Showing 15 results for Treatment
S. Nokar , R. Baghaee-Naeeni ,
Volume 17, Issue 3 (8-2004)
Abstract
Statement of Problem: In the treatment of edentulous patients with implant supported fixed partial dentures several factors such as implant numbers, implant position, superstructure pattern and cantilever length must be considered. Mandibular flexture in function exerts forces in peri-implant bone, however this phenomenon has received little attention.
Purpose: The goal of this finite element analysis (FEA) study was to evaluate the effect of mandibular dimensional changes on peri-implant bone stress in different prosthesis and implant treatment plans.
Materials and Methods: In this experimental study, three dimensional finite element computer model of mandible was simulated according to data from CT-Scan in 0.5 mm sections. The model of 4.110 mm ITI implant, measured by profile projector, was simulated in solid works 2003 software. Implant models were inserted, in two different patterns, on mandible and three different superstructures were placed on implants. Two clenching tasks were modeled (incisal clench and right molar clench).
Results: Analysis of Von Misses stress for peri-implant bone revealed the lowest stress values in three-piece superstructure.
Conclusion: According to this study, additional placement of implants in order to fabricate independent prostheses and to achieve the freedom of mandibular flexture are recommended.
Sh. Rokni. , Sh. Mehdizade,
Volume 17, Issue 3 (8-2004)
Abstract
Statement of Problem: Ceramics and resins belong to the earliest tooth restorative materials. Nowadays new generations of these materials have provided a revolution in cosmetic dentistry. Ceramic Optimized polymer (Ceromer) is a newly made product that the bond between this material and base metal alloys, which are used widely today, is paid too much attention.
Purpose: The aim of this study was to evaluate the bond strength of targis (Ceromer) to three types of base metal alloys through three different surface treatment methods.
Materials and Methods: In this experimental study, ninety plates of Rexillium III, Silver cast and super cast alloys (3050.4) were prepared and surface treated through three different methods (air oxidation, vaccum oxidation and sandblast). All samples were then veneered with 1.mm thickness of Targis. After thermocycling, three-point bending test was performed by universal testing machine (Instron) to evaluate the amount of forces at crack or fracture times in Targis. The type of failure (cohesive or adhesive) was also evaluated microscopically. Statistical analyses were made using 2-factor ANOVA and Duncan tests.
Results: The type of surface treatment method caused a statistically significant difference in force rate required for crack and fracture in Targis. Sandblasting was found as the best method. The type of alloys, in all three methods, had a significant effect just on crack creation attributing the largest amount of force to Rexillium III. Adhesive type of failure occurred mostly in super-cast alloys through air-oxidation method, and cohesive type was more among silver cast alloys and sandblast method.
Conclusion: According to the results of this study, bond strength between Ceromer materials and base metal alloys is significantly great and Rexillium III alloy associated with sandblast technique the best combination.
Z. Dalili , A. Miandog ,
Volume 17, Issue 3 (8-2004)
Abstract
Statement of Problem: Considerable response to functional orthopedic appliances treatment in class II skeletal patients occurs during pubertal growth spurt. Therefore, it seems necessary to investigate indices indicating mandibular growth pattern. It has been proved that analyzing cervical vertebral maturation stage is a more valid index than that of hand wrist.
Purpose: The aim of this study was to evaluate the time status of functional orthopedic treatment in class II skeletal patients using CVMS index.
Materials and Methods: In this descriptive-inferential study, lateral cephalometric radiographs of 153 class II skeletal patients with mandibular deficiency, before treatment, were studied by an oral and maxillofacial radiologist using the index of cervical vertebral maturation stage (CVMS) and were categorized in three phases: CVMS I (desirable phase of treatment), CVMS II (ideal phase), and CVMS III (undesirable phase of treatment).
Results: Statistical analysis ranked the prevalence of treatment phases as: 41.8% in desirable phase (CVMS I), 28.1% in ideal phase (CVMA II) and 30% in undesirable phase (CVMS III). No significant differences were found between the three phases using Chi-square analysis. Time status of functional orthopedic treatment was also evaluated based on age and sex. The results showed significant differences between two sexes (P=0.032).
