ResearchPad - General Dentistry https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Single Nucleotide Polymorphisms (SNPs) of COL1A1 and COL11A1 in Class II Skeletal Malocclusion of Ethnic Javanese Patient]]> https://www.researchpad.co/product?articleinfo=Nbc226271-2b4d-416f-9837-de69edf71783

Background

The prevalence of malocclusion cases in the orthodontic specialist clinic in Airlangga University’s Dental Hospital in Surabaya, Indonesia, in 2014–2016 is fairly high, as 55.34% of the occurrences were identified as class II skeletal malocclusion. This type of skeletal malocclusion, which is usually recognized in adults, occurs as a result of variation during growth and development. Lately, there have been many reports on gene polymorphisms of COL1A1 and COL11A1, which are assumed to be associated with class II skeletal malocclusion in Caucasians.

Purpose

This study aims to analyze the relationship between single nucleotide polymorphisms (SNPs) of COL1A1 and COL11A1 with class II skeletal malocclusion in Javanese ethnic group patients with mandibular micrognathism.

Materials and Methods

The diagnosis of class II skeletal malocclusion was established using the lateral cephalometric radiographs (ANB angle ≥4°) (n=50). DNA was extracted from the patient’s peripheral blood. After that, PCR, electrophoresis, and DNA sequencing were conducted on the extracted DNA based on COL1A1 and COL11A1 primers.

Results

The SNPs in COL1A1 are c.20980G/A in 27 patients and c.20980G>A in 8 patients, whereas SNPs in COL11A1 are both c.134373C/A and c.134555C/T in 8 patients and both c.[134373A>C] and c.134582G>A in 10 patients. All samples show the deletion (c.[134227delA]) in COL11A1.

Conclusion

SNPs in COL1A1 and COL11A1 have been found in class II skeletal malocclusion of Javanese ethnic group patients. Seventy percent of SNPs in COL1A1 occur in rs.2249492, whereas 36% of newly discovered SNPs appear in COL11A1. All samples also have deletion in COL11A1.

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<![CDATA[The Occlusal Plane Inclination Analysis for Determining Skeletal Class III Malocclusion Diagnosis]]> https://www.researchpad.co/product?articleinfo=N274ca579-d2d2-4d0e-877a-bbcc4c7b2776

Introduction

The occlusal plane is very important in the stomatognathic and aesthetic dentofacial system. Manipulation of the occlusal plane plays an important role in class III malocclusion correction. For this reason, the strategy in establishing the diagnosis, prognosis and treatment plan becomes more complex, so a more comprehensive analysis of the occlusal plane inclination as a parameter of diagnosis is needed for more effective and efficient treatments.

Aim

The aim of this study was to determine the comparison of occlusal plane inclination between class III and class I malocclusions and to knowing the correlation of occlusal plane inclination in class III malocclusions with the direction of facial growth.

Materials and Methods

Samples were secondary lateral cephalograms collected at the Universitas Airlangga (UNAIR) Dental Hospital in October 2017–2018. Cephalograms were traced using the OrthovisionTM software; then, the Mann–Whitney comparative statistical test (p<0.05) was carried out followed by the canonical correlation test.

Results

Differences in class III and class I malocclusions were found in the OP-AB and OP-FH angles. The OP-AB angle is the occlusal plane inclination which has the strongest correlation compared to others. OP-AB angle is strongly correlated with horizontal growth parameter, especially theSNB. The OP-AB angle is also correlated with vertical growth parameters: the Y axis and the Facial axis.

Conclusion

The OP-AB angle is a parameter that can distinguish between class III and class I malocclusions. The OP-AB angle has a strong correlation with vertical and horizontal growth directions.

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<![CDATA[Socioeconomic-Related Inequalities in Dental Care Utilization in Northwestern Iran]]> https://www.researchpad.co/product?articleinfo=Ne80c5435-4966-4acf-9926-c5670fe3fa01

Introduction

There have been multiple studies on socioeconomic-related inequalities in the use of dental services in Iran, but the evidence is still limited. This study measured inequality in dental care utilization by socioeconomic status and examined factors explaining this inequality among households in Ardabil, Iran in 2019.

