Abstract: Aim: to determine the validity of the ala–tragus technique in orienting the occlusal plane in complete denture construction for edentulous patients by evaluation of the edentulous patient response. Materials and methods: Twenty edentulous patients were selected according to specific criteria. Sixty sets of complete dentures (three sets for each edentulous patient) with three different occlusal planes parallel to the imaginary line between the inferior border of the ala of the nose, and superior, middle and inferior borders of the tragus were constructed. The grade of participants' response in this research was studied to report the degree of their participation with the occlusal plane of the complete denture they used through answering of Denture Patient Satisfaction Questionnaire (DPSQ) after one month of using each of the three randomly selected complete dentures. Mean and percentage of all the scores (four scores totally satisfied and unsatisfied, fairly satisfied and unsatisfied) were calculated to give an idea about the participants' response. Results: showed greatest participants’ satisfaction (75–90%) were obtained in the complete denture with middle and inferior occlusal planes. Patients satisfaction with denture 2 range between 80–90% regarding speech and chewing ability. Denture 3 (inferior occlusal plane) showed the greatest fairly satisfaction in 60% of patients originated from mandibular denture. Conclusion: most patients were satisfied with the dentures having occlusal plane be oriented parallel to the middle and inferior ala–tragus lines.

Abstract: Aim: to investigate the level of ala–tragus line of dentulous nearest to be parallel to the three levels of occlusal plane orientation in the complete denture construction, by evaluation of cephalometric measurements. Designing new special direct and indirect computer digitalization program, to analyze the cephalometric radiographs, or their tracing in the best treatment for edentulous patient. Materials and Methods: Twenty dentate participants in addition to the same group of part I (20 edentulous participants) fulfill specific criteria to investigate the validity of using the ala–tragus line as visible soft tissue guidance in orienting the occlusal plane. Eighty lateral cephalometric radiographs were done (one for each dentate, and three radiographs; one for each set of complete dentures). Special computerized program named CoDiC, which was developed in Matlab and Photoshop programs to analyze digital the colour density of the hard and soft tissue with tracing. Results: showed the occlusal plane of dentulous participants was parallel to ala–tragus line located between the middle and inferior point of the tragus of the ear. This result was coincide with results of occlusal plane orientation of edentulous patient. Computerized digitalization program “CoDiC” was designed and applied for cephalometric tracing and analysis to improve treatment of edentulous participants. Conclusions: There is a strong relationship between the occlusal plane and other craniofacial measurements especially those determinei-ng skeletal jaw relationshipand those determining facial types.

Abstract: Aims: To detect the levels of fluoride (F), zinc (Zn) and lead (Pb) in primary teeth and drinking water and their relation to dental caries experience in school children aged 6–12 years living in two distinct areas in Ninevah Governorate using two different sources of drinking water supply. Materials and Methods: The samples consisted of 120 freshly extracted highly mobile free of dental caries human primary mandibular teeth and ten wells water samples with ten tap water samples which had been chosen randomly. The samples were analyzed for F by fluoride sensitive electrode and for Zn and Pb by computerized atomic absorption spectrophotometer. Assessments and recording of caries experience were done by application of decayed, missing and filled surfaces (dmfs) index for primary dentition. Results: Statistical analysis of the results indicated that the mean F and Zn concentrations in the teeth were 244.35 + 167.49 ppm; 87.41+ 36.64 ppm respectively of the rural children were significantly higher than in the teeth of urban children (104.53 + 52.75 ppm; 65.19+ 28.79 ppm respectively). Meanwhile the concentration of Pb in the teeth of the urban children (1.62+0.41 ppm) was significantly higher than in the teeth of rural children (0.94+ 0.80 ppm)(p<0.001). Statistically significant higher F concentration in the wells water (3.39+ 0.25 ppm) than urban water supply (0.19+ 0.07 ppm) (p<0.001). Statistically significant higher Zn concentration in the urban water supply (0.1.34+ 0.31 ppm) than wells water (0.07+ 0.03 ppm) (p<0.001), but Pb concentration in wells water was not detected. Statistically significant higher caries experience was found in urban children than in rural (p<0.001). In the rural and urban areas, a negative correlation in the dmfs with F and Zn concentrations in teeth while a positive correlation with Pb was observed. Conclusions: A highly significant F and Zn concentrations in primary teeth were found in rural area than the urban and the opposite was true for Pb concentration. High significant F concentration was found in the wells water than urban water supply, and the opposite was true for Zn, but Pb concentration in wells water was not detected. High significant differences in dental caries indices were found in urban children than in rural children.

