Effect of 5 Popular Disinfection Methods on Microflora of Laboratory: Customized Implant Abutments.

PURPOSE: To compare the efficacy of 5 different decontamination methods of titanium abutments and to assess their possible effects on surface roughness of titanium. MATERIALS AND METHODS: Micrococcus luteus, Acinetobacter baumannii, Enterococcus faecalis, and Candida albicans were cocultured to form a multispecies biofilm on 18 titanium discs. In another group, Bacillus subtilis, a spore-forming species, was cultivated on another set of 18 titanium discs. Each group was further divided into 5 test groups: high-pressure steam cleaning (4 Mpa, 5 seconds), NaOCl (1% active chlorine, 5 minutes), H2O2 (3%, 5 minutes), GaAlAs laser (810 nm, CW, 1 W, 400-µm fiber, 1-mm distance, 1 minute), Er:YAG laser (2940 nm, pulse mode, 100 mJ, 10 Hz, 230-µm noncontact handpiece, 4-mm distance, 50/50% air/water, 1 minute), and a control group of no treatment. After each decontamination procedure, the remaining microbial load was reported as colony-forming unit/disc. To evaluate the effect of each treatment on titanium discs, surface roughness parameters including Sa, Sq, Ssk, Sku, Sal, and Sdr were measured at 6 points of each disc using an atomic force microscope. RESULTS: Complete disinfection was achieved using high-pressure steam, NaOCl, H2O2, and Er:YAG laser. GaAlAs laser was able to reduce microbial count over 90%. Sa and Sq parameters were only increased significantly in diluted NaOCl group in comparison with control group, whereas Sdr was increased significantly in both absolute and diluted NaOCl groups. CONCLUSION: All the methods could decontaminate machined titanium surfaces, although complete microbial elimination was not achieved by diode laser. None of the treatments altered surface roughness significantly, except for sodium hypochlorite (NaOCl).

Vitamin K and Bone Metabolism: A Review of the Latest Evidence in Preclinical Studies.

Bone is a metabolically active tissue that renews itself throughout one's life. Cytokines along with several hormonal, nutritional, and growth factors are involved in tightly regulated bone remodeling. Accordingly, vitamin K as a multifunctional vitamin has been recently deemed appreciable as a topic of research as it plays a pivotal role in maintenance of the bone strength, and it has been proved to have a positive impact on the bone metabolism. Vitamin K exerts its anabolic effect on the bone turnover in different ways such as promoting osteoblast differentiation, upregulating transcription of specific genes in osteoblasts, and activating the bone-associated vitamin k dependent proteins which play critical roles in extracellular bone matrix mineralization. There is also credible evidence to support the effects of vitamin k2 on differentiation of other mesenchymal stem cells into osteoblast. The main objective of the present paper is to comprehensively outline the preclinical studies on the properties of vitamin K and its effects on the bone metabolism. The evidence could shed light on further clinical studies to improve osteogenesis in bone graft surgeries.

Effect of Semelil, an Herbal Selenium-Based Medicine, on New Bone Formation in Calvarium of Rabbits.

BACKGROUND: This study aims to analyze the effect of Semelil, an herbal selenium-based medicine, on osteogenesis in rabbit calvarium defects. METHODS: Four identical bony defects (8 mm) were created in the calvarium of 16 New Zealand male rabbits and filled randomly with xenogenic bone substitute material (Bio-Oss®) and semelil herbal drug (ANGIPARS™). One site was filled with Bio-Oss (B); the second site was treated with ANGIPARS (A); the third site was treated with ANGIPARS + Bio-Oss (AB); and the fourth site was left as untreated control (C) and defects were left unfilled. Rabbits were randomly divided into two groups (n = 8) and sacrificed at four and eight weeks. Percentage of new bone formation, type of the newly formed bone, percentage of the remaining xenograft biomaterial, and foreign body reaction (FBR) were evaluated via histological and histomorphometric analyses. RESULTS: The percentage of new bone formation was significantly different among four groups. The highest effect was observed in AB, followed by A, B, and C groups, respectively. The difference in the mean percentage of new bone formation between four and eight weeks was significant for all four groups (P < 0.001). Regarding bone formation, the interaction effect of A and B was significant at four (P < 0.001) and eight weeks (P = 0.002). ANGIPARS alone and in presence of Bio-Oss enhanced new bone formation at both four and eight weeks (P < 0.001). The mean amount of new bone formation was significantly different at four and eight weeks in groups C (P = 0.008), A (P < 0.001), B (P < 0.001), and AB (P = 0.003). FBR was not observed in any group. CONCLUSION: Semelil may be useful as an adjunct to conventional osteoconductive materials in order to enhance osteogenesis.

