مجله دانشکده دندان پزشکی اصفهان
سال هشتم شماره 1 (پیاپی 29، بهار 1391)

Regenerative periodontal therapy with a combination of platelet-rich plasma (PRP), anorganic bovine bone mineral (ABBM) and guided tissue regeneration (GTR) has been shown to result in significantly higher clinical attachment level gains compared to open flap debridement. However, there is no data on the efficacy of PRP in combination with connective tissue graft as a membrane. The aim of this study was to evaluate the efficacy of ABBM and connective tissue graft (CTG) as a membrane with and without PRP in the treatment of alveolar intrabony defects.

In this double-blind randomized clinical trial 15 pairs of intrabony defects in 15 patients with chronic periodontitis were randomly treated with a combination of PRP+ABBM+CTG (test group) or ABBM+CTG (control group). The following clinical parameters were evaluated at baseline and at 6-month re-entry visit using a stent as reference point: probing pocket depth (PPD), clinical attachment level (PAL-S), free gingival margin position (FGM-S), crestal position (CREST-S), crest to defect depth and defect depth to stent. Independent t-test was used to compare parameter means between the two groups and paired t-test was used to compare the parameter means in each group before and after treatment.

No differences were observed in any of the parameters between baseline and 6-month re-entry between the two groups. At 6-month interval the test group showed mean PPD reduction of 2.8 ± 0.8 (p value < 0.0001), CAL gain of 2.5 ± 0. (p value < 0.0001) and bone fill of 2.6 ± 0.4 mm (p value < 0.0001).

Based on the results of this study both treatment modalities were effective in the treatment of intrabony defects and PRP had no additional effect on improving the clinical parameters. Furthermore, connective tissue graft was a good alternative membrane in the treatment of intrabony defects.

Disinfection of dental impressions is an essential step in dental infection control. The aim of this study was to evaluate dimensional accuracy of an irreversible hydrocolloid impression material after disinfection with either immersion in or being sprayed on by ozonated water. In this in vitro study, 50 irreversible hydrocolloid impressions were made from an acrylic maxillary model including 4 Straumann abutment analogues and divided into 5 groups: control group, groups with 5 and 10 minutes of immersion in an ozone solution, and groups with 5 and 10 minutes of ozone solution sprayed on (n = 10). The impressions were then poured in type IV dental stone. Dimensions and distances of stone dies in each group were measured using Coordinate Measuring Machine with an accuracy of 1 micrometer. Percentages of dimensional changes in the diameter and height of the dies and the distances between them were statistically analyzed using ANOVA, one-sample t-test and paired t-test (α = 0.05). One-way ANOVA did not reveal any significant differences in dimensional changes between the test and control groups. Diameters and heights of the dies in all the groups decreased in comparison to the model. One-sample t-test showed that except for the height of the die without undercut in groups of 5- and 10-minute spray (p value = 0.01 and p value = 0.02) and the diameter of the die with undercut in the 10-minute spray group (p value = 0.02) there were no significant differences in any of the dimensions in comparison with the model. Paired t-test did not show any significant differences between dimensions of the dies with and without undercuts between the groups under study. The accuracy of irreversible hydrocolloid impressions is not affected by immersion in ozonated water. Spraying for 5 and 10 minutes will lead to smaller dies.

Zirconia frameworks are generally shaded with colorant oxides before or after sintering in order to have more natural looking restorations. The aim of this in vitro study was to evaluate the effect of A3, B3 and D3 shading on biaxial flexural strength of Cercon zirconia ceramic system. A total of 40 Ceron ceramic discs were prepared in four groups of 10. The discs were placed in a sintering oven. The first three groups were shaded into A3, B3 and D3 using liquid coloring agents based on manufacturer’s instructions. The fourth group (the control group) was not shaded. The discs underwent biaxial flexural strength test in a universal testing machine after sintering. Five specimens from each group underwent EDDX (energy-dispersive x-ray analysis) for the evaluation of constituent elements. After evaluation of normal distribution of data, one-way ANOVA was applied; a post hoc Tukey test was used for two-by-two comparison of the groups (α = 0.05). Shading and its type resulted in significant differences in flexural strengths of the groups (p value < 0.03). Disks of B3 shade revealed the highest strength among the shaded disks, with no statistically significant differences from the control group (p value = 0.63). Only the discs with A3 shade exhibited significantly less flexural strengths in comparison to the unshaded discs (p value < 0.03). Shading can significantly decrease flexural strength of Ceron ceramics, which should be clinically considered when Ceron zirconia cores are used; however, further studies are necessary.