Conclusion: The present study suggests the analysis of CVMS index, along with clinical criteria, in the determination of an ideal time for functional orthopedic treatment to prevent patients’ exhaustion during treatment Period.
Z. Dalili ,
Volume 17, Issue 4 (1-2005)
Abstract
Evaluation of skeletal age and determination of growth status had important and special roie in orthodontic treatment planning (such as functional orthopedic treatment and orthognatic surgery) and also in stability of it. There were several biologic indicators for the detection of the peak in mandibular growth. Due to the limitations of biological indicators application, idea of new indicators was seemed importantly. Cervical vertebral maturation (CVM) method is one of them. At first the detection of the peak in mandibular growth was based on the analysis of the second through sixth cervical vertebrae in six developmental stages. But a few improvements of the original CVM analysis were still needed. In this method, the peak in mandibular growth was determined based on the analysis of the second through fourth cervical vertebrae in five developmental stages. This method is easy, applicable and more valid than hand-wrist analysis method.
F. Nejatidanesh , O. Savabi , B. Sarrafpour , D. Mirabi ,
Volume 20, Issue 2 (5-2007)
Abstract
Background and Aim: Designing removable partial dentures is one of the most important phases of prosthetic treatments. Computer can be used to facilitate and increase accuracy of removable partial denture design. The aim of this study was to develop a software for removable partial denture design.
Materials and Methods: A questionnaire (discussed in part I) and major textbooks, were used to determine the design rules. The software (RPD Graph) was developed using Visual C++ and Maryam program. The RPD Graph can determine the classification of partial edentulous arch. With defining the missing teeth and providing data about prognosis and conditions of abutment teeth, the removable partial design will be developed by RPD Graph. This software is a knowledge-based system which has specific characteristics. It can be used as an educational tool for teaching RPD design and as a clinical tool for supporting clinician's decision. In addition it can be developed to more complete softwares.
M. Mirzaei, E. Yassini, M. Ghavam, A. Pahlavan, M. Hasani Tabatabaie, S. Arami, H. Kermanshah, B. Esmaieli,
Volume 21, Issue 2 (11-2008)
Abstract
Background and Aim: Various studies have shown that reliable bond at the root - post - core interfaces are critical for the clinical success of post - retained restorations. Severe stress concentration at post - cement interface increases post debonding from the root. To form a bonded unit that reduces the risk of fracture, it is important to optimize the adhesion. Therefore, some post surface treatments have been proposed. The purpose of this study was to investigate the influence of various surface treatments of tooth - colored posts on the bonding of resin cement.
Materials and Methods: In this interventional study, 144 tooth colored posts were used in 18 groups (8 samples in each group). The posts included quartz fiber (Matchpost), glass fiber (Glassix), and zirconia ceramic (Cosmopost) and the resin cement was Panavia F 2.0. The posts received the following surface treatments: 1- No surface treatment (control group), 2- Etching with HF and silane, 3- Sandblasting with Cojet sand, 4- Sandblasting with Cojet sand and application of silane, 5- Sandblasting with alumina particles, 6- Sandblasting with alumina particles and application of silane. Then, posts were cemented into acrylic molds with Panavia F 2.0 resin cement. The specimens were placed in water for 2 days and debonded in pull - out test. Statistical analysis was performed using ANOVA followed by Tamhane and Tukey HSD. Failure modes were observed under a stereomicroscope (10 ). P<0.05 was considered as the significant level.
Results: Surface treatments (sandblasting with Cojet and alumina particles ,with or without silane) resulted in improved bond strength of resin cement to glass fiber post (Glassix) and zirconia ceramic (Cosmopost) [p<0/05], but not to the quartz fiber post (Matchpost). In general, higher bond strengths resulted in a to higher percentage of cohesive failures within the cement.
Conclusion: Based on the results of this study, sandblasting with cojet and alumina particles increases bond strength of resin cement to glass fiber post (Glassix) and zirconia ceramic (Cosmopost).Generally, the bond strength of resin cement to the posts is affected by the post's composition and surface treatment.
