An in vivo comparative clinical and radiographic evaluation of a mixture of zinc oxide-Ocimum sanctum extract, zinc oxide-ozonated oil, and zinc oxide-eugenol as obturating materials in primary molars.

Background: To overcome some of the disadvantages of the current primary root canal obturating materials, there is a continued interest in search for chemical compounds with broader and more effective antibacterial action and less cytotoxicity. Aim: This study aimed to evaluate and compare in vivo the clinical and radiographic success of mixtures of zinc oxide-Ocimum sanctum extract, zinc oxide-ozonated oil, and zinc oxide-eugenol (ZOE) as obturating materials in pulpectomy of primary molars. Settings and Design: This was an in vivo randomized controlled clinical trial. Materials and Methods: Ninety primary molars selected were randomly divided into three groups. Group A was obturated with zinc oxide-O. sanctum extract, Group B with zinc oxide-ozonated oil, and Group C with ZOE. All the groups were evaluated for success or failure based on clinical and radiographic criteria at the end of 1, 6, and 12 months. Statistical Analysis Used: The intra- and inter-examiner reliability of the first and the second co-investigators was calculated by Cohen's kappa statistic. The data were analyzed using Chi-square test, P ≤ 0.05 (indicates statistical significance). Results: By the end of 12 months, the overall clinical success rate was 88%, 95.7%, and 90.9% in Groups A, B, and C, respectively; whereas the radiographic success rate was found to be 80%, 91.3%, and 86.4% in Groups A, B, and C, respectively. Conclusion: On the basis of the overall success rates of all the three obturating materials, the following order of performance can be concluded: zinc oxide-ozonated oil > ZOE > zinc oxide-O. sanctum extract.

Clinical and Radiographic Success of Low-Level Laser Therapy Compared with Formocresol Pulpotomy Treatment in Primary Molars.

Purpose: The purpose of this study was to assess and compare the clinical and radiographic success rates of low-level laser therapy (LLLT) and formocresol (FC) for pulpotomy in primary teeth. Methods: Utilizing a split-mouth technique, 106 primary molars of 36 five- to eight-year-olds were included. The teeth were selected according to specific clinical and radiographic inclusion criteria and randomly assigned to the LLLT group and FC group. A pulpotomy was performed on each molar; 53 teeth were treated with LLLT, and 53 teeth were treated using FC. Children were followed at six and 12 months for clinical and radiographic evaluation. Results: At six months, the clinical success rate was 98 percent for each group. Radiographic success was 100 percent for the LLLT group and 98 percent for the FC group. At 12 months, both groups showed a clinical success of 96.1 percent. Radiographic success at 12 months was 100 percent and 98 percent for LLLT and FC, respectively. Conclusions: Both low-level laser therapy and formocresol pulpotomy techniques showed favorable clinical and radiographic outcomes in human primary molar teeth over 12 months. Further longitudinal studies with longer follow-up periods and larger sample sizes are encouraged.

The effect of hydrochloric acid (HCl) on permanent molars: A scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) study.

It is well established that acid disposal is a potentially effective method used by criminal syndicates to hinder the identification of victims. This study documents the effects of continuous immersion in hydrochloric acid (HCl, 37%) on molars using macroscopic analysis, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The goal of this study is to aid in distinguishing visually unrecognizable fragments of dental remains when drastic changes in morphology have occurred as a result of acid exposure. Macroscopic, SEM, and EDS analysis were conducted on seven maxillary molars before and after HCl treatment. Molars reduced in weight relative to the length of time immersed in HCl and the dissolution time was over 40 hours longer than reported in previous studies, at just over 66 hours. SEM and EDS analysis showed acid-treated teeth exhibited morphological patterns such as cracking and layering visible at high magnification. Calcium/phosphorous ratios fell within the expected range of 1.6-2.5, indicating that HCl-treated teeth are still identifiable as osseous or dental tissue even when not visually identifiable as teeth. This is the first study to present SEM images of molar cementum before and after immersion in HCl and to present EDS results. This information can assist researchers and investigators in determining the presence of dental tissue in a forensic context associated with acid disposal.

