Does implant location influence the risk of peri-implantitis?

Peri-implantitis is characterized by nonreversible and progressive loss of supporting bone and is associated with bleeding and/or suppuration on probing. Peri-implant disease is considered as the main etiologic factor related to implant failure. Peri-implant disease has a pathogenesis similar to that of periodontal disease, both being triggered by an inflammatory response to the biofilm accumulation. Although the prevalence of peri-implantitis has been evaluated by several clinical studies with different follow-ups, there are currently little data on the impact of implant location and the prevalence of peri-implantitis. The aim of this review, therefore, was to summarize the evidence concerning the prevalence of peri-implantitis in relation to implant location and associated risk predictors. Even though most studies evaluating the prevalence of peri-implantitis in relation to implant location are cross-sectional or retrospective, they suggest that the occurrence of peri-implantitis is most prevalent in the anterior regions of the maxilla and mandible. Moreover, it seems that there is a higher prevalence of peri-implantitis in the maxilla than in the mandible.

Is a digital surgical guide superior for implant placement in the first molars areas?

Design The study was a randomised clinical trial comparing two independent groups for implant placement. One group was a computer-aided design/computer-aided manufacturing (CAD/CAM) implant guide (digital) and the other one used the traditional implant guide (traditional impression).Aim The study aimed to compare the outcomes of two different methods of guidance for surgical implants for missing first molars. One was prepared by intraoral digital scanning. The other was the conventional impression, which includes time to make an impression and perform surgery, fit of intraoral guide and deviation in screw access channels position. The purpose of the study was not only to find the most suitable implant guide but also to allow dentists to justify their chosen method.Methods The authors of this study included 42 participants with first molars missing and distributed them into two groups, one group using a digital production guide and the other using a traditional impression. The evaluation measured the deviation length and direction of the screw access channel position relative to implant alignments. In addition, labour time for implant guides and the intraoral fit were assessed as secondary outcomes.Results The impression time and implant surgery time for patients in the digital group were shorter than for those in the traditional group. The intraoral first fit of the guide was better for patients who underwent treatment with a digital system than it was for control patients (p <0.05). The one-time satisfaction rate of the digital group was 100%, while five cases in the control group required repetition. The difference between screw access channel positions on the left and right sides for both groups showed no significant differences.Conclusions The digital surgical guide for a first molar implant reduces the clinical, operative time and screw access deviation and therefore improves efficiency. Improved clinical outcomes indicated that there is evidence to support the use of CAD/CAM guides in dental implant placement for a single missing tooth replacement.

Are the imaging-based techniques for early diagnosis of oral potentially malignant lesions effective?

Design The study was a systematic review and meta-analysis conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and the guidelines from the Cochrane handbook for systematic reviews of interventions.Data sources Literature searches of free text and MeSH terms were performed using Medline (PubMed), Scopus, Google Scholar and the Cochrane Library (from 2000 to 30 June 2020). The search strategy was: ("oral screening devices" or "autofluorescence" or "chemiluminescence" or "optical imaging" or "imaging technique") and ("oral dysplasia" or "oral malignant lesions" or "oral precancerosis").Data analysis After identification of 1,282 potential articles, an analysis applying the eligibility criteria to the research identified 43 articles for qualitative evaluation and 34 for quantitative analysis.Results The results presented were inconsistent, both in the whole and in technique groups. There was evidence of high risk of bias in the evaluated studies. Moreover, the results were homogeneous across studies, which makes it challenging to carry out a reliable comparison of measures like specificity or positive/negative predictive values.Conclusions Imaging-based techniques for early diagnosis of potentially malignant oral lesions must improve technology and accuracy. In addition, none of the evaluated methods can substitute the oral biopsy.

The Use of Hydroxyapatite Loaded with Doxycycline (HADOX) in Dentoalveolar Surgery as a Risk-Reduction Therapeutic Protocol in Subjects Treated with Different Bisphosphonate Dosages.

