Correlation between cervical vertebral maturation and chronological age in a group of Iranian females

BACKGROUND

Correlation between chronological age at different stages of cervical vertebral maturation (CVM) is important in clinical orthodontic practice. The objective of this study was to evaluate the correlation between CVM stage and chronological age in a group of Iranian female patients.

MATERIALS AND METHODS

This study was conducted on 196 digital lateral cephalometry of female patients with the age ranged 9-14 years. The CVM stage was determined with two calibrated examiners, using the method developed by Baccetti and its correlation with mean chronological age was assessed by the Spearman rank-order. The intra and inter-agreements were evaluated by weighted Kappa statistics in overall diagnosis of stages, in addition to determination of presence or absent of concavities at the lower border of second, third and fourth cervical vertebrae and the shapes of the third and fourth vertebrae. P < 0.05 was considered as significant.

RESULTS

The correlation coefficient between CVM stages and chronological age was relatively low (r = 0.62). The least amount of inter-observer agreement was determined to be at the clinical decision of the shape of the fourth vertebra.

CONCLUSION

Regarding the low reported correlation, the concomitant usage of other skeletal indicators seems necessary for precise determination of physiological age of the patients.

The effect of the combination of dry needling and MET on latent trigger point upper trapezius in females

AIM

The purpose of this clinical trial experiment was to compare the effects of the combination of dry needling (DN) and the muscle energy technique (MET) on the upper trapezius latent myofascial trigger point.

METHOD

Sixty female patients, aged 18-30 with latent myofascial trigger points in the upper trapezius muscle were randomly divided into three groups: group 1 (n = 20) received DN and MET, group 2 (n = 20) received only MET, and group 3 (n = 20) received only DN. The visual analogue scale (VAS), pressure pain threshold (PPT), and range of active contra lateral flexion (CLF) were measured before each treatment. The patients were treated for three sessions in a one-week period with at least a two-day break between each session, and in session four, an assessment of primary outcomes was conducted without any treatment.

RESULTS

All three treatment groups showed decreases in pain (p = 0.001) and increases in PPT levels (p = 0.001) as well as increases in CLF (p = 0.001). But the group receiving trigger point DN together with MET showed more significant improvement than the other two groups in VAS, PPT and ROM. No significant differences were found between the MET-only group and the DN-only group.

CONCLUSION

Our results indicate that all three treatments used in this study were effective for treating MTP. According to this study, DN and MET is suggested as a new method for the treatment of MTP.

Application of hurdle model with random effects for evaluating the balance improvement in stroke patients

BACKGROUND

Stroke is a prevalent cause of disability in adults. The fall is the most common balance and motor impairments, which affects the quality of life in stroke patients. This study aims to employ random effects hurdle model for evaluating the balance improvement in stroke patients under the occupational therapy.

METHODS

In this longitudinal study with repeated measurement during one year between 2013 and 2014, the data was collected using non-random sampling method from three occupational therapy clinics. For a total of 38 stroke patients, the number of falls was recorded every two weeks. The random effects hurdle model and random effects zero inflated Poisson (ZIP) model were fitted to the data and were compared together. Data analysis was carried out using SAS Software version 9.2.

RESULTS

The results of random effects ZIP model showed that the covariates of sex and age and affected side of stroke and follow up duration had statistically significant effect on balance improvement (p< 0.05). The occupational therapy has been effective on balance improvement more than 40% during one year.

CONCLUSION

The ZIP model with random effects can capture zero inflation and correlation structure in longitudinal count data simultaneously. Older patients, women and patients with left-side impairments were more at risk of fall and balance impairment, so they need more care and therapy.

The effect of two types chewing gum containing casein phosphopeptide-amorphous calcium phosphate and xylitol on salivary Streptococcus mutans

AIM

The aim was to evaluate the effect of sugar-free chewing gum containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and xylitol on salivary Streptococcus mutans.

MATERIALS AND METHODS

A total of 60 dental students of 20-25 years old, who volunteered after checking their health condition and signing an informed consent, were randomly allocated to receive one of the following interventions: (A) Chewing gum containing CPP-ACP; (B) containing xylitol. Subjects within the experimental groups were taken the gums 3 times daily, after each meal for a period of 3 weeks. Pre- and post-intervention unstimulated saliva samples were quantified for S. mutans counts.

RESULTS

A statistically significant reduction of salivary S. mutans was displayed in both groups A and B after the intervention when compared with baseline (P < 0.001), and group A shows more statistically significant reduction of salivary S. mutans than group B (P = 0.011).

