Journal of Islamic Dental Association of IRAN
Volume:20 Issue: 2, 2008

Some studies have reported direct relationship between mouth breathing and increased susceptibility of patients to develop periodontal diseases. The present study was designed to evaluate the correlation between periodontal diseases and mouth breathing in Iranian population. This historical cohort study was conducted with 90 participants aged 20-35 years-old, who were referred to Isfahan Dental School and few other private dental clinics in the city of Isfahan in the year 2003. All participants had to be free of relevant systemic conditions. The cases were defined as patients with mouth breathing, having dome-shaped palate and open mouth (lips) when in rest position. Oral examination was conducted using 3 diagnostic criteria. Forty-five patients who were confirmed by all three criteria were included in the study as cases. The control group was composed of subjects who had normal breathing from their nose. The gingival index was determined for posterior and anterior regions of all participants. The statistical analysis was conducted and Mann–Whitney U tests was used in order to determine group differences. The gingival indices in the anterior region of cases were determined. The number of individual with scores 1, 2 and 3 were five (11.1%), 36 (80%) and four (8.9%) respectively. The scores in control group for five subjects (11.1%) was (0) or had no gingival condition, 32 (71.1%) subjects had score one and eight (17.8%) had score 2. The group differences were statistically significant (P<0.001). No significant difference was detected in posterior gingival indices (P>0.05). Mouth breathing can be a contributing factor in increasing the risk of periodontal diseases. Key words: Mouth breathing - Periodontal diseases - Gingival index. Corresponding Author: Dr. Abrishami MR., Department of Periodontology, Faculty of Dentistry, Shahid Beheshti University of Medical Sciences. Tehran, Iran

Prepared cavities are usually treated with liners prior to amalgam placement. Light cured glass ionomer (RMGI) have been widely used for this purpose. The aim of this study was to compare the effect of RMGI on decreasing postoperative sensitivity with a new method of applying self etch bonding and glass ionomer simultaneously. In a blind randomized clinical trial study, A total of 36 patients with 2 deep caries in their posterior teeth (cavities with less than 2 mm distance from pulp in radiography) were included. Diagnostic tests (cold–heat, percussion, electric pulp test) were performed for each tooth prior to final restoration. After cavity preparation, one tooth was treated by light cured glass ionomer, the next one with SE bond and glass ionomer randomly, followed by amalgam restoration. Diagnostic tests were performed three days, thirty days and three months after amalgam restoration. The statistical analysis was performed using SPSS software version 11.5 as well as Friedman and Wilcoxon signed-rank tests. In second follow up, the sensitivity to cold was significantly less than the conventional method (P<0.05) in our suggested compound method. However, there was no significant difference between the two groups when using the other vitality tests. Using SE bond and light cured glass ionomer simultaneously was an effective new method of decreasing the postoperative sensitivity in short term, (1 month), although, there was no difference between the two groups in the long term.

Previous studies on the severity of periodontal diseases and dental caries in renal dialysis patients reported conflicting results. The aim of present study was to evaluate the effect of renal dialysis on DMFT and periodontal status in patients atending to three reftrrtl hospitals located in Tehran, Iran. A total of 120 volunteer subjects comprising of 60 dialysis patients, and 60 healthy controls participated in this study. The subjects in both groups were matched according to their age, sex and plaque index. After obtaining the written consent forms, the demographic and clinical examination was conducted in order to collect information on their DMFT and PDI indices. The data was analyzed by using student t-test. The DMFT was not statistically different in two groups (P>0.05). The attachment loss was about 68.3% in dialysis patients, while this condition was present in 18.3% of healthy control individualf. Gingivitis was noticed in 31.7% of dialysis patients, although it was present in 81.7% of control subjects. The group difference was highly significant for this condition. (P<0.0001) The observed higher rate of periodontal diseases in dialysis patients, warrant for higher levels of intervention in this group of special patients. Therefore it can be suggested that regular dental examination should be added to their treatment protocol.

