Abstract: Aims: To study the effect of stress and fear on blood pressure that are imposed on student before attending examination in particular final year examination at the College of Dentistry. Subjects and Methods: Arterial blood pressure (indirect method ) was measured for 99 dental student (21 + 0.6 years) before 30 minutes of final examination on a particular subject and immediately after examination. Result: The data reflected a significant increase in systolic blood pressure before passing the final examination, whereas there was no significant increase in the diastolic blood pressure in all students. Conclusions: Stress produces a significant elevation in blood pressure that can be controlled by systemic defense mechanisms naturally present.

Abstract: Aims: To identify the cephalometric features of three skeletal jaw relations (Class I, II and III). Materials and methods: one hundred thirty four students were selected aged 12–15 years from secondary schools in Mosul City, 45 with Class I normal occlusion as control, 44 with Class II malocclusion and 45 with Class III malocclusion, after taking the lateral cephalometric radiographs according to ANB angle. A 20 variables (12 angular and 8 linear) were used in this study to correlate these variables in the three skeletal Classes. Results: No significant sex differences were observed for the majority of angular and linear measurements for the three skeletal types. Anterior cranial base length (S–N) and saddle angle (NSAr) didn’t show significant difference among the three skeletal Classes, the posterior cranial base (S–Ar) was shorter in Class III which indicate the anterior articulation of the mandible. The length of maxillary base (ANS–PNS) was longer in Class II than Class I and III which lead to maxillary prognathism. The body length of the mandible (Go– Pog),effective mandibular length (Ar–Gn) and lower anterior face height was significantly longer in Class III which lead to mandibular prognathism. The SNA angle was significantly smaller in Class III than in the others. SNB and SNPog angles were larger in Class III followed by Class I and then Class II. The gonial angle (Ar–Go– Me) was larger in Class III which acts to increase mandibular effective length. The (N–A–Pog) showed as convex in Class II and concave in Class III. (The U1–PP) angle was larger in Class II followed by Class I and then by Class III. The (L1–MP) angle in Class II and III was significantly smaller than in Class I. Conclusion: Most of the angular and linear measurements indicated that the skeletal differences between the Class I, Class II and Class III are concentrated with in the maxillary and mandibular bases in both the anteroposterior and vertical dimensions and their type of articulation. The dental measurements appear to be compensated with that of skeletal one. Also these variables showed no significant sex differences in the majority of their measurements

Abstract: Aims: To determine the most accurate impression techniques and materials to transfer the exact position of a single implant to stone die to construct the prosthesis for selected clinical cases. Materials and methods: Five clinical cases were selected with special criteria to construct implant (Frialit–2) prosthesis on a stone die with high accuracy according to the results of study. Four impression techniques were used (direct and indirect, each with one and two steps) using condensation, addition (heavy, medium and light consistencies) silicone impression materials. Ten impressions were taken for each patient to produce a total number of 50 stone casts. The direct and indirect measurements were performed by using digital vernier. Results: The significant differences between the impression techniques at the three axes of dimensions (p ≤0.05) were applied clinically to construct the fixed prosthesis for each patient. The results of this study showed that the high dimensional change of laboratory cast was related to indirect one step impression technique to transform the implant position from patient mouth to laboratory cast. Addition curing (medium consistency) silicone impression material produced the lowest accurate stone die. Conclusions: The results of this study showed that the direct two steps impression technique was the accurate impression technique for transformation of implant position from patient mouth to laboratory cast. Additional curing (light and heavy consistency) silicone impression material produced the most accurate stone die and gave a successful treatment to the patient.

Abstract: Aims: To determine the level of oral health knowledge, attitude and behavior among first year university students in Mosul city, to compare this level among different Colleges also between males and females. Then the obtained results were compared with those of other studies carried out on similar age groups in other countries, to see if there was any significant difference between them. Materials and Methods: Nine Colleges were randomly selected from Mosul University, from each College a fifty random sample was selected to complete the questionnaires in the classroom. The questionnaires’ language was in Arabic included a number of questions related to oral health knowledge, attitude and behavior. Incomplete questionnaires were neglected. The size of the sample was 425 students, 216 males and 209 females. Statistical analysis included calculation of frequency, percentage of answers, and chi-square test. Results: Most of the students (93.2%) brushed their teeth and the majority of them (54.8%) engaged in once daily brushing, less than half of them (48.7%) using other means of teeth cleansing aids. A large percent of them had no ideas about the causes of dental caries (75.5%), and how to avoid it (76%). Their knowledge was poor regarding the age at which the primary and permanent teeth erupted( 23.8%, 22.8%) and completed (18.6%, 27.3%). More than half of the students (54.6%) had gingival bleeding but they didn’t know the cause of the bleeding (75.1%) and how to avoid it (75.5%). Most of them like eating sweets (82.1%). Small percent (22.4%) knew what is fluoride and its benefit in reducing dental caries (17.9%). Regarding sex differences, females’ answers were in general better than those for males. Conclusion: College students seemed to have appropriate knowledge and behavior on some oral health topics but these were limited on the others. Health education needs to be done at universities for enhancing their knowledge attitude and behaviors