CONCLUSION

Daily consumption of chewing gum containing CPP-ACP and xylitol significantly reduces the level of salivary S. mutans, but chewing gum containing CPP-ACP can reduce the level of salivary S. mutans in more than xylitol chewing gum.

Bleaching effect of ozone on pigmented teeth

Background:

There have been numerous researches on ozone application in dentistry; yet the data regarding its whitening effect is very limited. The present study compares the bleaching effect of ozone with office bleaching.

Materials and Methods:

In this experimental study, 15 maxillary premolar teeth were selected and sectioned mesio-distally and bucco-lingually. The sections were then placed in tea for 1 week according to the Sulieman method and were divided into three groups each comprised of 15 sections. The samples were bleached as followed; Group I: Bleached with 35% hydrogen peroxide in three intervals of 8 min each, Group II: Underwent ozone treatment using Ozotop unite for 4 min and Group III: Bleached with a combination of both methods. The color indices of the samples, i.e., (a) green-red pigment, (b) blue-yellow pigment, (L) brightness, (ΔE) overall color change, were evaluated pre- and post-bleaching utilizing a digital camera, Photoshop software and CIE lab index. The color changes of specimens then were calculated and analyzed through randomized analysis of variance and Tukey tests. P < 0.001 was considered to be significant.

Results:

The color change (ΔE) in Group II was significantly lower than those in the two other groups (P < 0.001). There was no significant difference between the color change of Groups I and III (P = 0.639). In addition, the results of L, a and b brought forth a similar pattern to the findings obtained from ΔE.

Conclusion:

The hydrogen peroxide gel has a more powerful whitening effect than ozone; in addition, ozone has no synergistic effect when is used simultaneously with hydrogen peroxide.

Efficacy of a Newly Designed Cephalometric Analysis Software for McNamara Analysis in Comparison with Dolphin Software

OBJECTIVES

Cephalometric norms of McNamara analysis have been studied in various populations due to their optimal efficiency. Dolphin cephalometric software greatly enhances the conduction of this analysis for orthodontic measurements. However, Dolphin is very expensive and cannot be afforded by many clinicians in developing countries. A suitable alternative software program in Farsi/English will greatly help Farsi speaking clinicians. The present study aimed to develop an affordable Iranian cephalometric analysis software program and compare it with Dolphin, the standard software available on the market for cephalometric analysis.

MATERIALS AND METHODS

In this diagnostic, descriptive study, 150 lateral cephalograms of normal occlusion individuals were selected in Mashhad and Qazvin, two major cities of Iran mainly populated with Fars ethnicity, the main Iranian ethnic group. After tracing the cephalograms, the McNamara analysis standards were measured both with Dolphin and the new software. The cephalometric software was designed using Microsoft Visual C++ program in Windows XP. Measurements made with the new software were compared with those of Dolphin software on both series of cephalograms. The validity and reliability were tested using intra-class correlation coefficient.

RESULTS

Calculations showed a very high correlation between the results of the Iranian cephalometric analysis software and Dolphin. This confirms the validity and optimal efficacy of the newly designed software (ICC 0.570-1.0).

CONCLUSION

According to our results, the newly designed software has acceptable validity and reliability and can be used for orthodontic diagnosis, treatment planning and assessment of treatment outcome.

Effects of Three Mastic Gums on the Number of Mutans Streptococci, Lactobacilli and PH of the Saliva

OBJECTIVE

In the recent years, herbal oral hygiene products have gained increasing attention. The aim of this study was to assess the effects of three types of mastic gums on the level of Mutans streptococci, Lactobacilli and pH of the saliva.

MATERIALS AND METHODS

Forty-two students in the age range of 20-30 years were divided into three parallel groups; each of them separately used pure mastic gum, xylitol mastic gum and probiotic mastic gum for three weeks. Number of microorganisms and pH of the saliva were assessed before and after the intervention. The data were analyzed using Wilcoxon Signed Rank, paired-sample-t, Kruskal-Wallis and Tukey's post-hoc tests and Oneway ANOVA.

RESULTS

Level of Mutans streptococci showed a significant reduction compared to its baseline value in all three groups (P<0001 for all). Salivary Lactobacillus count increased in the groups using pure and xylitol mastic gums but decreased in the group using probiotic type, albeit these changes were only significant in the group using probiotic mastic gum (P<0.001). Use of pure and xylitol mastic gums increased the pH of the saliva but not significantly. In the group using probiotic mastic gum, the pH of the saliva decreased significantly (P=0.029).