Medication-related osteonecrosis of the jaw (MRONJ) is considered as a severe adverse side effect of specific drugs such as anti-resorptive and anti-angiogenic medications. Evidence suggests that MRONJ is linked to invasive dental procedures, mainly dentoalveolar surgery. Several preventive strategies to minimize the risk of developing MRONJ have been investigated. However, no investigation has been attempted to evaluate the therapeutic effect of local drug-delivery technology as a preventive strategy protocol. The aim of this study is to evaluate the efficacy of hydroxyapatite-containing doxycycline (HADOX) in rats with high-risk MRONJ development. All the rats used in this study were divided into seven groups. Six groups of rats out of seven were exposed to two different doses of antiresorptive drug therapy for four weeks before undergoing an upper incisor extraction. After 28 days, all the animals were euthanized, and the bone blocks were processed for histological and histomorphometrical evaluation. The histomorphometric analysis confirmed that newly formed bone (NFB) was present in all groups, with significant differences. NFB in the HADOX group treated with zoledronic acid at 4% showed (28.38; C.I. 22.29-34.48), which represents a significant increase compared to HA (15.69; C.I. 4.89-26.48) (p = 0.02). A similar pattern was observed in the HADOX group treated with zoledronic acid 8% ZA treatment (p = 0.001). Conclusions: HADOX did not inhibit any bone repair and reduced early inflammatory response. Hence, HADOX could promote bone healing in patients undergoing antiresorptive drug therapy.

Does obesity directly correlate to periodontal disease, or could it be only one of the risk factors?

Design The study was a cohort study that conformed with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines for reporting observational studies.Cohort election Obesity is identified as a risk factor for several non-communicable diseases (NCDs) and the study aimed to evaluate the risks for NCDs (for example, diabetes or high blood pressure). The study included participants from the Electric Generation Authority of Thailand. The workers were randomly selected from urban and rural areas. They were asked to answer a health survey every five years.Data analysis The authors evaluated 2,216 workers and the evaluation consisted of a sociodemographic, medical and oral health examination.Results The ten-year incidence of periodontal disease progression was 59.6 cases per 100 persons. In addition, the univariate analysis revealed that being obese was linked to a 15% higher risk of progression of periodontal disease than in non-obese subjects.Conclusions Despite the higher prevalence of periodontal disease among obese individuals, it is not considered an independent risk factor for the development of periodontitis.

Osteosphere Model to Evaluate Cell-Surface Interactions of Implantable Biomaterials.

Successful biomaterials for bone tissue therapy must present different biocompatible properties, such as the ability to stimulate the migration and proliferation of osteogenic cells on the implantable surface, to increase attachment and avoid the risks of implant movement after surgery. The present work investigates the applicability of a three-dimensional (3D) model of bone cells (osteospheres) in the evaluation of osteoconductive properties of different implant surfaces. Three different titanium surface treatments were tested: machined (MA), sandblasting and acid etching (BE), and Hydroxyapatite coating by plasma spray (PSHA). The surfaces were characterized by Scanning Electron Microscopy (SEM) and atomic force microscopy (AFM), confirming that they present very distinct roughness. After seeding the osteospheres, cell-surface interactions were studied in relation to cell proliferation, migration, and spreading. The results show that BE surfaces present higher densities of cells, leaving the aggregates towards than titanium surfaces, providing more evidence of migration. The PSHA surface presented the lowest performance in all analyses. The results indicate that the 3D model allows the focal analysis of an in vitro cell/surfaces interaction of cells and surfaces. Moreover, by demonstrating the agreement with the clinical data observed in the literature, they suggest a potential use as a predictive preclinical tool for investigating osteoconductive properties of novel biomaterials for bone therapy.

Silane-Coating Strategy for Titanium Functionalization Does Not Impair Osteogenesis In Vivo.

Silane-coating strategy has been used to bind biological compounds to the titanium surface, thereby making implant devices biologically active. However, it has not been determined if the presence of the silane coating itself is biocompatible to osseointegration. The aim of the present study was to evaluate if silane-coating affects bone formation on titanium using a rabbit model. For this, titanium screw implants (3.75 by 6 mm) were hydroxylated in a solution of H2SO4/30% H2O2 for 4 h before silane-coating with 3-aminopropyltriethoxysilane (APTES). A parallel set of titanium screws underwent only the hydroxylation process to present similar acid-etched topography as a control. The presence of the silane on the surface was checked by x-ray photoelectron spectroscopy (XPS), with scanning electron microscopy (SEM) and atomic force microscopy (AFM). A total of 40 titanium screws were implanted in the tibia of ten New Zealand rabbits in order to evaluate bone-to-implant contact (BIC) after 3 weeks and 6 weeks of healing. Silane-coated surface presented higher nitrogen content in the XPS analysis, while micro- and nano-topography of the surface remained unaffected. No difference between the groups was observed after 3 and 6 weeks of healing (p > 0.05, independent t-test), although an increase in BIC occurred over time. These results indicate that silanization of a titanium surface with APTES did not impair the bone formation, indicating that this can be a reliable tool to anchor osteogenic molecules on the surface of implant devices.

Effects of rotor angle and time after centrifugation on the biological in vitro properties of platelet rich fibrin membranes.

