Abstract: Aims: To find the association between different Angle’s classes of malocclusion and to estimate the distribution of hypodontia according to gender, number of missing teeth and the site of the missing teeth. In addition, the heredity role in hypodontia was investigated. Materials and Methods: About 3415 subjects, 1750 females and 1665 males aging between 18–30 years were examined clinically in addition periapical radiographs were taken for each patient to exclude a possibility of impaction. A family history of hypodontia for each patient was taken (for father, mother, brothers and sisters). Then the sample was divided into 3 groups depending on Angle’s classification of malocclusion. Results: No clear association was found between Angle's classes and hypodontia, females showed higher prevalence of hypodontia than males. Family history was obvious in patients with hypodontia. The upper lateral incisor was the most frequent absent tooth. Conclusions: No association was found between Angle’s classification and hypodontia. The upper lateral incisor was the most frequent missing tooth. Maxilla was affected by hypodontia more than mandible. Females were affected more than males with very obvious effect of family history on hypodontia.

Abstract: Aims: To detect the variation in cranial base parameters among the skeletal relationships of Class I, II and III for both sexes. Materials and Methods: The sample was consisted of 90 lateral cephalometric radiographs 30 for each class (Class I, II and III skeletal relationships of ANB angle 0–2, over 2 and less than 0 degree respectively). The radiographs were for Iraqi adolescents who live in Mosul City of age 15–18 years. The subjects were collected from the Department of Pedodontics, Orthodontics and Preventive dentistry, College of Dentistry, University of Mosul. The radiographs were traced to determine the ANB angle to group the sample into Class I, II and III skeletal relationships, the statistical analysis of cranial base lines (SN, SBa, SCo, SAr and SBa), and the cranial base angles (NSBa, SBaAr, SBaCo, SBaN) was carried out to find their variation among the three skeletal relationships. Results: Revealed that there was no significant difference at (p < 0.05) significant level between sexes. There were significantly increase in mean value of Class II in comparing to Class I and III skeletal relationships for both sexes in the cranial base parameters (lines SN, SBa, NBa, and angle NSBa) and insignificantly greater in the cranial base parameters (line SCo and angle SBaN). Conclusion: There were significantly differences among the Class I, II and III groups in the (SN, SBa, NBa and NSBa) parameters for males, while in females were in the (SN, SBa, NBa and NSBa) parameters. The sex variation was insignificant difference for all the parameters in the three skeletal group

Abstract: Aims: To determine the prevalence and severity of dental fluorosis in relation to age and sex for primary school children, aged 6 – 12 years old in Thamar -Yemen. Material and methods: The study included 600 primary school children aged 6, 9 and 12 years old randomly selected (300 males, 300 females) in Thamar – Yemen, who had lived since birth in moderate natural fluoride level (1.8 – 2.2 ppm) by the use of Dean index to assess dental fluorosis. Results: Showed that the prevalence of dental fluorosis was 19.83 % and 5.23 % within students and teeth respectively, ranging from very mild to moderate form of dental fluorosis with no significant sex difference for individuals at p ≤0.05 as total and significant difference between males and females for teeth as total at p ≤ 0.001, the percentage of severity had been found to be increasing with age. The community fluorosis index for Thamar Province was 0.4 %, which was regarded low. Conclusion: The prevalence of dental fluorosis had been increased with increasing age with no sex difference

Abstract: Aims: To detect the most accurate impression materials and technique to transfer single or multiple implants position from the master model to the stone dies by two methods of measurement. Materials and methods: Two master models (Cl III Kennedy with single implant Frialit–2, and Cl II free end saddle with double implants) were fabricated. Four impression techniques were used (direct, and indirect, each with one, and two steps) using condensation, addition (heavy and light consistencies) and addition (medium consistency) silicone impression materials. Five impressions were taken for each technique to produce a total number of 100 stone casts. A mechanical apparatus was carefully designed to allow constant repeatable position of stock impression tray to the master model, and to allow vertical removal of the impression tray that helps to standardize the path of removal. The measurements were performed by using digital caliber and optical micrometer microscope. Results: Showed that the direct (open tray) two steps technique was the accurate technique for transferring implant position to the laboratory cast. The two steps impression technique was the most accurate one than one step. There were no significant differences between single, and double implants. There was significant difference between the two methods of measurements in (Z) axis for both single and double implants case. Conclusion: The direct (open tray), two steps impression technique, and addition impression material is the most accurate technique. The numbers of dental implants had no significant effect on accuracy of stone cast.