Methods

A total of 436 household heads participated in this cross-sectional study. Using a validated questionnaire, face-to-face interviews were conducted to collect data on dental care utilization, unmet needs, sociodemographic characteristics, economic status, health insurance, and oral health status of the participants. We used the concentration curve and relative concentration index (RCI) to visualize and quantify the level of inequality in dental care utilization by income. Regression-based decomposition was also applied to understand the causes of inequality.

Results

About 59.2% (95% CI 54.4%–63.7%) and 14.7% (95% CI 11.6%–18.4%) of participants had visited a dentist for dental treatment in the previous 12 months and for 6-month dental checkups, respectively. The RCI for the probability of visiting a dentist in the last 12 months was 0.243 (95% CI 0.140–0.346). This suggests that dental care utilization was more concentrated among the rich. The RCI for unmet dental care needs was negative, which indicates more prevalence among the poor. Monthly household income (20.9%), self-rated oral health (6.9%), regular brushing (3.2%), and dental health insurance (2.5%) were the main factors in socioeconomic inequality in dental care utilization.

Conclusion

This study reveals that dental care–service utilization did not match the need for dental care, due to differences in socioeconomic status in Ardabil, Iran. Policies could be implemented to increase the coverage of dental care services among socioeconomically disadvantaged groups to tackle socioeconomic-related inequality in dental care utilization.

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<![CDATA[Apical dye leakage of two single-cone root canal core materials (hydrophilic core material and gutta-percha) sealed by different types of endodontic sealers: An in vitro study]]> https://www.researchpad.co/product?articleinfo=5bfd57aed5eed0c4843bf928

Aim of the Study:

The aim of this study was to compare the apical sealing ability of two single-cone filling materials when sealed with different types of root canal sealers.

Materials and Methods:

Eighty extracted maxillary and mandibular canines were selected and their crowns were cut. The root canals were prepared using ProTaper Universal rotary system until size F4 and then divided into seven experimental groups (n = 10 each) and two control groups (n = 5 each). Samples of Groups 1, 2, and 3 were filled with single-cone gutta-percha and AH Plus, MTA Fillapex, and EndoSequence BC, respectively. Samples of Groups 4, 5, and 6 were filled similar to the previous groups with the exception of using a single-cone CPoint. Samples of Group 7 were filled with cold gutta-percha lateral condensation technique. To assess apical microleakage, the apical linear dye penetration was measured microscopically and data were statistically analyzed.

Results:

All experimental groups showed significantly different dye apical leakage values (P = 0.000). No significant differences were found between Groups 1, 2, 4, 6, and 7 (P < 0.05). The lowest mean leakage value was observed in Group 6 (0.95 ± 0.56 mm) while Groups 3 (2.68 ± 0.71 mm) and 5 (2.61 ± 0.71 mm) showed significantly higher mean leakage values.

Conclusions:

The lowest apical leakage value was observed with single-cone CPoint/EndoSequence BC but without significant differences when compared with single-cone gutta-percha/AH Plus, single-cone gutta-percha/MTA Fillapex, single-cone CPoint/AH Plus, and lateral condensation technique. Higher apical leakage values were observed with single-cone gutta-percha/EndoSequence BC and CPoint/MTA Fillapex.

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<![CDATA[Effect of acid etching on the micro-shear bond strength of resin composite–calcium silicate interface evaluated over different time intervals of bond aging]]> https://www.researchpad.co/product?articleinfo=5bfd57bfd5eed0c4843bff00

Introduction:

With the introduction of calcium silicate materials, pulp capping procedure has been simplified due to their therapeutic pulp capping capabilities and ability to be used as a provisional bulk restorative material simultaneously. The quality of the adhesive bond between these cements and composite is of clinical significance with regard to the longevity of the final laminate restoration. Thus, this study aims to compare the in vitro microtensile bond strengths of resin composite to different calcium silicate cements versus glass ionomer cement (GIC).