CONCLUSION

Three weeks use of all mastic gums resulted in a significant drop in the number of Mutans streptococci in the saliva. However, the drop in the saliva pH due to the use of probiotic mastic gum is not in favor of dental health.

Effect of Self-etching Adhesives on the Bond Strength of Glass-Ionomer Cements

STATEMENT OF PROBLEM

Adequate bond strength between glass ionomer cements and composite resin is necessary for the success of the sandwich technique.

PURPOSE OF STUDY

This study assessed the micro-shear bond strength of composite resin to glass-ionomer cements (GIC) using self-etch adhesives with different pH values.

MATERIALS AND METHODS

One hundred specimens (6×4×2 mm) were made using Fuji II and Fuji II LC GICs and treated with different adhesives as follows: Group 1:Fuji II+ Adper Prompt L-Pop, Group-2: Fuji II+SE bond, Group-3: Fuji II + AdheSE, Group-4:Fuji II+ Protect bond, Group-5: Fuji II + Single bond, Group-6:Fuji II LC+ Adper Prompt LPop, Group-7: Fuji II LC+SE bond, Group-8:Fuji II LC+ AdheSE, Group-9: Fuji II LC+ Protect bond, and Group-10: Fuji II LC+ Single bond. Each group consisted of 10 specimens. A cylinder of Z100 composite resin was placed on each sample and light cured. After 24 hours of water storage (37°C), the specimens were subjected to micro-shear bond strength tests (0.5 mm/min). Data were analyzed using two-way ANOVA and Tukey's test.

RESULTS

The mean micro-shear bond strength of groups 1-10 was 11.66±1.79, 16.50±1.85, 18.47±1.77, 13.95±1.77, 15.27±1.49, 15.14±0.90, 20.03±1.19, 17.48±3.00, 16.24±1.98 and 16.03±1.49 MPa, respectively. There were significant differences between groups 1 and 7 (P<0.05). No significant difference was observed between other groups (P>0.05). Fuji II LC showed higher bond strength than Fuji II (P<0.05).

CONCLUSION

Type of self-etch adhesive had no significant effect on micro-shear bond strength of glass-ionomer to composite resin. Resin modified glass ionomer cement (RMGIC) exhibited higher bond strength than the conventional GIC.

Effect of aging on saccular function

BACKGROUND

Aging can cause loss of balance, which may lead to physical and psychological problems. As the role of the otolith organs in maintaining postural stability has been emphasized in recent years, the present study investigated the effect of aging on saccular function using cervical vestibular evoked myogenic potentials (cVEMP).

METHODS

The participants were assigned into two groups; group one included 31 young adults with a mean age of 22.15 (range: 19-26 yr) and group two consisted of 31 old adults with a mean age of 69.76 years (range: 61-79 yr). All participants hearing sensitivity was normal with no history of balance problems. VEMP was recorded for all subjects using tone burst 500 Hz stimuli at the threshold level and 95 dB nHL intensity level through air-conduction stimulation via an insert receiver.

RESULTS

There was a significant difference in the cVEMP response threshold (p< 0.001), P1 wave latency (p<0.001), P1/N1 amplitude (p< 0.001), and asymmetry ratio of P1/N1 amplitude (p< 0.05) between the two groups. No significant difference was found between the left and right ears or in N1 wave latency between the two groups.

CONCLUSION

VEMP abnormalities observed in healthy older adults showed the sensitivity of this test in identifying early signs of vestibular dysfunction. VEMP is an easy-to-use test that requires a short time to be performed. Therefore, it can be used as a selective objective screening test to detect vestibular disorders.

Effects of menthol essence and breast milk on the improvement of nipple fissures in breastfeeding women

BACKGROUND

Nipple fissure is a common disorder during breastfeeding. With high prevalence of nipple fissures and its impacts on breastfeeding, as well as the existence of evidence in favor of the application of peppermint as an antiinflammatory and antiinfection herb, the purpose of this study is to determine the effect of Menthol essence on improving nipple fissures in the primiparous breastfeeding women.