Microflora of Laboratory-Customized Dental Implant Abutments.

OBJECTIVE: This study aimed to detect and categorize the microorganisms of customized abutments returned from laboratories due to probable contamination and their role in peri-implantitis. METHODS: The samples included 202 abutments from 10 laboratories. Ten µL aliquots obtained from the microbial suspension of each abutment were inoculated on sheep blood agar (as non-selective enriched media), MacConkey agar (selective media for Gram-negative bacteria), Columbia agar with colistin and nalidixic acid agar (selective media for Gram-positive bacteria) and Sabouraud Dextrose Agar with antibiotics (selective media for fungi). They were then incubated in an aerobic atmosphere at 37°C. The molecular methods based on 16S rRNA gene sequence analysis were used in the identification of isolates that did not fi t with any recognized biochemical profi les. The distribution of qualitative variables was presented numerically and according to frequency. Complex sample analysis with a 95% confidential interval was used for analysis. RESULTS: The results showed that the mean number of teeth increased in the more recent study: for the age category 35 - 44 years, this increased from 19.2 to 23.8 teeth; however, both studies described a signifi cant decrease in the number of teeth at later ages. Values for the extent and severity index were high in both studies. A larger proportion of subjects was affected by mild and generalized attachment loss in the new study, but the percentages of participants affected by moderate and severe attachment loss were similarFrom a total of 49 detected microorganisms, 44 were aerobic bacteria and 5 were fungi. Micrococcus luteus, Bacillus subtilis, Staphylococcus epidermis and Candida (the dominant genus among fungi) were the dominant species observed in samples from all 10 laboratories, and on average presented on 13.7, 6.2, 5.0 and 4.1 abutments, respectively. The most abundant Gram-positive and Gram-negative bacteria were M. luteus and Acinetobacter baumannii, respectively. B. subtilis was the most common bacillus, and M.luteus was the most common coccus. CONCLUSION: Certain decontamination protocols and regulations must be defined to eliminate bacteria and fungi, as both were present in samples from all of the laboratories.

Oral health status, knowledge, attitude and practice of patients with heart disease.

BACKGROUND: The aim of this study was to investigate knowledge, attitude and practice (KAP) of cardiovascular disease (CVD) patients about their oral health status. METHODS: In this cross-sectional study, we analyzed the data of 150 CVD patients that collected by a self-administered questionnaire consists of demographic characteristics and KAP. Oral health indicators calculated based on the results of oral examination by an expert dentist. RESULTS: CVD patients had an overall moderate level of knowledge and attitude, but their practice was lower than moderate. There were important associations between knowledge scores with gender, education, residential area and financial status, between attitude scores with education and residential area, and between practice scores with education and financial status. There were no associations between KAP and age, marital status or job. Significant positive correlations were found between KAP components. Significant negative correlations were found between oral hygiene index with knowledge and practice. CONCLUSION: The practice of heart disease patients about their oral health was poor, and declares that increasing awareness and attitude may not promote practice. Efficient programs are needed to promote oral health practice of adult populations in special groups.

Effect of Microthread Design on Marginal Bone Level Around Dental Implants Placed in Fresh Extraction Sockets.

