Emerging factors affecting peri-implant bone metabolism.

Implant dentistry has evolved to the point that standard implant osseointegration is predictable. This is attributed in part to the advancements in material sciences that have led toward improvements in implant surface technology and characteristics. Nonetheless, there remain several cases where implant therapy fails (specifically at early time points), most commonly attributed to factors affecting bone metabolism. Among these patients, smokers are known to have impaired bone metabolism and thus be subject to higher risks of early implant failure and/or late complications related to the stability of the peri-implant bone and mucosal tissues. Notably, however, emerging data have unveiled other critical factors affecting osseointegration, namely, those related to the metabolism of bone tissues. The aim of this review is to shed light on the effects of implant-related factors, like implant surface or titanium particle release; surgical-related factors, like osseodensification or implanted biomaterials; various drugs, like selective serotonin reuptake inhibitors, proton pump inhibitors, anti-hypertensives, nonsteroidal anti-inflammatory medication, and statins, and host-related factors, like smoking, diet, and metabolic syndrome on bone metabolism, and aseptic peri-implant bone loss. Despite the infectious nature of peri-implant biological complications, these factors must be surveyed for the effective prevention and management of peri-implantitis.

Influence of Implant Length and Associated Parameters Upon Biomechanical Forces in Finite Element Analyses: A Systematic Review.

PURPOSE: The aim of this systematic review is to provide an overview of finite element analyses comparing standard and short dental implants concerning biomechanical properties and to detect the most relevant parameters affecting periimplant stress concentrations. MATERIAL AND METHODS: After screening the literature and assessment of studies, 36 studies were included in this review. RESULTS: Eighty-three percent of the studies state that short dental implants have to bear higher stress concentrations compared with standard length implants. At the same time, 44% of articles note that implant diameter can be considered a more effective design parameter than implant length to reduce stress concentrations and to avoid an overload of periimplant bone. Regardless of implant dimension, in all studies, the highest stress concentrations are found in the cortical section around the upper part of the implant. CONCLUSIONS: Unaffected of bone quality, implant diameter is found to play a key role to minimize periimplant stress concentrations. Concerning stress reduction implant length gains increasing relevance with decreasing bone density. Furthermore, splinting of short implants constitute an appropriate tool to avoid crestal overloading.

Diagnostic accuracy of the implant stability quotient in monitoring progressive peri-implant bone loss: An experimental study in dogs.

OBJECTIVES: To investigate the impact of progressive bone loss in an experimental peri-implantitis model in the dog upon the implant stability quotient (ISQ) measured in the course of induced and spontaneous conditions of disease, and to evaluate the association between the clinical parameters and ISQ. MATERIALS AND METHODS: Seventy-two implants were placed in 12 Beagle dogs. Of these, 36 implants in six dogs were assessed during ligature-induced peri-implantitis (three timepoints) and at one timepoint following a period of spontaneous progression. The ISQ was recorded using resonance frequency analysis (RFA). Furthermore, the clinical peri-implant parameters were registered at four sites per implant at each timepoint. Marginal bone loss (MBL) was determined using computed tomography at four sites per implant and bone-to-implant contact (BIC) was assessed from histological samples. A linear regression model was estimated by generalized estimation equations (GEEs) in order to study the MBL-ISQ values at each measurement timepoint. Pearson's correlation test was applied. RESULTS: None of the implants failed during the study period. At implant level, a strong negative correlation was found for all timepoints between ISQ and MBL (r = -0.58; p < 0.001). Accordingly, as follow-up progressed, lower ISQ and higher MBL values were observed. A prediction of MBL depending on the ISQ values and timepoints showed a decrease in one ISQ unit to be related to ~1 mm of MBL. Likewise, a statistically significant correlation was found between BIC and ISQ evaluated after spontaneous chronification of peri-implantitis (r = 0.34; p = 0.04). Nevertheless, the ISQ values failed to correlate to any of the clinical parameters recorded. CONCLUSION: Resonance frequency analysis seems accurate in diagnosing progressive bone loss, as a statistically significant decrease in ISQ was recorded in the course of peri-implant disease. Nevertheless, the clinical relevance of this observation as a diagnostic tool is debatable, since implant stability remains high.