There are several glass-ionomer cements available in the Iranian market. However, no sufficient information is available on mechanical properties of these materials. Therefor, this study was designed in order to investigate the flexural strength of conventional glass-ionomer cements; the Fuji II (Fu II), Kavitan plus (Kp), Securafil (SF) as well as two Resin modified glass–Ionomer cements: The Fuji II Lc (Fu II Lc), Kavitan Lc (K Lc) and two newly developed glass poly phosphonate cements: Diamond carve & 90 (DC & 90) were evaluated. The method used in this investigation was based on the standards of Iso 4049 (1988) and BS 5199 (1989) for resin–based filling materials. The test specimens of 25mm (length) X 2mm (width), and 2mm thickness were prepared. About fifteen minutes after the setting time, the specimens were removed from the mould and then immersed in water and stored at 37°C, until the testing time started. Three points flexural strength were determined with universal testing machine (0.02N, 1mm/s) at 1 day, 1 week and 1 month after the start of the mixing time. The tow-way analysis of variance was conducted in order to determine the effect of two variants of time and substance type on flexural strength. Group differences were analyzed using one way ANOVA and Tukey HSD tests. Fu II Lc showed significantly higher flexural strength at all three testing intervals compared to other materials. After 1 day, DC & 90 became stronger than Fu II, but weaker than Fu II Lc. The strength of these cements was comparable to other conventional cements after 1 week and 1 month. There was no significant difference between the flexural strength of the three conventional cements at three testing periods. The flexural strength of KLc at 1 day and 1 month was lower than Fu II Lc and it was comparable to conventional cements at 1 month. The conventional cements in this study showed similar strengths. Flexural strength of DC & 90 was comparable to conventional cements.

Numerous Clinical studies have reported the effectiveness of fissure sealants in prevention of dental caries. However, the retention and longevity of sealants are highly dependent on clinical methods. The purpose of this study was to examine the effect of different rinsing direction (45º, 90º angles) of etched enamel surfaces on sealant-enamel bond strength. This experimental study was conducted on 31 premolar teeth, with two bonding surfaces located on the buccal and lingual sides. The selected smooth and vertical enamel surfaces that were prepared using a high-speed hand-piece that was mounted on a surveyor. After etching the enamel, the buccal surfaces were rinsed at 90º and the lingual surfaces were rinsed at 45º angles. After drying and application of sealant, the specimens were stored in distilled water at 37◦C for 24 hours prior to testing with Instron testing machine. Data were analyzed using Pearson correlation and paired T-tests. The statistical analysis revealed that the bond strength in 90º angle group was higher than the 45º angle group. However, the group difference was not statistically significant. (P=0.221) This experimental study showed that there was no significant difference in sealant bonding strength with different rinsing angles (90º, 45º).

Diabetes Mellitus (DM) has destructive effects on various tissues and organs including the dental pulp and periodontal tissues. The aim of this study was to collect information about the influence of DM on pulpal and periradicular tissues in healthy and diabetic cases. Data was collected by searching PUBMED and Cochrane databases using keywords such as diabetes, periradicular infection, periradicular lesion, periapical infection, periapical lesion, pulp, periodontium. Selected reference textbooks were searched using the same search strategy. The search results were categorized according to methodological strengths and selected only if qualified for our inclusion criteria. In diabetic patients numerous histopathologic changes happen in dental pulp and periodontium, accompanied by qualitative and quantitative alterations in normal oral microflora and disturbances in immune system. Usually these three factors accompany each other just like the three sides of a triangle. These cases are not only vulnerable to pulpal necrosis and periradicular disease, but also cause the infection to follow an unusual pathway which requires different treatment regimens compared to nondiabetic patients. Pulpal and periapical infections in diabetics have a completely different pattern which affects the treatment outcomes in these cases compared to nondiabetic individual.

A thorough knowledge about the shelf life of various types of instrument packing is necessary in order to avoid unnecessary re-sterilization of dental instruments. The aim of this study was to evaluate the shelf life of five commonly used packing systems in routine dental practice. This experimental study was conducted with 1400 orthodontic wires. They were divided into five groups (n=280) in order to be packed by Steriperfect (St), TECNO-GAZ (TG), SOGEVA (SO), E-Line (E) and linen (L) brand materials. These packs were then stored in an active dental office environment after proper sterilization by autoclave. Forty packs of each group underwent culture test at 7 different time intervals of 0, 1, 2.5, 4.5, 7 and 9 months. Fisher’s exact test was used to compare group differences. Only 5 packs of L, 6 of St, 3 of TG, 1 of SO and 2 of E showed positive culture results at 0 month samples. Likewise positive culture results were reported for 2 of (L), 1 of (St), 2 of (TG), 3 of (SO) and 1 of (E) in the first month. No significant difference was detected among different packing materials. The findings of this study support the previous findings that contamination is more of event related, not time related; meaning that, sterile instrument packs remain sterile for at least 9 months unless the integrity of pack is violated.

