradionecrosis (ORN) is considered one of the most severe complications of radiotherapy (RT). Treatment modalities for ORN may vary considerably, including conservative or surgical procedures. Recently, alternative managements such as the combination of photobiomodulation therapy (PBMT) and antimicrobial photodynamic therapy (aPDT) have also yielded promising results in patients presenting ORN or delayed healing post-RT. Herein, it is reported a case of ORN manifested as an oral fistula on the mandibular alveolar mucosa in which a combination of PBMT and aPDT was used every 15 days for six weeks. A laser device with an optical fiber was introduced into the fistula for light delivery. Seven days after the first laser session, it was noted complete resolution of both edema and erythema; after six weeks, the ORN fistula was no longer present. According to the current case, the combination of PBMT and aPDT with an optical fiber to deliver the laser light seems to be a suitable alternative for restricted areas such as fistula paths.

Synergism between recombinant human bone morphogenetic protein 2/absorbable collagen sponge and bone substitutes favors vertical bone augmentation and the resorption rate of the biomaterials: Histomorphometric and 3D microcomputed tomography analysis.

BACKGROUND: Recombinant human bone morphogenetic protein 2 (rhBMP-2) is an osteoinductor frequently used for bone regeneration in oral and maxillofacial surgery. There is no consensus about the ideal carrier for this growth factor. The aim of this study was to compare the bone augmentation, bone microarchitecture, and biodegradation rate of additional carriers to rhBMP-2/absorbable collagen sponge (ACS) in a vertical guided bone regeneration model. METHODS: Four titanium cylinders were fixed onto the calvaria of rabbits (n = 20) that received (n = 10) or not (n = 10) rhBMP-2/ACS in conjunction with one of the carriers: beta-tricalcium phosphate (ß-TCP), biphasic calcium phosphate (BCP), bovine bone mineral (BBM) or blood clot. The samples were analyzed by means of microcomputed tomography and histomorphology after 14 weeks. RESULTS: All the materials with rhBMP-2/ACS exhibited improvement on bone augmentation, mainly BCP (P = 0.033) and ß-TCP (P = 0.038), in the upper portion of the cylinder. Although trabecular anisotropy was improved in all the materials groups, trabecular connectivity was diminished when the biomaterials received rhBMP-2/ACS. Resorption rate of the remaining biomaterial was improved by rhBMP-2/ACS, mainly in BBM (P <0.01) and ß-TCP (P <0.01). BBM exhibited the highest osteoclast density compared with the other materials groups. CONCLUSIONS: BCP and ß-TCP biomaterials exhibited a synergic effect with rhBMP-2/ACS, acting as suitable and viable carriers for vertical bone augmentation. The addition of rhBMP-2 significantly affected the biodegradation of ß-TCP and BBM, accelerating the resorption of these materials.

Bone Formation in Grafts with Bio-Oss and Autogenous Bone at Different Proportions in Rabbit Calvaria.

BACKGROUND: The aim of this study was to assess the volumetric stability and bone formation in grafts with Bio-Oss and autogenous bone at different proportions in rabbit calvaria. Material and Methods. Ten rabbits received four titanium cylinders in their calvaria and randomly divided into the following groups: Group I: Bio-Oss (100%), Group II: Bio-Oss (75%) + autogenous bone (25%), Group III: Bio-Oss (50%) + autogenous bone (50%), and Group IV: autogenous bone (100%). After twelve weeks, the animals were euthanized, and samples were collected for clinical and histological analysis. RESULTS: Clinical analysis showed that Groups I (90.43 ± 8.99) and II (90.87 ± 7.43) had greater dimensional stability compared to Group IV (P=0.0005). Histologically, Groups I, II, and III showed areas of bone formation with particles of biomaterial remaining in close contact with the newly formed bone. However, there were no significant differences between the groups regarding the newly formed bone area. CONCLUSION: It was concluded that the use of Bio-Oss either alone or associated with the autogenous bone at a proportion of 25% showed superior dimensional stability compared to the use of autogenous bone in the proposed experimental model.

The Effects of Annual Maintenance on Peri-implant Health in Patients Rehabilitated with Overdentures: A Retrospective Cohort Study.

