Monitoring of Virulence Factors and Metabolic Activity in Aggregatibacter Actinomycetemcomitans Cells Surviving Antimicrobial Photodynamic Therapy via Nano-Chitosan Encapsulated Indocyanine Green

Aggregatibacter actinomycetemcomitans is an etiological agent frequently found in both chronic and aggressive periodontitis as well as peri-implantitis. This study assessed the effect of antimicrobial photodynamic therapy (aPDT), as an alternative treatment modality, by nano-chitosan encapsulated indocyanine green (CNPs/ICG), as a photosensitizer, on the virulence features of cell-surviving aPDT against A. actinomycetemcomitans. The cell cytotoxicity effect of CNPs/ICG was evaluated on primary human gingival fibroblast cells. A. actinomycetemcomitans ATCC 33384 photosensitized with CNPs/ICG was irradiated with diode laser at a wavelength of 810 nm for 1 min (31.2 J/cm2), and then bacterial viability measurements were done. The biofilm formation ability, metabolic activity, and antimicrobial susceptibility profiles were assessed for cell-surviving aPDT. The effect of aPDT on the expression of the fieF virulent gene, encoding the ferrous-iron efflux pump, was evaluated by the quantitative real-time PCR. CNPs/ICG-aPDT resulted in a significant reduction of cell viability (91%), biofilm formation capacity (53%), and metabolic activity (48%) of A. actinomycetemcomitans when compared to the control group (P < 0.05). Moreover, fieF gene expression was downregulated by 14.8 folds after the strains were treated with aPDT. The virulence of A. actinomycetemcomitans strain reduced in cells surviving aPDT with CNPs/ICG, indicating the potential implications of aPDT for the treatment of A. actinomycetemcomitans infections in periodontitis and peri-implantitis in vivo

Comparison of Implant Stability Using Resonance Frequency Analysis: Osteotome versus Conventional Drilling

Objectives: Implant primary stability is one of the important factors in achieving implant success. The osteotome technique may improve primary stability in patients with poor bone quality. The aim of this study was to compare implant stability using two different techniques namely osteotome versus conventional drilling in the posterior maxilla. Materials and Methods: In this controlled randomized clinical trial, 54 dental implants were placed in 32 patients; 29 implants were placed in the osteotome group and 25   in the conventional drilling group. Implant stability was assessed at four time intervals namely at baseline, one, two and three months after implant placement using resonance frequency analysis (RFA). Results: Primary stability based on implant stability quotient (ISQ) units was 71.4±7 for the osteotome group and 67.4±10 for the control group. There was no statistically significant difference between the two groups in implant stability at any of the measurement times. In each group, changes in implant stability from baseline to one month and also from two months to three months post-operatively were not significant but from one month to two months after implant placement, implant stability showed a significant increase in both groups.   Conclusion: The results of this study revealed that in both techniques, good implant stability was achieved and osteotome technique did not have any advantage compared to conventional drilling in this regard

Photobiomodulation Therapy for the Management of Patients With Inferior Alveolar Neurosensory Disturbance Associated With Oral Surgical Procedures: An Interventional Case Series Study: Photobiomodulation THERAPY for Inferior Alveolar Neurosensory Disturbance

Introduction:: Inferior alveolar nerve (IAN) injury is a serious complication during intraoral surgeries. We aimed to evaluate the outcome of photobiomodulation (PBM) therapy in patients with IAN injury associated with third molar or implant procedures. Methods: Eight patients with alteration of sensory function of the IAN after third molar or implant surgeries were enrolled in this case series study. The patients received 10 sessions of PBM therapy (810 nm diode laser, 200 mW, 10 J/cm2 per point, three times a week). Pinprick (PP) and visual analog scale (VAS) neurosensory tests were recorded at each treatment session and 14 days after the last treatment.  Results: The median percentage change of outcomes from first to last visit was as follows: VAS score: +125.00% (range: 50.00 to 166.67); PP score: +350% (range: 150 to 800). The duration of paresthesia was inversely correlated with changes of VAS and PP scores. No significant association was found between the gender or age of patients and changes in VAS and PP scores. Conclusion: Considering the limitations of this study, PBM with the parameters used in this study presented positive effects on neurosensory recovery in patients suffering from IAN injury associated with routine intraoral procedures. Patients with a shorter duration of paresthesia tended to respond more favorably to PBM therapy

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&rsquo;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&rsquo;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. &nbsp; Keywords: Questionnaires, Reproducibility of Results, Validation Studies, Validity, Reliability, Oral Health, Periodontal Diseases&nbsp;</div

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

Effects of two types of anorganic bovine bone on bone regeneration: a histological and histomorphometric study of rabbit calvaria.

The purpose of this study was to evaluate the efficacy of two types of bone substitutes, Bio-Oss and NuOss, for repair of bone defects.This study was performed on the calvaria of 14 New Zealand rabbits. The 6mm critical size defect (CSD) models of bone regeneration were used. Three CSDs were created in each surgical site. The first defect was filled with NuOss, the second one with Bio-Oss and the third one remained unfilled as the control. After healing periods of one and two months (seven animal for each time point), histological and histomorphometric analyses were carried out to assess the amount of new bone formation, presence of inflammation, foreign body reaction and type of new bone. Qualitative variables were analyzed by multiple comparisons, Wilcoxon, Friedman and Mann Whitney tests. Quantitative variables were analyzed using the Mann-Whitney and Wilcoxon tests. Level of statistical significance was set at 0.05.The level of inflammation was not significantly different at four and eight weeks in the Bio-Oss (P=0.944), NuOss (P=1.000) and control groups (P=0.71). At four weeks, foreign body reaction was not observed in Bio-Oss, NuOss and control groups. There was no significant difference in the type of the newly formed bone at four and eight weeks in any group (P=0.141 for Bio-Oss, P=0.06 for NuOss and P=0.389 for the control group).Deproteinized bovine bone mineral can be used as a scaffold in bone defects to induce bone regeneration

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

Accuracy of Linear Measurements Using Cone Beam Computed Tomography in Comparison with Clinical Measurements

Objectives: This study sought to evaluate the accuracy and errors of linear measurements of mesiodistal dimensions of Kennedy Class III edentulous space using cone beam computed tomography (CBCT) in comparison with clinical measurements. Materials and Methods: Nineteen Kennedy Class III dental arches were evaluated. An impression was made of each dental arch and poured with dental stone. The distance was measured on dental cast using a digital Vernier caliper with an accuracy of 0.1mm and on CBCT scans. Finally, the linear mesiodistal measurements were compared and the accuracy of CBCT technique was evaluated by calculating absolute value of errors, intra-class correlation coefficient and simple linear regression model. Results: In comparison with the cast method, estimation of size on CBCT scans had an error of -8.46% (underestimation) to 5.21% (overestimation). In 26.5% of the cases, an accepted error of ±1% was found. The absolute value of errors was found to be in the range of 0.21-8.46mm with an average value of 2.86 ±2.30mm. Conclusions: Although the measurements revealed statistically significant differences, this does not indicate a lower accuracy for the CBCT technique. In fact, CBCT can provide some information as a paraclinical tool and the clinician can combine these data with clinical data and achieve greater accuracy. Undoubtedly, calibration of data collected by clinical and paraclinical techniques and the clinician’s expertise in use of CBCT software programs can increase the accuracy of implant placement.