Abstract: Aim: To evaluate the effect of loops geometry (design) on the rate of space closure, degree of rotation, and degree of tipping. Materials and Methods: The sample consisted of 8 type of loops, namely vertical–loop, vertical with helix–loop, T–loop, readymade loop, PG (universal retraction spring)–loop, opus–loop, teardrop–loop, and L–loop. The method adapted in present study was carried out on Typodont simulation system. The data subjected to the descriptive and variance statistics at 0.05 significant level. Results: There was a significant difference between loops in rate of space closure, rotation and tipping. Vertical loops gave higher significance of rate of space closure and also higher significance degree of rotation and tipping when compared with other loops, while the readymade loop is lowest significance a rate of space closure but it gave low degree rotation and tipping. Although T–loop gave a rate of space closure less than vertical loops but it had the lowest significant degree of rotation and tipping. Conclusion: The T–loop is so more controls and simplest than other loops performing low significance of rotation and tipping tooth movements and achieving higher significance in rate of space closure,

Abstract: Aims: To evaluate the effect of amalgam alloy types, surface treatments, bonding agents, on the shear bond strength between set amalgam and resin composite restorative materials. Materials and Methods: Three hundred and thirty eight holes (6 mm in diameter and 2 mm depth) prepared in a 2x2.5 cm cold cure acrylic resin blocks in which amalgam was condensed. The 338 samples were divided into two groups, the control group which consisted of 26 intact amalgam samples, and the repair group consisted of 312 repair amalgam samples. Each group (intact, and repair) was subdivided into two groups according to the type of amalgam alloy. Half of the samples were filled with spherical amalgam alloy and the other were filled with admixed amalgam alloy. The repair samples then divided in to four groups according to the surface treatment, in turn each sub-group divided into three groups according to the bonding agent. The samples were thermocycled, before shear bond strength was tested. The mode of failure was observed for each specimen. Results and Conclusion: The statistical analysis showed that the repair strength was 50% of the intact strength, and the admixed amalgam samples showed higher shear bond strength than spherical amalgam samples. The group roughened with diamond bur showed higher repair bond strength than the groups received other surface treatment. The use of dentin bonding agent (All–Bond 2 and Alloybond) would increase the repair bond strength between the amal

Abstract: Aim: To assess the relation between the anterior dental crowding in Class I molar occlusion with the dental arch parameters in both dental arches and for both sexes. Materials and Methods: This study presented data from examination of the study casts for a sample of 106 maxillary and 142 mandibular dental arches of pupils of the intermediate school in Mosul City aged 12–15 years of Iraqi origin. The sample was divided into three main groups according to anterior dental crowding degree (0–2.0 mm, 2.1–4 mm and over 4.0 mm). This was done by calculation of dental arch space available (dental arch perimeter) by utilizing the segment arch technique. The six segment technique assessed by using a modified sliding caliper gauge. The mesio–distal crown width of each tooth was measured, to get the space necessary, and the difference between the space available and the space necessary is negative value represent the amount of crowding. The data was analyzed utilizing statistical analyses at p≤0.05 significant level. Results: all the dental arch parameters were insignificantly decreased throughout the three groups accompanied by increase in the degree of anterior dental crowding except the dental arch perimeter which decreased significantly, while intercanine and the canine–molar parameters were insignificantly increased in both dental arches and for both sexes. Conclusion: The inter–canine parameter increase in crowding case whereas the other parameters are decrease.

