Evaluation of calcium hydroxide root canal filling materials by cone beam computed tomography and three-dimensional modeling.

AIM: The aim of this study was to compare the effectiveness of filling pastes in resin prototype primary molars by cone beam computed tomography (CBCT) and 3D modeling.

Monochorionic Twinning in Bioengineered Human Embryo Models.

Monochorionic twinning of human embryos increases the risk of complications during pregnancy. The rarity of such twinning events, combined with ethical constraints in human embryo research, makes investigating the mechanisms behind twinning practically infeasible. As a result, there is a significant knowledge gap regarding the origins and early phenotypic presentation of monochorionic twin embryos. In this study, a microthermoformed-based microwell screening platform is used to identify conditions that efficiently induce monochorionic twins in human stem cell-based blastocyst models, termed "twin blastoids". These twin blastoids contain a cystic GATA3+ trophectoderm-like epithelium encasing two distinct inner cell masses (ICMs). Morphological and morphokinetic analyses reveal that twinning occurs during the cavitation phase via splitting of the OCT4+ pluripotent core. Notably, each ICM in twin blastoids contains its own NR2F2+ polar trophectoderm-like region, ready for implantation. This is functionally tested in a microfluidic chip-based implantation assay with epithelial endometrium cells. Under defined flow regimes, twin blastoids show increased adhesion capacity compared to singleton blastoids, suggestive of increased implantation potential. In conclusion, the development of technology enabling large-scale formation of twin blastoids, coupled with high-sensitivity readout capabilities, presents an unprecedented opportunity for systematically exploring monochorionic twin formation and its impact on embryonic development.

Effect of 38% silver diamine fluoride on fracture resistance of leucite reinforced feldspathic ceramic CAD/CAM class I inlay restorations.

INTRODUCTION: Silver diamine fluoride (SDF) is a topical agent that has recently gained popularity for its ability to stop and prevent dental caries.

Can sleeping habits be associated with sleep bruxism, temporomandibular disorders and dental caries among children?

BACKGROUND: Sleeping problems are common in the pediatric population. Their potential relationship with oral manifestations is in the scope of researchers' interest. OBJECTIVES: The aim of the present study was to evaluate the possible associations between sleeping habits and sleep bruxism, temporomandibular disorders (TMD) and dental caries among children by using Children's Sleep Habits Questionnaire (CSHQ). MATERIAL AND METHODS: A cross-sectional study was carried out at the Faculty of Dentistry of Istanbul Aydin University, Turkey, with a representative sample of 100 children aged 6-13 years. The CSHQ was completed by their parents. In addition, an intraoral examination was carried out in a clinical setting and sleep bruxism was recorded. The temporomandibular joints (TMJ) were examined and TMD were rated according to the Helkimo anamnestic and clinical dysfunction index. Data was analyzed with Fisher's exact test and the χ2 test. RESULTS: Among sleeping habits, bedtime resistance was found to be significantly associated with sleep bruxism and TMD symptoms in children. Sleep behavior problems were also found to be related to TMD. Untreated dental caries was significantly associated with sleep fragmentation. CONCLUSIONS: Sleep bruxism, TMD and untreated dental caries might have a negative impact on children's sleeping habits and characteristics. Pediatricians and pedodontists should collaborate to identify the causes and clinical features of sleeping habits and disorders in order to avoid adverse effects on the child's stomatognathic system.

Evaluation of Postoperative Pain Following Single-Visit Root Canal Treatment with Rotary and Reciprocal Ni-Ti File Systems in Children.

