comparative study on micro hardness and structural changes of dentin floor cavity prepared by ER: YAG laser irradiation and mechanical bur

Statement of Problem: Laser irradiation makes structural and chemical changes on the dental hard tissues. These changes alter the level of solubility and permeability of dentin

Purpose: The aim of this study was to compare the microhardness and the structural changes in the dentin cavity floor prepared with Er: YAG laser and bur

Material and Methods: In this experimental study, fifteen intact human molars were selected. Two square cavities were prepared on the buccal and lingual surfaces of each tooth. One side was randomly prepared by Er:YAG laser and the other side by bur

The specimens were divided into two halves. Consequently, there were 30 samples in every group. One half was assigned for the Vickers's hardness test and the other one, for determination of Ca and P percentage and atomic elements analysis. The data were analyzed by Paired T-tests through SPSS16 [ alpha

Results: The means and the standard deviation of the microhardness were 69.77+/-25.62 and 51.33+/-9.31 Kg/mm2 in the laser and bur groups, respectively. Statistical analysis showed significant differences between the two groups [p=0.017]. Weight percentage of calcium in the laser cavity [65.5] was less than the bur cavities [68.21] and the difference was significant [p= 0.037]

Conclusion: The hardness of dentin in laser group was higher than the bur group because of the higher mineral content of the dentin. The hardness and the mineral content of dentin are important factors in the bonding effectiveness of the dental materials so with laser cavity preparation, good mineral substrate are available for a better bonding

[Knowledge, attitude and practice of physicians and pediatricians regarding the prevention of oral disease in children]

Statement of Problem: General practitioners and pediatricians are in an ideal position to advise families about the prevention of oral diseases in their children because of their frequent contacts with families for routine preventive visits in the child's first few years of life

Purpose: The aim of this study was to determine the knowledge, attitude and practice regarding the prevention of oral diseases among an Iranian group of physicians and pediatricians

Methods and Material: This cross-sectional study was conducted on 296 physicians and pediatricians in Isfahan. A self-administered questionnaire was used to determine the socio-demographic information, knowledge on risk factors, attitude and practice about the prevention of oral diseases. The collected data were analyzed using t-test and Chi-square statistical tests

Result: The mean scores of knowledge, attitude and practice on the prevention of oral diseases among physicians and pediatricians were 62 +/- 14, 94 +/- 8 and 38 +/- 17, respectively. No significant differences were detected between physicians and pediatricians in their scores [p >0.05]. Knowledge and also their practice showed a correlation with their attitude. Physicians who worked at governmental centers had better oral health practice

Conclusion: Based on the findings of this study, the present educational courses about oral health in medical school both in undergraduate and postgraduate curricula are insufficient. The good level of knowledge and attitude but weakness in oral health practice revealed that the increased level of knowledge and attitude does not necessarily lead to good practice in prevention of oral diseases. Therefore, practical education on oral health and training for referring the cases to dentists during medical students. education can improve their practice in oral health preventive measures

[Comparative study of CBC, CRP and coagulation factors as the possible risk factors of cardio vascular diseases in patients with gingivitis in comparison with the control group]

Patients with periodontitis have more risk factors for cardio-vascular diseases in comparison with healthy people. Considering higher prevalence of cardio-vascular and gingival inflammatory diseases in the society, the present study was carried out to evaluate the means of CBC, CRP and coagulation factors as possible risk factors of cardio-vascular diseases in patients with gingivitis. In the case-control retrospective study, 40 male patients [2D-25 years old] referred Isfahan Dental School, who were selected by non-randomized sample method, were divided into 2 groups: group 1: gingivitis cases and group 2: controls [healthy gingiva]. The patients underwent clinical examinations and their bleeding index [CBI] was recorded. Blood sampling was carried out in the patients meeting the study criteria VII-factor were investigated. Data were analyzed statistically by t-test and ANOVA. RBC was 5.3x10[6] and 5.08x10[6] in case and control samples, WBC was 6.35x10[3] and 6.16x10[3] in case and controls and HB was 13.52 and 13.93 gr/dlit in case and control groups. Hematocryte, CRP, fibrinogen and VII factor were respectively 42.72%, 2.05, 215.3 and 176 in cases and 43.07%, 2 04, 183.5 and 181mg/dlit in controls. No significant differences were found between two groups in these factors. The results showed no significant differences between the patients having gingivitis and healthy gingival, but due to a strong probability for the bacteria and their products to enter the blood in gingivitis and aggravating atherosclerosis, it s recommended to inform the patients and society about these risk factors

clinical effectiveness of screw type Implant [Nisastan system] in the posterior - region of the mandible: a 2 year prospective study

