Surface EMG analysis of clenching and chewing showed that fixed implant-supported prostheses and implant overdentures were functionally equivalent. Neuromuscular coordination during chewing was inferior to that found in subjects with natural dentition.

The technique of guided tissue regeneration using expanded polytetrafluoroethylene (ePTFE) membranes has been shown to be effective in implant dentistry (bony defects, extremely thin alveolar ridges, and implants placed in fresh extraction sockets). One of the drawbacks associated with the use of membranes is their premature exposure with consequent bacterial contamination. The aim of this study was to examine the possibility that oral bacteria migrate through the occlusive portion of ePTFE membranes and to determine the time needed for microorganisms to pass from the outer surface to the inner surface of the membranes. A removable acrylic device was adapted to the molar-premolar region of one quadrant of the jaws in each of three volunteers. Five cylindrical teflon chambers were glued to the buccal aspect of each device. The chambers were divided into two rooms separated by the inner portion of a ePTFE membrane. The outer room was open to the oral cavity allowing plaque accumulation; the inner room was isolated from the oral cavity by the ePTFE membrane. One of the 5 chambers was completely closed and used as control. The test period lasted for 4 weeks. Every week, one chamber was removed from each device and processed for scanning electron microscopic and histologic examinations. Our study showed the possibility that oral bacteria may contaminate ePTFE membranes exposed to the oral cavity. One specimen showed partial bacterial penetration after 2 and 3 weeks, but after 4 weeks, all membrane specimens demonstrated bacterial contamination.(ABSTRACT TRUNCATED AT 250 WORDS)

A lack of information exists about the influence of different implant abutment materials on bacterial colonization and its role in the development of perimplantar infections. In order to study these aspects, removable acrylic devices, harboring samples of titanium and novel ceramic abutments (Nobel Biocare) were adapted to the molar-premolar region in 2 mandibular quadrants of 4 volunteers. Samples of each material were collected at 6 and 24 h, 7 and 14 days. Samples were observed by scanning electron microscopy and bacterial counts were made by means of ATP detection and direct plate count. The electron micrographs demonstrated that the bacteria colonization was already present after 6 h of presence in the oral cavity. After 24 h, both the materials were covered by several layers of bacterial cells. No differences in microbial colonization were observed between titanium and ceramic samples. The microbiological analysis confirmed the presence of relevant amounts of microbial cells on the tested samples. The maximum of colonization was achieved after 24 h in the oral cavity and the bacterial counts remained constant over the 14 day period. No significant differences were observed between the two materials analyzed in this study. In addition, ATP-bioluminescence technology was demonstrated to be a suitable system to evaluate bacterial colonization in the oral cavity.

BackgroundThe aim of this paper is to contribute to the discussion on how to approach patients taking new orally administered anticoagulants (NOAs) dabigatran etexilate (a direct thrombin inhibitor), rivaroxaban and apixaban (factor Xa inhibitors), before, during and after dental treatment in light of the more recent knowledges.DiscussionIn dentistry and oral surgery, the major concerns in treatment of patients taking direct thrombin inhibitors and factor Xa inhibitors is the risk of haemorrhage and the absence of a specific reversal agent. The degree of renal function, the complexity of the surgical procedure and the patient’s risk of bleeding due to other concomitant causes, are the most important factors to consider during surgical dental treatment of patients taking NOAs. For patients requiring simple dental extraction or minor oral surgery procedures, interruption of NOA is not generally necessary, while an higher control of bleeding and discontinuation of the drug (at least 24 h) should be requested before invasive surgical procedures, depending on renal functionality.SummaryThe clinician has to consider that the number of patients taking NOAs is rapidly increasing. Since available data are not sufficient to establish an evidence-based dental management, the dentist must use caution and attention when treating patients taking dabigatran, rivaroxaban and apixaban.

