Abstract: Aims of the study: The aims of this study are to evaluate the transverse strength of relined acrylic den-ture base (additional curing by water bath or microwave), and to evaluate the best thickness of relining material in relation to denture base. Materials and Methods: Thirty five samples were prepared from Major heat cured resin in dimensions of 65102.5±0.03mm (length, width and thickness) respective-ly, for the transverse strength test (ADA specification No.12). Three different ratios of relining material thickness to denture base were examined and two curing techniques ( microwave curing cycle and the water bath curing cycle). Statistical analysis of variance (ANOVA) and Duncan’s multiple range tests were used to compare the groups. Results: There was no significant difference in the transverse strength between the different thicknesses of relining material in relation to denture base for both cur-ing methods .There was a significant difference in the transverse strength between the control group and the relined groups (microwave and water bath relining). Conclusions: Different ratios of thickness of relining material in relation to denture base had no significant effect on the transverse strength of the relined denture base. Relining the heat cure denture base material significantly decreases the transverse strength of the relined denture base.

Abstract: Aims: To evaluate the mean value and compare the: elasticity and plasticity of the Nickel Titanium and Elgilloy arch wires after emersion in artificial saliva for one , two and four weeks. Materials and Me-thods: The sample consisted of 80 piece of Nickel Titanium and Elgilloy wires; Each wire divided into four groups (10 wires for each group: control. one, two and four weeks of emersion in artificial saliva). The specimens were tested with tensile procedure and plotted the load stress– strain curve, form this curve can calculate the elasticity modulus, elasticity limit and plasticity limit. The results were subjected to the descriptive statistics, ANOVA and Duncan’s Multiple range analyses at p≤ 0.05 significant level. Results: The Results demonstrated that the modulus of elasticity, elasticity limit and plasticity limit of the Nickel Titanium and Elgilloy arch wires decrease significantly as the emersion time in the artificial saliva increase. Conclusions: The decrease of the biomechanical properties (mod-ulus of elasticity, elasticity limit and plasticity limit) of the Nickel Titanium Elgilloy arch wires which subjected to the artificial saliva did not encourage the using of these arch wires clinically for long time.

Abstract: Aims: This study investigates the condyle position in temporal fossa of completely and partially den-tated patients pre and post prosthetic treatment, and compares between right and left condyles in both groups by radiographic Examination. Materials and Methods: Twenty two completely dentate pa-tients (20-28) years old, and thirty partially dentate patients (35-65) years old meet the criteria of the study. For each patient a temporary removable acrylic partial denture was constructed. By using plan-meca digital radiography device (Finland), the radiograph for TMJ were taken by special panoramic technique in open and close mouth position for both groups (Pre, at, and Post insertion of dental pros-thesis). By using Dimaxis software program the linear measurements of the narrowest anterior and posterior joint spaces made by using program tools, the articular eminence inclination angle in closed mouth position also measured, and statistical analysis by using SPSS program version 11.5 for all data. Results: The results showed that in completely dentated patient, 76.5% had condyles in concentric po-sition, patients who had lost posterior teeth support showed a predominance of posterior condylar posi-tions and significant decreased in displacement after prosthodontic treatment (P=0.015 for right side and P=0.032 for left side) at significant level 0.05. Asymmetry in concentric position of condyle be-tween right and left side, but insignificant value P>0.05. There is significant difference in the inclina-tion of articular eminence angle between completely and partially dentate patients P=0.01 for the right side and P=.005for the left side. Conclusions: Posterior displacement of the condyle associated with loss of posterior teeth. Significant change in the condylar position occurred after prosthetic rehabilita-tion, patient's comfort obtained when the position of condyle in glenoid fossa is (concentric position + 0.35mm). The loss of teeth caused remodeling of articular eminence inclination.