Abstract: Aim: to determine the prevalence of erosion in children and to compare different etiological factors related to dental erosion. Materials and Methods: A study of dental erosion conducted among 3125 children, 11–12 years old which represent delay mixed dentition in 27 primary schools in Mosul city, comprising a study group with 35 erosion children, 22) males and 13 females. The other compared controlled subject are 35 children without erosion and caries free random sampling matching for both age and sex. The level of erosion was recorded using modified tooth wear index (MTWI), standardized methods for salivary flow rate and PH measurements were conducted. The role of various possible factors related to oral health in general and to dental erosion in particular was assessed for both study and control groups by means of multiple choice questionnaire. Results: showed that the prevalence of erosion in the sample was 14.3% distributed as mild erosion (7.55%), moderate erosion (5.6%) and only sever erosion (1.15%). A significant lower salivary flow rate mean (0.38 + 0.38 ml/min) and salivary PH mean (7.35 + 0.37) in erosion group were found, whereas in the control group they were 0.47 + 0.19 ml/min and 7.50 + 0.25 respectively. The results demonstrated a significant higher fruit juice intake, carbonated drink intake in erosion group than in their controls. The erosion group showed no significant difference in drinking habit and time of drinking of the soft drink compared with control group. Conclusion: The dental practitioners must be aware of their important role to recognize dental erosion and understanding its pathogenesis so that correct diagnosis and management of erosion can be performed.

Abstract: Aim: To evaluate of the effects of using different methods of elastic chain attachment, different shapes of base arch wire (round and rectangular) and different ligation techniques on the rate of space closure, degree of tipping and degree of rotation of canine during translatory displacement of canine's bracket via wire using Typodont simulation system. Materials and Methods: Typodont teeth situated in well–aligned position, The criteria of the subject are covered and immobilized by the acrylic bite except canine; Elastic chain exerting 180gm of force on canine measured carefully by Tension Gauge; The available space was (14 mm) measured by digital vernia; The angle between bite plane extension bar and canine extension bar were (90) measured by protractor directly on a photograghs that were taken for Typodont using digital camera from both vertical and horizontal direction. The data were subjected to the statistical analysis at P≤ 0.05 significant level. Results: Canine sliding over rectangular arch wire gave rise to significant decrease in degree of tipping and rotation with significant reduction in rate of space closure, Second, stainless steel ligature and elastomeric ties of conventional ligation technique gave rise to a significant decrease in the degree of tipping and rotation with significant reduction in rate of space closure, elastic chain onto hook of canine bracket, gave rise to significant decrease of tipping and rotational degree with significant increase in rate of space closure. Conclusions: the methods in which elastic chain is attached to canine's hook using rectangular wire with elastomeric ties and the elastic chain is attached to canine's hook using rectangular wire with stainless steel ligature are favorable affecting canine sliding, where both were produced significantly the lowest degree of tipping and rotation with satisfactory rate of space closure.

Abstract: Aims: to determine the bactericidal efficiency of 0.75% Chlorhexidine in vitro . The time required for this irrigant to start its antimicrobial effect on the selected microorganisms isolated from the infected root canals and unidentified samples taken from root canals with necrotic pulps were evaluated. Materials and Methods: The substantive antimicrobial effect of 0.75% Chlorhexidine in vitro is also considered. Samples taken from 13 teeth with necrotic pulp from patients attended the Department of Conservative Dentistry, College of Dentistry at Mosul University. The turbidity method was applied to determine the antimicrobial effect of 0.75% Chlorhexidine and the combination of 0.5% Chlorhexidine and 0.5% sodium hypochlorite comparing with the antimicrobial effect of 2.5% sodium hypochlorite, the time required for these materials to start their antimicrobial effect on the selected microorganisms was determined using contact test. The antimicrobial effectiveness were evaluated at different time intervals, immediately, 5, 10, 15 minutes after the contact of the microorganisms with the irrigating solutions. Results: Both 0.75% Chlorhexidine and 2.5% sodium hypochlorite are effective on microorganisms collected from root canal. There is no significant difference between Chlorhexidine and sodium hypochlorite in their antimicrobial effect on the anaerobic microorganisms, but Chlorhexidine is more effective on the aerobic microorganisms. Conclusion: Chlorhexidine 0.75% and 2.5% sodium hypochlorite has an immediate effect on the selected microorganisms and unidentified samples from the teeth with necrotic pulps. The combination of Chlorhexidine 0.5% and 0.5% sodium hypochlorite has an effect started after 5 minutes

