Print ISSN: 1812-1217

Online ISSN: 1998-0345

Volume 9, Issue 2

Volume 9, Issue 2, Summer and Autumn 2013, Page 184-265


The Effect of Bleaching on the Color Stabil-ity and Microhardness of Tooth-Colored Restorative Materials

The Effect of Bleaching on the Color Stabil-ity and Microhardness of Tooth-Colored Restorative Materials

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 184-191

Aims: This study investigated the effect of two home- bleaching regimens (7.5% hydrogen peroxide, 16% carbamide peroxide) on the color change and microhardness of microhybrid composite (Compo-san) and hybrid composite (TetricCeram) and RMGIC (Vivaglass). Materials and Methods: Thirty six disk – shaped specimens (5 × 2 mm)(of each restorative material for each test) were prepared and di-vided into three subgroup (n = 12).An unbleached group was used as control, while the remaining spec-imens in the two subgroups were bleached with bleaching regimens . Color change was assessed by using Vita Easy shade device , and the microhardness was determined by a Vicker,s microhardness tester. Means values were compared statistically with one way analysis of variance (ANOVA) followed by Duncan's Multiple Rang Test to determine the significant differences among the tested groups at (p = ≤ 0.05 )level of significance. Results: TetricCeram displayed unacceptable color change after bleach-ing with(16% carbamide peroxide) bleaching regimen. Decreasing in microhardness of Vivaglass after bleaching regimens, and microhardness of Composan after16% carbamide peroxide. Conclusion: The 16% carbamide peroxide bleaching regimen has significant effects on color change of TetricCeram and decreasing microhardness of Vivaglass and Composan restorative materials.

Comparison of Lip Analyses in Skeletal Class I Normal Occlusion and Class II Divi-sion 1 Malocclusion

Saleem; Niam R Al

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 192-201

Aims: To 1. Assess the horizontal lip position and lip thickness in both Class I and Class II Division 1 subjects; 2. To investigate the effect of gender on the horizontal lip position and lip thickness; 3. To identify the effect of skeletal differences on lip position and thickness. Materials and Methods: The sample consisted of 60 cephalometric radiographs of 30 dental and skeletal Class I subjects (15 males, 15 females) and 30 dental and skeletal Class II Division 1 subjects (15 males, 15 females). The hori-zontal lip position and thickness was analyzed using 11 linear and 4 angular measurements. Using SPSS software package (version 11.5), descriptive statistics and independent sample t–test were meas-ured to compare between the two Classes and two genders. The differences were considered significant at p < 0.05. Results: In Class I no significant differences were noticed in most of the variables except in upper lip (Ls) to Steiner line and lower lip (Li) to Holdaway line where females showed more retruded position and larger nasolabial angle (NLA) when compared to males. In Class II Division 1 subjects, the upper and lower lips were significantly protrusive in males when compared with females in relation to Sushner line (S2). Class II Division 1 males showed more protruded upper and lower lips in relation to S2 line, significantly smaller Z angle and higher H angle when compared with Class I males. Comparison between Class I and Class II Division 1 females showed a significantly higher val-ue of upper lip in relation to Steiner line (S1), and significantly smaller upper and lower lips in relation to E line, smaller Z angle and larger H angle. Conclusions: Some of the variables were not affected neither by gender nor by skeletal base while other showed statistically significant differences following gender or skeletal Class or both. However, the effect of skeletal base difference was more obvious as higher number of significant differences were seen between the two Classes

The Effect of Surface Treatment on the Transverse and Tensile Bonding Strength of Relined Acrylic Resin Denture Base (Part I)

Nadira A Hatim

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 202-210

Aims: To investigate the effect of the thickness of relining material, curing method (water bath or mi-crowave), and the surface treatment by methyl methacrylate on transverse and tensile strength of re-lined acrylic resin denture base. Materials and methods: A pilot study was done by preparing 65 sam-ples to evaluate the effect of the thickness of relining material in relation to denture base on the trans-verse strength of acrylic resin denture base, and to study the effect of surface treatment by methyl methacrylate on the transverse strength of acrylic resin denture base. The main study was done by pre-paring 320 samples and divided into two parts to study the mechanical properties of samples represent-ing a denture base cured by water bath and other group cured by microwave curing technique, and then the effect of relining by the two curing methods and the effect of surface treatment were evaluated. Analysis of variance (ANOVA) and Duncan's multiple range tests were used for statistical analysis. Results: of this study showed that the different thickness of relining material in relation to denture base had no significant difference on the transverse strength of the relined denture base. The transverse strength and tensile bonding strength of the relined samples were significantly improved (P=0.05) by monomer surface treatment for 180 seconds. Conclusions: Transverse and tensile strength of the acryl-ic resin denture base were affected by relining. Microwave curing method gave better mechanical properties of the relined acrylic resin denture base.