Abstract: Aims: To measure candidal biofilm activity using pH changes of stomastat, to evaluate the effect of different types of curcumine solution on Candida albicans biofilm that attached on acrylic resin denture base material (A.R.D.B.M.) and the correlation of initial number of yeasts inoculated with the pH value of stomastat after 24 hours incubation period. Materials and Methods: In general, the number of acrylic resin samples that had been used in this study was 20 samples. Curcumine solution had been dissolved in three different solvents, those were ethanol, viscous (glycerine), and sterile distilled water, while cholrhexidine (CHX) alone used as a control negative and distilled water used as a control positive. The diameter of inhibition zone for the different curcumine solution had been measured and compared with control (–ve, and +ve); the biofilm activity of Candida albicans on A.R.D.B.M. was measured by a new method using pH change of stomastat. Results: Demonstrated that the ability of curcumine solution to decrease fungal biofilm activity on A.R.D.B.M varied depending upon the type of solvent in which the solution had been dissolved, and ethanolic solution (50%) was the most effective in reducing biofilm activity of C. albicans on A.R.D.B.M. when compared with CHX solution which is the most commercially used solution as denture cleanser. Conclusion: The ethanolic solution of Curcumine can be used in prosthetic dentistry as a new denture cleansing agent.

Abstract: Aims: To reveal the possible soft tissue difference in the upper and lower lip heights, separations and coverage of lower lip to upper incisors in different Angle’s classes of malocclusion, to determine any difference in the mean between males and females for each variable and to find any correlation among the variables. Materials and Methods: Nightly nigh students (52 males, 47 females), 20–23 years of age that was randomly selected from the college of dentistry, University of Mosul.The overall sample was classified depending on Angle’s classification of malocclusion into four groups (Class I, II.1, II.2 and III). For each group, four facial soft tissue variables were measured directly using electronic digital viernier caliper. Results: A major findings that emerged from the research is that the Class I subjects possessed higher values of upper lip length followed by Class II then Class III, this difference is significant between Class I,III and II,III and non significant between I,II. Where as Class III subjects possessed non significant higher values of lower lip length followed by Class II then Class I. The lip separation value is non significantly higher in Class II subjects followed by Class III then Class I. While Class III subjects possessed non significant higher values of lower lip to incisor superior followed Class I then Class II. Conclusions: For each specific Angle’s class of malocclusion, a specific facial soft tissue parameters. The upper lip length is greater in Class I subjects. Class III subjects have the greater lower lip length. The inter–labial gap is larger in Class II subjects.While the coverage of the lower lip to incisor superior is greater in Class III subjects. Most of the variables are higher in males than females. Complex correlations among the studied variables are found that varied between weak to high positive or negative with varying degree of significance.

Abstract: Aims: To evaluate different steps of endodontic procedures done by the dentists in Mosul city. Materials and Methods: A dental questionnaire sheet that consisted of 21 questions regarding numerous steps of endodontics starting from pre–operative (diagnostic) phase to post–operative (final restoration) phase was distributed randomly to 150 dentists working in Mosul city. The dentists involved in the study were both specialists and non–specialists. Then, the sheets were collected and the data analyzed. Results: Revealed that there was a difference in performing specific steps of endodontics between the dentists. In some questions there was no great difference between specialists and non–specialists, but in other procedures, a great difference could be observed. This difference was not only between specialists and non–specialists groups, but also inside these groups as well. Conclusions: The dentists in Mosul city generally lack information about some important steps in endodontic work that may affect negatively the outcome of the procedure as a whole. This deficiency can be compensated for by holding continuous education programs in addition to the dentists’ responsibility in staying in contact with the most modern advancements in different fields of dentistry.

Abstract: Aims: To assess the effect of water contamination on the shear bond strength of moisture insensitive Fuji Lc. glass ionomer and to compare it with the shear bond strength of (transbond) light cure composite. Materials and methods: Sixty extracted human premolar were cleaned and dried and embedded in cylinders filled with dental stone and the teeth were divided into three groups (20 teeth of each) which were etched and washed and dried the teeth in group 3 were slightly moistened in a cotton pellet and then the brackets were bonded to the teeth according to the manufacture instructions. Group1: using light cure composite (transbond); Group2: using glass ionomer cement (Fuji Lc.) in dry condition; Group3: using glass ionomer cement (Fuji Lc.) in moist condition. The shear bond strength was measured using instron mechanical test machine. Statistical analysis including descriptive statistics were applied to the results and then the findings were compared among the three groups using ANOVA and Duncan tests. Results: Light cure composite (transbond) had the highest shear bond strength followed by Fuji Ortho. Lc. (moist condition) and then Fuji Lc. (dry condition), which had the significant lowest shearbond strength. Conclusions: Transbond light cure composite had the highest shear bond strength. The presence of moisture enhances the shear bond strength of light cure glass ionomer cement (Fuji Lc.).