Association of Inflammatory Status and Maxillary Sinus Schneiderian Membrane Thickness.

OBJECTIVES: Certain Schneiderian membrane thicknesses (SMT) have shown to be more prone to tearing/perforation, and some pathologies might influence SMT. Henceforth, we aimed at studying the correlation of inflammatory status to SMT in human fresh cadaver heads. MATERIAL AND METHODS: A total of 14 fresh cadaver heads including 27 Schneiderian membrane specimens were histologically collected. A 10-item inflammatory score was determined in the entire sample and also in the thinner and thicker areas of each sample. Data was analyzed by using the Wilcoxon rank test and the Spearman's rank correlation. RESULTS: The mean measured SMT was 0.40 ± 0.12 mm and the median was 0.33 ± 0.12 mm. A weak positive correlation was found between the mean SMT and inflammation score without a statistical significance. (r = 0.385, p = 0.115). The Wilcoxon signed-rank test showed a statistical difference between the medians of the thinner and thicker areas (p < 0.001). The mean inflammation score of the thinner and thicker areas was 8.55 ± 2.57 and 11.61 ± 2.65, respectively. A moderate positive and statistically significant correlation was found between the inflammation score and the thickness of the thinner and thicker areas (r = 0.638, p = 0.000). CONCLUSION: A moderate association between the Schneiderian membrane thickness and the level of inflammation exists.

Mechanical characteristics of the maxillary sinus Schneiderian membrane ex vivo.

OBJECTIVES: It has been speculated that certain Schneiderian membrane thickness (SMT) might be more prone to perforation. This investigation was aimed at studying the mechanical characteristics of the Schneiderian membrane under one- and two-dimensional tests and their correlation to the histological SMT in human samples. MATERIAL AND METHODS: Sixteen Schneiderian membranes were collected from 11 cadaver heads treated with Thiel's embalming method. The samples were processed and analyzed clinically and histologically. One-dimensional maximum elongation until perforation and two-dimensional resistance to ball penetration were performed after the biopsy. Data was analyzed by using the Wilcoxon rank test and the Spearman's rank correlation. RESULTS: The histological SMT was 1.36 ± 0.42 mm, whereas the clinical thickness was 0.27 ± 0.21 mm, yielding statistical significance (p = 0.000). The resistance under ball penetration was 0.59 ± 0.43 N and the mean maximum elongation in the one-dimension test 11.19 ± 7.14 mm. Expressed in percentage, the mean stretch was 241.36 ± 227.97% (range 31.5 up to 947%). A weak positive correlation was found between the ball penetration test and the SMT (r = 0.10, p = 0.711), while a weak negative correlation was found between stretching test and the SMT (r = -0.021, p = 0.94). CONCLUSIONS: Mechanical tests seem to indicate that SMT might not significantly predispose to Schneiderian membrane perforation. Hence, other anatomical and operator's factors should be considered of surpassing importance. CLINICAL RELEVANCE: Thinner SM might be more prone to perforation when detaching it from the maxillary sinus antrum; however, a thick membrane is not prevented to tear, as their resistance under elastic forces is not higher than thinner ones.

Accuracy of Schneiderian membrane thickness: a cone-beam computed tomography analysis with histological validation.