Allium sativum extract as an irrigant in pulpectomy of primary molars: A 12-month short-term evaluation.

This study indented to assess the clinical and radiographic assessment of Allium sativum extract as an intracanal irrigant for pulpectomy of primary molars. Ninety children with 110 teeth submitted were categorized into two groups. Clinical and radiographic success rates were checked at 3, 6, and 12 months. Qui-square test at a level of significance was ˂0.05. There was no statistically significant difference (p Ë‚ .05) between the two groups that has not been detected clinically or radiographically. Clinical and radiographic success rates of garlic extract at 3 months were (80% and 72.7%), which declined at 6 and 12 months to be 76.4% 6 and 74.5% respectively. For NaOCl group, clinical and radiographic success rates were 87.3% and 85.5% at 3 months, 87.3% and 87.3% at 6 months and 89.1% and 87.3% at 12 months. A. sativum extract can be used efficiently as an irrigant for pulpectomy of primary molar root canals.

Evaluation of 3Mix-MP and pulpectomies in non-vital primary molars.

Pulpectomies in primary molars are often hindered by several factors, including anatomical and physiological characteristics of posterior primary teeth and young patients' lack of cooperation with laborious treatments. This study was undertaken in search of easier but equally effective therapies that could eliminate infection, preserve the teeth and avoid extractions. The aim of the study was to estimate and compare clinical and radiographic success between pulp treatment with 3Mix-MP and pulpectomy with Maisto-Capurro paste in primary necrotic molars. A longitudinal prospective study was conducted at the Department of Comprehensive Pediatric Dentistry of the Faculty of Dentistry of the University of Buenos Aires (20152017). The study included 46 primary molars with necrotic pulp of children without immune or metabolic compromise. Children and their legal guardians provided assent and informed consent. Selected molars were randomly divided into 2 groups: G1: Pulpectomy treatment with Maisto-Capurro paste; and G2: Treatment with 3Mix-MP paste. Treatments were evaluated at 1, 3, 6,12 and 18 months (intra and inter-rater agreement 0.92 and 0.84). Clinical success was considered to be the absence of any of the following: pain, sensitivity to percussion or palpation, swelling, fistula and non-physiological mobility, while radiographic success was considered to be: absence of internal or external non-physiological resorption, no progression or reduction of radiolucent periapical/interradicular lesion and evidence of bone regeneration. Percentages, 95% C.I., and CHI2 were calculated for the comparison between groups. Overall clinical success was 91.5% and 87.5% (p=0.48) and overall radiographic success was 88.3% and 82.3% (p=0.31) for G1 and G2 respectively. No significant clinical or radiographic difference was found between groups. Both treatments showed similar clinical and radiographic behavior during the study periods.

Las pulpectomías en molares primarios se ven dificultadas frecuentemente por las características anatómicas y fisiológicas de éstos y por la escasa colaboración que brindan los pacientes de corta edad ante tratamientos tan laboriosos. En búsqueda de terapéuticas más sencillas, pero igualmente eficaces, que consigan eliminar la infección para conservar las piezas y evitar las exodoncias, se ha planteado como objetivo de este estudio: estimar y comparar la proporción de éxito clínico y radiográfico entre el tratamiento pulpar con 3Mix-MP y la pulpectomía con pasta de Maisto-Capurro en molares primarios con necrosis. Se realizó un estudio longitudinal y prospectivo en la Cátedra de Odontología Integral Niños de la Facultad de Odontología de la Universidad de Buenos Aires (2015 - 2017). Formaron parte del estudio 46 molares primarios con diagnóstico de necrosis pulpar, de niños sin compromiso inmunológico ni metabólico y que junto con sus responsables legales brindaron el asentimiento y el consentimiento informado. Los molares seleccionados fueron divididos aleatoriamente en 2 grupos: G1: Tratamiento de pulpectomía con pasta de Maisto-Capurro y G2: Tratamiento con pasta 3Mix-MP. Los tratamientos fueron evaluados al mes, 3, 6, 12y 18 meses (concordancia intra-examinador 0,92 e interexaminador 0,84), considerando como éxito clínico la ausencia de dolor, sensibilidad a la percusión y palpación, edema, fístula y movilidad no fisiológica; y como éxito radiográfico, ausencia de reabsorción interna o externa no fisiológica, no progresión o reducción de la lesión radiolúcida interradicular/periapical y evidencia de regeneración ósea. Se calcularon porcentajes, I.C 95% y CHI2para la comparación. El éxito clínico global fue de 91,5%y 87,5% (p=0.48) y el éxito radiográfico global de 88,3% y 82,3% (p=0.31)para G1 y G2 respectivamente, sin diferencias significativas entre ambos grupos. En los periodos estudiados ambos tratamientos mostraron comportamientos clínico y radiográfico semejantes.