PURPOSE: The aim of this retrospective cohort study was to assess the effects of annual maintenance over a 7-year period on the peri-implant health of patients rehabilitated with overdentures using clinical and radiographic parameters. MATERIALS AND METHODS: In order to be considered for inclusion in the study, patients had to have been rehabilitated with overdentures that had at least two implants placed in the mandible and four implants in the maxilla. Patients were divided into two groups: group 1 comprised individuals who had undergone annual maintenance over the previous 7 years, and group 2 comprised those who had not attended any dental appointment over the previous 7 years. All patients were submitted to clinical peri-implant examinations and radiographic assessments. RESULTS: Sixty-six patients received 396 implants of the external hexagon type, 132 in the mandible and 264 in the maxilla. Group 1 (44 patients with 264 implants) had a mean probing depth of 2.72 mm, while group 2 (22 patients with 132 implants) had a mean probing depth of 3.10 mm. It can be concluded that the mean of the variable probing depth is influenced by the presence of bleeding (P = .0005) and the implementation of maintenance (P = .0188), whereas plaque and local variables were not otherwise significant (P = .0605 and .0796, respectively). CONCLUSION: In this study, it was possible to observe better clinical conditions in individuals who had attended annual appointments for maintenance purposes.

Sandblasted/acid-etched vs smooth-surface implants: implant clinical reaction to experimentally induced peri-implantitis in Beagle dogs.

This study uses a sandblasted/acid-etched implant vs a smooth-surface implant to compare implant mobility and clinical reactions of peri-implant tissues to experimentally induced peri-implantitis in Beagle dogs. The right and left mandibular premolars were extracted from 5 Beagle dogs, and 2 smooth-surface (SS) implants and 2 sandblasted/acid-etched (SLA) implants were placed in each animal. After 120 days, healing abutments were connected. Fifteen days later, the prosthetic abutments were connected, the hygiene regimen was suspended, and peri-implantitis was induced by the insertion of cotton ligatures into the soft tissue around the implants. At baseline and 30, 60, and 90 days later, clinical attachment level (CAL), probing depth (PD), and mobility (MO) were measured. Probing depth increased significantly in the SLA group alone when baseline PD was compared with 30-, 60-, and 90-day evaluations (P < .05). No significant differences were noted between the 2 implant groups (P > .05). The loss in CAL was significant in both groups when the baseline value was compared with 30-, 60-, and 90-day evaluations (P < .02). Comparison between the 2 implant groups revealed a greater loss in CAL in the SLA group at the 90-day evaluation period (P = .04). A significant increase in mobility was seen in both groups when baseline values and 90-day evaluations were compared (P < .04). However, no statistically significant differences were noted between the 2 implant groups (P > .05). Experimentally induced peri-implantitis results in a greater loss of CAL in SLA implants than in SS implants in dogs; however, no differences in mobility or in PD have been noted between the 2 implant groups.

Bone autografts & allografts placed simultaneously with dental implants in rabbits.

OBJECTIVE: This study compared stability, removal torque, bone implant contact (BIC) and area (BA) of implants installed simultaneously with onlay autografts or allografts in rabbits' tibias. MATERIAL AND METHODS: Total of 18 rabbits were used in this study. Fresh frozen allografts were obtained from six animals at T(-6). Two implants with autogenous grafts (Group 1) or allografts (Group 2) were simultaneously inserted into both sides of the tibiae in a vertical periimplant defect model at T0. The resonance frequency (ISQ) was measured in implant proximal epiphysis on the day of installation of T0 and T18 (18 weeks post-surgery). At T18 the removal torque was assessed at the distal implants, the implants' proximal epiphysis and surrounding bone were harvested to perform histomorphometric analysis. The BIC and BA within the limits of the implants threads were evaluated. RESULTS: The ISQ revealed a statistically significant difference between T0 and T18 in each group (p = 0.024, p = 0.003). The removal torque indicates that there was no significant difference between the two groups (p = 0.47). No significant differences were observed between the groups regarding both BIC (p = 0.3713) and the BA (p = 0.3883). CONCLUSION: Both grafts and implants demonstrated the same stability, torque removal and the BIC and BA.

Periodontal clinical evaluation before and after surgically assisted rapid maxillary expansion.

INTRODUCTION: The surgically assisted rapid maxillary expansion is a procedure that reduces the resistance of the sutures correcting the posterior crossbite in adults. OBJECTIVE: The aim of this study was to evaluate the periodontal status of 17 adults submitted to this procedure. METHODS: The clinical attachment level (CAL), gingival recession, attached gingiva and bleeding were evaluated in maxillary first premolars and molars, central and lateral incisors of right and left sides before surgery, 5 days and 6 months after. Means, standard deviation, medians, minimum and maximum values were compared among the evaluations using the Friedman and McNemar tests. RESULTS: There was a statistically significant increase in CAL in the right central incisor, right and left premolars and right and left molars. There was a statistically significant increase in gingival recession in the right and left premolars and molars. The amount of attached gingiva significantly decreased in right premolars and right and left molars. There was increase in bleeding in most of the teeth. CONCLUSION: Results indicated that the surgically assisted rapid maxillary expansion might cause alterations in periodontal tissue.