This study evaluated the impact of rotor angle and time of storage after centrifugation on the in vitro biological properties of platelet-rich fibrin (PRF) membranes. Blood samples (n = 9) were processed with a vertical fixed-angle (V) or a swing-out horizontal (H) centrifuge, with 20-60 min of sample storage after centrifugation. Leukocytes, platelets, and red blood cells were counted, and fibrin architecture was observed by scanning electron microscopy (SEM). The release of FGF2, PDGFbb, VEGF, IL-6, and IL-1ß was measured after incubation on culture media for 7-21 days. Cell content was equivalent in all experimental groups (p > .05). The fibrin matrix was similar for fixed-angle and horizontal centrifugation. Horizontal centrifugation induced a twofold increase in PDGF and 1.7× increase on FGF release as compared to V samples, while IL-1ß was significantly reduced (p < .05). No significant difference was observed on the release of growth factors and cytokines at different times after centrifugation (p < .05). These data suggest that both angles of centrifugation produce PRF membranes with similar structure and cellularity, but horizontal centrifugation induces a higher release of growth factors. Higher times of storage after centrifugation did not impact on cell content and the release of growth factors.

What evidence is there for the use of antibiotic prophylaxis in patients with periodontal disease to decrease the risk of prosthetic joint infections?

Design Systematic review.Study population The present study evaluated articles about patients with prosthetic joint infections after the surgical procedure and the correlation with periodontal disease.Data analysis The evaluation was performed using case reports and previous systematic reviews.Results In this study, the authors did not include studies using qualitative analysis. They did not find studies which correlated periodontal disease with the development of a prosthetic joint infection.Conclusions In conclusion, the authors did not have evidence to support or exclude the need of antibiotic prophylaxis as a means to decrease the risk of prosthetic joint infections in patients with periodontal disease.

Nanostructured Carbonated Hydroxyapatite Associated to rhBMP-2 Improves Bone Repair in Rat Calvaria.

Many biomaterials are used for Bone Morphogenetic Proteins (BMPs) delivery in bone tissue engineering. The BMP carrier system's primary function is to hold these growth factors at the wound's site for a prolonged time and provide initial support for cells to attach and elaborate the extracellular matrix for bone regeneration. This study aimed to evaluate the nanostructured carbonated hydroxyapatite microspheres (nCHA) as an rhBMP-2 carrier on rats calvaria. A total of fifteen male Wistar rats were randomly divided into three groups (n = 5): clot (control group), rhBMP-2 associated with collagen membrane (COL/rhBMP-2) or associated with the microspheres (nCHA/rhBMP-2). After 45 days, the calvaria defect samples were evaluated through histological, histomorphometric, and SR-µCT analyses to investigate new-formed bone and connective tissue volume densities. The descriptive histological analysis showed that nCHA/rhBMP-2 improved bone formation compared to other groups. These results were confirmed by histomorphometric and SR-µCT analysis that showed substantially defect area filling with a higher percentage of newly formed (36.24 ± 6.68) bone than those with the COL/rhBMP-2 (0.42 ± 0.40) and Clot (3.84 ± 4.57) (p < 0.05). The results showed that nCHA is an effective carrier for rhBMP-2 encouraging bone healing and an efficient alternative to collagen membrane for rhBMP-2 delivery.

How can we reduce the risks of SARS-CoV-2 (COVID-19) for dentists and their patients?

Design Special report.Study population This paper presented a report about the experience of the oral and maxillofacial surgeons (OMS) of Peking University School and Hospital of Stomatology, during the COVID-19 (SARS-CoV-2) pandemic.Data analysis The experience of that department formed the content of the report.Results In this study, the authors presented an informative description of experience of treating patients under a pandemic condition. The authors offer some methods of trying to protect oro-maxillofacial surgeons, using an algorithm of diagnosis and classifying the risk of contamination and the materials required in order to avoid it.Conclusions In conclusion, the authors suggest the use of the algorithm for patient admission during the COVID-19 outbreak.

The use of leukocyte- and platelet-rich fibrin in the management of soft tissue healing and pain in post-extraction sockets: A randomized clinical trial.