Abstract: Aims: To isolate and identify Actino–bacillus actinomycetemcomitans because of its importance in periodontal diseases, to show their incidence in periodontal infections, and to study their important virulence factors. Materials and Methods: The isolating procedure had been done through using the selective Dentaid–1 medium, with anaerobic cultivation at 37 °C for 48 hours, and different microscopic features and biochemical activities were carried out. Also the study included the detection of virulence factors that owned by this type of bacteria through various tests. Results: The rate of infection was 45% in patients suffering from periodontal disease and the isolated bacteria had the ability to adhere to human epithelial cells of the mouth, also had the ability to produce bacteriocins as the substantive factors for the bacterial growth among the closer species of bacteria, and the presence of capsule, which was the most important virulence factor. Susceptibility of the isolated bacteria to selected types of antibiotic showed that 100% of the isolates were sensitive to tetracycline and ciprofloxacin, 100% were resistant to erythromycin and vancomycin. Conclusion: Actinohatillus actinomycetemcomitans was very important periodontal pathogen; having a large number of pathogenic and virulence factors; ciprofloxacin is the drug of choice.

Abstract: Aims: to measure the shear bond strength of composite restoration in vitro. Materials and Methods: The adhesion ability of dentin after chemomechanical method (Carisolv™) was measured compared to conventional one (bur) with the sound group which acts as a control. Three age groups (primary, young and old permanent teeth), in addition to two systems of adhesives (All Bond 2 and Optibond FL) were used. After the trimming and polishing of dentin surfaces to expose flat occlusal surfaces of the teeth, the carious lesion was removed by Carisolv™. Sixty teeth were used in this method, also 60 teeth were used in bur method, which are compared to 60 sound teeth. The composite resin was applied to the confined area of bonding measuring 3 mm in diameter, and two layers of composite core measuring 4 mm in height were applied to the rubbery mould. After thermocycling, the samples were stored in distilled water with crystals of thymol for 24 hours before testing. The interfaces between composites and dentin surfaces were loaded with a knife edge rod perpendicular to the long axis of the tooth by the Universal Testing Machine at across head of speed of 1mm/min., the load required to dislodge the restorations and modes of failure were recorded. Results: the primary teeth in sound group have the highest value of shear bond strength than Carisolv and bur treated surfaces with both dentin adhesives. Conclusion: Chemomechanical caries removal has no adverse effects on bonding to caries-affected dentin when modern bonding systems are used and old teeth dentin shows lower bond strength compared to young permanent teeth dentin.

Abstract: Aim: To evaluate the differential diagnosis of Angle Class III malocclusion in adolescents of Mosulcity. Materials and Methods: A sample of 170 Iraqi subjects aged 12–15 years, 85 subjects with ClassIII malocclusion (42 males and 43 females) were selected on the basis of molar and incisorrelationships. Eighty fife subjects with Class I normal occlusion (42 males and 43 females) werechosen. Lateral cephalometric radiographs were taken for each subject and thirty six measurementswere determined (20 angular, 14 linear and 2 ratios). Results: There were 7 subgroups in Class IIImalocclusion. Pure maxillary retrognathism was the most common subgroup, which represented31.8%; whereas pure mandibular prognathism was the second subgroup with 23.5%. When the loweranterior facial height (LAFH) was considered with both maxillary and mandibular position, 14subgroups were found. The most common subgroup included subjects with retrognathic maxilla,normal mandible and normal (LAFH) with 16.5% of total sample. The second subgroup includedsubjects with retrognathic maxilla, normal mandible and increased (LAFH) with 15.3%. The thirdsubgroup included subjects with normal maxilla, prognathic mandible and normal (LAFH) whichrepresented 10.6%. Conclusion: the maxillary retrognathism is more common than mandibularprognathism in Mosul City