OBJECTIVES: Cone-beam computed tomography (CBCT) has been used in the literature to evaluate Schneiderian membrane thickness (SMT), but its accuracy has never been validated. The primary aim of this study was to compare the SMT measured by CBCT to the gold standard histological assessment. The correlations between SMT and anatomical structures of the maxillary sinus and alveolar bone were also tested. MATERIALS AND METHODS: Fourteen fresh cadaver heads were used for the study, and 28 sinus lift augmentation procedures were performed to obtain the membrane samples. Samples were fixed in formalin and stained with hematoxylin-eosine and Masson trichrome. Specimens were measured by optic microscope at three points, and a mean was obtained. Anatomical landmarks were used to accurately position the CBCT slice, so the SMT could be measured in predetermined locations. Wilcoxon signed-rank test was used to compare values of histological and CBCT measurements, and Spearman's correlation coefficient was calculated to examine the relationship between thickness and anatomical parameters. RESULTS: A total of 597 histological measurements were performed, and the mean SMT thickness was 0.30 ± 0.17 mm. The mean CBCT membrane thickness was 0.79 ± 0.52 mm. A statistically significant difference from histological and radiological readings was observed (P = 0.000). Interestingly, 87.77% histological measurements had membrane less than 0.5 mm in thickness compared to 26.66% in CBCT assessment. CONCLUSIONS: Within the limitation of this study, the median histological Schneiderian membrane thickness was 0.30 mm. Cone-beam computed tomography assessment was 2.6 times higher than the histological examination.

Web-Based Information on the Treatment of Tobacco Dependence for Oral Health Professionals: Analysis of English-Written Websites.

BACKGROUND: Studies have been conducted on the content and quality of Web-based information for patients who are interested in smoking cessation advice and for health care practitioners regarding the content of e-learning programs about tobacco cessation. However, to the best of our knowledge, there is no such information about the quality of Web-based learning resources regarding smoking cessation dedicated to oral health professionals. OBJECTIVE: The aim of this study was to identify and evaluate the quality of the content of webpages providing information about smoking cessation for oral health care professionals. METHODS: Websites were identified using Google and Health on Net (HON) search engines using the terms: smoking cessation OR quit smoking OR stop smoking OR 3As OR 5As OR tobacco counselling AND dentistry OR dental clinic OR dentist OR dental hygienist OR oral health professionals. The first 100 consecutive results of the 2 search engines were considered for the study. Quality assessment was rated using the DISCERN questionnaire, the Journal of the American Medical Association (JAMA) benchmarks, and the HON seal. In addition, smoking cessation content on each site was assessed using an abbreviated version of the Smoke Treatment Scale (STS-C) and the Smoking Treatment Scale-Rating (STS-R). To assess legibility of the selected websites, the Flesch Reading Ease (FRES) and the Flesch-Kinkaid Reading Grade Level (FKRGL) were used. Websites were also classified into multimedia and nonmultimedia and friendly and nonfriendly usability. RESULTS: Of the first 200 sites selected (100 of Google and 100 of HON), only 11 met the inclusion criteria and mainly belonged to governmental institutions (n=8), with the others being prepared by Professional Associations (n=2) and nonprofit organizations (n=1). Only 3 were exclusively dedicated to smoking cessation. The average score obtained with the DISCERN was 3.0, and the average score in the FKRGL and FRES was 13.31 (standard deviation, SD 3.34) and 40.73 (SD 15.46), respectively. Of the 11 websites evaluated, none achieved all the four JAMA benchmarks. The mean score of STS-R among all the websites was 2.81 (SD 0.95) out of 5. A significant strong positive correlation was obtained between the DISCERN mean values and the STS-R (R=.89, P=.01). CONCLUSIONS: The mean quality of webpages with information for oral health care professionals about smoking cessation is low and displayed a high heterogeneity. These webpages are also difficult to read and often lack multimedia resources, which further limits their usefulness.

Available web-based teaching resources for health care professionals on screening for oral cancer.