Abstract: Aims: To compare the efficacy of celebrex 400 mg orally one time daily with paracatamol 1000 mg orally four times daily on reducing post operative oral complication (facial swelling, trismus and pain) after third molar surgery. Materials and Methods: A total of 45 patients (24 females, 21 males) with impacted lower third molars divided into two groups; Group I: Twenty patients treated with paracetamol 1000 mg orally four times daily. Group II: Twenty five patients treated with celebrex 400 mg orally one time daily. Results: The mean age of patients was (29.17 ± 5.0) in group I and (27.1± 4.9) in group II with no significant differences, with a higher percentage of mesioangular impaction 40% among other type of impaction in two groups. Patients in group II suffer from less facial swelling and trismus with a significant differences p ≤ 0.05 compared with group I, but the two groups showed no significant differ-ences in related to pain (p> 0.05) after third molar's surgical removal. Conclusions: Celebrex is more effective than paracetamol with less frequency of administration and longer duration of action in reduc-ing post operative oral complication (swelling and trismus), but with some analgesic effect after surgical removal of lower third molars

Abstract: Aims: In this study, triamcinalone acetonide was applied topically in the tooth socket following surgic-al removal of teeth to evaluate its anti-inflammatory effect. Materials and Methods: Forty medically fit patients were selected with an age range between (18-50) years of both genders, non smoker, no pregnant or lactating woman. The patients were divided equally into a trial and control group. Surgical extraction was done for all patients. In the first group, the socket was covered with a piece of sterile gauze (2 X 2 cm) impregnated with triamcinalone acetonide ointment %1. In the control group, the extracted socket was covered with sterile gauze only. The sterile gauze was removed 24hrs postopera-tively. Postoperative pain and swelling were examined in 1st, 2nd and 7th days. Results: Mann-Whitney test revealed no significant difference in the pain level and swelling at the 1st day but with a significant difference in the 2nd and 7th days between both groups. Conclusions: The pH of saliva in male pa-tients with (RAU) was more toward acidic pH than normal male subjects.

Abstract: Aims: To evaluate and to compare the shear bond strength of new brackets, new microetched brackets and debond microetcher clean brackets when bond to virgin and previously bond teeth. Materials and methods: Thirty human premolars were randomly assigned into three groups, 10 teeth for each. Group V1 (virgin teeth bonded by new brackets), group V2 (virgin teeth bonded by new microeched brack-ets), and group V3 (virgin teeth bonded by debonded micretched cleaned brackets). All groups tested for shear bond strength. After that all teeth cleaned from composite and randomly assigned again into three groups, 10 teeth for each group. Group P1 (previously bonded teeth rebonded by new brackets), group P2 (previously bonded teeth rebonded by new microetched brackets), and group P3 (previously bonded teeth rebonded by debonded microetched clean brackets) and again all groups tested for shear bond strength. Results: There are no significant differences between virgin teeth groups and previously bonded teeth when clean previously bonded teeth from old adhesive as descried in this study however the previously bonded teeth groups showed the lower mean value than virgin teeth. New microetched and debonded micretched brackets groups showed significantly higher value in comparing with new bracket groups while there were no significant differences between new micretched and debonded mi-croetched groups with greater mean value for new micretched groups. Conclusion: Bracket recycled by microetching using 50–μm aluminum oxide particle was appears to be very effective method for bracket accidental debonded and Previously bonded teeth had shear bond strengths comparable to vir-gin teeth(new bonded) when adhesive remnant removed by

Abstract: Aims: To investigate for any difference in facial height measurements between Iraqi Arabs and Kurds adolescents. Materials and Methods: lateral cephalometric radiographs Of 42Arabic adolescents in Mosul city and 43 Kurdish adolescents in Arbil city were assessed for anterior and posterior facial height measurements. Results: No significant difference was found in facial height measurements be-tween Arabic males and females. In Kurds, males showed significantly higher facial measurements than females. Kurdish adolescents had significantly greater facial height measurements than Arabic counterparts. Conclusions: Our results revealed that there is an overall difference in the facial height measurements between Arabic and Kurdish Iraqi adolescents

Abstract: Aims: To determine the amount of force degradation of three types of orthodontic traction aid polyure-thane elastomeric chain (PEC), nickel titanium closed coil spring (NiTi CCS) and stainless steel closed coil spring (SS CCS). Material and methods: Samples were extended to a specific distance which was 18 mm in case of PEC and 20 mm in case of NiTi CCS and SS CCS. Each extended sample will then incubated in dry condition, artificial saliva, and mouthwash solution, for total incubation period of three weeks. Results: showed that samples in dry condition always showed minimum force degrada-tion percent than in wet conditions. It also showed that the increase of incubation time leads to increase in force degradation percent with major degradation percent located within first twenty four hours. Conclusions: in dry and two wet conditions, NiTi CCS reflects the lowest percent of force degradation, PEC showed highest percent, while SS CCS showed intermediate one