Abstract: Aim: To examine the efficacy of chemo–mechanical dentin removal method in vitro. Material and Methods: Forty eight extracted permanent teeth with occlusal caries. The dentin caries of each tooth was removed either with chemo–mechanical method using Carisolv™ or mechanically using round bur. Cutting and caries removal monitored by checking the hardness of dentin with a dental explorer and stopped when teeth in each group showed either a leather hard texture or a sharp scratching sound was heard. The caries activity of the remaining dentin was assessed by using an acid red as a caries indicator. The mean surface areas of the pink zone (caries active, pH <5.5) and yellow zone (caries inactive, pH >5.5), of each caries lesion was calculated using AutoCAD computer software. Result: Revealed that for teeth treated with Carisolv,™ the surface area of remaining carious dentin was significantly more when it compared with teeth that treated mechanically in each group, using unpaired t– test regardless of the clinical criterion for caries removal. Conclusion: Carisolv™ is effective in caries removal when used as chemomechanical caries removal than conventional mechanical method and the mean surface areas of remaining affected carious dentin was more in chemomechanical than conventional mechanical meaning that more tooth structure is preserved using chemomechanical method.

Abstract: Aims: To estimate the best profile design used for repair at the fractured area, the suitable space to be left between the two fracture pieces, and to determine the percentage of residual monomer calibration curve of heat cured acrylic resin polymerized by water bath. Material and methods: Forty five samples of heat cured acrylic denture base resin were prepared, and repaired by water bath with different profile designs, and different space distances at fractured area, the samples were tested to measure transverse strength. In addition to five samples prepared for determination of the light absorbency of aqueous solution by spectrophotometer. Analysis of variance (ANOVA), and Duncan’s multiple range test were used for statistical analysis. Results: showed that there is no significant difference between different profile designs, and no significant differences between repaired samples with 2 and 3 mm space at fracture area. The absorbency of aqueous solution at 0.125–0.005 mg/ml concentration is helpful for this study. Conclusion Repaired specimens showed less transverse strength than control group.Repaired samples with 2 mm repair space and 3 mm repair space were significantly higher than that of 1mm repair space.

Abstract: Aim: To investigate the effect of repair techniques, surface treatment, and repair space design (3 mm space and no repair space) on the transverse, and tensile strengths of repaired denture base. Materials and methods: Four hundred and sixteen samples of two brand heat cured acrylic resin were repaired by four different techniques (water bath, microwave, thermo press, and chemically cured acrylic resin), treated and untreated with monomer, and repaired with 3 mm space, or no space at fracture area. The samples were tested to measure transverse, and tensile strengths, of repaired, and intact (control) samples. Results: Showed that transverse strength of acrylic denture base repaired by chemically cured acrylic resin was significantly lower (P<0.001) than that of water bath, microwave and thermo press. Transverse strength of repaired acrylic denture base was significantly improved (P<0.001) by monomer surface treatment for 180 seconds, and no space repair design showed the lowest transverse strength compared to 3 mm space repair design. The tensile strength of acrylic denture base repaired by microwave was significantly higher than that of water bath, thermo press, and chemically cured acrylic resin. Acrylic denture base treated with monomer for 180 seconds showed the highest tensile strength compared to untreated acrylic denture base. Conclusion: Acrylic denture base with 3 mm space and treated with monomer that repaired with microwave and water bath techniques were better than other techniques. The samples repaired by chemically cured acrylic resin without surface treatment showed significantly the lowest mean tensile strength. And microwave repairing technique was more time saving and more clean process than water bath technique.

Abstract: Aims: To evaluate the effect of repair techniques, surface treatment with monomer, and additional curing cycle on the color change, and residual monomer of the repaired denture base. Materials and methods: Two hundred and seventy two samples of two brands heat cured acrylic resin were repaired by four different techniques (water bath, microwave, thermo press, and chemically cured acrylic resin), treated, and untreated with monomer, and repaired with 3 mm space at fracture area. The samples were tested to measure color change and residual monomer of repaired, and intact (control) samples. Results: Color change of acrylic denture base repaired by chemically cured acrylic resin was significantly higher than that of water bath, microwave, and thermo press. Microwave repairing technique had lower residual monomer than other techniques. The highest content of residual monomer was released in water after the first 24 hours and decreased in the subsequent days. Acrylic denture base that has additional curing cycle showed a residual monomer content lower than those with single curing cycle. Conclusion: Color changes of repaired denture with chemically cured resin are high and the lower adverse effect of monomer are shown with microwave and water bath curing cycle. Long storage period of repaired denture base are beneficial to reduce monomer release