Abstract: Aims: To explore the upper lip thicknesses, height and it's relationship to the esthetic line. Materials and Methods: The studying sample included 48, 41, 50 and 44 individuals of age 11, 12, 13 and 14 years respectively. The subjects were Iraqi individuals of Class I normal occlusion, who live in center of Mosul City. All subjects were radiographed with lateral cephalometric films, these films were traced, the tracing included the upper lip thickness at skeletal points (A–A´ ), upper lip thickness at labrale superius (Ls–Ls´), upper lip height at stromion superior to palatal plane and the upper lip relationship to the esthetic line. All these measurements were measured and then subjected to the statistical analysis. Results: The results were demonstrated that the upper lip thickness (A–A`) and (Ls–Ls`) were only significant increase at 14 year age groups as compared with 11 years age group in males. In female the upper lip thickness was only significant at 13 years group as compared with 11 years age group, while the upper lip relationship to esthetic line showed only significantly greater value at 14 years age group as compared with 13 years age group. Sex variation appeared a significant greater value in male than female for the (Ls–E line) at 11 years age group, (A–A`) and (Ls–E line) at 12 years age group, (Ls–Ls`) at 13 years age group and upper lip height at 14 years age group and upper lip height at 14 years age group. Conclusions: The soft tissue of upper lip profile parameters were increased with increasing age group, and the upper lip significantly larger behind the esthetic line in female than male at 11, 12 and 14 years age groups.

Abstract: Aims: To evaluate some of the physical properties which are transverse strength, tensile strength, surface hardness, water sorption and solubility of the auto–cured acrylic resin when copolymerized with epoxy resin at two different ratios 10% and 20% of its weight and then compared with that of auto–cured alone and heat–cured acrylic resin alone. materials and methods: The tested samples were divided into four groups according to the materials to be used and the samples of each group were subdivided according to the test to be done. The samples were prepared according to ADA Specification No. 12. Statistically analysis of the physical properties was with (ANOVA) and Duncan's multiple range test to determine significant different at (p ≤ 0.05 ) level of significance, and the mean value of the water sorption and solubility ratios compared with accepted limit of ADA Specification No. 12. Results: The transverse strength, tensile strength and surface hardness in this study showed that there was a highly significant difference between the four tested groups. The result appeared improving of the mechanical properties and decreasing the ratio of water sorption and solubility of the auto–cured acrylic resin and the resin was reinforced when copolymerized at 10%, but the values still not reached that of the heat–cured acrylic resin and they became worse when copolymerized at 20%.

Abstract: Aims: To compare the compressive strength of refractory casts made from investments for cobalt– chromium and investment for titanium and to study the effect of mixing fluid on compressive strength. Materials and Methods: Three types of investments were used, one for titanium and two for cobalt– chromium, each one is mixed with three types of mixing fluids; tap water, distilled water and special liquid, to produce refractory casts. Compressive strength test was carried out using compression testing machine. Results: Showed significant differences in compressive strength between the types of investments, with titanium investment mixed with special liquid showed the highest value. There were significant differences between subgroups of the same type by changing mixing fluid type. Conclusions: Refractory casts made from titanium investment showed significantly higher compressive strength than refractory casts made from Co–Cr investments, and there was a difference between the two special liquids used, and tap water in which it produced casts with higher compressive strength than distilled water in two out of the three investment materials tested.