Materials and Methodology:

Resin composite was bonded to standardized disks of Biodentine, mineral trioxide aggregate (MTA), and GIC. The samples were divided into the following three groups, and each group was further divided into two subgroups based on the aging time (1 and 2 weeks) of the samples: (1) Group 1 – phosphoric acid etching on Biodentine. (2) Group 2 – phosphoric acid etching on MTA. (3) Group 3 – phosphoric acid etching on GIC. After bond aging, the microtensile bond strength was analyzed using the Instron universal testing machine.

Results:

There was no significant difference in micro-SBS between 1- and 4-week bond aging of MTA and Biodentine group, while a significant decrease is seen in the GIC group.

Conclusion:

Calcium silicate cements are weak in the early setting phase. Thus, placing the overlying composite is best delayed for at least 2 weeks to allow adequate maturation of the material.

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<![CDATA[Shear bond strength of ceramic fused to CAD-CAM milled alloys]]> https://www.researchpad.co/product?articleinfo=5b58a0e2463d7e4d042bbfe2

Background

This study evaluated the metal ceramic bond strength of cast Ni-Cr, cast Co-Cr, sintered Co-Cr and milled Co-Cr alloys to ceramic through two application procedures including the ceramic layering technique and ceramic pressed-on technique.

Material and Methods

Ceramic materials (Ø 8 mm, 1.5 mm thickness) were veneered by either the layering or pressed-on technique to cast Ni-Cr, cast Co-Cr, sintered Co-Cr and hard milled Co-Cr alloy disc (12 × 12 × 0.5 mm) (n=15). All specimens were treated with a thermal cycle process for 500 cycles at the temperature between 5 °C and 55 °C with immerse time of 30 seconds and 5 seconds for specimen transfer. The shear bond strength was determined on a universal testing machine at a crosshead speed of 0.5 mm/min. The de-bonding surfaces were examined under visual inspection and SEM. The metal ceramic interface of specimens for each group was examined in SEM and EDS. The means of bond strength were compared using two-way ANOVA followed by post-hoc Tukey HSD multiple comparison test to determine for statistically significant difference at 95% level of confidence. The Weibull analysis was used for determination survival probability of shear bond strength.

Results

The bond strength of ceramic to sintered Co-Cr alloys was higher than that to others metal alloys. The metal-ceramic mean bond strength was significantly higher for the ceramic pressed-on technique than that of the ceramic layering technique for all tested alloys (p<0.05). Weibull analysis of the shear bond strength indicated that the sintered Co-Cr alloys veneered with heat pressed ceramic provided the highest characteristic strength of metal ceramic bond.

Conclusions

The sintered Co-Cr alloys significantly contributed the appropriate bond strength for metal ceramic. Ceramic pressed-on was a reliable technique to enhance bond strength for fabrication the metal ceramic restoration.

Key words:Bond strength, sintered alloy, milled alloy, Co-Cr alloys, metal ceramic.

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<![CDATA[Do hypoxia and L-mimosine modulate sclerostin and dickkopf-1 production in human dental pulp-derived cells? Insights from monolayer, spheroid and tooth slice cultures]]> https://www.researchpad.co/product?articleinfo=5b4bda92463d7e7e0dcdb8a1

Background

To understand the responses of the dental pulp to hypoxia is of high relevance for regenerative endodontics and dental traumatology. Here, we aimed to reveal the effects of hypoxia and the hypoxia mimetic agent L-mimosine (L-MIM) on the production of sclerostin (SOST) and dickkopf-1 (DKK-1) in human dental pulp-derived cells (DPC).

Methods

DPC in monolayer, spheroid and tooth slice cultures were treated with L-MIM or hypoxia. Resazurin-based toxicity and MTT assays were performed to determine cell viability. mRNA and protein levels of SOST and DKK-1 were measured with quantitative reverse transcription PCR and ELISA, respectively. To validate the hypoxia-like response, SDF-1, VEGF and IL-8 were assessed. In addition Western blots for HIF-1α, HIF-2α and HIF-3α were done.