Antrokinon is an herbal compound with anti-inflammatory properties. This substance is usually used for treatment of skin lesions and burns. The aim of this study was to assess the clinical therapeutic effects of Antrokinon on oral aphthous lesions. In a double blind clinical trial study, the therapeutic effect of Antrokinon was evaluated against placebo in 80 individuals attending the school of Dentistry, Mashhad University of Medical Sciences. To receive dental treatment. The Antrokinon and placebo were exactly similar in color and they were in drop form (5cc). Five drops of drug or placebo were instructed to be used locally, 4 times a day, in regular intervals. The collected data was analyzed using Mann-Whitney U test at 95% confidence level (P≤0.05). The statistical analysis showed that, the drug had positive effects on clinical improvement of aphthous lesions in the oral cavity when compared with placebo. A significant decrease in clinical wound healing time was observed after using the drug in comparison with placebo (P=0.001). Likewise, Mann-Whitney U test revealed that the, burn-healing time was significantly shortened in comparison with placebo group as well (P=0.003). Useing Antrokinon can significantly decrease both, the wound-healing time and burn-healing period in oral aphthous lesions.

The presence of microbial plaque not only can cause unpleasant appearance but it can also cause oral tissue inflammation, malodor as well as digestive system and respiratory tract infection. The aim of this study was to evaluate the efficacy of lemon juice 10% and effervescent cleanser tablet, in removing microbial plaque from the surface of removable orthodontic appliances. This study was conducted by using interventional design. Total of 30 patients were randomly selected regardless of their gender status. They were between 9-14 years old (mean age 12) and had maxillary removable orthodontic appliances. Initially, all the removable appliances were cleaned thoroughly using ultrasonic device. Patients were instructed to come back in four days. During this period, patients were not allowed to use any kind of mouthwash or other oral hygiene products to clean their appliances. On the first recall appointment, the removable appliances were first placed in Erythrosine solution for 7 minutes and they were scored for the amount of microbial plaque present. These appliances were rescored after immersing into10% lemon juice solution for 30 minutes. The ultrasonic device was used to clean appliances before returning them to patients. A 4 day recall visit was scheduled for patients. The same plaque scoring procedure was conducted in the second appointment. This time, the appliances were immersed in a solution containing effervescent tablet for 30 minutes.This process was repeated two times in order to increase data validity. After completion of data collection, analysis was conducted using Sign Rank test. The plaque scores were decreased in 33 percent of cases (n=10) after using the first method (10% Lemon Juice); but there was no change observed in 66 percent of cases (n=20) (P=0.002). When using the second method (effervescent tablet), although plaque scores slightly decreased in all cases, the complete removal of plaque were observed in 36.6 percent of the patients (n=11) only (P<0.001). The score comparison between the two methods revealed that 93.4 percent of the cases (n=28) showed less plaque when using the second method (effervescent tablet) (P<0.001). The 10% Lemon Juice solution has little effect on reducing the microbial plaque. However, the solution made out of effervescent cleanser tablet is more effective than 10% Lemon Juice solution in removing microbial plaque from removable orthodontic appliances.

The dual cured resin cements are conventionally used for cementing indirect restorations, such as composite and ceramic inlays and onlays. The aim of this investigation was to evaluate the efficacy of two light-curing units, LED & QTH in polymerization of dual cured resin cement that were placed beneath the ceramic onlays. This experimental study was conducted using 20 specimens. Ten specimens were cured with QTH and the rest with LED light curing devises. Metal rings with 5mm in diameter and 0.5mm in thickness were placed next to the surface of the curved dentin of the molar teeth that were mounted in self cured acrylic resin. A Mylar strip was placed beneath the metal rings and they were filled with Maxcem dual cured resin cement; they were then covered with another Mylar strip. Next, the ceramic onlays with 2mm thickness were placed over the Mylar strips. The specimens were stored in a dry and dark incubator at 37◦C for 24 hours, after cemented onlays were cured for 60 seconds. The Vickers hardness was determined for each sample and data were analyzed by using student T-test and SPSS statistical software. The mean Vickers hardness for QTH cured specimens was 24.75(± 3.59), and this value was 33.92 (±2.28) for the LED light cured specimens. The mean group difference was statistically significant (P<0.001). Based on these findings, the efficacy of LED light curing unit was significantly more efficient in polymerization of resin cements that were placed underneath the ceramic onlays compared with QTH light-curing unit. Key words: Resin cement - Micro hardness test - Radiation effects - Light curing units. Corresponding Author: Dr. Feiz A., Department of Operative Dentistry, School of Dentistry, Isfahan University of Medical Sciences. Isfahan, Iran.