Abstract: Aims: To evaluate the porosity that occur in the acrylic resin denture base polymerized by the microwave cycle and conventional water bath with two different thickness, relation between the thickness of specimen and its percentage of porosity. Material and methods: Forty rectangular resin specimens with the following dimensions (65×40×6mm), (65×40×3mm) were subdivided according to polymerization method into microwave cycle and conventional heat polymerization method to obtain 10 specimens with different polymerization method and thickness, for each one of 4 groups. Porosity was calculated by measure the specimen volume before and after its immersion in water, data were analyzed by student t–test analysis at ( p< 0.05). Results: Showed that specimens of (6mm) that cured by microwave polymerization method showed significantly higher percentage of porosity when compared to the same thickness of conventional water bath polymerized acrylic resin at (p<0.05), while no significant difference between the percentage porosity of the conventional and microwave heat cured acrylic resin of (3mm) thickness specimens. Also there is no significant difference between the thickness of specimen and the conventional water bath method of heat cured acrylic resin. While for microwave curing method of heat cured acrylic resin there is significant difference for increase of percentage of porosity with increase of thickness of specimens. Conclusions: The conventional acrylic resin of (≥3mm) specimens thickness can be polymerized with microwave curing method safely with less porosity , while for (≥ 6mm) specimens thickness is preferred to be polymerized by conventional water bath curing method

Abstract: Aims: To evaluate the oral hygiene and gingival health among secondary school students and to find if there was any variation between age and sex groups in Mosul City Centre. Material and Methods: A sample of 630 students aged 16–18 years old (278 males, 352 females) were examined using plaque index score and gingival index. The clinical examinations were carried out in the school using plane mouth mirrors, WHO periodontal probes to detect the dental plaque and gingival health. Results: Showed that the mean plaque score for the total sample was 0.96, the plaque index increased with age. Females reported less mean plaque scores than males with statistically significant difference between them. The mean gingival score was 0.56 for the total sample and it increased with age. There was a significant difference between males and females. The study revealed that 35.9% of the total sample did not brush their teeth. Therefore the objective of dental health education to those subjects is to brush their teeth regularly and to improve the effectiveness of oral hygiene practice. Conclusion: Periodontal disease is indirectly related to the exposure of bacterial plaque for long time which calls for coordinated planning of preventive strategies and urgent priorities

Abstract: Aims: To evaluate the effect of the different curing methods conventional water bath heat–curing and microwave energy curing method and different immersion periods on the water sorption and solubility of the different types of heat–cured acrylic resins. Materials and methods: Water sorption and solubility were measured by means of mass change in the materials after water saturation and dehydration. Two different commercial heat–cured acrylic resins Major Base 2, and Quayle Dental resins were used in this study. Specimens were divided into two groups depending on the curing method. Thirty two specimens were prepared, eight specimens for each material in each group. Specimens were immersed in distilled water, and then subsequently removed from their containers at 1 week and 1 month of immersion for evaluation. Mean values wear compared statistically with one way analysis of variance followed by Duncan's multiple range test to determined the significant different among the groups at (p< 0.05) level of significance. Results: showed that the curing method and immersion period have a significant effect on the water sorption and solubility ratios of the resins. Curing by microwave energy method and increasing immersion period caused increasing in the ratios. The type of heat–cured acrylic resin has an effect but the difference was not significant. Conclusion: the curing method, immersion period and types of the acrylic resin have an effect on the absorption and solubility ratios.

Abstract: Aims: To study the effect of different curing modes of Light emitting diodes (LED) curing unit on the depth of cure (DOC) of composite resin with light and dark shades and compare the results with conventional curing method by the use of halogen curing light. Materials and Methods: A total of 40 cylindrical composite resin samples (4mm diameter and 6mm height) were prepared, 20 of light shade and 20 of dark shade. They were subjected to four curing modes (n=5 for each group): conventional halogen light, and three modes related to the LED light curing unit (LCU) which were: Fast (F); Ramped (R); and Pulsed (P). The samples were irradiated to the time required by the manufacturer for each curing mode, and a digital micrometer was used to measure the depth of cure according to scraping method described in ISO 4049:2000. Data were collected and analyzed for comparison. Results: No significant difference was found in the DOC of composite irradiated by LED curing light for all of the three curing modes or shade. However, the LED produced significantly greater depths of cure when compared with conventional halogen curing unit for both shades. The lighter shade was cured to a significantly greater depth than dark one when considering halogen LCU. Conclusions: All curing modes of the LED light can produce similar DOC regardless of composite shade when irradiated to the time recommended by the manufacturer. However, Curing with conventional halogen curing unit yielded the least DOC values for light or dark shades when compared with LED units. Longer irradiation times are needed to cure dark shades by the use of halogen LCUs.