Background and Objectives: Postoperative pain is a common symptom of a flare-up after root canal treatments (RCTs). Insufficient instrumentation, extrusion of irrigation solutions and debris, and the existence of a periapical lesion are the factors affecting postoperative pain after root canal treatments. The aim of this study was to evaluate the postoperative pain and instrumentation time of the single-file reciprocating system and multiple-file Ni-Ti rotary system in children ages 9-12 years old. Materials and Methods: Our study was conducted on 51 permanent mandibular molars with the diagnosis of irreversible pulpitis. Patients were randomly assigned into two groups, and RCTs were completed with either the Reciproc Blue or Protaper NEXT file systems. Instrumentation time for each system was noted, and patients were given a pain scale that included a visual analog scale for 6, 24, 48, and 72 h after treatment. Postoperative pain scores and instrumentation times were analyzed statistically with a chi-square test and Student's t-test. Results: There was no statistically significant difference in postoperative pain between the Reciproc Blue and Protaper NEXT systems at all time intervals. Instrumentation time was significantly shorter in the Reciproc Blue group in comparison with the Protaper NEXT group. Conclusions: Postoperative pain findings following RCT using single-file reciprocating systems were similar to the rotary system group. However, chair time in the reciprocating system group was significantly lower. This provided a comfortable and patient-friendly treatment approach for children, and could enhance their cooperation.

Effects of short-term xylitol chewing gum on pro-inflammatory cytokines and Streptococcus mutans: A randomised, placebo-controlled trial.

INTRODUCTION: Dental caries is an infectious disease with predominantly of cariogenic bacteria such as Streptococcus mutans (S mutans). Xylitol is considered as one of the effective agents that can limit this dental infection. In this randomised, placebo-controlled trial, we aimed to evaluate the potential reflection of short-term xylitol consumption on pro-inflammatory cytokines (TNF-α, IL-6 and IL-8) and S mutans counts by ELISA and qPCR (Quantitative real-time PCR), respectively. METHODS: In this study, 154 participants were assigned to two groups, control and xylitol. Dental examination, saliva and swab samples were done at baseline and at 3-week for clinical and microbiological assessment. RESULTS: In xylitol group at the end of 3-week, gingival and plaque index scores were significantly decreased with respect to baseline values (P < .001 and P < .05, respectively). The salivary concentration of TNF-α, IL-6 and IL-8 were statistically declined at 3-week, more so than those at baseline in xylitol group (P < .001). S mutans expression was reduced about fivefold at 3-week use of xylitol and it was a statistically significant difference compared to baseline (P < .001). CONCLUSION: Intriguingly, even short-term consumption of xylitol might play a favourable role in maintaining the oral health status, possibly as a result of decreasing the release of pro-inflammatory cytokines and the counts of S mutans. Nonetheless, this investigation warrants further endorsement.

Psychometric evaluation of the child oral impacts on daily performances (C-OIDP) for use in Turkish primary school children: a cross sectional validation study.

BACKGROUND: As patient-reported outcome, the Child Oral Impacts on Daily Performances (C-OIDP) has been commonly used for assessing children's oral health needs in order to facilitate oral health service planning. It was translated and cross-culturally adapted into Turkish in 2008. Since then, there is no study to assess its psychometric properties in Turkish child population. This cross-sectional study aimed to investigate the psychometric properties and factor structure of the Turkish version of the C-OIDP for use in Turkish primary school children. METHODS: The Turkish translated version was tested on a convenience sample of primary school children aged 11 to 12 years attending two public schools in Istanbul. Data were collected by clinical examinations, face-to-face interviews and self-completed questionnaires. The internal consistency, test-retest reliability, construct validity using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), criterion related validity (concurrent and discriminant) were evaluated. RESULTS: A total of 208 children were subjected to the tested the C-OIDP. Overall, 93.7% of them reported at least one oral impact in the last 3 months. The most frequently affected performances were "eating" (72.1%) and "cleaning mouth", while the performance with the lowest impact was "studying" (13%). The internal consistency and reproducibility of the C-OIDP were acceptable, with a Cronbach's alpha of 0.73 and an intra-class correlation coefficient of 0.83. The EFA yielded a two-factor model termed "functional limitation" and "psychosocial limitation". CFA identified the two- factor model which fit the data better than the previously proposed three-factor model, namely physical, psychological and social health. Having malocclusion, the presence of gum disease, reported history of oral problems in the mouth, dissatisfaction with oral health, bad self-rated oral health and having a problem-oriented pattern of dental attendance were found to be the most important factors related to worse oral health- related quality of life, supporting its criterion-related validity. CONCLUSION: This study provided preliminary evidence the psychometric properties of the C-OIDP index among Turkish school children aged 11-12 years. It may be applied to evaluate the oral health impact on quality of life in this population.