A. Azari, S. Nikzad, F. Geramipanah, H. Mahgoli, L. Sedighpor,
Volume 21, Issue 3 (12-2008)
Abstract
Amelogenesis imperfecta is an inherited disease that disturbs the formation of the enamel. It occurs as two main categories, hypomineralized and hypoplastic. Both deciduous and permanent teeth are affected, and the disorder may create unaesthetic appearance, dental sensitivity, and severe attrition. In this article through performing a structured literature review, numerous treatment modalities which so far advocated in rehabilitation of amelogenesis imperfecta in adults and children is discussed. The progressive changes on open bite, the problem of bonding during restorative phase of treatment , the rehabilitation difficulties of deciduous as well as permanent teeth is also discussed in detail and finally the interdisciplinary approach for treatment of this disability is demonstrated and some points for decision making in treatment protocols are suggested.
Imaneh Asgari, Arezo Ebn Ahmady, Mohammad Hossein Khoshnevisan, Faezeh Eslamipour,
Volume 25, Issue 2 (4-2012)
Abstract
Background and Aims: Normative need assessments should be substituted or integrated by patient-based outcome measures regarding their shortages in health-oriented approach . This study aimed to assess and compare the ability of an index of oral health-related quality of life measured by Child Oral Health Impact Profile (COHIP) questionnaire and the Aesthetic Component of Index of Orthodontic Treatment Need (AC-IOTN) to identify the normative need to orthodontic treatment using Dental Health Component-IOTN in a sample of the Iranian adolescents.
Materials and Methods: Target population of this cross-sectional analytic study was 597 of the 13 to 18 year-old schoolchildren enrolled in middle and high schools of the city of Isfahan, Iran. They completed the COHIP questionnaire and then were examined by two calibrated trained dentists (agreement coefficient:0.9) to record the DHC grading. The students scored their AC in according to the images of the scale. The association between subjective indicators and clinically defined need were evaluated by the correlation analysis and the statistics for the diagnostic validity of tests.
Results: Of 568 examined students, 16.7% and 2.1% had definite need according to DHC and AC criteria, respectively. 10% of orthodontic patients had perceived distinct impact on their quality of life. The significant association (P=0.001) between the severity of malocclusion and quality of life was at moderate level by AC (R=0.37), but it was not convincing enough by DHC (R=0.16). The specificity of AC to detect the healthy ones showed to be excellent but its low sensitivity disabled the recognition of patients, precisely.
Conclusion: The considered patient-based indices did not meet the competencies to define the orthodontic need in the adolescents, but it could be employed to identify the persons with impaired quality of life and it would probably benefit the process of prioritization.
Sina Haghanifar, Valiollah Arash, Farhad Soboti, Nasim Jafari,
Volume 25, Issue 2 (4-2012)
Abstract
Background and Aims: Apical root resorption is an adverse side effect of fixed orthodontic treatment which cannot be repaired. The aim of this study was to use panoramic radiographs to compare the root resorption before and after the orthodontic treatment with standard edgewise .018 appliance.
Materials and Methods: The before and after treatment panoramic views of sixty-three patients needed fixed orthodontic treatment included 1520 teeth were categorized into 3 Grades (G0: without resorption, G1: mild resorption with blunt roots or ≤ 1/4 of root length, G2: moderate to severe resorption or > 1/4 to 1/2 of root length. Relationship between root resorption and sex and treatment duration was analyzed with Mann-whitney and Spearman's correlation coefficient, respectively.
Results: The findings showed that 345 teeth were categorized as Grade 1. Grade 2 of root resorption was not found in this study. The highest amount of root resorption was recorded for the mandibular lateral incisor. In both gender, the root resorption of the mandible was more than that of the maxilla. The males showed significantly higher rate of resorption than the females (P<0.05). Root resorption was not significantly related to the treatment duration and the side of the jaws (P>0.05).
Conclusion: The mandible and male patients showed higher amount of root resorption. In addition, root resorption was not related to the treatment duration and the side of the jaws.