Abstract: Aims: To measure the microhardness of root canal dentin using two types of irrigating solutions( 0.2% Chlorhexidine and 5.25% Sodium Hypochlorite) with and with out use of different types of root canal files (Stainless Steel-K files, Nickel-Titanium K-files or rotary Nickel-Titanium files). Materials & methods: The teeth divided in to four groups according to the type of irrigating solutions that used during root canal instrumentation with the use of normal saline as a control group, then each group sub divided in groups according to the instrument used in the root canal preparation, then after irrigation and preparation the roots sliced and root dentin microhardness measured using Vicker,s microhardness machine. Results: The result of this study showed that the type of instrument and Chlorhexidine have no effect on the microhardness of root canal dentin while Sodium Hypochlorite significantly decrease the microhardness of root canal dentin especially when use with Stainless Steel K-files and Nickel-Titanium K-files than when used with rotary Nickel-Titanium files. Conclusion: The microhardness of root canal dentin not affected by the type of root canal instruments.,The use of 5.25% Sodium Hypoch-lorite as a root canal irrigation significantly reduce the microhardness of root dentin within 3 mi-nutes., The use of Sodium Hypochlorite as a root canal irrigant with stainless steel K-files or Nickel-Titanium K-files reduce the microhardness of root canal dentin to greater extend than when use with rotary Nickel-Titanium files because the working time required with Stainless Steel K-files or Nickel-Titanium K-files was on the average three times longer than the working time with rotary Nickel-Titanium files. The use of sodium hypochlorite as a root canal irrigant with stainless steel K-files or Nickel-Titanium K-files reduce the microhardness of root canal dentin

Abstract: Aims: To identify the clinical picture and the association between dry socket and severe postoperative development with one of the systemic risk factors (typhoid fever). Materials and Methods: Twenty adult (both sexes) patients attended dental clinic searching for different dental treatments were studied. The clinical picture of 6 months period study was evaluated by completing two case sheet forms. They were diagnosed having dry sockets and severe postoperative pain. Blood samples were taken for bacte-riological, serological and hematological study to diagnose typhoid fever. These tests included WAT, WFT, WBCs and blood culture. Results: Significant correlation existed between postoperative pain and typhoid fever examined by BC and the highest percentage was with dry socket (61.5%) followed by WFT (57.1%(, WAT (44.4%) using two tests for diagnosis showed that WFT and BC gave 97.9% positive for dry socket and Kappa test was 88%, while WAT and WBCs or WFT and WAT gave the least non significant correlation. Conclusion: There was a strong correlation between dry socket and typhoid fever and the most sensitive tests for diagnosis was BC followed by WFT, WBCs and WAT.

Abstract: AIMS: To determine the effect of different denture cleansers on hue, value, and chroma of permanent silicone soft liner at different immersion periods. MATERIALS AND METHODS: Soft liner speci-mens were immersed in four denture cleansers (“citric acid + soda”, salt, “apple vinegar + soda”, and alum) for periods of 1, 3, 7, and 14 days. A digital spectrophotometer was used to access color differ-ences of soft liner before and after each storage period in each solution. RESULTS: The citric acid and salt cleansers decrease the value, chroma, and hue. The apple vinegar cleanser does not affect signifi-cantly any color property. The alum cleanser decrease value and chroma, but does not affect hue of soft liner. CONCLUSIONS: The effects of different denture cleansers tested on different color properties of soft liner were different. The effect of the immersion period on the different color properties tested was different for each denture cleanser.

Abstract: Aim: Using scanner image to digitally analyze the brightness and the effect of the type the of material, thickness and immersion of material in different solutions on the color change of the heat-cured acrylic resin denture base material. Materials and Methods: Two types of heat-cured acrylic resin denture base material were used. Totally 30 samples were prepared for uniform dimension for each color test. Sample scanner imaged and color metric is analyzed with software program Adob Photoshop 9.0. The CommissionInte´rnationale de l’E´ clairage for characterizing color ( CIE L*a*b*) color difference metrics were used for the performance analysis. Color change (ΔE) value calculated to determine clini-cally acceptable color change. Statistically ANOVA, Student's t–test , Dunnett pairwise multiple com-parison t–test and Duncan's multiple range test were carried out to determine the significant differences at p≤ 0.05 . Results: The results appeared that there is a significant differences of the brightness value before and after polishing of the acrylic resin samples. And statistically there is a significant effect of type, thickness, and immersion in different solution on the color change of the tested materials which is clinically not acceptable . Conclusion : The result appeared that scanner gives an accurate image to digitally evaluate brightness and color change of dental materials with CIE L*a*b*color system.