Abstract: Aims: To compare the immediate loaded implants with the non–loaded type by pull–out force test measured with aids of semiautomatic strength tester machine and mobility test using orthodontic gauge and digital vernier. Materials and Methods: Twenty implants (Denti Dental implant system Ltd. Hungary) of screw type 10mm length with 4, and 4.5mm diameter were inserted in the mandible of 5 local breed dogs. Four implants for each animal, 2 of them were immediately loaded two days after surgery with Nickel Chrome crowns. Primary implant stability measured at the base line time, pull–out force test and mobility test done after three months of healing process. One–way analysis of variance with Duncan multiple range test were used for statistical analysis. Results: Revealed that there was no significant difference between the immediate loading and control group for the 4.5mm implant diameter, with significant difference for the 4mm diameter implant. No effect of time on the mobility of implant between the initial stability and final mobility of implants. The success rate of immediate loaded implants was 75% when compared to 100% success rate of non–loaded type. Conclusion: the immediate loading of screw type single–tooth implant of 4.5 mm diameter, 10mm length do not jeopardize tissue inte

Abstract: Aim: To evaluate the effect of cranial base parameters on mandibular parameters in class II division 1 malocclusion in three dimensions. Materials and Methods: The sample consists of 103 students age range between (18–24) years, 103 students (50 males and 53 females) having class II division 1malocclusion. Lateral and posteroanterior radiographs were taken for each subject. Cranial base measurement included (five angular and seven linear measurements). Mandibular measurement included (six angular and eleven linear measurements). Descriptive statistical analysis was used to describe the data using Pentium computer using SPSS program. Results: Cranial base flexures play a role in determination of lower jaw position which represented by significant effect of cranial base angles (N–S–Ba, N–S–Ar and S–Ba–N) on the angles (SNB, SN–Pog and SN–Id). The increase in the anterior and posterior cranial base lengths (S–N and S–Ba) will affect mandibular dimensions in class II division 1 malocclusion represented by significant effect on (Go–Me, Ar–Go, RW, N–Me , ANS–Me and S–GO). Conclusion: Total cranial base length increase (N–Ba) will have significant effect on all mandibular dimensions in class II division 1 malocclusion (Go–Me, Ar–Go, RW, N–Me, ANS–Me, S–Go, and Co–Gn). Significant effect of both anterior and posterior cranial base widths (GL–GL and Mas–Mas) on mandibular width measured at Condyle, Gonion and Antegonion points. Only (GL–GL) have effect on mandibular width (Lm–Lm).

Abstract: Aim: To evaluate the effect of the cranial base on the nasomaxillary complex in class II division 1 malocclusion. Materials and Methods: The study was carried out on a sample of 104 Iraqi subjects in Mosul City aged 18–24 years 53 females and 51 males having class II division 1 malocclusion. Lateral and posteroanterior radiographs were taken for each subject and twenty three measurements were used (Nine angular and fourteen linear). Results of the analysis were the median (NSBa), lateral cranial base (NSCo) and saddle angle (NSAr) showed a significant effect on the inclination of the Frankfort plane from the anterior and posterior cranial base in same direction, For the saddle angle significantly affect the inclination of the Frankfort plane but in the opposite direction while on anteroposterior position of alveolar process of the premaxilla (SNPr) in the same direction. The anterior part (SN), second lateral posterior part (SCo) and depth of cranial base (NBa) significantly affect the maxillary length (ApMax–PNS), upper anterior (N–ANS) and posterior facial height (S–PNS). For the median posterior part (SBa) and first lateral posterior part (SAr) no significant effect on (upper anterior facial height). The anterior cranial base width (GL–GL) showed a significant affect [facial (Zy–Zy), maxillary (J–J) and upper intermolar width (U6–U6)]. While posterior cranial base width (Mas–Mas) was significantly affect [facial (Zy–Zy), maxillary (J–J) and nasal width (Nc–Nc)].Conclusion: The median, lateral cranial base and saddle angles showed correlation with the inclination of the Frankfort plane from the anterior and posterior cranial base. The observed impact of the cranial base widths on the nasomaxillary complex widths were for anterior cranial base width there was a significant effect on bizygomatic, bimaxillary and intermolar width