Loghman Ghahramani, Hanieh Nokhbatolfoghahaei, Sima Shahabi, Mohsen Tamizi, Mostafa Fatemi,
Volume 27, Issue 3 (9-2014)
Abstract
Background and Aims: Debonding of denture teeth from the denture base can be frustrating for both clinician as well as patient. The aim of this study was to determine the effect of different tooth preparations on the tensile bond strength of composite denture teeth to acrylic denture base material.
Materials and Methods : In this experimental study, 108 anterior Glamour teeth were selected and divided into 9 groups, based on their preparation (physical: no physical change, glaze removal, creating two slots with 1.5 mm depth, creating a hole with 2.5mm depth, chemical: (without chemical materials, monomer, silane). Specimens were prepared and tested according to the methods of the International standards organization (ISO 20795-1). After attachment of teeth to acryl, the tensile bond stregth test was performed in a Universal Testing Machine (UTM) with a crosshead speed of 1mm/min and specimens were subjected to tensile force until failure. Data were analyzed with one-way ANOVA, Tukey HSD and Two-way ANOVA.
Results: There were significant differences between the bond strength of tested groups (P=0.012). Based on Tukey test, there was a significant difference between monomer/without physical change group and without/without (P<0.001) and control group. No significant differences were found between the bond strengths of the other groups (P=0.17) . All specimens were debonded as cohesive failure.
Conclusion: Application of monomer on the ridge lap surface led to improve the tensile bond strength between glamour composite denture teeth and Iranian acrylic resin, however physical changes were not effective. According to the cohesive failure of all the specimens, it can be concluded that the bond strength between this type of teeth and acrylic resin was stronger than the strength of teeth.
Katayoun Sargeran, Amir Jalal Abbasi, Faegheh Fazeli,
Volume 30, Issue 2 (8-2017)
Abstract
Background and Aims: In modern societies, the incidence of oral cancer is increasing. It may be due to the increased population, life expectancy, and exposure to risk factors. This increase can particularly be seen in women and in our own country, Iran. The aim of the present study was to explore the status of care and treatment of patients with oral cancer referring to Shariati educational hospital in Tehran, during the years 2003-2013.
Materials and Methods: The present study was a cross-sectional descriptive survey on oral cancer patients attending the Shariati hospital in Tehran during a ten-year period. Data were collected through patient records and statistically analyzed by SPSS21 software.
Results: Regression analysis was performed in 5 models, where variables such as age, gender, location of the tumor, stage and grade was entered as independent variables and delay in treatment (time interval from diagnosis to treatment) entered as the dependent variable. The analysis showed that the elapsed time from diagnosis to treatment had a positive association with age of the patients. It means that the higher the age, the more delay in treatment (P<0.05). No relationship was found between the treatment delay and gender, tumor location, grade, and stage.
Conclusion: Considering the consequences of oral cancer for patients, there was necessity to formulate plans for preventing, early detection and improving quality of life in oral cancer patients.
Mohammad Hosain Lotfi Kamran, Mahnaz Hatami, Abbas Fallah Tafti, Mohammad Malekzadeh,
Volume 30, Issue 3 (10-2017)
Abstract
Background and Aims: To create a good adhesion between porcelain veneers and zirconia restorations has been important issues is the prosthesis. The aim of this study was to identify an effective way to prepare the zirconia surface infrastructure to increase its shear bond strength to the porcelain veneer.
Materials and Methods: 75 samples of zirconia (Y-TZP) cylinders (diameter of 7 mm and a thickness of 3 mm) were fabricated. Based on the surface treatment, specimens were randomly divided into 3 groups: control, air abrasion and
Er-YAG laser. After surface treatment, the specimen surfaces were examined by SEM. Using a metal mold, the porcelain was veneered on the zirconia surface and then fired. After thermocycling, the shear bond strength of porcelain to zirconia was measured and then the failure mode of each specimen was analyzed using a stereo-microscope. Data were analyzed by one-way ANOVA and Tukey test.