Abstract: Aims: To evaluate shear bond strength of four types of orthodontic adhesive systems including two–paste composite (Concise), light–cured composite (Transbond), no–mix composite (Alpha–dent) and light–cured glass ionomer cement (Fuji), and to compare shear bond strength between these four types of orthodontic adhesive systems. Materials and Methods: Forty extracted premolars and forty stainless steel mesh edge–wise brackets were used. Each type of orthodontic adhesives were used for bonding of ten brackets according to its manufacturer instructions, after setting the brackets were debonded and the shear bond strength were measured using Instron testing machine. Results: Showed that the two–paste composite (Concise) and the light–cured composite (Transbond) gives the highest bond strength, the bond strength of the glass ionomer cement (Fuji) significantly lower than that of Concise and Transbond but it was remained within the accepted level for clinical use, the no–mix composite (Alpha–dent) showed very low shear bond strength which was below the accepted value for clinical application. Conclusions: Concise and Transbond have high bond strength so that it can be used to fix orthodontic attachment in areas subjected to high force. The bond strength of the glass ionomer cement (Fuji) remains within the accepted level for clinical use with the benefit of fluoride release. Also the shear bond strength of the no–mix composite (Alpha–dent) is very low makes it not suitable for clinical use.

Abstract: Aims: The purpose of this study was to determine the age differences for deep bite malocclusion concerning facial skeletal and dentoalveolar height. Materials and Methods: It was carried out on a sample of (50) students (16 males and 34 females), aged (12–15) years with class I deep bite malocclusion present when the incisal edge of the lower central incisor is at least in contact with the gingival third of the upper central incisor in normal healthy individuals with full set of permanent teeth in both jaws. The sample were divided into two age groups (12–13) and (14–15) years old. Lateral cephalometric radiograph was taken for each subject. Twenty–one cephalometric measurements (nine angular and twelve linear) and five ratios had been determined. The data were statistically analysed using statistical package for social statistics. Results: The results revealed that upper anterior facial height, ramus height, total posterior facial height, lower posterior facial height, upper posterior dental height and lower anterior dental height were significantly increase with age in total sample. Males showed increase of total posterior facial height and lower posterior facial height with age while females showed increase of lower posterior facial height and upper posterior dental height with increasing age. Concerning ratios, total posterior facial height to total anterior facial height ratio was increased significantly with age in males opposite to the lower anterior facial height to total anterior facial height ratio which was decreased significantly with age in males. Upper posterior dental height to upper anterior dental height ratio showed significant increase with age in males, females and total sample. Angular measurements revealed that males, females and total sample showed significant decrease of the angle formed by the intersection between occlusal plane and palatal plane (Occ–pp) with increasing age. Conclusions: Deep bite was affected by age only for posterior skeletal facial dimensions and not for anterior skeletal facial measurements.

Abstract: Aims: To determine the prevalence of dental caries in primary and permanent dentition (dmft, DMFT) and to investigate the reason for seeking dental treatment and the type of treatment carried out for children. Material and Method: The study includes (1178) case sheets which represent the total number of children attending the Pedodontics Department during the academic year of (2004 – 2005). The WHO methodology was used to assess the individual tooth status. Results: Indicated that the highest percentage group of attends was 11–12 years group, and the children attended to clinic seeking treatment for painful condition had higher percentage (60.10 %). The DMFT for the total sample was 2.68% and increased with increasing age with a statistically significant age differences, the percentage of caries free children for total sample was 10.3 %, while mean dmft for primary dentition was 3.05% and increasing from the first age group till the third age group and then decreased till the last age with no gender variation. Conclusions: The priority of dental health services for children attending Pedodontic clinic is primary prevention (fluoride application, scaling and polishing) followed by tertiary prevention (extraction) and then secondary prevention as a totally (amalgum, light cure and root canal filling).