Comparative evaluation of pro-inflammatory cytokine levels in pulpotomized primary molars.

The present in vivo study was performed to investigate the levels of the pro-inflammatory cytokines, interleukin (IL)-1α, IL-6, and IL-8, in primary molars for which pulpotomy was clinically indicated, and to evaluate the success rates of three different pulpotomy agents employed for cariously (CExp) or mechanically exposed (MExp) primary molars. Forty-seven primary molars were classified as MExp or CExp according to the type of pulpal exposure. Pulp tissue was harvested and analyzed using enzyme-linked immunosorbent assay (ELISA). Subsequently, three pulpotomy agents-calcium hydroxide (CH), mineral trioxide aggregate (MTA), and formocresol (FC)-were applied randomly, and the outcome was observed radiographically for 18 months. Levels of IL-6 and IL-8 were significantly higher in CExp pulp than in MExp pulp (P < 0.05). In the CH pulpotomy group, MExp teeth showed a higher success rate than CExp teeth. There was no significant difference in success rate between MExp and CExp teeth in both the FC and MTA groups. The levels of IL-6 and IL-8 have the potential to become indicators of pulp status and can be monitored by researchers to make the prognosis of vital pulp therapies less uncertain. As MTA and FC yielded higher rates of success than CH in CExp teeth, the choice of pulpotomy agent appears to be important in this context.

Comparative evaluation of microleakage of nano-filled resin-modified glass ionomer: An in vitro study.

OBJECTIVE: This in vitro study evaluated the microleakage of a nano-filled resin-modified glass ionomer and a high viscosity glass-ionomer restorations in class V cavities. MATERIALS AND METHODS: Thirty-two class V cavities prepared on the buccal and lingual surfaces of 16 sound, third molar teeth were randomly assigned into two groups and restored by one of the glass ionomer material; Group A: A high viscosity (Ketac Molar, 3M ESPE) Group B: A nano-filled resin-modified (Ketac N100, 3M ESPE) glass ionomer. One clinician prepared all the cavities. The materials were used according to the manufacturers' recommendations. The restored teeth were then stored in distilled water at 37°C for 24 h, thermocycled at 5-55°C for 1000 cycles. The specimens were immersed in aqueous solution of Indian ink dye for 48 h at room temperature. They were embedded in resin polyester and sectioned longitudinally in a buccolingual direction. Microleakage was assessed according to the depth of dye penetration along the restoration. The extent of dye penetration at the occlusal and gingival margins was assessed using a stereo microscope. Randomly selected samples from each group were prepared for scanning electron microscope evaluation. The data were statistically analyzed with Friedman and Wilcoxon signed ranks tests. RESULTS: There were statistically significant differences between the microleakage scores of the two groups for both occlusal and gingival scores (P = 0.001). Occlusal and gingival scores for high viscosity glass ionomer (P = 0.024) and nanoionomer (P = 0.021) using Wilcoxon signed ranks tests showed statistically significant differences. High viscosity glass ionomer showed significantly less microleakage compared to the nano-filled resin-modified glass-ionomer (RMGIs) at occlusal margin (P = 0.001). No significant differences were found between the groups at gingival margin (P = 0.0317). CONCLUSION: Within the limitations of this in vitro study, nano-filled RMGIs restorations did not perform better than high viscosity glass ionomer in class V cavities in terms of microleakage assessment.

Lidocaine versus mepivacaine in sedated pediatric dental patients: randomized, prospective clinical study.