Results

Cells were vital upon treatment procedures and showed increased levels of HIF-1α, and HIF-2α. In monolayer cultures, mRNA levels of SOST and DKK-1 were downregulated by L-MIM and hypoxia, respectively. A significant downregulation of SOST by hypoxia was found at the protein level compared to untreated cells while the effect on DKK-1 and the impact of L-MIM on SOST and DKK-1 did not reach the level of significance at the protein level. In spheroid cultures, mRNA levels of SOST and DKK-1 were downregulated by L-MIM. A significant downregulation of DKK-1 upon hypoxia treatment was found at the protein level while the impact of hypoxia on SOST and the effect of L-MIM on SOST and DKK-1 did not reach the level of significance. SOST and DKK-1 were also produced in tooth slices, but no pronounced modulation by L-MIM or hypoxia was found. Evaluation of SDF-1, VEGF and IL-8 showed a hypoxia-like response in the culture models.

Conclusions

There is no pronounced influence of hypoxia and L-MIM on DPC viability, SOST and DKK-1 protein production. However, the specific response depends on the culture model and the level of evaluation (mRNA or protein). These results deepen our understanding about the role of hypoxia and the potential impacts of hypoxia-based strategies on dental pulp.

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<![CDATA[Knowledge, Attitude, and Perceived Confidence in the Management of Medical Emergencies in the Dental Office: A Survey among the Dental Students and Interns]]> https://www.researchpad.co/product?articleinfo=5b4a15e8463d7e40ecbbc4f0

Aims and Objectives:

Many situations in the dental office can provoke medical emergencies. Lack of training and inability to overcome the medical emergencies can lead to serious consequences and legal actions. The aim of the study is to investigate and assess the knowledge, attitude, and perceived confidence of dental students and interns in the management of medical emergency.

Materials and Methods:

A self-administered structured questionnaire was distributed to 153 of the undergraduate dental students and interns in Qassim province. Questionnaire consisted of nineteen questions pertaining to knowledge and awareness regarding syncope, cardiopulmonary resuscitation (CPR), intravenous drugs, measuring vital signs, and handling situation of aspiration of a foreign body, bleeding, and choking. Data were analyzed by Statistical Package for Social Sciences (SPSS) version 21.0.

Results:

Fifty-seven percent was the response rate received from the questionnaire. Eighty-nine percent and 30% of the participants inquired about the medical history and vital signs before dental treatment, respectively. Only 37% of participants were confident to handle any medical emergency in the dental office. Seventy percent knew the correct location of chest compression and 67% were familiar about the right compression ventilation ratio showing significant difference between academic years and interns (P = 0.003). Females were significantly more aware about the management of bleeding after extraction than the males (65%, and 47%, respectively; P = 0.035). Thirty-five percent and 53% chose the correct management to relieve choking in responsive and unresponsive adult or child, respectively. A total of 28% of the participants reported syncope as the most common emergency situation.

Conclusion:

Participants were lacking confidence in handling medical emergencies even though the majority of them inquired the medical history. Most of them have a good knowledge regarding CPR, but regarding airway obstruction, the knowledge was not at an acceptable level. Annual basic life support and emergency courses should be mandatory in dental teaching curriculum.

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<![CDATA[Evaluation of new technique of sterilization using biological indicator]]> https://www.researchpad.co/product?articleinfo=5b4a1441463d7e40ecbbc4ea

Background:

A novel technique of sterilization of endodontic files is introduced in this article.

Aims:

Newly introduced sterilization unit, named “SteriFast” is compared with autoclave and glass bead sterilizer using biological indicator.

Materials and Methods:

Spore strips of Bacillus pumilus were cultured in nutrient broth. This cultured media was used to contaminate the experimental samples of endodontic files. These contaminated files were sterilized using three different techniques. The sterilized files were transferred into nutrient medium under aseptic condition. The results were observed after 24 h, 48 h, and 7 days.

Results:

The results showed that autoclave and new sterilization device (SteriFast) showed complete sterilization. The files sterilized using glass bead sterilizer showed bacterial growth (80%).

Conclusions:

Thus, it proves that autoclave and SteriFast are ideal techniques of sterilization of endodontic files. Glass bead sterilizer does not completely sterilize the files. The article also compares SteriFast and autoclave in other aspects such as its design, basic principle, advantages, and disadvantages. The article also describes features and design of SteriFast, used for all kind of small dental instruments.