Growth Dynamic of Allogeneic and Autogenous Bone Grafts in a Vertical Model.

Several techniques have been proposed for vertical bone regeneration, and many of them use bone autogenous and allogeneic grafts. The purpose of this study was to compare demineralised freeze-dried bone allografts (DFDBA), fresh-frozen (FF) allografts, autogenous bone grafts to find differences between volumetric and histological quantity of bone formation and vertical bone growth dynamic. A vertical tissue regeneration bone model was performed in rabbit calvarias under general anaesthesia. Four hollow cylinders of pure titanium were screwed onto external cortical bone calvarias in eight rabbits. Each one of the cylinders was randomly filled with one intervention: DFDBA, FF, autogenous bone, or left to be filled with blood clot (BC) as control. Allogeneic grafts were obtained from a ninth animal following international standardised protocols for the harvesting, processing, and cryopreservation of allografts. Autogenous graft was obtained from the host femur scraping before adapting hollow cylinders. Animals were euthanized at 13 weeks. Vertical volume was calculated after probe device measurements of the new formed tissue inside the cylinders and after titanium cylinders were removed. Histomorphometry and fluorochrome staining were used to analyse quantity and dynamic of bone formation, respectively. Results showed that DFDBA and fresh-frozen bone improved the velocity and the quantity of bone deposition in distant portions of the basal plane of grafting. Remaining material in allograft groups was more intense than in autogenous group. Both allografts can be indicated as reliable alternatives for volume gain and vertical bone augmentation.

Vertical Bone Augmentation Using Deproteinized Bovine Bone Mineral, Absorbable Collagen Sponge, and Recombinant Human Bone Morphogenetic Protein-2: An In Vivo Study in Rabbits.

PURPOSE: The objective of this investigation was to assess vertical bone augmentation using deproteinized bovine bone mineral (DBBM) infused or not with recombinant human bone morphogenetic protein (rhBMP-2) in rabbit tibiae. MATERIALS AND METHODS: A total of 18 female rabbits (New Zealand) received two blocks of DBBM in each tibia. The DBBM blocks were randomly assigned into four experimental groups: DBBM (only the bone graft); DBBM associated with absorbable collagen sponge (ACS); DBBM plus rhBMP-2 (1.5 mg/mL); and DBBM infused with rhBMP-2 (1.5 mg/mL) in an ACS carrier. Animals were sacrificed after 12 weeks, and the tibiae containing the DBBM blocks were dissected and analyzed radiographically (microcomputed tomography [micro-CT]), histologically, and immunohistochemically. RESULTS: Micro-CT analysis showed a considerable increase in bone volume (BV) and BV/tissue volume in the rhBMP-2/ACS group compared with all the others. Trabeculae thickness also increased in the rhBMP-2/ACS group compared with the DBBM/ACS group. Trabecular number, separation, and bone mineral density were not different among groups. Histomorphometric evaluation showed increased newly formed bone in the rhBMP-2/ACS group compared with the DBBM and DBBM/ACS groups. The amount of residual bone graft was statistically higher in the rhBMP-2 groups compared with the DBBM/ACS group. Immunohistochemical analysis showed that the vascular endothelial growth factor (VEGF) expression was more intense in the rhBMP-2/ACS group compared with the DBBM/ACS group. The immunopositivity for type 1 collagen tended to be higher in the two groups with rhBMP-2. CONCLUSION: Collectively, the results of this study suggest that the addition of rhBMP-2 in an ACS carrier placed on top of the DBBM graft enhanced bone formation in this animal model.

Evaluation of the Prevalence of Maxillary Sinuses Abnormalities through Spiral Computed Tomography (CT).

Introduction Maxillary sinus disease is common and numerous disorders can affect this anatomical area. Abnormalities can be classified as: non-neoplastic, neoplastic benign, and neoplastic malignant. Objective Evaluate through CT the prevalence of diseases in maxillary sinuses, using the Radiology Department's database of a hospital in São Paulo city. Methods The sample consisted of 762 facial CT scans that we divided into three groups: Group A (12-19 years old); Group B (20-49 years old); Group C (above 50 years old); and male or female. We considered the following pathological processes: I - Mucoperiosteal Thickening; II - Chronic Sinusitis; III - Chronic Odontogenic Sinusitis; IV - Rhinosinusitis; V - Polypoid Lesions; VI - Bone Lesions; VII - Neoplasms; VIII - Antrolith; IX - Foreign Bodies; X - Oroantral Fistula. Results Our study found that 305 exams (40.02%) were normal and 457 exams (59.97%) were abnormal. We found the following disease frequencies: focal mucoperiosteal thickening (21.25%); polypoid lesions (10.76%); chronic sinusitis (7.48%); chronic odontogenic sinusitis (2.29%); neoplasms (2.03%); rhinosinusitis (1.77%); bone lesions, foreign bodies and oroantral fistula in 0.65%; 0.13% and 0.06% respectively. There was no significant difference between male and female, and Groups A, B, or C when relating the frequencies of abnormalities found. There was no significant difference between male and female and the age group for the side of the altered maxillary sinus. Conclusion We observed a high prevalence of sinus maxillary diseases. Mucoperiosteal thickening; acute, chronic, and odontogenic sinusitis; polypoid lesions and neoplasms have high prevalence in maxillary sinuses. Thus, facial CT exam was effective for the evaluation of diseases in maxillary sinuses.