UNLABELLED: Dental anxiety is usually seen in the pediatric patients. specially in the case of minor oral surgical procedures and exodontia, cooperation of the patients and their families with the dentist will lead to superior treatment outcomes. Pain control is important in dentistry. The aim of this randomized prospective clinical study is to compare the local anaesthetic and haemodynamic effects of 2% lidocaine (Group 1) and 3% mepivacaine (Group 2) in sedated pediatric patients undergoing primary tooth extraction. STUDY DESIGN: 60 pediatric patients undergoing sedation for elective primary tooth extraction was prospectively included in the study in a randomized fashion. Inclusion and exclusion criteria were assigned. Patients were given premedication via oral route. Local anesthesia was achieved before extraction(s). RESULTS: There were no significant differences between the groups in patient demographics, number of teeth extracted, duration of the operation and time from the end of the procedure to discharge (p ≥ 0.05). FLACC pain scale scores were not statistically significant between the groups, except at 20 minutes post-operatively when the score is significantly lower in Group 2 (p=0.029). CONCLUSION: Prevention of pain during dental procedures can nurture the relationship of the patient and dentist. Tooth extraction under sedation in pediatric patients could be safe with both local anesthetics.

The effect of different enamel surface treatments on microleakage of fissure sealants.

OBJECTIVE: The aim of this study was to evaluate the effects of different techniques of surface treatment on the microleakage of fissure sealants in permanent molar teeth in vitro. MATERIALS AND METHODS: 96 extracted impacted human third molars were randomly divided into 8 surface treatment groups (n=12/group) as 1. Er: YAG laser ; (Fidelis II, Fotona, Ljubljana, Slovenia) (125 mj, 20Hz) ; 2. Er: YAG laser + 37% H3PO4 (15s) ; 3. ER: AG laser + 37% H3PO4+Prime&Bond NT ; 4. Er: YAG laser + G Bond ; 5. Er: YAG laser + Prime&Bond NT ; 6. 37% H3PO4 ; 7. 37% H3PO4 + Prime&Bond NT ; 8. G Bond. Sealant material (Clinpro, 3M ESPE, Seefeld, Germany), was applied into the fissures and light-cured for 20s with LED (Bluephase C5, Ivoclar-Vivadent, Schaan, Liechtenstein). Specimens were subjected to thermocycling (1000×, 5-55°C, dwell time: 15s) and immersed in 0.5% basic fuchsin solution for 24h at 37°C. The samples were sectioned and scored on a 3 point rating scale using a light microscope with a magnification of ×20. One-way analysis of variance was used to analyze data. Multiple comparisons were analyzed using Bonferroni test (p=0.05). RESULTS: Er:YAG laser showed the highest microleakage scores whereas Er YAG laser + 37% H3PO4 showed the lowest. Although 37% H3PO4 group showed higher scores than Er:YAG laser + 37% H3PO4, the difference was not statistically significant. CONCLUSION: Etching fissures with phosphoric acid is sufficient prior to fissure sealant application.

Effect of orthodontic appliances on oral microbiota--6 month follow-up.

OBJECTIVE: This study investigates the effect of fixed and removable orthodontic appliances among children on salivary Streptococcus mutans, Lactobacillus sp. and Candida albicans. STUDY DESIGN: The study was conducted on 69 patients aged between 6-17 years who used fixed or removable orthodontic appliances. Five ml samples of unstimulated saliva from each patient were collected at baseline and at the 1, 3 and 6 month periodic controls. Samples were diluted and plated on Mitis Salivarus Agar (MSA), Man Rogosa Sharp Agar (MRS) and Saboroud Dextrose Agar (SDA). The growths on the plates were examined under a stereomicroscope. Numbers of colony forming units (CFU) per plate were counted. For statistical analysis, the paired t test and Chi-Square were used. RESULTS: S mutans and Lactobacillus sp counts increased significantly 6 months after the insertion of fixed/removable orthodontic appliances in the oral cavity. A significant increase for C albicans presence was noted after 3 months compared with baseline for fixed appliances. CONCLUSION: Long-term utilization of orthodontic appliances may have a negative effect on microbial flora and increase the risk of new carious lesions and periodontal problems. Patients should be recalled within short time intervals to be motivated for oral hygiene during their orthodontic therapy.