Squamous cell carcinoma (SCC) emerges from a dysplastic epithelial surface and comprises about 90% of head and neck cancers. VEGF (vascular endothelial growth factor) is one of the growth factors which directly affects vascular endothelial cells and evokes proliferation, migration and chemotaxis of endothelial cells. The aim of the present study was to assess and compare VEGF expression in the normal and dysplastic oral mucosa and in SCC.

In this analytical-descriptive study, 20 normal mucosa, 20 dysplastic mucosa, and 20 SCC samples, which had been fixed with formalin and embedded in paraffin, were evaluated for expression of VEGF, using immunohistochemical technique and standard biotin streptavidin method. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests at 95% confidence interval (α=0.05).

Means of VEFG expression were significantly higher in SCC samples compared to dysplastic samples (p value = 0.024). In addition, VEGF expression in SCC samples was higher than that in the normal samples (p value = 0.001). However, there was no significant relationship between the expression of VEFG in the dysplastic and normal mucosa samples (p value = 0.108).

Based on the results of the present study, there is an increase in the expression of VEGF during transition from normal mucosa to dysplastic mucosa to SCC.

In some cases repair of composite resin restorations is preferable to replacement. Various surface treatment methods have been introduced to improve the weak bond strength between the new and old composite resins. The aim of this study was to evaluate the effect of various surface treatment methods on repair bond strength of composite resin restorations. In this in vitro study, 56 composite resin specimens (Filtek Supreme) were prepared and randomly divided into seven groups (one control group and six experimental groups). Then one of the surface treatment methods was used in the experimental groups as follows: group 1: diamond bur + phosphoric acid + bonding agent (Single Bond); group 2: diamond bur + phosphoric acid + silane + Single Bond; group 3: air abrasion (50-µm AL2O3 particles) + phosphoric acid + Single Bond; group 4: air abrasion (50-µm AL2O3 particles) + phosphoric acid + Silane + Single Bond; group 5: diamond bur + phosphoric acid + Clearfil Repair; group 6: diamond bur + phosphoric acid + Clearfil SE Bond. After bonding fresh composite resin, all the specimens were stored in distilled water at 37°C for 24h prior to measuring shear bond strength using a universal testing machine. Data were analyzed with one-way ANOVA and Tukey test (α=0.05). The highest bond strength values were recorded in groups 2 and 5, with no significant differences (p value = 0.064); the lowest bond strength was recorded in group 1. Clearfil SB exhibited better results than Single Bond (p value = 0.039) and Clearfil Repair Bond exhibited better results than Clearfil SB Bond (p value = 0.038). Surface treatment with diamond bur was more effective than air abrasion. Use of silane was affective in increasing bond strength. Clearfil Repair Bond had the best effect on repair bond strength of composite resins.

Squamous cell carcinoma comprises approximately 94% of all the oral cavity malignancies. P53 is considered an indicator of malignant transformations and P63 can play an important role in epithelial dysplastic changes. In addition, HPV is associated with early stages of cancer development in the oral cavity. The aim of this study was to evaluate P53 and P63 expression and their correlation with the presence of HPV in oral dysplastic lesions. In this descriptive-analytical study forty paraffin blocks were collected, which included thirty samples with histopathologic reports of dysplastic lesions (mild, moderate, severe) and ten with a diagnosis of mucocele. Immunohistochemical staining with Envision method was performed for P53 and P63 markers and polymerase chain reaction (PCR) technique was used for detection of HPV virus. Statistical analysis was carried out with SPSS software and Kruskul-Wallis, Mann-Whitney U and Spearman tests (α = 0.05). In this study the nuclear P53 and P63 staining was predominant in the basal/parabasal layers of the epithelium. There was a significant difference in P53 staining only between mucocele and mild dysplasia (p value < 0.05). A significant difference in P63 staining was observed between mucocele and all the dysplastic lesions (mild, moderate, and severe) (p value < 0.05). Human papilloma virus was detected in all the groups, with no significant differences between them (p value > 0.05). Based on the results of the present study there was no statistically significant correlation between P53 and P63 expression and presence of HPV virus in oral dysplastic lesions; however, there was a significant correlation between P53 and P63 intensity and expression in the two layers.