OBJECTIVES: To identify websites with adequate information on oral cancer screening for healthcare professionals (HCPs) and to assess both their quality and contents. STUDY DESIGN: Websites were identified using Google and HON medical professional search engines using the terms "screening for oral cancer". The first 100 sites retrieved by each engine were analysed using the DISCERN questionnaire (reliability), the V instrument (contents on oral cancer) and further by the Flesch-Kinkaid Reading Grade Level and the Flesch Reading Ease (readability). RESULTS: The overall rating showed minimal shortcomings in the quality of the information in the websites. The coverage and correctness of information on "visual examination" was rated as fair/good, whereas updating of contents resulted very variable (eg: 81% for visual examination and 18.2% for molecular biomarkers). These results permitted to rank the websites housing relevant information for oral cancer. Top ranking websites were affiliated to the Oral Cancer Foundation (USA), WHO Collaborating Centre for oral cancer (UK) whose webpage is entitled "Oral Cancer Education and Research", and the Clinical Guidelines maintained by the British Columbia Cancer Agency (Canada) and the British Dental Association (UK) respectively. CONCLUSIONS: There are web-based, HCP-addressed, resources on screening for oral cancer housing heterogeneous information both in quality and contents. The use of specific evaluation tools permits the selection of reliable websites on this topic with a potential to improve the existing educational gaps among HCPs.

Clinical Implications of Buccinator Fiber Attachment on Interventions Aiming at Enhancing the Peri-Implant Keratinized Mucosa: An Ex-Vivo Study.

A clinical observation usually encountered after vestibuloplasty or interventions aiming at deepening the vestibule with or without simultaneous free epithelialized grafts in the posterior ridges is that they are subjected to major dimensional changes attributed to the buccinator fibers attachment. Hence, this study aimed at assessing the attachment of the buccinator muscles in relation to other anatomical landmarks. An ex-vivo study was performed in cadaver heads to explore the association of fibers attachment in relation to the distance from the crestal aspect of edentulous alveolar process (CAP) and the vestibular depth (VD), crestal band of keratinized mucosa (KM), and ridge height (RH). Interestingly, VD and KM were found to be strongly correlated. Likewise, VD/KM and CAP-BUC were further noted being correlated. CAP-BUC was negatively correlated with RH. Accordingly, the more atrophic the alveolar ridge (being more noticeable in the mandible) is, the shallower the vestibule, the lesser the crestal band of KM and the more crestal attachment of the buccinator muscular fibers. That might be the reason why whenever performing free epithelized graft in the posterior ridges to enhance the peri-implant soft tissue phenotype and deepening the vestibule, the graft is subjected to major dimensional changes.

Diagnostic Accuracy of Cone Beam Computed Tomography in Identifying Peri-implantitis-Like Bone Defects Ex Vivo.

This pilot study aimed to assess the diagnostic accuracy of CBCT in identifying peri-implantitis-like bone defects in cadavers. Three cadaver dental arches treated with the Thiel embalming method were used. Three different types of peri-implant bone defects (buccal dehiscence, two- to three-wall defects, and circumferential defects) were prepared on 15 implants. Defect depths and lengths were identified clinically using a periodontal probe, radiologically by means of CBCT images, and histologically with a micrometer using an optic microscope. Peri-implant bone defect morphology evaluated using CBCT images matched the clinical defect configuration (100% accuracy). CBCT assessment demonstrated lower values in defect depth and defect length when compared with the clinical evaluation. A statistically significant difference in defect depth (0.35 ± 0.45 mm; P = .037) was recorded between the clinical and CBCT data. Regarding defect length, a statistically significant mean difference of 0.81 ± 0.83 mm (P = .003) was noted between the clinical and CBCT data. Similarly, a mean difference of 1.09 ± 1.52 mm was recorded between the defect length assessed histologically and the CBCT data (P = .031). No statistically significant differences were observed between the other evaluated variables. CBCT is a reliable tool for peri-implantitis diagnosis and treatment planning, though the underestimation of defect severity may affect the prognosis and clinical decision-making. Clinicians need to be flexible in establishing prognoses and treatment based on CBCT assessment.