Abstract: Aims: To evaluate and compare the effect of human saliva, artificial saliva and propolis extract on the wettability of heat−cured and visible light −cured denture base material .Materials and Methods: A total of 80 samples were prepared , 40 samples prepared from heat cured resin and the other 40 samples were prepared from light cured resin. These two groups were divided into four subgroups, control group, human saliva, artificial saliva and propolis. Contact angle measurements by sessile drop method with a micropipette using digital camera to determine the wettability of these samples. Mean values were compared statistically with one way analysis of variance (ANOVA),Duncan's multiple range test and t−test to determine the significant difference among the tested groups. Results: There is a signifi-cant differences of the mean values of the contact angle among the tested groups. The contact angle significantly decreased in all the treated samples. Conclusion: Heat cured resin has more wettability than light cured resin. Human saliva, artificial saliva and propolis increased the wettability of both heat cured and light cured resin

Abstract: Aim: To evaluate the response of intraoral soft tissue by low level laser light, histologically and bio-chemically. Materials and methods: The study was performed on (20) healthy rats. A clean two sided mucoperiosteal flap was raised opposite to the area of lower incisors. The rats were divided into two groups, ten for each. Histological specimens were taken at days 5th,9thand 11th postoperative period .The dose of laser therapy in each session was 0.75 J/cm2. Each rat in each group received this dose daily for 11thdays at an interval of 15 minutes. Histopathological analysis were made for both groups detecting number of blood vessels (neovascularization),collagen arrangements and number of fibrob-lasts. Biochemical analysis of C-reactive protein(CRP) was also conducted. Results: Laser therapy showed enhancement of neovasculazation at days 5and 9 postoperatively .While collagen arrangement showed significant changes at the 5th ,9th and 11th postoperative days. Biochemical analysis showed significant increase of CRP at the 5th postoperative day. This increase was followed by a significant decrease at the 7th postoperative day in comparison with the control group. Conclusion: The present results indicated that low level laser therapy at a dose of 0.75 J/cm2 enhanced wound healing .

Abstract: Aims: To determine the effect of risk factors such as income level, socioeconomic status, parents education, brushing behavior , dental attendance, type of treatment performed and others on dental ca-ries severity of permanent teeth. Materials and Methods: Sample size was (531) students (260 males and 271 females) who were selected randomly from (10) primary and intermediate schools in Mosul City, their ages were ranged between (6-16) years. Risk factors considered on caries severity included parent's income level, parent's education, visiting the dentist, types of dental treatment performed and brushing behavior. Distribution of dental caries on each side of the mouth, DMFT and the percentage of caries free students were also considered. Caries severity was measured using International Caries Detection and Assessment System. Results: These factors have an effect to increase or decrease caries severity either significantly or not significantly. Conclusion: These risk factors should be kept in mind when we decide to reduce caries severity.

Abstract: Aims: The study aims to evaluate the influence of various denture cleansers on colonization of Candi-da albicans to Cobalt–Chromium alloy denture base and the subsequent roughness assosiated with these cleansers. Materials and methods: Thirty–six samples of Co–Cr denture base and five cleansers, four prepared(alum, salt, soda+vinegar, soda+thymol), one commercial ( protefix ) and distilled wa-ter(D.W) as a control were used. Samples were immersed in denture cleansers for one month in which each cleanser had 6 samples excluding 6 samples in D.W as a control. Half of samples for each cleans-er were immersed ½ hr per day and the other half immersed 8hrs per day through one month, before microbiological examination, samples were tested for surface roughness using profilometer. Candida albicans cell suspension was incubated with the test samples for 1hr at 37°C after which the test sam-ples were immersed in their cleansers for 1hr. Visualization, inspection and enumeration of adherent C.albicans cells and detection of the anti–adherent effect of the cleansers was achieved by using light microscopy. Results: The results demonstrated insignificant difference in surface roughness of Co–Cr alloy denture base in the cleansers at 1/2 hr and a significant difference at 8 hrs immersion. There was a significant difference in C.albicans colonization to Co–Cr denture base in which all the cleansers showed less adhesion than control. The results also revealed that (soda+Thymol oil) cleanser ex-pressed the least values of colonization and roughness among other cleansers. Conclusions: The cleansers were effective as anti–adherent yeast cells to Co–Cr denture base and showed roughness de-grees less than control

