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Showing 5 results for Thickness
Soft tissue profile changes following incisor retraction at the age range of 15 to 24 years
A. Khavari , S. Yassaei ,
Volume 14, Issue 4 (1-2002)
Abstract
The purpose of this study was to investigate the soft tissue profile changes of the lower face following premolars extraction and incisor retraction. In order to do that, pre-and post treatment lateral cephalometric radiographs of 40 female orthodontic patients, with cl. II div. I malocclusion (22 patients) and bialveolar protrusion (11 patients) were analyzed. At beginning of orthodontic treatment, their mean age was 18.10 years, ranging from 15-24. All cephalometric radiographs were analyzed by a conventional and confirmed method called "combination analysis". The findings revealed that "lip tension" is a significant factor in soft tissue response to orthodontic treatment, so that in patients with lip strain, nasolabial angle increase was significantly more that those without lip strain. Moreover, regarding the increase of vermilion thickness of the upper lip, a significant difference was observed between two groups. In patients with lip strain, following premolars extraction and incisors retraction, lip strain was reduced or eliminated and upper lip vermilion thickness increased, following incisors retraction, the slope of nasal inferior border, in the group with lip strain, was reduced, while in the group without lip strain, this slope increased.
Evaluation of marginal circumference and marginal thickness changes in precrimped stainless steel crowns, after recrimping
H. Afshar , M Mozafari Kojidi ,
Volume 19, Issue 2 (5-2006)
Abstract

Background and Aim: The need for recrimping precrimped stainless steel crowns by the dentist in clinic is controversial. This study aimed to evaluate the rate of marginal circumference and marginal thickness change of precrimped stainless steel crowns after recrimping.

Materials and Methods: In this experimental study, 30 primary photos were taken from margins of 30 S.S.Cs (3M, Ni-Cr) related to tooth 85 with a digital camera fixed at a determined distance. Margins of crowns were crimped by 114 and 137 pliers with a controlled force (0.2 N) and then 30 secondary photos were taken in the same conditions. The circumference of crown margins in primary (group A) and secondary (group B) photos were assessed by a digitizer system. Comparing the circumferences of crown margins in primary and secondary photos showed a significant decrease after crimping. Thickness of 30 random points on the crown margins of a crown similar to mentioned cases was measured by SEM (×150). Then similar procedures including taking a primary photo, crimping and taking a secondary photo was done for the sample crown. After significant reduction in margin circumference, thickness of 30 other random points on the crown margin were measured by SEM. Data were analyzed by paired sample t-test with p<0.05 as the limit of significance.

Results: The mean marginal circumference of precrimped stainless steel crowns was reduced by 7.3% which was significant (P<0.001). On the other hand the mean marginal thickness of sample stainless steel crown showed 18µ increase.

Conclusion: According to the results of this study, marginal circumference of precrimped stainless steel crowns (3M, Ni-Cr) showed a significant decrease after crimping. It is concluded that crimping the stainless steel crowns even for precrimped ones seems necessary.


Evaluation of the physical properties of the Iranian temporary cement, Tem Band, and the foreign one, Temp Bond, compared to ISO 3107
V. Soltan Karimy , Sm. Bayanzadeh ,
Volume 19, Issue 3 (6-2006)
Abstract

Background and Aim: Iranian temporary cement, Tem Band, has been manufactured by Golchai company, and introduced to market as a suitable material but its properties have not been tested yet. The aim of this study was to investigate the setting time, film thickness, compressive strength, disintegration and arsenic content of Tem Band and Temp bond temporary cements and compare them to ISO 3107. Materials and Methods: In this experimental study, 12 samples from each cement were obtained and setting time, film thickness, compressive strength, solubility and disintegration were tested according to ISO 3107. In addition, arsenic content was tested based on ASTM 6052. Data were analyzed with t-test and p<0.05 was considered as the limit of significance.