Nestin Expression Is Associated with Relapses in Head and Neck Lesions.

BACKGROUND: The aim was to investigate the clinical significance of nestin immunohistochemical expression in head and neck area lesions and to study its role in patient survival and recurrence. METHODS: 39 (44.3%) nasosinus, 37 (42%) major salivary gland (6 submandibular and 31 parotid) and 12 (13.6%) oral cavity lesions of paraffin-embedded samples were retrospectively included. RESULTS: The expression was categorized into grades, negative for 55 (62.5%) cases, grade 1 in 10 cases (11.4%), grade 2 in 12 cases (13.6%), and grade 3 in 11 cases (12.5%); 100% of pleomorphic adenomas were positive for nestin with grade 3 intensity, 100% of polyps and inverted papillomas were negative (p < 0.001). The lowest estimate of disease-free-survival (DFS) was for grade 1 expression, with 50 months, confidence interval (CI): 95% 13.3-23.9 months and the highest for grade 3 expression, 167.9 months (CI: 95% 32.1-105 months; Log-Rank = 14.846, p = 0.002). ROC (receiver operating characteristic) curves revealed that the positivity for nestin (+/-) in relation to malignancy, presented a sensitivity of 50.98%, a specificity of 81.08%, with an area under the curve of 0.667 (p = 0.009). CONCLUSIONS: Nestin could be a useful marker to detect the presence of stem cells in head and neck tumors that have a role in tumor initiation and progression.

Understanding Peri-Implantitis as a Plaque-Associated and Site-Specific Entity: On the Local Predisposing Factors.

The prevalence of implant biological complications has grown enormously over the last decade, in concordance with the impact of biofilm and its byproducts upon disease development. Deleterious habits and systemic conditions have been regarded as risk factors for peri-implantitis. However, little is known about the influence of local confounders upon the onset and progression of the disease. The present narrative review therefore describes the emerging local predisposing factors that place dental implants/patients at risk of developing peri-implantitis. A review is also made of the triggering factors capable of inducing peri-implantitis and of the accelerating factors capable of interfering with the progression of the disease.

Morphology and severity of peri-implantitis bone defects.

BACKGROUND: Peri-implant defect morphology has shown to potentially impact upon the reconstructive outcomes for the management of peri-implantitis. Given the role that defect morphology plays upon the decision-making in the treatment of peri-implantitis, the present study aimed at assessing the morphology and severity of peri-implantitis bone defects and to insight on the patient-, implant- and site-related variables associated to these. MATERIAL AND METHODS: A cone-beam computed tomography study was carried out to classify peri-implantitis defects according to the type of defect, number of remaining bony walls and severity according to the extension of vertical bone loss. Three major defect categories were proposed: class I-infraosseous; class II-horizontal; class III-combined of class I and II. These were then subclassified into: (a) dehiscence; (b) 2/3-wall; and (c) circumferential-type defect. According to the severity the defects were further subclassified into: A: advanced; M: moderate; and S: slight. In addition, 20 site-, implant-, and patient-related variables were analyzed by generalized estimating equations (GEEs) of multilevel logistic regression models. RESULTS: Based on an a priori power calculation, 332 implants were screened in 47 peri-implantitis patients. Of these, 158 peri-implantitis implants were eligible. The most prevalent defect morphology type was class Ib (55%) followed by class Ia (16.5%), and class IIIb (13.9%). On the contrary, the less frequent defect was class II (1.9%). The most frequent degree of severity was M (50.6%) with S (10.1%) being the least prevalent. Buccal bone loss was significantly greater compared to the other bony walls in class I and class III defects. Age was associated with the type of defect. Age and smoking habit were associated with the morphology of the defects, while smoking habit, type of prosthesis and distance to adjacent implant were associated with the severity of the defects (vertical bone loss). CONCLUSION: Peri-implantitis defects frequently course with an infraosseous component and often with buccal bone loss. Certain patient-, implant-, and site-specific variables are related with defect morphology and severity. However, morphological patterns for peri-implantitis bone defects could not be proven (NCT NCT03777449).