Abstract: Aims: To determine the prevalence and severity of attachment loss and bone loss among smokers and to compare them with non smokers and to assess the effect of cefepime compared to doxycycline in the outcomes of healing of these periodontal diseases in smoker patients. Materials and Methods: This study was carried out on 80 patients, half of which were smokers(40) and the other were nonsmokers, aged from 20 – 50 years, attending the teaching dental clinics in the College of Dentistry, University of Mosul. Questionnaire of smoking habit was applied on smoker patients. Clinical measurements were done including attachment loss and carried out according to Ramfjord gingival sulcus measurement index, Bone loss was measured radiographically with an x – ray unit. A total of 40 smoker patients were received supportive periodontal therapy and then randomly divided into 2 groups, first group (20 patients) were treated by cefepime powder mixed with distilled water and second group (20 patients) were treated by doxycycline powder mixed with distilled water. Both drugs were injected into peri-odontal pocket and remained in the oral cavity for 15 min then rinsed with distilled water. Each patient receive one session of treatment / once a week for 6 months. Clinical and ragiographical parameters of attachment and bone loss were measured at baseline , 2, 4 and 6 months recall visits. Results: Un-paired t – test was used for statistical analysis of the data and there were significant differences of at-tachment loss (p≤ 0.000) and bone loss (p≤ 0.001) between smoker and non smokers . There were no significant differences between smokers treated with cefepime compared to those treated by doxycyc-line for attachment loss (before treatment p≤0.893, after treatment p< 0.668) and for bone loss (before treatment p<1.000, after treatment p< 0.849). Conclusions: Tobacco use is an important variable af-fecting the health of periodontal tissues. Topical application of antimicrobial agents at the site of peri-odontal diseases may be a useful adjunct to the conventional periodontal treatment.

Abstract: Aim: To evaluate the effect of two bonding systems and two curing systems on sealing ability of class V composite restorative materials. Materials and methods: This study was performed in vitro on 40 caries free upper first premolar teeth. The Standardized class V cavity preparation on buccal and lin-gual surfaces of each tooth was done. Then the teeth were randomly divided into two major groups each of twenty. 40 cavities were performed on these teeth and the first group7th generation bonding agent (i Bond) were applied according to the manufacturer instructions and single increment of univer-sal composite (XRV Herculite) from kerr were applied and twenty of the cavities were cured with con-ventional light cure device (astralis-5) and the other twenty cavities were cured with a LED. While the second group 5th generation (Excite bonding agent) applied according to the manufacturer instructions. And filled with universal composite (tetric).Twenty of the cavities light cured with conventional light cure device and the other twenty cavities cured with LED light cured device. Then the teeth were stored in normal physiological saline in an incubator at (37Co) half of each sub group (10 cavities) were stored for one day and the second half stored for one week. Then the teeth were thermo cycled for (200) cycles, after thermo cycling all teeth were immersed in a freshly prepared solution of 2% methylene blue for (24) hours at (37Co). Results: The results showed that there was no statistically significant difference between samples cured using conventional light curing system and those cured using LED light curing system. The type of bonding system and composite material used in this study had no sig-nificant effect on reducing microleakage. Samples aged for seven days produced significantly higher levels of microleakage than that for one day. Conclusions: All samples in this study showed microlea-kage with different levels. Microleakage increases as the age increases. Neither the types of light curing system nor the types of bonding were able to reduce microleakage.