Delayed replantation of an avulsed tooth after 5 hours of storage in saliva: a case report.

This article reports a clinical case of a 8-year-old boy, who underwent an avulsion of the upper left central incisor. The avulsed tooth was kept in the oral cavity in direct contact with saliva for 5 h from the moment of trauma until its replantation. Treatment guidelines for avulsed mature permanent teeth were followed. The clinical and radiographic findings after 2 years revealed absence of root resorption, ankylosis or mobility of the replanted tooth.

Monomer Release from Resin Based Dental Materials Cured With LED and Halogen Lights.

OBJECTIVES: To measure the release of TEGDMA and BisGMA from two commercially available composite resins; Filtek Z 250 (3M ESPE, Germany), Leaddent (Leaddent, Germany) and two fissure sealants; Helioseal F (3M ESPE, Germany) Enamel Loc (Premiere Rev, USA) over 1, 3 and 7 days after polymerization with standard quartz-tungsten halogen Coltolux II (QHL) (Coltene Switzerland) and a standard blue light emitting diode Elipar Freelight 2 (3M ESPE, Germany). METHODS: 9 samples of each material were placed in disc shaped specimens in 1 mm of thickness and 10 mm in diameter (n=36). Each material was polymerized using LED for 20 s (n=12), 40 s (n=12) and halogen for 40 s (n=12), respectively. High Performance Liquid Chromatography (HPLC) was used to measure the amount of monomers released over 1, 3 and 7 days. Data was analyzed using one way ANOVA and Bonferroni test for multiple comparisons with a significance level of .05. RESULTS: LED 20 sec group showed the highest release of monomers at 1, 3 and 7 days in sealant groups. Halogen 40 sec group resulted highest release of monomers for Leaddent at all time intervals (P<.05) CONCLUSIONS: Efficiency of the curing unit and applying the recommended curing time of the light activated resin based dental materials is very important to protect the patient from potential hazards of residual monomers.

Managing dental caries in children in Turkey--a discussion paper.

BACKGROUND: This paper describes the oral healthcare system and disease situation amongst children in Turkey. Considering the high prevalence and severity of dental caries, a proposal for improvement of oral health in this population group is formulated. DISCUSSION: A virtual absence of palliative, preventive and restorative care characterises juvenile oral healthcare in Turkey. Consequently, carious cavities remain untreated, which may lead to pain, discomfort and functional limitation and, further, may impact negatively upon general health and cognitive development. As a first step to controlling dental caries, a national health programme including promotional, preventive and minimal intervention approaches for managing dental caries is proposed. The pros and cons of community-oriented caries-preventive measures are discussed. Daily tooth brushing with fluoridated toothpaste at home, in mother- and child-care centres, kindergartens, and schools is highlighted. SUMMARY: The dental profession, government, university officials and other stakeholders need to meet and determine how best the oral health of children in Turkey can be improved. The present proposed plan is considered a starting point.

Two years survival rate of class II composite resin restorations prepared by ART with and without a chemomechanical caries removal gel in primary molars.

The aim was to test the null hypotheses that there is no difference: (1) in carious lesion development at the restoration margin between class II composite resin restorations in primary molars produced through the atraumatic restorative treatment (ART) with and without a chemomechanical caries removal gel and (2) in the survival rate of class II composite resin restorations between two treatment groups after 2 years. Three hundred twenty-seven children with 568 class II cavitated lesions were included in a parallel mouth study design. Four operators placed resin composite (Filtek Z 250) restorations bonded with a self-etch adhesive (Adper prompt L pop). Two independent examiners evaluated the restorations after 0.5, 1, and 2 years using the modified Ryge criteria. The Kaplan-Meier survival method was applied to estimate survival percentages. A high proportion of restorations were lost during the study period. Therefore, the first hypothesis could not be tested. No statistically significant difference was observed between the cumulative survival percentages of restorations produced by the two treatment approaches over the 2-year period (ART, 54.1 +/- 3.4%; ART with Carisolv, 46.0 +/- 3.4%). This hypothesis was accepted. ART with chemomechanical gel might not provide an added benefit increasing the survival percentages of ART class II composite resin restorations in primary teeth.