Estimation of the diagnostic accuracy of clinical parameters for monitoring peri-implantitis progression: An experimental canine study.

BACKGROUND: Lack of consensus on the clinical parameters of peri-implantitis may complicate accurate diagnosis of the disorder. Furthermore, the lack of reliable estimates of the diagnostic capacity of the clinical endpoints precludes the definition of an effective treatment protocol for peri-implantitis. The present canine study assesses the diagnostic accuracy of the clinical parameters for monitoring the peri-implant tissues in a controlled ligature-induced peri-implantitis model followed by a spontaneous progression phase. METHODS: Six beagle dogs were followed-up on during three episodes of ligature-induced peri-implantitis and a further episode of spontaneous progression. Probing depth (PD), bleeding on probing (BOP), mucosal recession (MR), and suppuration (SUP) were recorded at four sites per implant and at four study timepoints. Moreover, the implant mucosal index (IMI) was calculated at implant level. Marginal bone loss (MBL) was determined using computed tomography at four sites per implant. A linear regression model was used to estimate clinical and radiological parameters during peri-implantitis progression. RESULTS: Progressive peri-implant bone loss is characterized by an increase in PD, more profuse BOP, MR, and SUP in advanced cases (p < 0.001). However, even in the presence of severe bone loss, SUP was not a common finding, with an incidence of approximately 10% at the last timepoint. These clinical parameters were significantly correlated to MBL at most of the timepoints. The IMI, in turn, showed a positive correlation to MBL and the peri-implant inflammatory signs (r = 0.39; p < 0.001), with a tendency to exhibit higher scores during ligature-induced peri-implantitis, followed by a slight decrease during the spontaneous progression period. CONCLUSION: The clinical features of peri-implantitis and spontaneous progression of the disorder may facilitate an accurate monitoring of peri-implant pathologic bone loss.

Impact of Sex, Age, and Season on Sinus Membrane Thickness.

PURPOSE: Sinus membrane thickness has been associated with the incidence of membrane perforation during the sinus elevation procedure. Understanding the sinus membrane thickness is essential for prevention of this specific surgical complication. Therefore, the aim of this retrospective study was to investigate the impact of sex, age, and season on the membrane thickness. MATERIALS AND METHODS: The charts of 144 healthy patients were included in the study. Cone beam computed tomography (CBCT) images from these patients were analyzed to determine the sinus membrane thickness in the coronal and sagittal views. Sex, age, and season were correlated with the membrane thickness. RESULTS: The mean thickness of the sinus membrane was 1.81 ± 1.66 mm (range: 0.47 to 9.49 mm). In 22.12% of the CBCT images, the sinus membrane was not visible. Membrane thickness of less than 2 mm was found in 70.8% of the cases. Age was found to be strongly correlated (P < .05) with sinus membrane thickness but not sex or season. CONCLUSION: Based on CBCT assessment, age was found to be a factor influencing sinus membrane thickness but not sex or season.

Patient-Centered Perspectives and Understanding of Peri-Implantitis.