Results: The average setting time of Tem Band was 5 minutes and 47 seconds (4.17 minutes for Temp Bond), the average film thickness was 6.67 micrometer for Tem Band and 4.08 micrometer for Temp Bond. There was no difference between two cements regarding setting time and film thickness and for both was at the standard range. Compressive strength of Tem Band was 5.67 MPa and 8.5 MPa for Temp Bond. The difference was statistically significant but for both cements was less than standard (35 MPa). There was no significant difference regarding the solubility and disintegration tests. In both samples, the solubility and disintegration values were in standard ranges. Both cements did not contain arsenic but lead level was at the maximum standard range in Tem Band.

Conclusion: Considering these results, both cements are applicable to different clinical situations based on their physical properties. Studies on the biocompatibility of the Iranian cement is recommended.


Comparative evaluation of soft tissue characteristics around implant and tooth.
M. Paknejad, M. Kashfi, N. Moslemi,
Volume 21, Issue 3 (12-2008)
Abstract

Background and Aim: Soft tissue condition around dental implant is an essential part for long term healthy and esthetic outcome. The aim of this study was to compare soft tissue dimensions between implant supported single  tooth replacement and the contra-lateral natural tooth.

Materials and Methods: This retrospective study was performed on dentate patients treated with anterior single  tooth implant at least 1 year ago. Of twenty eight, fourteen patients had been treated with one stasge method and others with two stage method. Biologic width (BW), papilla index (PI), and mucosal thickness (MT) were evaluated around implants and contra-lateral teeth clinically and compared with each other. The Wilcoxon test, Mann-Whitney test, and Student pair t-test were used to assess the differences between one stasge and two stage implants, and implant and tooth groups.

Results: The mean BW around one stasge implants, two stage implants, and contra-lateral teeth were 1.42±0.48 mm, 1.67±0.48 mm, and 1.47±0.60 mm, respectively. The mean PI adjacent to one stasge implants, Two stage implants, and contra-lateral teeth were 2.50±0.52, 2.53±0.55, and 2.72±0.47, correspondingly. The mean MT around one stasge implants, two stage implants, and contra-lateral teeth were 3.10±0.48, 3.09±0.75, and 2.57±0.88, respectively. There was no statistically significant difference among one stasge implants, two stage implants, and contra-lateral teeth with regard to measured variables.

Conclusion: Based on the results of this investigation, in standard condition, it seems that there is no noticeable difference in indicators of biologic width, papilla index, and mucosal thickness around one stasge implants, two stage implants, and contra-lateral teeth.


Measuring the thickness of buccal cortical bone of maxillary premolar teeth by cone beam computed tomography technique
Sara Mogharrabi, Asadallah Ahmadzadeh, Safoura Ghodsi, Farzad Bazmi, Sara Valizadeh,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: Immediate implant placement following tooth extraction is a treatment with many advantages. Alveolar bone preservation after immediate implant, need minimum of 2 mm thickness in buccal bone plate. The aim of this study was to evaluate the thickness of buccal cortical bone of maxillary premolars by Cone Beam Computational Tomography (CBCT) technique.
Materials and Methods: In this descriptive epidemiological study, Cone Beam Computed Tomography image was obtained from 29 patients (male and female) referred to the radiology department of Jundi Shapoor dental school of Ahvaz from 1393 (Mehr) to 1394 (Shahrivar) for implant insertion insertion. The thickness of buccal cortical bone was measured in 3 and 5 mm apical to the CEJ and root apex, perpendicular to the longitudinal axis. All the measurements were done by two oral and maxillofacial radiologists, separately. Data were analyzed by SPSS22 software, using descriptive statistics, and T-test.
Results: The thickness of buccal cortical bone in second premolar was significantly more than 1 mm (P=0.001), but in first premolar, the thickness was close to 1 mm with a non-significant difference (P=0.29).
Conclusion: The results of this study showed that immediate implant insertion could be done in the maxillary second premolar area with more predictability compared to the first premolar area.

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