PURPOSE: This study was designed to compare radiographically the effect of microthread on the coronal portion of the fixture on marginal bone level (MBL) around immediately placed dental implants in human subjects. MATERIAL AND METHODS: Forty-one roughened surface screw type Dentium oral implants (Dentium) were inserted in fresh extraction sockets of the anterior segment of maxilla of 30 patients. The implants were selected randomly using either microthread design on coronal portion of the fixture (Implantium) (test group) or without microthread thread design (Superline) (control group). MBL was measured using digital subtraction radiography technique after 3, 6, and 12 months. RESULTS: At month 3, the microthread groups have been associated with more marginal bone loss than the control group (P = 0.04). At months 6 and 12, both groups had comparable bone levels (P = 0.21). CONCLUSION: The microthread design of the implant collar could not have a positive effect in maintaining the MBL around implants placed in fresh extraction socket in anterior maxilla.

Comparison of Bone Loss around Bone Platform Shift and Non-Bone Platform Shift Implants After 12 Months.

OBJECTIVES: The aim of the present randomized clinical trial was to evaluate marginal bone loss around two types of implants modified at the neck area: Nobel Active and Nobel Replace Groovy, both manufactured by Nobel Biocare. MATERIALS AND METHODS: A total of 25 Nobel Active and 21 Nobel Replace Groovy implants were included in the present study. The implants were placed based on the relevant protocol and patient inclusion and exclusion criteria. The amount of bone loss around implants was compared at 6 and 12-month intervals using digital periapical radiographs. RESULTS: The mean bone loss values in the Nobel Active and Nobel Replace Groovy groups were 0.682 mm and 0.645 mm, respectively, with no statistically significant difference based on the results of independent t-test (P=0.802). CONCLUSION: Use of both implant types yielded favorable results, with high durability. The two implant types exhibited no superiority over each other in terms of bone loss.

Evaluation of Platform Switching on Crestal Bone Stress in Tapered and Cylindrical Implants: A Finite Element Analysis.

PURPOSE: To analyze and compare the stress distribution around tapered and cylindrical implants and investigate how different abutment diameters influence crestal bone stress levels. MATERIALS AND METHODS: Six finite element models of an abutment (5 mm, 4.3 mm, and 3.5 mm in diameter) and supporting implants (tapered and cylindrical) were designed. A vertical force of 100 N and a 15-degree oblique force of 100 N were applied separately on the occlusal surface, and von Misses stresses were evaluated in the cortical and cancellous bone. RESULTS: Higher stress was observed under oblique loading than under vertical loading of both tapered and cylindrical implants. Tapered implants demonstrated more stress under both vertical and oblique loading. Platform switching reduced peri-implant crestal bone stress in all models under vertical and oblique forces. The peri-implant crestal bone around tapered implants experienced 4.8% more stress under vertical loading and 35% more stress under oblique loading in comparison to bone around cylindrical implants (2.62 MPa with vertical loading, 8.11 MPa under oblique loading). Oblique loads resulted in much higher stress concentrations in the peri-implant crestal bone than vertical loads (238% in cylindrical and 308% in tapered implants). When the abutment diameter decreased, both models showed reductions of stress in the crestal bone under both types of loading. CONCLUSION: In this finite element analysis, tapered implants increased crestal bone stress upon loading, and platform switching minimized the stress transmitted to the crestal bone in both tapered and parallel wall implants.

Frequency of Dental Implants Placed in the Esthetic Zone in Dental Clinic of Tehran University: A Descriptive Study.

