مجله تحقیق در علوم دندانپزشکی
سال نهم شماره 3 (پیاپی 33، پاییز 1391)

This study was aimed to compare the treatment success rate following immediate loading of single Vs. double retained Mandibular over dentures In this randomized clinical trial 20 subjects with problematic conventional complete dentures were studied. The chief complaint was poor retention of the mandibular dentures. Subjects were divided randomly in to two groups(A or B). All subjects received 3 (3/8 ´ 10mm) implants including one implant in the symphysis area located in the midline of mandible and two others located10-12 mm a way from midline. In group A, midline Implants were loaded immediately after surgery and the lateral Implants remained unloaded. In group B: lateral implants were loaded immediately and midline implants remained unloaded. Six months later,Denture retention, implant stability and periodontal parameters (PPD, BOP), crestal bone loss and survival rate of Implants were measured. The results within each group were analyzed using Pair t.test while results between the two groups were analyzed using Mann-whitney, T.test and Fisher tests. No significant difference in denture retention was reported(P < 0/6)with respect to implant stability (P < 0/3), crestal bone loss (P<0/3), PPD(P<0/7), BOP (P < 0/7) and survival of implant(P < 0/9) between over dentures retained by single implant or double implant. Single retained mandibular overdenture may be considered as an alternative treatment plan For socioeconomically under privileged patients.

The aim of this study was to comparison Salivary Cortisol, sIgA & Anxiety in oral Lichen Planus (OLP) patients and control group without OLP. 46 patients with OLP and46 without OLP were admitted to this case – control study. Salivary cortisol &sIgA were detected by ELISA and anxiety was investigated by the Spielberger state-trait tools. The level of stress and anxiety were compared with other variables by t- test and ANOVA and Logistic regression were carried out. ROC curve was utilized as an anticipator for variables and sensitivity and specificity for salivary cortisol and sIgA were established 36women and 10 men with mean age 47.1 years were recruited in this study. The mean salivary cortisol level 3.42 nmol/L (95% CI 2.69-4.14) and mean sIgA level 191.59 nmol/L(95% CI 155.19-227.97)had significant difference (p < 0.0001). No significant differences were shown by anxiety states tool (42.95 vs. 47.67). (P<0.4) Salivary cortisol’s cut-off point (1.6nmol/L) and sIgA (296.15nmol/ L) were determined respectively in oral lichen planus patients. Area under Curve were estimated for salivary cortisol (0.851) and sIgA(0.797).By rising per unit in salivary cortisol the risk of OLP were increase (OR: 5.9, 95% CI 2.36-4.97) otherwise by decreasing per unit of sIgA the risk of OLP may rise (OR: 0.9, 95% CI 0.989-0.995). Findings revealed that levels of salivary cortisol and sIgA had significant correlation with OLP; hence it could be a possible indicator for the pathogenesis and/or progression of OLP.

The anthropometric measurement of any ethnic group is imperative for clinicians to successfully treat patients with dentofacial deformities. The purpose of this study was analysis of the craniofacial anthropometric measurements in Iranian young adults (18-30 years) in Tehran. In this descriptive study, 100Iranian young adults (50 males, 50 females) with normal face and occlusion in all three dimensions based on reference books were selected. They had no history of orthodontic treatment, trauma or plastic surgery in head and face. Nineteen linear and four angular measurements and nine indices were taken over 5 craniofacial regions. The methodology was adapted from Farkas et al. Shapiro-wilk test showed normal distribution of measurements. Statistical analysis of the data and comparing the study groupwith the North American Caucasians’ norms was done using one sample t-test and paired t-test respectively. Based onthe indices,brachycephalic head (81.7±3.5 males, 81.4±2.9 females), along with a leptorrhin nose,as well as aleptoprosopic face (90.3±4.4 males, 91.4±5 females)were seen in the study group.In comparison with North American Caucasians, besides the differences in angular and linear measurement, there was a significant differencesin head and eye indices in both genders and facial and nasal indices in females of thetwo races(p<0.01). Variability between these two races suggests that norms of other races cannot be applicable in Iranian population for treating dentofacial deformities. Therefore,further studies in different racial groups of Iranian population is recommended.

Cone beam computed tomography (CBCT) is an alternative to a CT scan in dental treatments. Metals used in dentistry may cause production of artifacts due to beam hardening phenomenon. The aim of this study was to compare the beam hardening artifacts produced in New Tom VG, PlanmecaPromax 3D, Max and Somatom Sensation 64-Slice CT. In this descriptive study an implant drilling model was used [IMP 1003-L-HD].The implants (Dentis) were placed in the canine, premolar and molar areas. The identical images were evaluated by two radiologists. The number of artifacts in each image was determined using the scale provide due to reference books Kruskal-Wallis test was used to compare mean values of data. NewTom VG had the maximum resolution (4.53±0.48) and PlanmecaPromax had the lowest resolution. (1.8±0.84). The results showed significant difference between the three Scanners (P<0.001). Given the high quality of the images produced by NewTom VG and the lower exposure dosesand costs in comparison to CT, the use of this scanner in dental procedures is recommended, especially in patients with extensive restorations, multiple prostheses and previous implants.

The purpose of this study was to evaluate the diagnostic precision of intra oral digital radiography in detection of dentinal occlusal caries in primery molars.

43 extracted primary molars with no clinical apparent caries were selected at first, then Occlusal surface of 40 tooth with 007 ss white bur cavity was made to a depth of one millimeter from DEJ. At final digital radiography was taken with Dr suni sensor. 83 radiographs observed by 4 observer. Statistical analyzes by SPSS13 and five indices were calculated by a T.Test.