This study aimed to evaluate the clinical effect of leukocyte- and platelet-rich fibrin (L-PRF) to improve epithelialization and decrease postoperative pain in post-extraction sockets. Thirty two participants requiring extractions of posterior teeth were randomized into two groups: 1) extractions and socket filling with L-PRF membrane (test group) and 2) extraction with spontaneous healing (control group). One week after extraction, an assessment of soft tissue healing around the sockets was performed using the healing index. Also, postoperative pain by visual analog scale (VAS) and number of consumed analgesic tablets were recorded. In the first week, the sockets of the test group presented a significantly (mean of 3.81 ± 0.54; p = 0.0138) higher level of healing when compared to the sockets of the control group (mean of 3.18 ± 0.65). The participants of control group reported a significantly (mean of 5.12 ± 1.08; p = 0.0128) higher level of postoperative pain when compared to the test group (mean of 4 ± 1.15). Also, the control group consumed a greater number of analgesics (mean of 1.75 ± 0.85; p = 0.0136) when compared to the test group (mean of 1 ± 1.15). The results of the present study demonstrate that whenever improved healing of the extraction socket is needed, the use of L-PRF should be considered. In addition, the use of L-PRF decreases postoperative pain and discomfort.

How should we anaesthetise painful mandibular premolars?

Design Randomised clinical trialStudy population The present study evaluated patients of different genders aged between 18-65 years old. The study design and the language of the consent form were approved by the Ethics Committee at Tehran University of Medical Sciences (TUMS) (approval code: IR.TUMS.REC.1394.1906). The study was registered in the Iranian Registry of Clinical Trials.Data Analysis The evaluation was performed using the Heft-Parker Visual Analog Scale (HP VAS) and complemented with the electrical pulp test accuracy to determine the success of anaesthesia Results In this study, the success rate was 93.8% (95% CI 79.19-99.23) for mental/incisive nerve block (MINB), and 81.2% (95% CI 63.56-92.79) for inferior alveolar nerve block (IANB). The difference was not significant (p = 0.26). An interesting result was the combination of both techniques was 100% successful in the failed cases (2 in MINB group; 6 in IANB group).Conclusions In conclusion, MINB using 4% Articaine showed a similar success rate as IANB using 4% Articaine in local anaesthesia for mandibular premolars with irreversible pulpitis. The beginning of anaesthesia was faster for MINB, and the injection was painless. The post-injection pain for MINB was higher than for IANB. Both techniques showed similar efficacy.

Usefulness of platelet-rich fibrin as a hemostatic agent after dental extractions in patients receiving anticoagulant therapy with factor Xa inhibitors: a case series.

PURPOSE: To evaluate the clinical outcomes of platelet-rich fibrin (PRF) application for hemostasis after dental extraction in patients receiving anticoagulant therapy with factor Xa inhibitors. METHODS: In total, 25 patients receiving anticoagulant therapy with rivaroxaban or apixaban who required routine dental extraction were evaluated. In all patients, PRF was used for hemostasis in addition to adapting sutures. Bleeding was subjectively assessed using a sterilize gauze pad at 24, 48, and 72 h after the procedure. RESULTS: All invited participants (n = 25) consented to participate. The PRF clots successfully arrested bleeding after extraction in all patients, with no complications at any time point after the procedure. Favorable soft tissue healing was observed during suture removal at 10 days after the procedure in all patients, with no signs of infection or late healing. CONCLUSIONS: The results of this case series indicate that PRF is a promising natural hemostatic agent for the management of bleeding after dental extraction in patients receiving factor Xa inhibitor therapy. Further controlled clinical studies with larger patient samples are necessary to clarify the findings of this case series.

In Vitro Physico-Chemical Characterization and Standardized In Vivo Evaluation of Biocompatibility of a New Synthetic Membrane for Guided Bone Regeneration.

This study's aim was to evaluate the biocompatibility and bioabsorption of a new membrane for guided bone regeneration (polylactic-co-glycolic acid associated with hydroxyapatite and ß-tricalcium phosphate) with three thicknesses (200, 500, and 700 µm) implanted in mice subcutaneously. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and the quantification of carbon, hydrogen and nitrogen were used to characterize the physico-chemical properties. One hundred Balb-C mice were divided into 5 experimental groups: Group 1-Sham (without implantation); Group 2-200 µm; Group 3-500 µm; Group 4-700 µm; and Group 5-Pratix®. Each group was subdivided into four experimental periods (7, 30, 60 and 90 days). Samples were collected and processed for histological and histomorphometrical evaluation. The membranes showed no moderate or severe tissue reactions during the experimental periods studied. The 500-µm membrane showed no tissue reaction during any experimental period. The 200-µm membrane began to exhibit fragmentation after 30 days, while the 500-µm and 700-µm membranes began fragmentation at 90 days. All membranes studied were biocompatible and the 500 µm membrane showed the best results for absorption and tissue reaction, indicating its potential for clinical guided bone regeneration.

Does the association of blood-derived growth factors to nanostructured carbonated hydroxyapatite contributes to the maxillary sinus floor elevation? A randomized clinical trial.