Abstract: Aims: . To investigate the rates of space closure achieved by elastomeric chain and nickel titanium coil springs with the evaluation of the effects of using different bracket types on the rate of space closure during its retraction along different sizes of orthodontic arch wires using typodont simulation system (Ormco). Materials and Methods: The standardization criteria were all typodont teeth situated in well aligned position, covered and immobilized by the acrylic bite except canine, elastic chain and nickel – titanium closed coil spring exerting 180 gm of force on canine measured carefully by tension gauge. The available space was 13.5mm (the rate of space closure). Results: The present study showed that when using elastic chain as a method of canine retraction gave rise to a a significant decrease in the rate of space closure as compared with nickel – titanium closed coil spring also sliding the canine using ceramic brackets gave rise significant reduction in the rate of space closure than when using stainless steel brackets. Another finding of the present study showed that sliding the canine on large rectangular arch wire (0.019x0.025 inch) gave rise to a significant reduction in the rate of space closure when com-pared with 0.018 inch and 0.018x0.022 inch arch wires were used. Conclusions: It was concluded that the canine retraction with 0.018 inch wire on Roth stainless steel bracket by closed coil spring gave rise a large amount of space closure rate. While the opposite is true for canine retraction with 0.019x0.025 inch wire on standard ceramic bracket by elastic chain retraction method.

Abstract: Aims: This study aimed to assess the relationship between upper and lower incisors and soft tissue fa-cial profile. Materials and methods: The sample included forty eight Iraqi adults (22 men, 26 women) with Class I normal occlusion. Seven soft tissue parameters and six skeletal and incisal parameters were measured on lateral cephalometric radiographs. The data were analyzed using independent sample t test and Pearson correlation analysis. Results: sexual dimorphism was reported only for soft tissue convexity angle and interlabial angle. The results also showed correlation between incisor parameters and soft tissue parameters. Lower incisor inclination showed negative correlation with soft tissue pro-file angle for male and total samples. While both upper and lower incisors positions showed positive correlation with upper lip/NP angle and soft tissue pogonion/NP distance. Positive correlation was no-ticed between interincisal angle and soft tissue profile convexity angle for the total sample. Conclu-sions: upper and lower incisors are correlated to the overlying soft tissue structures. This correlation was mostly significant for the upper lip vermilion, upper lip base and tip of the nose.

Abstract: Aims: To prepare a newly designed diagnostic digital chart for orthodontic patients, and to help or-thodontist making decision in term of diagnosis and treatment planning by using Access program to determine the ideal orthodontic treatment of a patient to provide optimum orthodontic appliances for such treatment. Materials and Methods: A newly designed diagnostic digital chart for orthodontic patients was designed using Access program containing sixteen program forms of examination, diag-nosis and treatment plan. In order to evaluate this newly designed digital chart, Multiple Linear Re-gression Analysis was used. This analysis aims to reveal the importance, strength and direction of factors (26 independent variables= constant variables) and their effects on the 12 dependent variables (random variables) [parameter estimation],all of which representing the information and data taken from fifty randomly selected orthodontic patients' files available in the Department of Orthodontics-College of Dentistry-University of Mosul, who were treated with removable appliances by dental stu-dents of fifth class during year 2007-2008. The effects of the independent variables vary in negative or positive way, or even may have zero effect depend on the studied dependent variable. Results :R square measures the proportion of the variability in the dependent variable about the origin explained by regression. The least variability is in y1(right 1st molar occlusion),where as the highest one in y4(left canine occlusion),{R-Sq for y 1 =0.0%, y2=57.8%, y3= 41.1%, y4=65.6%, y5=32.0%, y6 = 50.9%, y7= 60.5% , y8=62.8%, y9=51.6%, y19=61 .3%, y11=28.2% and y12=51.5%}, each value representing the importance, strength and direction of independent factors and their effects on the dependent factors. Conclusions: New digital orthodontic examination and diagnosis chart was pre-pared. The creation of a digital chart that combines the use of information technology with a consis-tent analysis to aid orthodontic diagnosis will be a relevant contribution to the improvement of ortho-dontic care in POP Department in College of Dentistry/Mosul University.

Abstract: Aims: To determine the amount of force degradation of three types of orthodontic traction aid polyure-thane elastomeric chain (PEC), nickel titanium closed coil spring (NiTi CCS) and stainless steel closed coil spring (SS CCS). Material and methods: Samples were extended to a specific distance which was 18 mm in case of PEC and 20 mm in case of NiTi CCS and SS CCS. Each extended sample will then incubated in dry condition, artificial saliva, and mouthwash solution, for total incubation period of three weeks. Results: showed that samples in dry condition always showed minimum force degrada-tion percent than in wet conditions. It also showed that the increase of incubation time leads to increase in force degradation percent with major degradation percent located within first twenty four hours. Conclusions: in dry and two wet conditions, NiTi CCS reflects the lowest percent of force degradation, PEC showed highest percent, while SS CCS showed intermediate one.