MATERIALS AND METHODS

This study was conducted using a clinical trial method. Samples were divided randomly into two groups of 55 women. The women in the peppermint group applied four drops of Menthol essence on their nipple and areola after each feeding. The control group applied four drops of their own milk on the nipple and areola after each feeding. Then, the two groups were studied on days 10 and 14 postpartum. For intensity of pain, the visual analog scale (0-10 cm) and to measure the severity of damage, Amir scale (1-10 cm) were applied and the existence or lack of nipple discharge was also recorded. The data were analyzed using SPSS 17 software.

RESULTS

The mean intensity of pain and nipple fissure before treatment (8.55 ± 1.74) and day 10 after delivery (4.26 ± 1.57) and before treatment and day 14 after delivery in the case group (1.32 ± 1.02) had a significant difference (P < 0.001). Nipple discharge between the two groups, before treatment (%75.2) and day 10 after delivery (%31.6) and before treatment and day 14 after delivery (%15.7), the case group had a significant difference (P < 0.001).

CONCLUSION

Menthol essence can improve nipple fissures in the primiparous breastfeeding women.

Detecting and Accommodating Outliers in Meta-Analysis for Evaluating Effect of Albendazole on Ascaris lumbricoides Infection

Background:

Meta-analysis is a statistical technique in which the results of two or more independent studies, with similar objectives, are mathematically combined in order to improve the reliability of the results. The outliers, which may exist even in random models, can affect the validity and strength of meta-analysis results.

Objectives:

The current study uses "random effects variance shift model" to evaluate and correct the outliers in performing a meta-analysis study of the effect of albendazole in treating patients with Ascaris lumbricoides infection.

Patients and Methods:

The study used data from 14 clinical trials; each article was composed of two groups, a treatment group and a placebo group. These articles compared the effect of single dose intakes of 400 mg albendazole in treating two groups of patients with Ascaris lumbricoides infection. The articles were published in a number of internationally indexed journals between 1983 to 2013. For both groups in each article, the total number of participants, the number of those with Ascaris lumbricoides infection, and the number of those recovered following the intake of albendazole were identified and recorded. The relative risk (RR) and variance were computed for each article individually. Then, using meta-analysis, the RR was computed for all the articles together. In order to detect outliers the "random effects variance shift model" and "likelihood ratio test" (LRT) were used. Adopting the bootstrap method, the accuracy rates for sampling distribution of the tests, which were used for multiple testing, were obtained and the relevant graphs were depicted. For data analysis, STATA and R software were used.

Results:

According to meta-analysis results, the estimate for RR was 2.91, with a 95% confidence interval of 2.6 to 3.25. According to the method used in this study, three articles (articles number 4, 7, and 12) were outliers and, as such, they were detected in the graphs.

Conclusions:

We can detect and accommodate outliers in meta-analysis by using random effects variance shift model and likelihood ratio test.

Assessment of Microshear Bond Strength: Self-Etching Sealant versus Conventional Sealant

OBJECTIVE

Recently, self-etching fissure sealants have been introduced to reduce technical sensitivity; however, their efficacy should be assessed. The aim of this study was to assess of the microshear bond strength of self-etching and conventional fissure sealants.

MATERIALS AND METHODS

Thirty non-carious third molars were randomly divided into three groups (N=10). Microcylinders of Concise fissure sealant were bonded to prepared buccal and lingual surfaces using the two following procedures. In the first group, phosphoric acid was used to prepare the substrate; whereas in group two, Concise was used in combination with Prompt L-Pop. In group 3, a self-etching fissure sealant (Enamel Loc) was utilized per se. After 24 hours, the samples were subjected to 500 rounds of thermocycling and shear bond testing using a microtensile tester machine with a crosshead speed of 0.5mm/min. Data were analyzed using one-way repeated measure ANOVA and Bonferroni Post HOC tests (SPSS version 16).

RESULTS

THE MEAN AND STANDARD DEVIATION OF MICROSHEAR BOND STRENGTH OF THE GROUPS WERE AS FOLLOWS: Group 1: Concise+ etching (14.59 ± 1.19 MPa), Group 2: Concise+Prompt L-Pop (12.86 ± 1.98 MPa), and Group 3: Enamel Loc (5.59 ± 0.72 MPa). One-way ANOVA revealed that all the differences were significant and the conventional sealant exhibited the highest mean bond strength.

CONCLUSION

Conventional sealant using phosphoric acid etch application prior to fissure sealant application demonstrated more bond strength in comparison with that of self-etch bonding and self-etch sealant.