Abstract: Aims: To find the soft tissue changes of the total facial convexity, facial convexity and nasolabial convexity among four age groups. Materials and Methods: The studying sample subjects included 48, 41, 50 and 44 individuals of age 11, 12, 13 and 14 years respectively. The subjects were Iraqi individ-uals of class I normal occlusion, who lived in center of Mosul City. All subjects were radiographed with lateral cephalometric films, these films were traced, the tracing included the total facial convexity (Gl–Prn–Pgs angle), facial convexity (Gl–Sn–Pgs angle) and nasolabial convexity (Cm–Sn–Ls angle). Results: Displayed that the total facial convexity angle in both sexes appeared that no significant change among the four age groups, the facial convexity appeared insignificant differences among the four age groups in males, while in females showed significant increase between the 14 years age group as compared with 11 years age groups, and the nasolabial convexity demonstrated no significant changes among the four age groups for males, whereas in females showed no significant di-fference between 11 and 12 years age group and between 13 and 14 years groups, meanwhile, the 13 and 14 years age group explained significant decrease as compared with 11 and 12 years age groups. The sex variation showed the only significant increase in females than males at 11 years age group for the nasolabial angle. Whereas no significant change between males and females in all the angles at the 12 and 13 years age group. In 14 years age group, the facial convexity angle only showed a significant increase in females as compared with males. Conclusion: No significant change in total facial con-vexity, facial convexity and nasolabial convexity angles among the four age groups in males. Whereas, in females there were a significant increase at 14 years age group, than 11 years age groups for facial convexity and nasolabial convexity angles.

Abstract: Aim: To investigate the effects of chemotherapeutic agents on the oral health of children and to com-pare the action of two mouth rinses chlorhexidine digluconate 0.2 % and salty water (0.9% NaCl) in relation to their ability in controlling the plaque and gingival inflammation with children treated by cytotoxic agents. Materials and Method: In this clinical trial, the selected children were divided into two groups the first one comprised of 30 healthy children represented as a control group and the second one comprised of 30 children who were receiving chemotherapy for at least 6 months, they were se-lected from patients attended to pediatric wards of public hospitals in Mosul city .All children were of similar age groups and mean age of 5+ 1 years. The plaque and gingival indices were measured accord-ing to silness and lِöe for the six teeth at the baseline. Then the 30 children who were receiving chemo-therapy were randomly divided into two groups; each consisting of 15 children, they were instructed to use mouth rinses twice daily for 30 seconds after breakfast and before the bed time.The plaque and gingival indices were again measured one month after mouth rinsing for the six teeth at the baseline. Results: The results of this study revealed that the chemotherapeutic agents modify oral health and there was significant increase of plaque and gingival indices in children receiving chemotherapeutic agents (at p≤0.05), also results showed that there was a significant reduction after rinsing with chlor-hexidine digluconate for plaque and gingival indices (at p≤0.05), while non significant change for salty water mouth wash. Conclusion: In view of the possible factors that causes increase of the plaque and gingival indices, suggested myelosuppresion that is associated with chemotherapy which has effects on rate and pattern of hard and soft tissues resulting in reduced the ability to repair and maintain the oral health status.

Abstract: Aims: To determine the level and angulation of the occlusal plane of the artificial dental arch by measuring the level and angulation of the occlusal plane of completely dentulous subjects and to find the relation of these measurements to some of the vertical facial and intra oral dimensions. Materials and Methods: The sample of the study consisted from 54 completely dentulous adult subjects (24 female and 30 male) with class 1 normal occlusion aged 19–24 years. Dental casts were taken for each subject, the level and angulation of the occlusal plane, vertical facial, and intra oral dimensions were measured using digital vernier caliper and protractor. The data were analyzed with statistical package for social science program. Results: Sexual differences were found in the intra and extraoral measurements. Most of the measurements dealing with the occlusal plane level and angulation were correlated with each other and with facial measurements. Conclusions: The level and angulation of the occlusal plane of the maxillary and mandibular dental arches as measured on the dental casts are higher in maxilla than in mandible and the intra and extraoral vertical facial measurements are greater in male than female.

Abstract: Aims: To study the effect of recasting on the macrohardness of cobalt chromium (Co–Cr)alloy, and to evaluate the effect of finishing and polishing on it. Materials and methods: Two brand of Co–Cr alloys were used, divided into three groups, the specimens of the first group were casted from new materials, the second were casted from previously casted material without the addition of any new material (100% recast), the third were casted by combination 50% new material and 50% used material. Half of the specimens just finished and the other half were finished and polished , hardness for all of them were measured. Results: Showed that recasting, both 100% and 50%, significantly increase the macrohardness of Co–Cr alloys and no significant effect of finishing and polishing on it. Conclusion: Recasting may affect properties of Co–Cr alloy and new material should be used rather than recasted material.