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<![CDATA[Differentiating early stage florid osseous dysplasia from periapical endodontic lesions: a radiological-based diagnostic algorithm]]> https://www.researchpad.co/product?articleinfo=5b4734ac463d7e6c0337a13f

Background

Osseous dysplasia (OD) is the most common fibro-osseous lesion of the jaw affecting the periapical region. Early stages of OD can resemble periapical radiolucencies, thus mimicking the radiological aspects of an endodontic pathology. Such radiolucent lesions affecting previously decayed or treated teeth are even more complex to interpret.

Case presentation

The aim of this paper is to report a case-series of representative clinical situations describing the radiological features and illustrating the diagnostic workup of patients with florid osseous dysplasia (FOD). Emphasis is given to the endodontic implications of such periapical bone disease and the complexity of accurate diagnosis in the context of endodontic retreatment. We then propose a practical radiological-based diagnostic algorithm to assist the clinician in the diagnostic of OD periapical lesions.

Conclusion

Periapical lesions may be confused with bone diseases such as osseous dysplasia, especially in the radiolucent initial stage. Knowledge of clinical features associated with a careful reading of cone beam CT images, such as fine opacities within the hypodense periapical lesion, may help determine the right diagnostic.

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<![CDATA[Lost wax-bolus technique to process closed hollow obturator with uniform wall thickness using single flasking procedure]]> https://www.researchpad.co/product?articleinfo=5bf19907d5eed0c484cdf318 <![CDATA[Concentration and time-dependent effect of initial sodium hypochlorite on the ability of QMix and ethylenediaminetetraacetic acid to remove smear layer]]> https://www.researchpad.co/product?articleinfo=5b46dfed463d7e668881ca93

Aims:

The aim of this study was to compare the ability of 17% ethylenediaminetetraacetic acid (EDTA) and QMix with different concentrations and time exposures of initial sodium hypochlorite (NaOCl) to remove the smear layer from the root canals.

Materials and Methods:

Eighty maxillary central incisors were used. After instrumentation, the teeth were divided into eight experimental groups according to the initial and final rinse. About 2.5% and 5% NaOCl were used during instrumentation and for 1 or 3 min was used as postinstrumentation initial irrigants, and 17% EDTA and QMix used as final irrigants. The apical and middle parts of the specimens were observed by scanning electron microscope.

Statistical Analysis Used:

Data were analyzed using the Kruskal–Wallis, Mann–Whitney, and Friedman's test.

Results:

Regardless of the type of final irrigant, QMix allowed more smear layer removal than EDTA after using 5% initial NaOCl for 3 min. In the apical part of the root canal walls, the smear layer was not completely removed.

Conclusion:

QMix and EDTA were similarly effective in smear layer removal at the middle parts of the root canal regardless of the concentration and time exposure of initial NaOCl, while none of the irrigation protocols was able to remove smear layer at the apical parts.

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<![CDATA[Oral cancer screening practices of oral health professionals in Australia]]> https://www.researchpad.co/product?articleinfo=5b46caac463d7e6446d0e401

Background

To evaluate oral cancer-related screening practices of Oral Health Professionals (OHPs - dentists, dental hygienists, dental therapists, and oral health therapists) practising in Victoria, Australia.

Methods

A 36-item survey was distributed to 3343 OHPs. Items included socio-demographic and work-related characteristics; self-assessed knowledge of oral cancer; perceived level of confidence in discussing oral health behaviors with patients; oral cancer screening practices; and self-evaluated need for additional training on screening procedures for oral cancer.