High-power laser for periodontal surgery in a patient with glanzmann thrombasthenia / Laser de alta potência para cirurgia periodontal em paciente com trombastenia de glanzmann

Background: Glanzmann thrombasthenia (GT) is a rare autosomal recessive disorder characterized by platelet function impairment. Considering that the oral cavity is highly vascularized and performing some local hemostatic maneuvers may be difficult, GT patients are at high risk for hemorrhage related to invasive oral procedures. This study aimed to present an alternative method for periodontal surgery in a young GT patient. Case Report: A 15-year-old female GT patient with a recent history of excessive bleeding following dental surgeries was referred to a public dental center, presenting gingival hyperplasia. The procedure was performed using a high-power laser (HPL), and except for local anesthesia with epinephrine, no further hemostatic agent was necessary. Conclusion: According to the case, the HPL seems to be an efficient tool for preventing perioperative bleeding in GT patients submitted to minor oral surgeries(AU)

Introdução: A trombastenia de Glanzmann (TG) é uma doença autossômica recessiva rara caracterizada por comprometimento da função plaquetária. Tendo em vista que a cavidade oral é altamente vascularizada e a realização de algumas manobras hemostáticas locais pode ser difícil, pacientes com TG apresentam alto risco de hemorragia relacionada a procedimentos orais invasivos. Este artigo teve como objetivo apresentar uma técnica alternativa para cirurgia periodontal em um paciente jovem com TG. Relato de Caso: Paciente com TG, sexo feminino, 15 anos, com história recente de sangramento excessivo relacionado a cirurgias odontológicas prévias, foi encaminhada a um centro odontológico público apresentando hiperplasia gengival. O procedimento de remoção foi realizado com laser de alta potência e, com exceção da anestesia local com epinefrina, nenhum outro agente hemostático foi necessário. Conclusão: De acordo com o caso, o laser de alta potência parece ser uma ferramenta eficiente na prevenção de sangramento perioperatório em pacientes com TG submetidos a pequenas cirurgias orais(AU)

Lateralization Technique and Inferior Alveolar Nerve Transposition.

Bone resorption of the posterior mandible can result in diminished bone edge and, therefore, the installation of implants in these regions becomes a challenge, especially in the presence of the mandibular canal and its contents, the inferior alveolar nerve. Several treatment alternatives are suggested: the use of short implants, guided bone regeneration, appositional bone grafting, distraction osteogenesis, inclined implants tangential to the mandibular canal, and the lateralization of the inferior alveolar nerve. The aim was to elucidate the success rate of implants in the lateralization technique and in inferior alveolar nerve transposition and to determine the most effective sensory test. We conclude that the success rate is linked to the possibility of installing implants with long bicortical anchor which favors primary stability and biomechanics.

Stress Analysis on Single Cobalt/Chrome Prosthesis With a 15-mm Cantilever Placed Over 10/13/15-mm-length Implants: A Simulated Photoelastic Model Study.

The aim of study was to assess the stress around 10/13/15-mm implants in the mandibular area with a 15-mm cantilevered acrylic-resin-coated prostheses following the application force, using the photoelasticity method. Three photoelastic mandibular models were created containing 10-, 13-, and 15-mm implants in length and 3.75 mm in diameter. The implants had bore internal hex connections and were placed parallel to the intermental region. Abutments with 1-mm high cuffs were placed over the implants, and a single cobalt/chrome metallic prosthesis with a 15-mm cantilever, coated with thermoplastic acrylic resin, was placed on top. Loads of 1.0 and 3.0 bars were applied, and the images were photographed and assessed by photoelasticity method. The greatest stress levels were observed for the 10-mm implants. The stress pattern was the same regardless of implant length; only the magnitude of the stress along the implant body revealed changes. Increased implant length played a role in reducing stress on the investigated area of the model, and the 15-mm implants exhibited the best performance in regard to stress distribution. The highest stress levels were found in the implants closest to the cantilever and the central implant. The longest implants were more favorable in regard to the stress distribution on the peri-implant support structures in the 15-mm cantilevered prosthesis under loads.