OBJECTIVE: The combination of calcium phosphate with blood-derived growth factors (BDGF) has been widely used in bone regeneration procedures although its benefits are still unclear. The purpose of this study was to evaluate whether or not BDGF improves the efficacy of a modified carbonated calcium phosphate biomaterial in sinus floor augmentation. MATERIAL AND METHODS: Ten patients underwent 20 sinus floor augmentation procedures using nanostructured carbonated hydroxyapatite (cHA) microspheres alone or associated with BDGF in a randomized controlled clinical trial. The in vitro release of growth factors was assessed by an elution assay. Bone grafts were randomly implanted in the right and left maxillary sinuses of each participant, associated either with a 0.9% saline solution or BDGF. Bone gain was evaluated through cone beam tomography after 180 days. RESULTS: Nine women and one man composed the sample. The blood-derived concentrates were able to release high levels of growth factors and cytokines. A significant clinical advantage was observed in the use of the BDGF after fibrin polymerization around the biomaterial microspheres, optimizing the surgical procedures, thereby reducing the time and displacement, and improving the adaptation of the biomaterial in the maxillary sinus. No synergistic effect was observed in bone formation when cHA was associated with BDGF (p > 0.05). CONCLUSION: Equivalent new bone formation was observed for cHA in the presence or absence of the BDGF concentrate in bilateral sinus floor elevation after 6 months. Blood-derived growth factors did not improve bone repair when associated with calcium phosphate in sinus lift procedures.

Anatomic evaluation of the incisive canal with cone beam computed tomography and its relevance to surgical procedures in the mental region: a retrospective study in a Brazilian population.

BACKGROUND AND OBJECTIVE: To evaluate the prevalence, location, length, diameter, and distances related to the incisive canal (IC) and the need for cone beam computed tomography (CBCT) as a complementary exam prior to surgery in the mental region. MATERIALS AND METHODS: One hundred CBCT images from patients of both genders aged 27 to 73 years were evaluated. At every 3 mm, the diameter (DIAM) of the right and left ICs and their location, their distance to base of the jaw (BIC), the buccal (BAIC) and lingual (LAIC) aspects, and their length were measured. RESULTS: The 100 patients comprised 50 men (50%) and 50 women (50%). The IC was detected in 78 patients, more frequently in women (80%) than in men (76%). Measurements were taken in millimeters. The mean measurements for the two sides and for men and women combined were as follows: BIC = 10.0, BAIC = 4.0, LAIC = 6.2, ICL = 19.9, and DIAM = 1.4. CONCLUSIONS: The measurements show the need for care from professionals when performing intraosseous surgical procedures in the mental region. The distances between the IC and the references studied must be observed. Thus, CBCT becomes essential for surgical planning in the mental region. CLINICAL RELEVANCE: The mental region of the mandible is considered a safe area to perform surgical procedures such as the placement of osseointegrated implants, orthognathic surgery, and the removal of bone grafts. However, this region includes important neurovascular structures that must be considered or else hemorrhage and neurologic disorders can be experienced.

The use of platelet-rich fibrin as a hemostatic material in oral soft tissues.

The control of postoperative bleeding represents one of the main intercurrent events associated with soft tissue surgical procedures in the oral cavity. In this context, platelet-rich fibrin (PRF) membranes are materials with great potential for optimizing soft tissue healing and induction of hemostasis. This interventional case series describes the treatment of 10 patients with excisional biopsy of benign oral cavity lesions, following a screening sequence at the surgery clinic of a Brazilian dental school between the years of 2015 and 2017. After treatment with PRF, patients presented mean time for postoperative hemostasis of 10.3 ± 2.5 s, requiring the average use of three membranes to cover the surgical area. The results suggest that the use of platelet-rich fibrin membranes may represent a feasible alternative hemostatic material for the treatment of oral lesions.

Tratamento da osteonecrose dos maxilares associada aos bifosfonatos: revisão da literatura / Treatment of bisphosphonate related osteonecrosis of the jaw: literature review

A osteonecrose dos maxilares associada aos bifosfonatos(OAB) é uma condição que afeta pacientes que receberamtratamento com estes medicamentos. Sendo principalmenteutilizados no tratamento de neoplasias malignas ósseas, doençade Paget e mais comumente nos casos de osteoporose pósmenopausa.O mecanismo pelo qual os bifosfonatos promovemtal fenômeno ainda é desconhecido. O tipo de bifosfonato, a viade administração, bem como a duração do tratamento com essasdrogas parece ter relação direta com a incidência de OAB. Oobjetivo deste trabalho foi revisar alguns aspectos importantesdesta condição reforçando sua abordagem terapeutica.