Effect of Relining Curing Methods on Some Properties of Acrylic Resin Denture Base (Part II)

Nadira A Hatim

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 211-220

Aims: To investigate the effect of relining by using two curing methods (water bath, or microwave) on some properties ( surface hardness, color property, residual monomer, and porosity) of relined acrylic resin denture base. Materials and methods: The study was done by preparing 320 samples, divided into two parts, the first part involved studying surface hardness, color property, residual monomer, and porosity of samples representing a denture base cured by water bath curing method, and the samples of second part cured by microwave curing method, then the effect of relining by the two curing methods (water bath, and microwave) were evaluated. Samples with dimensions of 30×15×3 ± 0.03mm for the indentation hardness test, 45×10×2.5mm for the color property test, 20×20×3mm for residual monomer test were prepared in this study. Analysis of variance (ANOVA) and Duncan's multiple range tests were used for statistical analysis. Results: surface hardness of denture base cured by microwave was significantly higher (at P=0.05) than denture base cured by water bath, all the relined samples has sig-nificant higher absorbance, and showed that the elusion of monomer was higher at the 1st day. Conclu-sions: Surface hardness, color property and residual monomer of the acrylic resin denture base were affected by relining. Microwave curing method gave better mechanical, and physical properties of the relined acrylic resin denture base, the amount of residual monomer was less in the microwave curing method. Both curing methods gave samples free from porosities.

Evaluation of the Surface Roughness for Three Different Types of Composite Resin Materials Using (Sof–Lex) Finishing and Polishing Systems: A Comparative Study

Sabah A Ismail

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 221-227

Aim: To evaluate the surface roughness of three different types of light activated composite resin using (Sof-Lex) – polishing system, a profilometer study. Materials and Methods: A total of 30 resin com-posite disks were prepared from three different types of composite resin include 3 – groups. Group I: 10 specimens were prepared from light activated nano hybride (Tetric n – Ceram, Ivoclar – Vivadent – Liechtenstein). Group II: 10 specimens were prepared from light activated microhybride composite resin (Arabesk – Voco, Germany). Group III: 10 specimens were prepared from light activated poly-glas composite resin (Solitaire – 2, Heraeus, Kulzer, Germany). The resin blocks finished and polished using (Sof – Lex) polishing system. The specimens were analyzed for surface roughness using “Pro-filometer”. Results: Tetric n – Ceram composite resin showed the lowest roughness average (0.112 μm) followed by Arabesk composite (0.150 μm), Solitaire – 2 composite resin showed the highest roughness average (0.341 μm). Conclusions: Tetric n– Ceram (nano-hybride) was the best polished composite resin, showed the least roughness average.

Antibacterial Effect of Dentin Bonding Agents: (An in vitro Study)

Mahmoud Y Taha

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 228-234

Aims: To evaluate and compare the antibacterial effect of three types of dentin bonding agents. Also, to evaluate the antibacterial effect after different time intervals (24, 48, and 72) hs. Materials and Methods: Materials tested in this study were G bond, Single bond (SB), and Excite bond. Tested mi-croorganisms were Enterococcus faecalis (E. faecalis) and Streptococcus mutans (S. mutans). The antibacterial activity were investigated by agar diffusion test performed with adhesives cured on the surface of dentin discs. Also, the antibacterial effect were investigated by evaluation of growth inhibi-tion after 24, 48, and 72 hrs microplate direct contact test using spectrophotometer. The data were ana-lyzed statistically using one way ANOVA and Tukeyʼs test. Results: G bond had antibacterial effect by the two tests and against the two examined bacteria significantly higher than SB and Excite, also SB significantly had antibacterial effect better than Excite bond. The result also revealed that antibac-terial effect of SB and Excite Bond significantly decreased by the time while G bond was not signifi-cantly decrease. Conclusions: Under the limitation of the present study, it is concluded that G bond is able to delay bacterial growth during restorative treatment of dental caries