OBJECTIVES: Anterior maxilla, known as the esthetic zone, plays an important role in facial and smile esthetics. This study assessed the frequency of implant treatments in the esthetic zone of patients presenting to Dental Implant Department of Tehran University during 2002-2012. MATERIALS AND METHODS: This descriptive study was conducted on dental records of patients receiving implant treatment during 2002-2012. Patient records were retrieved from the archives and patient demographics, implant characteristics, failure rate, prevalence of complications and implant systems were collected. The data were reported as frequency and percentage. RESULTS: Of a total of 2,381 implants placed in the mentioned time period, 492 (20.8%) had been placed in the anterior maxilla and 531 (22.3%) had been placed in the anterior mandible from canine to canine. Timing of implant placement was immediate in 12.0%, early in 0.5% and late in 87.4%. Survival rate was 99.1%. Rate of failure was 0.8%. Failure rate was 0.4% in the maxillary and 1.1% in the mandibular canine to canine region. Complications were reported in 10.1% of patients. Rate of complications was 18.3% in the maxillary canine to canine, 8.9% in the mandibular canine to canine, 18.1% in the maxillary first premolar to first premolar and 9.5% in the mandibular first premolar to first premolar. The frequency of bone grafts placed in these areas was 17.6%, 33.9%, 13.6%, 32.1% and 14.3%, respectively. CONCLUSION: Of implants placed in our center, around 20% were in the anterior maxilla, and delayed implant placement was the most commonly adopted technique.

Tactile sense of the surgeon in determining bone density when placing dental implant.

PURPOSE: To evaluate the bone density using the surgeon's tactile sense and compare it to the Lekholm and Zarb classification and computed tomography (CT) scan to see if correlations exist. MATERIALS AND METHODS: Fifty-two implants were inserted in 22 patients. The bone densities of recipient site were preoperatively determined by density value as Hounsfield Units (HU) using CT scans. According to the Lekholm and Zarb classification, the bone quality scored 1 to 4 on cross-sectional CT. The clinical hardness of recipient sites were assessed on drilling by the surgeon's tactile sense and recorded as D1-D4 based on Misch criteria. Linear regression analysis was used to evaluate the relationship between density values of implant sites. RESULTS: The mean bone density was 536.94 ± 220.39 HU. There were 7.7% implants in bone type D1, 46.2% in D2, 32.7% in D3, and 13.5% in D4. Bone classification according to Lekholm and Zarb was significantly correlated to the surgeon's tactile sense (Spearman's rho = 0.36; P = 0.01) and with HU on CT images (Spearman's rho = -0.61; P < 0.001). The surgeon's tactile sense had a significant correlation with bone density in preoperative CT scans (Spearman's rho = -0.67; P < 0.001). A significant correlation was found between the bone density in HU with age (Spearman's rho = 0.34; P = 0.01). CONCLUSION: A high-quality cross-sectional CT may suffice as a site-specific preoperative diagnostic predictor that can confirm and complement the tactile sense of the surgeon to help differentiate good, moderate, and poor bone density.

Is biologic width of anterior and posterior teeth similar?

The biologic width (BW) includes attached epithelial cells and connective tissue attachment complex being very important in the periodontal health during prosthetic treatments as invading this zone can cause bone resorption and gingival recession. The present study investigated biologic width values in the normal periodontium in anterior and posterior teeth. 30 patients that referred from restorative department to periodontics department of Tehran University of medical sciences who need crown lengthening procedure on their teeth with no history of orthodontic, prosthodontic and periodontal treatment were randomly enrolled in this cross-sectional trial. Sulcus depths (SD) as well as the distance between free gingival margin and the bone crest (FB) of anterior and posterior teeth were measured by UNC-15 probe and compared. periodontium thickness was also assessed. The data were subjected to Student t test. Mean BW in the 43 anterior and 47 posterior teeth was measured and not significantly different (1.4651±0.39 mm vs. 1.6312±0.49 mm) was observed; however, BW was significantly more in the teeth with thick periodontium compared to those with thin periodontium (1.703±0.5 vs. 1.408±0.35; P=0.002). BW not only is different in individuals but also could be dissimilar in different teeth and should be calculated independently prior to restorative treatments.

Effect of low-level laser therapy irradiation and Bio-Oss graft material on the osteogenesis process in rabbit calvarium defects: a double blind experimental study.