Objectives The aim of this prospective comparative clinical study was to evaluate the effect of oral anticoagulants on peri-and post-operative bleeding during simple single tooth extractions, comparing patients in treatment with vitamin K antagonists (VKAs) and patients assuming direct oral anticoagulants (DOACs). Materials and methods Patients under oral anticoagulant therapy needing dental extraction were eligible for entering the study; patients were enrolled following inclusion and exclusion criteria and divided into VKAs and DOAC group according to the anticoagulation therapy. Included patients underwent a simple single dental extraction with elevators and forceps with a maximum surgical time of 15 minutes, without anticoagulation therapy discontinuation. All participants were assessed pre-operatively, during surgery, 30 min minutes and 7 days after surgery. Biological complications were registered and post-extraction bleeding was clinically defined according to Iwabuchi classification. Parametric and non-parametric tests were used to evaluate the variables between the groups. Results Sixty-five patients per group were enrolled and 130 teeth were extracted. The two groups were comparable for pre-, peri-, and post-operative variables. Only 1 patient of DOAC group and 2 patients for VKA group needed medical evaluation for postextractive bleeding. No statistically significant difference resulted in post-operative bleeding events between the groups (p = 0.425). Conclusions DOAC and VKA patients showed the same incidence of bleeding complications after simple single tooth extraction. Bleeding events were not statistically significant and not clinically relevant. Clinical relevance Patients assuming DOACs can be treated similarly to patients in VKAs therapy with INR index between 2 and 3. Non-ceasing of DOAC therapy seems to be appropriate for simple single dental extractions. KeywordsDirect oral anticoagulants . DOAC . Novel oral anticoagulants . NOAC . Simple single tooth extraction . Bleeding risk * Federico Berton

Background Neurological involvement is a serious complication associated to the surgical removal of impacted mandibular third molars and the radiological investigation is the first mandatory step to assess the risk of a possible post-operative injury to the inferior alveolar nerve (IAN). The aim of this study was to introduce a new radiological classification that could be normally used in clinical practice to assess the relationship between an impacted third molar and mandibular canal on cone beam CT (CBCT) images. Material and Methods CBCT images of 80 patients (133 mandibular third molars) were independently studied by three members of the surgical team to draw a classification that could describe all the possible relationships between third molar and IAN on the cross-sectional images. Subsequently, the study population was subdivided according to this classification. The SPSS software, version 15.0 (SPSS® Inc., Chicago, Illinois, USA) was used for the statistical analysis. Results Eight different classes were proposed (classes 0-7) and six of them (classes 1-6) were subdivided in two subtypes (subtypes A-B). The distribution of classes showed a prevalence of buccal or apical course of the mandibular canal followed by lingual position and inter-radicular one. No differences have resulted in terms of anatomic relationship between males and females apart from a higher risk of real contact without corticalization of the canal when the IAN had a lingual course for female group. Younger patients showed an increased rate of direct contact with a reduced calibre of the canal and/or without corticalization. Conclusions The use of this classification could be a valid support in clinical practice to obtain a common language among operators in order to define the possible relationships between an impacted third molar and the mandibular canal on CBCT images. Key words:CBCT, classification, inferior alveolar nerve, third molars.

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The aim of this systematic review was to evaluate the clinical effectiveness of the surgical technique of coronectomy for third molars extraction in close proximity with the inferior alveolar nerve.A literature survey carried out through PubMed, SCOPUS and the Cochrane Library from inceptions to the last access in January 31, 2014, was performed to intercept randomised clinical trials, controlled clinical trials, prospective cohort studies or retrospective studies (with or without control group) that examined the clinical outcomes after coronectomy. The following variable were evaluated: inferior alveolar nerve injury, lingual nerve injury, postoperative adverse effects, pulp disease, root migration and rate of reoperation. Ten articles qualified for the final analysis. The successful coronectomies varied from a minimum of 61.7% to a maximum of 100%. Coronectomy was associated with a low incidence of complications in terms of inferior alveolar nerve injury (0%-9.5%), lingual nerve injury (0%-2%), postoperative pain (1.1%-41.9%) and swelling (4.6%), dry socket infection (2%-12%), infection rate (1%-9.5%) and pulp disease (0.9%). Migration of the retained roots seems to be a frequent occurrence (2%-85.3%).Coronectomy appears to be a safe procedure at least in the short term, with a reduced incidence of postoperative complications. Therefore, a coronectomy can be indicated for teeth that are very close to the inferior alveolar nerve. If a second operation is needed for the remnant roots, they can be removed with a low risk of paresthesia, because the roots are generally receded from the mandubular nerve.