Results

A total of 380 OHPs responded this survey, achieving an overall response rate of 9.4%. Forty-five were excluded from further analysis. Of these 335 OHP, 72% were dentists; (n = 241); either GDP or Dental Specialists; 13.7% (n = 46) were dental hygienists; 12.2% (n = 41) were oral health therapists, and the remaining 2.1% (n = 7) were dental therapists. While the majority (95.2%) agreed that oral cancer screening should be routinely performed, in actual practice around half (51.4%) screened all their patients. Another 12.8% “Very rarely” conducted screening examinations. The probability of routinely conducting an oral cancer screening was explored utilising Logistic Regression Analysis. Four variables remained statistically significant (p < 0.0001). Results indicate that the likelihood of conducting an oral cancer screening rose with increasing levels of OHPs’ confidence in oral cancer-related knowledge (OR = 1.35; 95% CI: 1.09–1.67) and with higher levels of confidence in discussing oral hygiene practices with patients (OR = 1.25; 95% CI: 1.03–1.52). Results also showed that dental specialists were less likely to perform oral cancer screening examinations compared with other OHPs (OR = 0.18; 95% CI: 0.07–0.52) and the likelihood of performing an oral cancer screening decreased when the “patient complained of a problem” (OR = 0.21; 95% CI: 0.10–0.44).

Conclusion

Only half the study sample performed oral cancer screening examinations for all of their patients. This study provides evidence of the need for further oral cancer-related education and screening training for OHPs, which is vital to enhance oral cancer prevention and early detection.

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<![CDATA[Association of dietary habits and parental-reported sleep tooth grinding with tooth wear in children with mixed dentition]]> https://www.researchpad.co/product?articleinfo=5b46d088463d7e6446d0e416

Background

Tooth wear has a multifactorial etiology, thus it should be assessed within a multiple-variable framework. The objective of this investigation was to assess the association of dietary habits and parental-reported sleep tooth grinding (STG) with tooth wear in children with mixed dentition.

Methods

One hundred twenty-one (N = 121) subjects (mean age 9.6 years) participated in a cross-sectional study. Wear of 1637 teeth was evaluated using the screening module of the Tooth Wear Evaluation System (TWES). Parental-report of STG was evaluated by means of the Children’s Sleep Habits Questionnaire (CSHQ), whilst dietary habits were investigated by means of the Health Behaviour in School-Aged Children Food-Frequency Questionnaire (HBSC-FFQ). Data were analyzed with the Spearman correlation test and ordinal-multiple-variable regression analyses. Odds Ratio (OR) and ordinal OR were obtained for the independent variables included in the models.

Results

Parental-report of STG is not associated with tooth wear in the mixed dentition; some dietary habits were found to be correlated with specific tooth wear patterns, but the correlation values were weak. Associations were found between dietary habits and the increase-to-increase severity of occlusal/incisal and non-occlusal/non-incisal tooth wear of some teeth (OR > 2).

Conclusions

A strong correlation of dietary habits and sleep tooth grinding with tooth wear in the mixed dentition was not demonstrated. However, dietary habits showed to have effects in terms of increase-to-increase severity.

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<![CDATA[Clinical comparison of the stain removal efficacy of two air polishing powders]]> https://www.researchpad.co/product?articleinfo=5b434bab463d7e25f0425db6

Objectives:

Air polishing with sodium bicarbonate powders with a grain size of 40 μm is recommended for patient comfort. However, the efficacy of small grain size on stain removal has not been adequately studied. This study aimed to compare the stain removal efficacy of sodium bicarbonate powders with grain sizes of 65 and 40 μm and to evaluate patient acceptance and operator opinion after using both air polishing powders.

Materials and Methods:

A double-blind, randomized, split-mouth study was conducted with 35 participants with moderate to heavy dental staining on both sides of the upper teeth. Removal of dental stains on the index teeth was performed using sodium bicarbonate powders with a grain size of either 65 or 40 μm. The time taken to completely remove all dental stains was recorded. After treatment, a questionnaire was used to evaluate patient acceptance and the operator's opinion.

Results:

The average time for the removal of all stains by powder was 4.5 ± 3.6 min with a grain size of 65 μm and 4.4 ± 3.8 min with a grain size of 40 μm. The difference in the average time between the two groups was not significant (P = 0.461). The operator's opinions of the two powders were identical, and patient acceptance did not differ significantly between the two types of powders.

Conclusions:

The 40 μm sodium bicarbonate powder removed dental stains as efficiently as the 65-μm powder. Powder handling and patient acceptance were comparable between grain sizes of 65 and 40 μm.