Zero inflated statistical count models for analysing the costs imposed by GERD and dyspepsia

BACKGROUND AND STUDY AIMS

Recent studies have shown that the high prevalence and the various clinical presentations of gastro-oesophageal reflux disease (GERD) and dyspepsia impose an enormous economic burden on society. Economic cost data have unique characteristics: they are counts, and they have zero inflation. Therefore, these data require special models. Poisson regression (PR), negative binomial regression (NB), zero inflated Poisson (ZIP) and zero inflated negative binomial (ZINB) regression are the models used for analysing cost data in this paper.

PATIENTS AND METHODS

In this study, a cross-sectional household survey was distributed to a random sample of individuals between May 2006 and December 2007 in the Tehran province of Iran to determine the prevalence of gastrointestinal symptoms and disorders and their related factors. The cost associated with each item was calculated. PR, NB, ZIP and ZINB models were used to analyse the data. The likelihood ratio test and the Voung test were used to conduct pairwise comparisons of the models. The log likelihood, the Akaike information criterion (AIC) and the Bayesian information criterion (BIC) were used to compare the performances of the models.

RESULTS

According to the likelihood ratio test and the Voung test and all three criteria used to compare the performance of the models, ZINB regression was identified as the best model for analysing the cost data. Sex, age, smoking status, BMI, insurance status and education were significant predictors.

CONCLUSION

Because the NB model demonstrated a better fit than the PR and ZIP models, over-dispersion was clearly only due to unobserved heterogeneity. In contrast, according to the likelihood ratio test, the ZINB model was more appropriate than the ZIP model. The ZINB model for the cost data was more appropriate than the other models.

Random effect model for identifying related factors to virological response in HCV patients

AIM

This study aims to employ random effect model to evaluate prognostic factors of hepatitis C.

BACKGROUND

In recent years, Hepatitis C virus (HCV) infection has been a major cause of liver diseases worldwide and represents a major public health problem. Evaluation of risk factors and a community intervention in order to decrease the problem is one of the solutions which help protect people from the infection.

PATIENTS AND METHODS

The data was collected from a longitudinal study during 2005-2010. The response variable in this study was the viral load of each HCV patient during the treatment, immediately after the treatment and 3 to 4 months after the end of the treatment. The outcome variable of interest is the viral load of HCV patients. For analyzing repeated measure viral load of HCV patients, random effect models were used.

RESULTS

The results obtained from random effect model showed that treatment protocol and time statistically significant. The variance component was statistically differing with zero.

CONCLUSION

According to the results time had a positive effect on rate of viral load of patient. Combination therapy of Peg-interferon plus Ribavirin increased the rate of virological response.

Comparison of neutrophil apoptosis, α-defensins and calprotectin in children with and without severe early childhood caries

BACKGROUND

The infectious nature of severe early-childhood caries (S-ECC) points to the possible participation of immunologic host responses including neutrophils and their antimicrobial products.

OBJECTIVES

The aim of this study was to determine the neutrophil apoptosis, α-defensins (HNP1-3) and calprotectin levels in the saliva of preschool children and the association with S-ECC.

METHODS

Oral examinations were performed on 87 children aged 3-5 years and non stimulated whole saliva samples were collected. Thirty of these subjects were considered S-ECC children, 30 with moderate caries (MC) and 27 were caries free (CF). To detect apoptosis, cell staining was done with Annexin-V-Fluos and propidium iodide, and they were analyzed by fluorescent microscopy. The concentration of α-defensins and calprotectin were assessed using ELISA.

RESULTS

There were no statistical differences between groups considering the HNP1-3 or calprotectin salivary levels (p=0.06 and p=0.23, respectively). The HNP1-3 and calprotectin levels were negatively correlated and the correlation was significant in MC group (p=0.03). Lower levels of apoptotic neutrophils were obtained from CF subjects as compared with S-ECC children (p=0.03).

CONCLUSIONS

Our findings establish that apoptotic mechanisms could be implicated in the immunity responses associated with S-ECC. We cannot yet determine if the level of salivary α-defensins or calprotectin is predictive of S-ECC.

Periapical Status and Quality of Root canal Fillings and Coronal Restorations in Iranian Population

INTRODUCTION

This cross-sectional survey determined the dental prevalence of apical periodontitis (AP) in selected Iranian population, and evaluated the influence of the quality of root canal treatment (RCT) and their coronal restorations (CR) on the periapical status.