Abstract: Aims: To investigate the characteristic of patients attending College of Dentistry at Mosul University, the chief complaint which make them seeking dental treatment, and the final diagnosis of their problems .Materials and Methods: 760 patients attended to oral diagnosis were examined .The patients age ,sex & marital state were recorded & the reason for seeking dental treatment. Results: The research revealed that a total of 760 patients presented to the oral diagnosis clinic in a period of about one year. Of them 41.18% were males and the remaining 58.82% were females. The single patient percentage was 55.26%, while percentage of married patients was 44.74%. The predominant age was 20–29 years age group (28.81%). The most common chief complaint was pain (34.73%). The less common complaints were: check up, esthetic, and tooth replacement with percentages of 27.5%, 18.55%, and 6.05% respectively. It was found that the frequency of esthetic and check up were higher in the youngest age groups than in the older age groups. The percentage of esthetic complaint was more in female, while pain and check up were higher in male patients. Pain complaint was higher in married patients, while check up was more frequent in single patients. Esthetic complaint was equal in both groups. Conclusions: It was found that the most common diagnosis was dental caries (31.97%) this followed by pulpitis (21.05%) and periapical lesion (14.07%).

Abstract: Aims: A pilot study was done to evaluate the physical and mechanical properties of the Iraqi plaster (Al- Ahliya gypsum) and Plaster of Paris (British Gypsum), and to improve the quality by the incorporation of some additives. Materials and Methods: Two types of gypsum products were used in this study (Iraqi plaster, Plaster of Paris). Three types of additives {gum arabic at a concentration of (0.1%, 0.25%, 0.35%, 0.50%), calcium oxide at a concentration of (0.1%, 0.25%, 0.35%, 0.50%, 0.75%), and ferric oxide acts as a pigment (blue or red) at a concentration of (0.1%, 0.2%)} were incorporated after preparation into the weighted dried gypsum powder. The effects of these additives on the physical and mechanical properties of the experimental gypsum products (Iraqi plaster and Plaster of Paris) have been evaluated by measuring the water/powder ratio, setting time, linear setting expansion, and compressive strength. Four hundred sixty gypsum samples were prepared for this study. Mean, standard deviation, variance (ANOVA), and Duncan's multiple range tests were used to analyze the measurements. Results: ANOVA showed that there was a significant difference in the water/ powder ratio, setting time, linear setting expansion, and compressive strength between Iraqi plaster and Plaster of Paris depending upon the type and the concentration of each additive used. Conclusions: The last concentration of each additive (gum arabic 0.5%, calcium oxide 0.75%, or ferric oxide 0.2%) in all the experimental measurements that are incorporated within the two gypsum products showed

Abstract: Aims: To evaluate the effects of the micro–etching procedure on the bracket’s slot and base parameters and on the tensile bond strength of the recycled brackets. Materials and Methods: The sample was 20 stainless brackets grouped into; control brackets group(10) and de–bonded brackets group(10). The de–bonded brackets reconditioned with micro–etcher. the data subjected to the statistical analysis at ≤ 0.05 significant level. Results: demonstrated that the use of micro–etcher for recycling the de–bonded brackets do not affect the bracket’s slot and base parameters whereas affected the bond strength of the recycled brackets. Conclusion: The micro–etcher (sand basting) is recommended for recycling the de–bonded stainless steal brackets and reuse them in orthodontic treatments

Abstract: Aims: To assessing and comparing the prevalence of fractured permanent incisors between pupils of age (6–15 years) for the right and left banks of Mosul Province Materials and Methods: A cross–sectional survey carried out through clinical examination of upper and lower permanent incisors for ten thousand and 915 children and teenagers between the age 6–15 years of old, who enrolled in the public primary schools of both right and left banks of Mosul city. All the pupils examined at their schools. The diagnosis and recording of the permanent teeth crown fracture registered according to Ellis classification. Results: The most frequent traumatized teeth occurred among pupils aged 8–9 years old in both banks (49.4%). Boys demonstrated more crown fractures than girls (6.4%, 4.2% respectively), at P ≤0.001. Statistically; Pupils with class II division 1 malocclusion, inadequate upper lip coverage were significantly more affected with crown fractures (70.5% for boys, and 58.6% for girls) . The most common type of the fracture was the fracture that involve the enamel–dentin with out pulpal involvement (46.7%). The aggressive and the hyperactive behaviours of the pupils significantly showed more crown fractures, and were more common in pupils of the right bank as compared with the pupils of the left bank (P ≤0.001). While no significant difference found between pupils of both banks concerning season of the crown trauma occurrence Conclusions: The prevalence of the crown fracture was 5.4% for the total sample, while the prevalence of the crown fractures for pupils of the right bank was statistically highly significant (6.7%) than the prevalence for pupils of the left bank (4.3%).