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<![CDATA[Flexural properties and impact strength of denture base resins reinforced with micronized glass flakes]]> https://www.researchpad.co/product?articleinfo=5b3e55aa463d7e44f6232368

Objectives:

To investigate the effect of the addition of glass flakes on physical properties of conventional heat cure denture base resins and to compare it with a high impact strength denture base resin.

Materials and Methods:

Test specimens were divided into Group 1 - poly (methyl methacrylate) (PMMA) (Trevalon), Group 2 - Trevalon HI, Group 3 -5% glass flake +95% PMMA (Trevalon), Group 4 -10% glass flake +90% PMMA (Trevalon), and Group 5 -20% glass flake +80% PMMA (Trevalon). For glass flake modified groups, part of PMMA (powder) was substituted with the same weight of glass flake (GF003 m) as required, to bring it to 100% powder. Flexural strength was tested using three-point bending test and impact strength with Izod type impact tester.

Results:

Plain PMMA (Trevalon), showed the highest value of flexural strength followed by Trevalon HI. Trevalon HI (highly cross-linked PMMA) group showed the highest value of impact strength.

Conclusion:

Flexural strength of unmodified PMMA denture base resin decreases with increase in the concentration of glass flakes. Impact strength does not show any significant change at 5% concentration of glass flakes and impact strength significantly reduces with the addition of glass flakes in 10% and 20%.

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<![CDATA[Comparison between two tomographic sections in the diagnosis of external root resorption]]> https://www.researchpad.co/product?articleinfo=5b37824e463d7e6b6e6f58fc

Objectives

To assess the accuracy of coronal and sagittal CT sections to detect cavities simulating root resorption.

Material and Methods

60 mandibular incisors were embedded in plaster bases, and cavities with 0.6, 1.2 or 1.8 mm in diameter and 0.3, 0.6 or 0.9 mm in depth (small, medium and large cavities) were drilled on the buccal surfaces with high-speed round burs with diameters of 0.6, 1.2 and 1.8 mm to simulate external inflammatory root resorption. Simulations in the cervical, middle and apical thirds of each tooth root were made randomly. The Dental Scan software was used to obtain 1-mm-thick axial images from direct scanning, which were reconstructed in the coronal and sagittal planes using 3D software (Syngo FastView). Each series was loaded into the software. Fourteen images of each tooth were reconstructed in the coronal plane and 14 in the sagittal plane. A total of 1,652 images were obtained for analysis. Series information, tooth number and the plane reconstructed were stored. The images generated were saved on a CD-ROM together with the visualization software (Syngo FastView). Images were analyzed by a previously calibrated blinded, radiologist. Cochran’s Q test was conducted separately for each region analyzed followed by pair-wise comparison by the McNemar test (p=0.05).

Results

No statistically significant difference (p>0.05) was observed in the diagnosis of simulated resorption between the apical, middle, and coronal thirds. When the axial plane was assessed separately, diagnoses were statistically different (p<0.05) among the three root thirds. The apical third differed significantly (p<0.05) from the cervical and middle thirds. Diagnostic errors were more often observed in the apical third compared to the cervical and middle thirds. Mid-sized cavities revealed no statistically significant differences (p>0.05) between planes, irrespective of the third in which the resorptions were located.

Conclusion

When tomographic sections are requested for the diagnosis of buccal or lingual external root resorption, sagittal sections afford the best image characterization of the resorption process.

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<![CDATA[Collagen Hydrogel Scaffold and Fibroblast Growth Factor-2 Accelerate Periodontal Healing of Class II Furcation Defects in Dog]]> https://www.researchpad.co/product?articleinfo=5bce61a440307c77beee4916 <![CDATA[Cationic Lipid Content in Liposome-Encapsulated Nisin Improves Sustainable Bactericidal Activity against Streptococcus mutans]]> https://www.researchpad.co/product?articleinfo=5bce619f40307c77beee4914 <![CDATA[Immediate Dental Implant Placements Using Osteotome Technique: A Case Report and Literature Review]]> https://www.researchpad.co/product?articleinfo=5bce61a140307c77beee4915