Supernumerary primary tooth with facial and palatal talon cusps: a case report.

Talon cusp is a tooth anomaly originating from the tooth's lingual surface in most cases. To date, very rare cases have been reported documenting talon cusps both on the facial and palatal surface of an affected tooth in the dental literature. The purpose of this case report was to describe the facial and palatal talon cusps on an ectopic supernumerary primary maxillary tooth. A micro-CT investigation indicated no pulpal extensions within facial and palatal talon cusps.

Treatment of sequelae in permanent dentition after severe trauma in primary dentition.

A case with a dilacerated upper right central and hypoplastic upper right lateral incisors covered with gingiva of a 10-year-old female, with a history of trauma at the age of 18 months, is presented. After clinical and radiographical evaluations, esthetic problem was solved with gingivectomy followed by composite restorations of the involved teeth.

Effects of light curing method and exposure time on mechanical properties of resin based dental materials.

OBJECTIVES: The aim of this study was to investigate microhardness and compressive strength of composite resin (Tetric-Ceram, Ivoclar Vivadent), compomer (Compoglass, Ivoclar, Vivadent), and resin modified glass ionomer cement (Fuji II LC, GC Corp) polymerized using halogen light (Optilux 501, Demetron, Kerr) and LED (Bluephase C5, Ivoclar Vivadent) for different curing times. METHODS: Samples were placed in disc shaped plastic molds with uniform size of 5 mm diameter and 2 mm in thickness for surface microhardness test and placed in a diameter of 4 mm and a length of 2 mm teflon cylinders for compressive strength test. For each subgroup, 20 samples for microhardness (n=180) and 5 samples for compressive strength were prepared (n=45). In group 1, samples were polymerized using halogen light source for 40 seconds; in group 2 and 3 samples were polymerized using LED light source for 20 seconds and 40 seconds respectively. All data were analyzed by two way analysis of ANOVA and Tukey's post-hoc tests. RESULTS: Same exposure time of 40 seconds with a low intensity LED was found similar or more efficient than a high intensity halogen light unit (P>.05), however application of LED for 20 seconds was found less efficient than 40 seconds curing time (P=.03). CONCLUSIONS: It is important to increase the light curing time and use appropriate light curing devices to polymerize resin composite in deep cavities to maximize the hardness and compressive strength of restorative materials.

Micro-CT for measuring marginal leakage of Class II resin composite restorations in primary molars prepared in vivo.

PURPOSE: To evaluate the reliability of marginal leakage assessment of self-etch adhesive Class II resin composite restorations in primary molars prepared in vivo using the micro-CT. METHODS: Fourteen primary molars, divided over seven ART and seven traditional resin composite Class II restorations, were subjected to marginal leakage test using a 50% (w/v) silver nitrate solution for 4 hours by a micro-CT. Two evaluators selected the image with the deepest marginal dye penetration for each restoration from the occlusal and approximal surfaces on consensus. The deepest dye penetration depth and total length of the axial cavity wall from both the occlusal and from the approximl surface were measured manually using morphometric quantification software by three evaluators independently. ANOVA was applied to test for differences in marginal leakage scores between the three evaluators. RESULTS: There was no marginal leakage found in five traditional and one ART restoration. The percentage of silver nitrate penetration depth from the cervical-approximal site ranged from 10.2-92.6%. There was only a statistically significant difference observed in measuring total axial wall length from the cervical-approximal site between the three evaluators (P = 0.02). This explanatory investigation showed that the micro-CT was a very useful device for developing a standardized method for measuring marginal leakage from samples obtained in vivo. In combination with 50% (w/v) silver nitrate and 4-hour immersion, marginal leakage along the restoration-tooth tissue interface was accurately and reliably measured. (Am J Dent 2008;21:393-397).