The aim of this study was to evaluate the quality and effectiveness of Nisastan screw type implants over a two year follow-up period. 21 patients including 10 male and 11 female with the age range of 21-62 years old with anadontia in the posterior regions of their mandibles were selected to participate in this study. Total of 58 Nisastan implants were used in the lower jaws. After elapse of the osteointegration period, 64 units of fixed partial prosthesis were placed on these implants. Patients were evaluated clinically and radiographically at the loading time, one year and two years later. The survival rate and success indices like pocket depth, plaque index, bleeding index and crestal bone resorption were recorded. The success rates of implants were 94.4% and stability of the abutments and prosthesis were 96.1% after two years. The mean crestal bone loss was 1.08-1.43 mm. The plaque index in 56.5% of areas was zero at the loading time while 64.5% of areas were zero at the end of study. The bleeding index in the 49.5% and 65.65% of areas was zero at those times respectively. The Nisastan Implants showed acceptable performance during the two year period of study

Evaluation of need to pulse oximetry monitoring during inhalation sedation for periodontal treatments

Inhalation sedation is used for pain and anxiety control in dentistry. Hypoxia is the most important side effect which can be detected using pulse oximetry, however, there are different opinions about the use of this instrument. This study has been designed to investigate this subject. In this study, 32 adult patients from periodontal surgical department were selected for their surgical treatment to be performed under inhalation sedation with 50% oxygen and 50% nitrous oxide. Chances of hypoxia occurrence in these patients during and after surgery were evaluated, using pulse oximetry. Average arterial blood oxygen saturation before surgery was measured to be 98.8 +/- 0.61% while it was 99.4 +/- 0.17% during the surgery. Hypoxemia was seen in one case during the surgery. Average arterial blood oxygen saturation in the first and the fifth minute after disconnection from nitrous oxide were above 97%. Hypoxia occurred in one case which can be due to patient's malaise and movement. Inhalation sedation may be administered without the use of pulse oximetry. However, if the observed hypoxia is a sign of real hypoxemia, we conclude that pulse oximetry is necessary during relative analgesia. Due to our lack of adequate experience with inhalation sedation, it is advisable to employ pulse oximetry for this type of sedation in dentistry

Comparative evaluation of dentine surface changes following Nd:YAG laser irradiation by SEM

Dentine hypersensitivity is a common clinical problem in dental practices. So several methods such as, Nd: YAG laser have been used to treat this problem. Previous studies reported that Nd:YAG laser irradiation on root surface makes some thermal changes, like dentine melting and some other side effects which are related to power of laser irradiation. The aim of our study was to compare two different settings of Nd: YAG laser to evaluate their efficacy in occluding dentinal tubules and their side effects by means of SEM. 15 newly extracted mandibular molars were selected and the specimens with certain dimensions from buccal surface and below CEJ were prepared. Specimens were divided in 3 groups: group 1 [control], were not irradiated by laser; group 2, irradiated by Nd: YAG laser [0.5w, 10Hz, 60Sec, 2 times]; and Group 3, irradiated by Nd: YAG laser [1w, 10Hz, 60Sec, 2 times]. After preparation and gold coating of specimens, the photomicrographs were seen by SEM in magnification of 100 and 1500. Finally, the number and diameter of dental tubules, crater and microcraks were determined in each group. After that, the data was analyzed using ANOVA test. Results of this study showed that diameter of dentinal tubules were reduced in Nd: YAG irradiated groups, compared with control group. Also there were no significant differences in the mean number of open dentinal tubules between Nd: YAG [0.5 watt] and control group. On the contrary, there were significant differences between Nd: YAG [1 watt] and the other groups. Meanwhile, no group showed micro cracks or craters. The results of this study show that Nd:YAG laser irradiation can cause thermal effects such as decrease in dentinal tubules diameter or their occlusion. Also 1 watt power Nd:YAG laser is more effective than 0.5 watt power in tubules occlusion which is a necessary factor in dentine desensitization

Treatment of periimplantitis with an Er: YAG Laser and GBR. A case report

The increasing use of dental implants has led to a larger number of periimplant problems. Different therapeutic techniques have been suggested to restore the health of soft and hard tissues. The utilization of laser has been recently suggested for the preparation of implant surfaces and eradication of bacteria. Based on different investigations, there is no evidence of applying both guided bone regeneration [GBR] and laser techniques simultaneously for eradication of periimplant lesions. Bone loss was encountered on the mesial and distal surfaces of all implant before prosthetic loading in a female patient. Er:YAG laser and GBR by autogenous bone grafting were simultaneously applied for treatment of the defect. The prosthesis was fabricated and loaded after 4 months. The patient then received periodic clinical and radiographic examinations for 18 months, The bone defects on the mesial and distal surfaces resolved completely. There was no evidence of radiographic or clinical symptoms after 18 months