Results: Significant differences were observed between the mean shear bond strength of different groups (P=0.001). The greatest amount of shear bond strength was observed in the group (S) and the lowest bond strength in the control group. Analysis of failure modes showed no statistically significant difference in the type of failure among study groups. The adhesive failure was predominating failure at the intersection of porcelain veneers.
Conclusion: The highest shear bond strength between zirconia and porcelain was achieved by sandblasting the zirconia surfaces compare with that of Er_YAG application.
Rahim Asghari Salavat, Ahad Samadi,
Volume 30, Issue 3 (10-2017)
Abstract
Background and Aims: Poor adhesion between porcelain and some of the dental alloys is one of the most challenges to select the desirable alloy in dental restorations. Therefore, the aim of this study was to evaluate the bond strength of porcelain to some of the commercial alloys. This can help in selection of desirable alloy.
Materials and Methods: The shear bond strength of porcelain to the three of the most widely used nickel-base dental alloys commercially named as: Verabond, Damcast and Noritake were evaluated according to standard ASTM E4. The results were analyzed based on the statistical method of independent t with the meaningful level of P<0.05. Then, the bonding interface of the fired samples was evaluated using SEM equipped with EDX analyzer and X-ray diffractometry.
Results: The average bonding strength of porcelain to each of the above mentioned alloys were determined as: 27.54±5.48, 22.46±4.99 and 26.18±4.27 MPa, respectively. Due to the existence of Be and Al in the chemical composition of Verabond and Damcast and their higher appetencies to form the different surface oxides in preference to Cr2O3, not only the bond strength of porcelain to two these alloys was increased about 20 percent (compared with the Noritake), but also the color of their porcelain was not changed.
Conclusion: To replace the replacing of deleterious elements from the chemical composition of dental alloys. The added new elements should control through the oxide layer and the formation of Cr2O3 in porcelain-alloy interfaces for adequate bond strength.
Mehrnoosh Jafari, Neda Pournasir, Mojtaba Hosseini,
Volume 33, Issue 4 (1-2021)
Abstract
Background and Aims: Providing quality services is one of the important goals of the health system. Dental services and treatments are expensive. The aim of this study was to investigate the factors influencing the perceived quality of dental treatment services.
Materials and Methods: This descriptive-cross study conducted in 2 qualitative-quantitative phases. Data were collected using interviews and pairwise comparison matrix with 20 dentists working in NAJA dental clinics who were selected by targeted sampling. The validity and reliability of the interviews were determined by long-term engagement of their peers and negative case analysis. The validity of the pairwise comparison matrix was determined through the incompatibility rate (>0.1). Data were analyzed by coding and effect intensity tests (R+J), descriptive statistic test (mean, standard deviation) using SPSS23, Maxqda and matlab R2017b.
Results: Content analysis of the interview showed that tangible factors, assurance, trust, and empathy are the factors affecting the quality of dental treatment services. In the second phase, data analysis showed that trust and empathy (28.204), assurance (24.356), and tangible factors (17.798) are the most to the least important factors in the quality of dental treatment services (P=0.1).
Conclusion: Trust and empathy were the most important factors in the quality of dental treatment services. Managers of dental clinics and dentist need to improve the quality of dental treatment services by emphasizing respect for patients in accordance with the promise to act in the field of providing treatments to patients.
Narges Farhad Mollashahi, Eshagh Ali Saberi, Behnam Rousta, Seyed Mohammad Javad Aslani, Farnaz Faramarzian,
Volume 36, Issue 0 (5-2023)
Abstract
Background and Aims: Guided endodontics is a new technique that is now evolving. It is used in many treatments, especially in access cavity preparation and locating root canals in teeth with pulp canal obliteration (PCO), microsurgical endodontics, and fiber post removal in retreatments. In addition, this technique is independent of operator experience, requires less treatment time for the patient, and is more precise and safer than conventional endodontics. This technique involves the use of cone beam computed tomography imaging (CBCT), tooth surface scanning, and special software to provide guidance for performing endodontic treatment in a fast, safe, and minimally invasive manner. This review article aims to introduce guided endodontics and to describe its technique, advantages, and limitations.