Efficacy of Three Denture Cleansers on Candida-Related Denture Stomatitis

Lamia T Rejab

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 235-240

Aim: The aim of the study is to evaluate the efficacy of three dentures cleanser on Candida related denture stomatitis through assessing their ability to reduce the number of colony forming unit (CFU) of Candida on palate of the patient for different times. Materials and methods: Group of 12 patients who have denture stomatitis were divided into four groups according to the type of denture cleaners (Protefix, sodium hypochlorite solution 0.02%, saturated sodium chloride salt solution and control wa-ter). The microbiological examination was done to determine the efficacy of the cleansers that used by assessing the number of (CFU) at different times (day before treatment and after 14, 28days of treat-ment). The data were statistically analyzed, (ANOVA) followed by Duncan's multiple Range test to assess the significant difference between the groups at P≤0.05. Results: The results showed that there was a significant effect of three cleansers on reducing number of (CFU) of Candida species in the treatment of denture stomatitis after 14 and 28 days of treatment, but it was not significant for control water group. Sodium hypochlorite showed the highest efficacy. Conclusions: Result showed that there was no significant difference in the efficacy between the three cleansers indicating that all cleansers are effective in the treatment of denture stomatitis .

Trends of Oral Diseases and Treatment Needs in 13-15 Year Old Students in Mo-sul City Center

Tahani A Al-Sandook

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 241-250

Aims: To determine the trends of the two major dental diseases (dental caries and periodontal disease) in a group of 13-15 year old intermediate school and their treatment needs. Materials and Methods: A total of 516 intermediate school students were examined. Dental caries and treatment needs were as-sessed according to the WHO 1997 guidelines. The assessment of the gingival health and treatment needs of the students was performed using the CPITN index as recommended by the WHO 1987. Six index teeth were examined and the presence of gingival bleeding and calculus was recorded. Results: Dental caries in the sample has increased with a mean of 5.17. Dental caries increased with age with a statistically significant age difference. Females tended to have a higher DMFT of 5.5 compared to males 4.79 with significant difference, only 6.6% of the sample was caries free. The majority of the samples needed one surface fillings with a mean of 3.6/child. Other dental treatments were needed to a lesser extent. Regarding the periodontal status, the disease was present in 97.5% of the sample, there was no significant age difference regarding periodontal health. Females tended to have a healthier gin-giva compared to males with significant difference. Regarding periodontal treatment needs, 97.5% of the sample required dental health education, while 65.9 % required professional scaling and polishing. Conclusions: To improve children’s oral health, community school-based oral health educational pro-grams should be established starting from primary and extending to intermediate schools, stressing on sugar restriction and oral hygiene measures, fluorides and fissure sealants can effectively be used too.

Finite Element Analysis of Stress Distribution During Retraction of Mandibular Incisors

Nada M Al-Sayagh

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 251-258

Aims: The present study aimed to determine stress and strain distribution on the four lower incisors under the effect of (400g) calculated retracted orthodontic force. Materials and methods: Using finite element analysis method, frictionless retraction technique was successfully used with the aid of continuous (delta loop) on NiTi, Stainless steel wires without gable bends and stainless steel looped wire using 40°. gable bends(20° alpha, 20° beta gable) respectively. Results: High compressive stress concentration in labiolingual direction are observed near the point of force application and along the line of action of orthodontic wire at the crown of both lateral and central incisors. Conclusions: The stress distribution is not the same for the all retracted segment and there was independent movement of lateral incisors from the central incisors except for the retraction using NiTi wires which exhibits uniform movements for both lateral and central incisors.

Surgical Exposure and Orthodontic Treatment of Impacted Maxillary Central Incisors. A Case Report

Khudair A Al-Jumaili

Al-Rafidain Dental Journal, Volume 9, Issue 2, Pages 259-265

Aims: This report describes a case of eleven years old female with impacted maxillary central incisors and presence of two supernumerary teeth .The surgical exposure and orthodontic traction of bilaterally impacted central incisors after removal of impacted supernumerary teeth is presented in this report. Materials and Methods: Clinical, radiographic follow-up and treatment was conducted at the department of orthodontic and maxillofacial surgery in the college of dentistry ,mosul university .The surgical removal of supernumerary teeth done then surgical exposure and orthodontic traction done. Results: The impacted maxillary central in-cisors were successfully positioned and presented an acceptable gingival contour after treat-ment. Conclusion: Maxillary permanent central incisors were successfully positioned in the maxillary arch by surgical exposure and orthodontic traction, which showed good stability.