Microsphere controlled drug delivery for local control of tooth movement.

Background: Because orthodontic tooth movement is dependent upon osteoclast-mediated resorption of alveolar bone adjacent to the pressure side of tooth roots, biologic mediators that regulate osteoclasts can be utilized to control tooth movement. Objectives: To develop a novel method to locally enhance orthodontic anchorage. Methods: We encapsulated osteoprotegerin (OPG) in polymer microspheres and tested the effectiveness of microsphere encapsulated versus non-encapsulated OPG for enhancing orthodontic anchorage in a rodent model of tooth movement. A single injection of 1 mg/kg non-encapsulated or microsphere encapsulated OPG was delivered into the palatal mucosa mesial to the first maxillary molar 1 day prior to tooth movement. A positive control group received injections of 5 mg/kg non-encapsulated OPG every 3 days during tooth movement. After 28 days of tooth movement, hemi-maxillae and femurs were dissected. Molar mesial and incisor distal tooth movement was measured using stone casts that were scanned and magnified. Local alveolar, distant femur bone, and tooth root volumes were analyzed by micro computed tomography. Serum OPG levels were measured by ELISA. Osteoclast numbers were quantified by histomorphometry. Results: The single injection of microsphere encapsulated OPG significantly enhanced orthodontic anchorage, while the single injection of non-encapsulated OPG did not. Injection of encapsulated OPG inhibited molar mesial movement but did not inhibit incisor tooth movement, and did not alter alveolar or femur bone volume fraction, density, or mineral content. Multiple injections of 5 mg/kg non-encapsulated OPG enhanced orthodontic anchorage, but also inhibited incisor retraction and altered alveolar and femur bone quality parameters. Increased OPG levels were found only in animals receiving multiple injections of non-encapsulated 5 mg/kg OPG. Osteoclast numbers were higher upon tooth movement in animals that did not receive OPG. Osteoclast numbers in OPG injected animals were variable within groups. Conclusions: Microsphere encapsulation of OPG allows for controlled drug release, and enhances site-specific orthodontic anchorage without systemic side effects. With additional refinements, this drug delivery system could be applicable to a broad array of potential biologic orthodontic therapeutics.

Effects of corticopuncture (CP) and low-level laser therapy (LLLT) on the rate of tooth movement and root resorption in rats using micro-CT evaluation.

The aim of this study was to compare the rate of tooth displacement, quantity of root resorption, and alveolar bone changes in five groups: corticopuncture (CP), low-level laser therapy (LLLT), CP combined with LLLT (CP + LLLT), control (C), and negative control (NC). A total of 60 half-maxilla from 30 male Wistar rats (10 weeks old) were divided randomly into five groups: three (CP, LLLT, and CP + LLLT) test groups with different stimulation for accelerated-tooth-movement (ATM), one control (C) group, and one negative control (NC) group with no tooth movement. Nickel-titanium coil springs with 50 g of force were tied from the upper left and right first molars to micro-implants placed behind the maxillary incisors. For the CP and CP + LLLT groups, two perforations in the palate and one mesially to the molars were performed. For the LLLT and CP + LLLT groups, GaAlAs diode laser was applied every other day for 14 days (810 nm, 100 mW, 15 s). The tooth displacements were measured directly from the rat's mouth and indirectly from microcomputer (micro-CT) tomographic images. Bone responses at the tension and compression sites and root resorption were analyzed from micro-CT images. The resulting alveolar bone responses were evaluated by measuring bone mineral density (BMD), bone volume fraction (BV/TV), and trabecular thickness (TbTh). Root resorption crater volumes were measured on both compression and tension sides of mesial and distal buccal roots. The tooth displacement in the CP + LLLT group was the greatest when measured clinically, followed by the CP, LLLT, and control groups (C and NC), respectively (p <0.05). The tooth movements measured from micro-CT images showed statistically higher displacement in the CP and CP + LLLT groups compared to the LLLT and control groups. The BMD, BV/TV, and TbTh values were lower at the compression side and higher at the tension side for all three test groups compared to the control group. The root resorption crater volume of the distal buccal root was higher in the control group, followed by CP, LLLT, and CP + LLLT, mostly at the compression site. Combining corticopuncture and low-level laser therapy (CP + LLLT) produced more tooth displacement and less root resorption at the compression side. The combined technique also promoted higher alveolar bone formation at the tension side.