Odontogenic keratocyst is a developmental odontogenic cyst with aggressive behavior and tendency to high recurrence. The cyst’s epithelium shows more potential for growth than follicular cyst. On the other hand, BCL-2 is an anti apoptotic protein that can increase the longevity of epithelial cells. The purpose of this investigation was to compare the immunoreactivity in different layers and linings of both epitheliums of the follicular cyst and odontogenic keratacyst using BCL-2 anti-apoptotic marker. A retrospective descriptive study design was employed in order to evaluate 20 paraffin blacks of odontogenic keratocyst and 20 paraffin blocks of follicular cyst. The immunohistochemistry staining method was used together with BCL-2 marker(Anti BCL-2, Clone 124, Isotype: IgG, Kappa, Dako, Denmark).The cytoplasms of epithelial cells were immunostained in different layers and all linings of the epithelium for both cysts, in 1000 epithelial cell counts. The collected data was analyzed using SPSS statistical software, and Roc Curve analysis as well as student T-test in order to prepare and report the results. Immunoreactivity with BCL-2 marker was 98.5 (±1.4%) in Basal layer, 12.1 (±3.2%) in intermediate, and null (0) in the surface layer of odontogenic keratocyst. Immunoreactivity with BCL-2 marker in basal layer was 2.1 (±1.9%) but the surface and intermediate layers did not immunostained with BCL-2 marker. The mean number of epithelial cells, positive for BCL-2, in all linings of follicular cyst was 0.7 (±0.63%) and in odontogenic keratocyst was 36.8 (± 1.5%). The mean immunoreactivity difference in layers of odontogenic keratocyst was statistically significant (P<0.001). However, the mean difference in immunoreactivity with BCL-2 marker was not significant (P>0.05) in different layers of follicular cysts. Based on the results of this study, BCL-2 seams to be involved in pathogenesis of the odontogenic keratocyst. Likewise, the over-expression of BCL-2 marker in basal layer of odontogenic keratocyst was associated with increased recurrence and aggressive behavior of odontogenic keratocyst when compared with follicular cyst. Therefor, it can be suggested that the overexpression of BCL-2 in basal layer of odontogenic keratocyst can be considered as a useful marker to differentiate it from follicular cyst.

Easy retrieval is the main advantage of using provisional luting agents for cementation of cemented type implant supported prosthesis. However, adequate retention is also required. The purpose of this study was to compare the retention status of implant supported single restorations with different combinations of implant abutment surface conditions and provisional luting agents. This experimental study was conducted using twenty prepable titanium implant abutments (Biohorizons) 8mm in height. They were placed in implant analogs and torqued to 30 Ncm. Implant analogs were mounted in self cured acrylic resin blocks using surveyor. After fabrication of crowns for each abutment, provisional luting agents, such as TempBond, Dycal and TempBond NE were used to secure the crowns over the respective abutments. All specimens were stored in 100% humidity for 48 hours at 37°C prior to testing. Each crowns was pulled from the abutment with a 500 kg load cell in a universal testing machine at a crosshead speed of 0.5 cm/minute, and tensile strength was recorded (N). The specimens were then divided into 2 groups. Ten samples were abraded with 50 μm aluminum oxide and the other 10 were roughened by using a medium roughness diamond rotary cutting instrument. Temporary cements were used and tensile strength tests were performed similarly for all samples. Data were analyzed using paired T-Test and two-way ANOVA. Tensile strength was significantly higher for Dycal (26.01 ± 3.53) than TempBond NE and TempBond. The result of the two-way ANOVA indicated that a significant interaction existed between the provisional luting agents and the surface conditions. TempBond and TempBond NE showed significantly higher tensile strength when combined with airborne particle abraded surface or roughened surface with diamond burs. However no difference was detected in tensile strength for Dycal in different combinations. The surface modification of an implant abutment by airborne particle abrasion or diamond rotary cutting instrument may be an effective method to increase the retention of a crown when TempBond NE or TempBond was used. However, this process did not improve the retention of crown which was secured with Dycal.