This study aims to assess the effect of low-level laser therapy (LLLT) irradiation and Bio-Oss graft material on the osteogenesis process in the rabbit calvarium defects. Twelve white male New Zealand rabbits were included in this study. Four 8-mm diameter identical defects were prepared on each rabbit's calvarium. One site was left as an untreated control (C), the second site was filled with Bio-Oss (B), the third site was treated with laser irradiation (L), and the fourth site treated with Bio-Oss and laser irradiation (B + L). In the laser group, a diode laser (wavelength 810 nm, output power 300 mW, irradiation mode CW, energy density 4 J/cm2) was applied immediately after surgery and then one other day for the next 20 days. After 4 and 8 weeks, the animals were sacrificed and histological and histomorphometric examinations were performed and the data were subjected to Friedman and repeated measurements ANOVA tests. Significant differences were not found regarding inflammation severity, foreign body reactions, and vitality of newly formed bone on 4th and 8th week after operation. The mean amount of new bone was 15.83 and 18.5% in the controls on the 4th and 8th week; 27.66 and 25.16% in the laser-irradiated group; 35.0 and 41.83% in Bio-Oss and 41.83 and 47.0% in the laser + Bio-Oss treated specimens with significant statistical differences (p <0.05). Application of LLLT in combination with Bio-Oss® can promote bone healing. Therefore, LLLT may be clinically beneficial in promoting bone formation in skeletal defects.

Comparison of salivary epidermal growth factor levels in patients with gingivitis and advanced periodontitis and healthy subjects.

OBJECTIVE: Epidermal growth factor (EGF) is a polypeptide molecule, with important functions in epithelial growth and wound repair. It exerts its effects on cells by binding to receptors on the cell surface. The aim of this study was to evaluate and compare salivary EGF levels in patients with gingivitis and advanced periodontitis as well as in healthy controls. MATERIAL AND METHODS: Unstimulated salivary samples were collected from patients with gingivitis and advanced periodontitis and healthy individuals. The clinical parameters of plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment level (CAL) were measured and recorded using a Williams probe. The enzyme-linked immunosorbent assay (ELISA) was used to determine salivary levels of EGF. One-way ANOVA was used for data analysis. RESULTS: The mean salivary level of EGF in healthy individuals (99.27) was significantly higher than that in patients with gingivitis (61.53). This value in patients with gingivitis (61.53) was also significantly higher than that in subjects with periodontitis (36.14) (P<0.001). CONCLUSION: The reduction in salivary level of EGF in patients with periodontal disease may be related to the pathogenesis of periodontitis.

Designing and standardizing a questionnaire for evaluating knowledge, attitude, and practice of Iranian adults with cardiovascular diseases about oral health.

BACKGROUND: Cardiovascular diseases are the most common cause of death in Iran. Moreover, periodontal diseases are very common in our country. In this study, we have designed a standardized questionnaire for evaluating knowledge, attitude, and practice (KAP) of Iranian adult patients with cardiovascular diseases about oral health. METHODS: For designing and standardizing a self-administered questionnaire, we performed a cross-sectional pilot study on 51 cases with periodontal complaints. A dentist carried out the physical examination to determine oral health indicators. Twelve experts and ten lay people of the target population answered questions about validity. Cronbach's alpha, factor analysis, and Pearson correlation coefficients were used in the analysis. RESULTS: The cases of this pilot study were middle aged, with moderate financial and health status, but low oral health and educational level. Debris score was correlated with all other physical exam findings except decay, missing, and filled (DMF). Reliability was 0.826 according to Cronbach's alpha score. Face validity was higher than 80%. Content validities of the whole of the questionnaire were 85.98% for clarity, 78.05% for relevancy, 85.16% for simplicity, and 82.32% for consistency of each question with the question set. Factor analysis showed that 15 components explain 74% of the total variance. CONCLUSION: This questionnaire is culturally adjusted and appropriate for our community, valid and reliable, and sufficiently estimates the variance of the oral health status. It can be used as a standard tool in further studies in adult population of the Iranian middle aged patients with low level of education and moderate socioeconomic status.