Abstract: Aims: To assess the severity of dental caries and its relation to risk factors such as parents' education, income level, demographic variables, dental attendance….etc using the International Caries Detection and Assessment System on the primary teeth of kindergarten children in Mosul City Center. Materials and Methods: The study sample was randomly selected from (8) kindergarten in Mosul City. The sample size was (219) child (120 males and 99 females), their ages ranged between (3-6) years. Risk factors considered on caries severity included parent's income level, parent's education, visiting the dentist, types of dental treatment performed and brushing behavior. dmft and the percentage of caries free students were also considered. Caries severity was measured using International Caries Detection and Assessment System. Results: These factors have an effect to increase or decrease caries severity either significantly or not significantly. Conclusion: considerable efforts are required in prevention of dental caries in these children. There is a lot of untreated caries, which needs immediate attention.

Abstract: Aims : To evaluate the correlations between the skeletal measurements and soft tissue measurements in males and females. Materials and Methods: Eighty students (40 males and 40 females) were selected aged (12-14) years with class I normal occlusion from intermediate schools in Mosul City . A standar-dized lateral cephalometric radiograph was taken for each student, eighteen variables, 9 angular (6 ske-letal and 3 soft tissue ) and 9 linear (3 skeletal and 6 soft tissue) were used in this study. Results: In males, angle of facial convexity positively correlated with angle of skeletal convexity and negatively with the angle describes the relationship of the maxillary and mandibular bases in the sagittal planes.The length of mandibular corpus was positively correlated with upper lip thickness, lower lip thickness at labral inferius and upper lip height . Upper lip thickness at labral superius was positively correlated with angle defines the anteroposterior position of maxilla in relation to anterior cranial base and angle indicates the anteroposterior position of the mandible in relation to the anterior cranial base.Lower lip height was positively correlated with the mandibular plane angle .In females, angle of facial convexity was positively correlated with angle of skeletal convexity and negatively with the an-gle describes the relationship of the maxillary and mandibular bases in the sagittal planes. The angle measures the protrusion of upper lip relative to the inferior border of the nose was negatively correlated with angle of skeletal convexity and mandibular length and positively with angle describes the relation-ship of the maxillary and mandibular bases in the sagittal planes.Angle of skeletal convexity was posi-tively correlated with upper lip thickness at point A and upper lip thickness at labral superius . The mandibular plane angle was positively correlated with lower lip height. The angle describes the rela-tionship of the maxillary and mandibular bases in the sagittal planes was positively correlated with labiomental angle and negatively with upper lip thickness at labral superius . The mandibular length was negatively correlated with labiomental angle and positively with upper lip thickness at point A ,upper lip thickness at labral superius , lower lip thickness , soft tissue thickness at the chin , upper lip height and lower lip height . The length of the mandibular corpus was negatively correlated with labi-omantal angle and positively with upper lip thickness at point A and upper lip thickness at labral supe-rius .The length of the maxilla was positively correlated with upper lip thickness at point A , upper lip thickness at labral superius and lower lip thickness. Conclusions:There were no consistend correlations between soft and hard tissue structures , some are positively correlated others are negatively correlated and some of them are completely independent.

Abstract: Aims: To evaluate the effect of three different cleanser on the color stability of three different types of artificial teeth. Materials and methods: sixty samples of artificial anterior teeth were prepared which are Acry-Rock, RMH teeth and Porcelain teeth and immersed in three types of denture cleanser(Bony plus, Protefix and soda+ vinegar) for 8 hours and the color of the teeth was measured by Easyshade's spectrophotometer at 3 intervals(1,2and4weeks). Results: Showed that the a'b values of ceramic teeth and L value of RHM teeth were significantly differencent after 2 week of immersion in three type of denture cleanser. Analysis of variance demonstrated that L'a'b value for ceramic teeth and RHN teeth were statistically significant after 4 week immersion in three type of denture cleanser, The result of color change (ΔE) for three denture cleansers of three periods of immersion were clinically accepted. Conclusion: Long period of immersion of artificial teeth in denture cleanser cause significant color change for L*a*b* values but they were clinically accepted.