BACKGROUND: Patients undergoing dental treatment have an uncertain understanding about dental implant therapy and its complications. Therefore, the aims of this study assess the following: 1) level of knowledge, awareness, and attitudes about peri-implantitis; 2) information provided by dentists/specialists who perform the treatment; and 3) perceptions, level of satisfaction, and impact on patient quality of life (QoL). METHODS: Patients with implant restorative therapy currently undergoing peri-implant maintenance therapy were recruited. Participants completed an anonymous questionnaire that included general aspects of prognosis, including the following: 1) peri-implantitis; 2) etiology; 3) awareness; 4) attitudes; 5) treatment; 6) prevention; 7) risk factors; 8) quality of information; 9) level of patient satisfaction; and 10) QoL. Associations among questionnaire data were identified using univariate and multivariate analyses. RESULTS: Overall, 411 implants were included from 135 patients with implants. Frequency of peri-implantitis in the survey was 17.8% at the participant level, with 70% of them reporting high level of post-surgical satisfaction. Worry and concern were frequent findings among patients with peri-implantitis (64%), and 32% reported that living with the disease was terrible. The vast majority of patients (74.1%) did not have knowledge about peri-implant pathology. Patients with peri-implantitis showed statistically significantly better understanding of implant therapy (P <0.001) and also higher average concern (P = 0.004). CONCLUSIONS: Patients generally have a poor understanding and perception of peri-implantitis and its impact. QoL was impaired by the presence of peri-implantitis with high level of concern and low level of therapeutic satisfaction. Therefore, it is important to develop standardized information brochures to educate patients on risk factors and indicators of the disease to assist in the prevention of peri-implantitis.

Basis of bone metabolism around dental implants during osseointegration and peri-implant bone loss.

Despite the growing number of publications in the field of implant dentistry, there are limited studies to date investigating the biology and metabolism of bone healing around dental implants and their implications in peri-implant marginal bone loss. The aim of this review article is to provide a thorough understanding of the biological events taking place during osseointegration and the subsequent early and late phases of bone remodeling around dental implants. An update on the coupling mechanism occurring during bone resorption-bone remodeling is provided, focused on the relevance of the osteocytes, bone lining cells and immune cells during bone maintenance. An electronic and manual literature search was conducted by three independent reviewers in several databases, including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register databases for articles up to September 2016 with no language restriction. Local bone metabolism is subject to signals from systemic calcium-phosphate homeostasis and bone remodeling. Three areas of interest were reviewed due to recent reported compromises in bone healing including the putative effects of (1) cholesterol, (2) hyperlipidemia, and (3) low vitamin D intake. Moreover, the prominent influence of osteocytes and immune cells is discussed as being key regulators during dental implant osseointegration and maintenance. These cells are of crucial importance in the presence of biofilm accumulation and their associated byproducts that leads to hard and soft tissue breakdown; the so called peri-implantitis. Factors that could negatively impact osteoclastogenesis or osteal macrophage activation should be monitored in future research including implant placement/torque protocols, bone characteristics, as well as meticulous maintenance programs to favor osseointegration and future long-term stability and success of dental implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2075-2089, 2017.

The Sinus Membrane-Maxillary Lateral Wall Complex: Histologic Description and Clinical Implications for Maxillary Sinus Floor Elevation.

Maxillary sinus floor elevation has been documented as a safe and predictable procedure for gaining vertical bone height in the atrophic posterior maxillae. Conversely, there is a lack of basic research on the characteristics of the union between the sinus membrane (SM) and the bone. Clinical implications of an impaired union in healthy or pathologic membranes remain unknown. The objective of this study was to present a comprehensive histologic and morphologic description of the sinus membrane-lateral bone wall complex. In 14 fresh cadaver heads, 28 lateral wall sinus augmentation procedures were performed to obtain SM samples. Samples were assessed using hematoxylin-eosin, Masson trichrome, and toluidine blue staining and immunofluorescence and immunohistochemistry procedures. Specimens were coded and studied by a trained examiner using an optical microscope at ×4, ×10, ×40, and ×100 objectives. Thickness and inflammation status were assessed in these samples. Overall SM thickness of the samples was 0.40 ± 0.12 mm and was positively correlated to the inflammatory condition of the membranes. Such low values are the consequence of limited inflammation. Most of the fibers and cells in the deeper layers of the SM ran in a horizontal direction, oriented parallel to the underlying bone wall. In the immunohistochemistry study, 3 out of 7 samples showed a certain degree of nestin expression, suggesting osteogenic potential in spite of the elderly specimens. Large variations in thickness across the SM were found. These were noted to be partially correlated to the SM inflammatory status. The vast majority of the fibers were oriented parallel to the maxillary lateral wall, and only a few isolated areas showed a stronger perpendicular attachment. This might indicate the surpassing importance of the SM inflammatory status, operator skill, and other anatomical factors over the sinus membrane-maxillary lateral wall complex interface. Moreover, about half of the SM investigated were positive for nestin, indicating their osteogenic potential.