Positive.Predictive.Value and Negative.Predictive.Value to respectively 63/5% and 67/5% was detected, and False. Positive and False. Negative error rates was totally 34/9%, (P<0.7).

In accordance with the diagnostic performance, the digital system cannot be recommended for detection of dentinal occlusal caries in primary molars.

The wear resistance of acrylic teeth plays an important role in denture longevity. The purpose of this study was to compare the tooth wear rate of three Iranian manufactured artificial teeth with the one manufactured in Italy.

In this experimental in vitro study four brands of artificial teeth including Ivoclar, Glamour, Apple and B.star were used. Sixteen mandibular molars were selected from each band. Eight samples from each brand of teeth were loaded under 2 Kg compressive forces in the presence of artificial saliva. The aluminum oxide mullet was used with 5000 and 10000 cycles. The other 8 samples were loaded under a 4Kg compressive force under the same conditions. The data were analyzed with ANOVA test.

The results showed that weight loss (wear) by aluminum oxide mullet under 2kg force, 5000 cycle, for acrylic teeth was as follows: Ivoclar 0/0097 ± 0/0028, Glamor 0/0122 ± 0/0037, Apple 0/0120±0/0038And B.star 0/0098 ± 0/0030mgr. Also, under the same conditions and at 10,000 cycle, the weight loss was 0/0123 ± 0/0023, 0/0156 ± 0/0042,0/0147 ± 0/0039 and B.Star 0/0119 ± 0/0029mg respectively. There is not significant differences between the groups.. (p<0.4).by increasing the force to 4 Kg there is not significant differences between the groups (p<0.5).

The results of this in-vitro study showed that there is not any significant differences between wear resistance in four brand of artificial acrylic teeth.

One of the most common problems after tooth extraction is alveolar bone resorbtion and in sufficient remaining bone for future implant insertion or appropriate denture fabrication to obtain adequate function and aesthetics. The aim of this study is to assess the effect of Ceno-bone (allograft) on reduction of alveolar bone resorption after tooth extraction.

This research was rolled on 42 dental sockets in patients who were referred to oral and maxillofacial department of Shahed University during two years (2009-2011).The study design was split-mouth in which all sockets were divided in to case and control groups. Each socket was filled with Ceno-bone (FDBA) and sutured in case group and no material was added to the fresh sockets in control group.Follow-up radiographs were taken 1week, 2 months, and 6 months after surgical procedures. The results were statistically analyzed by pairedT- test.

Alveolar bone loss in case and control groups were (0.86±0.36) and (1.33±0.48). respectively. Six months after surgery and there was significantly differences between two groups (p<0.002). There was not any significant differences between two groups one week and two months after surgical procedures. (P>0.05)

Ceno-bone allograft (FDBA) seems to be an appropriate material for filling bony defects and accelerates bone regeneration and decreases resorption in remaining alveolar bone after tooth extraction.

The Geriatric Oral Health Assessment Index (GOHAI) is a valid measure to assess the impact of oral conditions on quality of life of elderly people. This study was done to translate this index into Persian language and to validate its use in an elderly Iranian population. In this validation study, the GOHAl scale was translated in a standardized way consisting of forward (Persian to English) and backward translation. Validity, reliability and responsiveness of the final version were assessed on 150 participants. Reliability was assessed by examining internal consistency (Cronbach’s alpha) and Test-retest and validity was tested by using clinical parameters. The mean GOHAI scores for validity were significantly lower for participants with poor perceived oral health, less dental attendance and less number of total teeth (P<0.05). The reliability in terms of a Cronbach’s alpha value was 0.92. The measure demonstrated (ICC=0.91) for test-retest reliability. The GOHAI sum score increased significantly after patients received periodontal therapy. The Persian version of the GOHAI had excellent reliability, acceptable validity and responsiveness to be used as measure of oral health-related quality of life in studies of the elderly.

Lichen Planus is a chronic mucocutaneus diseasefor which many etiologic factors have been introduced including dental amalgam restorations. The purpose of this study is to assess the relationship between amalgam restoration and oral LichenPlanus. In this case-control study 40patients with oral Lichen Planus presenting to dental faculties were selected as the case group and 44 healthy people without Lichen Planus presented to this center were selected as the control group. Case and control groups were examined and evaluated according to the number of amalgam restorations and the total number of amalgam surfaces. The relationship between amalgam restorations and oral Lichen Planus was analyzed with Mann- U- Whitney test. The average number of amalgam restorations in the case and control group s were 3.71 ±3. 12 and 3.16 ± 2.74 respectively and t he average number of total amalgam surfaces in the case and control group s were 5.62 ±6.96 and 4.53±4.07. respectively there was not any significant difference between two groups. (p=0.5),(p=0.1). there is no relationship between the number of amalgam restorations and total number of amalgam surfaces with oral Lichen Planus.

Talon cusp is an uncommon odontogenic anomaly that arises during the morphodifferentiation stage of tooth development. This cusp-like structure was first described in 1892 by Mitchell. Maxillary anterior teeth, especially lateral incisors are affected most commonly and it is very rare in the mandible. Occurrence of two talon cusps on a single tooth is very rare but possible. A case of two lingual talon cusps concurrently affecting the mandibular left permanent central incisor in an 8-year old male was reported. Early diagnosis of Talon cusps is imperative to prevent further complications. A precise medical and family history should always be taken from patients with any kind of dental anomaly.