Oral health-related quality of life evaluates the effect of orodental conditions on quality of daily life. The aim of this study was to evaluate relationship between quality of life and oral health in 18‒45 year-old men and women referring to Khorasgan School of Dentistry in 2010-2011.

In this descriptive-analytical study 270 subjects, 18-45 years of age, referring to Khorasgan School of Dentistry were randomly selected with equal numbers of males and females. All the subjects were examined clinically to determine DMFT (decayed, missing and filled teeth). Then the subjects completed OHIP (Oral Health Impact Profile), OIDP (Oral Impact on Daily Performance) and OHB (Oral Hygiene Behavior) questionnaires. Data was analyzed with Pearson’s correlation coefficient and t-test using SPSS 18 (α = 0.05).

The means of OHIP scores were 33.3 and 34.0 in males and females, respectively, with no statistically significant differences (p value = 0.65). OHIP scores in relation to performance management were significantly higher in males compared to females (p value = 0.03). The mean OHIP score in relation to emotional/mental dissatisfaction was significantly higher in females compared to males. There was a direct and significant relationship between all the parameters of OHIP questionnaire (p value = 0.04). OIDP scores were significantly higher in females compared to males (p value = 0.03). OHB scores did not exhibit significant differences between males and females (p value = 0.32).

The results of the present study showed that as the OHB scores increase and DMFT scores decrease, OHIB scores will decrease and the individual will have a better oral health-related quality of life; therefore, everyday life will be less affected by orodental problems.

Minor aphthous stomatitis, with an unknown etiology, is a recurrent inflammatory oral condition, which affects almost 20% of the population. Hereditary, hematologic and immunologic factors have been reported to be the main etiologic factors for aphthous stomatitis. Another factor has been reported to be an imbalance between oxidative and anti-oxidative agents in the body. The aim of this study was to evaluate the amount of lipid peroxidase and anti-oxidative vitamins in the sera of patients with recurrent aphthous stomatitis (RAS).

In this cross-sectional descriptive-analytical study, 25 patients suffering from RAS were compared with 24 healthy individuals. ELISA was used to determine serum lipid peroxidase of which malondialdehyde (MDA) is an indicator, as well as vitamins A, E and C levels in a fasting state in both groups. The results were analyzed by SPSS 11.5 using t-test and chi-squared test (α=0.05).

No significant differences were detected in serum levels of vitamins A, E and C and MDA between the patient and control groups (p values = 0.53, 0.53, 0.78, and 0.32, respectively).

Under the limitations of the present study there was no relationship between RAS ulcers and serum levels of vitamins A, E and C and MDA. Further studies are necessary in this regard.

Fluorosis is defined as a special form of injury to tooth structures, which is caused by excessive intake of fluoride during tooth development. The last fifty years have witnessed an increase in the incidence of fluorosis, necessitating special attention to the esthetic issues, diagnosis and treatment of these defects. The aim of this study was to investigate the causes, indicators, diagnosis and treatment of dental fluorosis.Review report: In this review article, the related articles were evaluated by running a Pubmed search from 1985 up to the present. After classification of the papers the most important relevant papers were selected and evaluated with an emphasis on practical therapeutic procedures. Fluorosis appears when the fluoride content of drinking water is more than 1 ppm. Severity of fluorosis depends on the duration of exposure to fluoride. The host specific body response, weight, the extent of physical activity, nutritional factors, and bone growth and development result in different severities in individuals who have been exposed to the same fluoride level. Fluorosis is classified as very mild, mild, moderate and severe. There are three special indicators for dental fluorosis: Thylstrup and Fejerskov, Dean, and TSIF. Depending on the severity of fluorosis, different treatment modalities are recommended, including bleaching, microabrasion, macroabrasion, veneers and crowns. There are different classifications for fluorosis. In addition, there are specific indicators for fluorosis, each with some advantages and disadvantages. Treatment of fluorosis is different depending on the severity of the problem and treatment outcomes are usually satisfactory.