Schneiderian Membrane Thickness and Clinical Implications for Sinus Augmentation: A Systematic Review and Meta-Regression Analyses.

BACKGROUND: Schneiderian membrane thickness (SMT) has been regarded as a key factor for influencing membrane perforation, which may jeopardize the final clinical outcome of sinus augmentation. Hence, this systematic review aims at studying the mean SMT and further investigating patient-related factors that may affect SMT. As a secondary goal, the association between SMT and membrane perforation rate was studied. METHODS: Three independent reviewers in several databases, including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register databases, conducted electronic and manual literature searches. This review was written and conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and MECIR (Methodological Expectations of Cochrane Intervention Reviews) guidelines. Quantitative assessment was performed for articles that met the inclusion criteria to investigate the mean SMT, its contributing factors, and the influence on membrane damage and surgical complications. RESULTS: Thirty-one studies that reported maxillary SMT were considered for qualitative analysis. Nineteen were further meta-analyzed. Overall mean ± SE SMT was 1.17 ± 0.1 mm (95% confidence interval [CI] = 0.89 to 1.44). Although mean SMT for the three-dimensional radiography (3DR) group was 1.33 mm (95% CI = 1.06 to 1.60), for the histology group, it was 0.48 mm (95% CI = 0.12 to 1.1). Random-effects model showed that, although there is a trend for thicker SMT as determined using 3DR compared with histologic analysis, such difference did not reach statistical significance (P = 0.15). Also, regression analyses demonstrated that the variables periodontitis (P = 0.13) and smoking (P = 0.11) showed thicker SMT. Inconclusive data were obtained when correlating SMT and perforation rate, although it seems that thicker SMT might be more prone to perforation (P = 0.14). CONCLUSIONS: SMT is, on average, 1 mm in patients seeking sinus augmentation. Three-dimensional technologies overestimate approximately 2.5 times SMT when compared with histologic analysis. Periodontitis and smoking may result in thickening of the sinus membrane. However, current data were inconclusive to link SMT to the rate of membrane damage.

Available web-based teaching resources for health care professionals on screening for oral cancer

OBJECTIVES: To identify websites with adequate information on oral cancer screening for healthcare professionals(HCPs) and to assess both their quality and contents. Study DESIGN: Websites were identified using Google and HON medical professional search engines using the terms "screening for oral cancer". The first 100 sites retrieved by each engine were analysed using the DISCERN questionnaire (reliability), the V instrument (contents on oral cancer) and further by the Flesch-Kinkaid Reading Grade Level and the Flesch Reading Ease (readability).RESULTS: The overall rating showed minimal shortcomings in the quality of the information in the websites. The coverage and correctness of information on "visual examination" was rated as fair/good, whereas updating of contents resulted very variable (eg: 81% for visual examination and 18.2% for molecular biomarkers). These results permitted to rank the websites housing relevant information for oral cancer. Top ranking websites were affiliated to the Oral Cancer Foundation (USA), WHO Collaborating Centre for oral cancer (UK) whose webpage is entitled "Oral Cancer Education and Research", and the Clinical Guidelines maintained by the British Columbia Cancer Agency (Canada) and the British Dental Association (UK) respectively. CONCLUSIONS: There are web-based, HCP-addressed, resources on screening for oral cancer housing heterogeneous information both in quality and contents. The use of specific evaluation tools permits the selection of reliable websites on this topic with a potential to improve the existing educational gaps among HCPs