MATERIALS AND METHODS

A total of 1064 panoramic radiographies were evaluated by two observers during 2009. The quality of RCT i.e. length/density of root fillings and CR in addition to periapical status of endodontically treated teeth were recorded. Their interrelationship was analyzed by Chi-squared, logistic regression and Spearman's rho statistics. Hosmer and Lemeshow tests were used for assessing fitness of logistic regression model and one sample k-s test was used for evaluating of normality of the data.

RESULTS

Our results showed that 527 teeth (52%) of the endodontically treated teeth presented with AP radiographically. The percentages of teeth which fulfilled the criteria of an acceptable RCT or CR radiographically were 42.3 and 62.5 respectively. Incidence of AP among teeth with acceptable RCT (29.1%) was significantly lower than those suffering from unacceptable RCT (68.8%) (P<0.001). Moreover, adequate CR demonstrated a significantly better periapical status (58.6%) compared to teeth with inadequate CR (30.3%) (P<0.001). The incidence of AP ranged from 25.6% (good qualities) to 79.5% (bad qualities) (P<0.001). Cases with both unacceptable RCT/CR were 11 times more likely to have AP than cases with acceptable RCT/CR. The quality of RCT and CR were found to impact the periapical health of endodontically treated teeth.

CONCLUSION

There are a significant high number of technically unacceptable endodontic and restorative treatments in Iran; therefore considerable efforts are needed to improve the standards of endodontic and restorative treatments.

Comparing alveolar bone regeneration using Bio-Oss and autogenous bone grafts in humans: a systematic review and meta-analysis

INTRODUCTION

Bone regeneration grafts (BRG) are widely used in the treatment of osseous defects and oral surgery. The various techniques and associated success rates of bone augmentation require evaluation by systematic review and meta-analysis of eligible studies. The aim of this systematic review was to compare alveolar bone regeneration in humans using Bio-Oss and autogenous bone graft.

MATERIALS AND METHODS

The computerized bibliographical databases including Pubmed, Google, ScienceDirect and Cochrane were searched for randomized and cohort studies in which autogenous grafts were compared to Bio-Oss in the treatment of periodontal defects. The inclusion criteria were human studies in English that were published 1998-2009. Exclusion criteria included non randomized observation and cohort studies, papers which provided summary statistics without the variance estimates, and studies that did not use BRG intervention alone, were excluded. The screening of eligible studies, assessment of the methodological quality of the trials and data extraction were collected by two observers independently. For comparing autogenous grafts used alone against Bio-Oss used alone 5 situations were investigated. Thirteen studies were included in the review which compared autogenous against Bio-Oss, autogenous combined with guided tissue regeneration (GTR) against GTR, Bio-Oss combined with GTR versus GTR, autogenous alone versus Open Flap Debridement (OFD), Bio-Oss versus OFD. In meta-analysis, changes in bone level (bone fill) was used as the measure. Data were analyzed using Bayesian meta-analysis by WinBUGS and Boa software.

RESULTS

Only one comparison demonstrated that the difference in bone augmentation between Bio-Oss and OFD was statistically significant.

CONCLUSION

There is insufficient evidence to show that Bio-Oss is superior to autogenous grafts in bone augmentation techniques however autogenous bone involves donor site surgery and thus donor site morbidity, so we can conclude that Bio-Oss is better than autogenous for alveolar regeneration. [Iranian Endodontic Journal 2009;4(4):125-30].

Particle size of a new endodontic cement compared to Root MTA and calcium hydroxide

INTRODUCTION

Particle size and distribution can influence the properties of materials. This study analyzed and compared the particle size of Root MTA, calcium hydroxide (CH), and a new endodontic cement called calcium enriched material (CEM).

MATERIALS AND METHODS

The particle size of each material was analyzed three times using 0.05 mg of test material with a particle size analyzer. The particle size distribution ranges, the cumulative percentage and the mean of particle sizes were calculated. One-way ANOVA, Tukey, and Chi-square tests were used for statistical analyses.

RESULTS

Results demonstrated that the distribution of particles was dissimilar. Particle mean size in the three different materials was not significantly different. However, the cumulative percentage of CH and CEM cement particles size demonstrated significant difference (P<0.05). Among the various particle size distributions, the particle distribution in the size range of ≤30 μm showed significant difference between materials (P<0.05). Interestingly, the smallest range of particle size belonged to CEM cement.

CONCLUSION

The high percentage of small particles found in CEM cement provides desirable properties such as effective seal, good setting time and film thickness in addition to favorable flow and adaptability.