Comparative evaluation of ankaferd blood stopper, ferric sulfate, and formocresol as pulpotomy agent in primary teeth: A clinical study.

AIM: The aim of the study was to provide a comparative evaluation of the clinical and radiographic success of Ankaferd blood stopper (ABS), formocresol (FC), and ferric sulfate (FS) as pulpotomy agent in primary teeth. SETTINGS AND DESIGN: This is a clinical study. MATERIALS AND METHODS: A total of 45 primary mandibular molar teeth in 26 children aged 6-9 were selected for the study. Teeth were randomly divided into three groups according to the pulpotomy agents (ABS, FC, FS). Following treatment, for 24 months, teeth were clinically and radiographically evaluated once every 3 and 6 months respectively. STATISTICAL ANALYSIS USED: SPSS version 15 software was used in data analysis. Kaplan- Meier, Log Rank and Fisher's exact tests were used to analysis. RESULTS: After follow-up periods ranging from 6 to 24 months (average 20.8±0.56), the clinical success rates for ABS, FC, and FS were 87%, 87%, and 100% respectively. The overall radiographic success was 87%, 80%, and 87%. When success rates of the ABS were compared with other agents, there were no significant differences between groups (P > 0.05). CONCLUSION: Similar success was achieved in the pulpotomy treatment of primary teeth that using ABS, FC, and FS. ABS would be considered a suitable agent for pulpotomy treatment and can be used as an alternative to other agents.

Evaluation of antibiotic mix in Non-instrumentation Endodontic Treatment of necrotic primary molars.

AIM: To compare the clinical and radiographic success rates of an antibiotic mix consisting of metronidazole, minocycline and ciprofloxacin (3Mix-MP) and another mix where minocycline was replaced with clindamycin (3Mix-MP-R) in non-instrumentation endodontic treatment (NIET) of necrotic primary molars and to determine the effect of root resorption on the success of the treatment. MATERIALS AND METHODS: Forty-two necrotic mandibular primary molars from 22 healthy children were randomly assigned to either mixture. Blinded clinical evaluation was conducted after 1, 3, 6 and 12 months by the operator, and blinded radiographic evaluation was conducted at 6 and 12 months follow-ups by other two investigators with inter-examiner reproducibility of 0.95. RESULTS: Overall success rates of 3Mix-MP and 3Mix-MP-R were 80.96% and 76.20% respectively, with no statistically significant difference. Radiographically, resorption of more than one third of the root length had a lower failure rate with no statistically significant difference (p<0.5). CONCLUSION: Primary teeth with necrotic pulp can be treated with 3Mix-MP or 3Mix-MP-R irrespective of the degree of root resorption.

Supplementary Steps for Removing Hard Tissue Debris from Isthmus-containing Canal Systems.

INTRODUCTION: The purpose of this ex vivo study was to evaluate the percentage reduction of accumulated hard tissue debris (AHTD) in the mesial root canal system of mandibular molars under different final irrigation regimens by means of micro-computed tomographic imaging. METHODS: Sixty curved mesial roots of mandibular molars with 2 independent canals joint apically by an isthmus (Vertucci type II) were selected. Specimens were scanned at a resolution of 12.5 µm, anatomically matched, and distributed into 3 groups (n = 20) according to the preparation protocol: Self-Adjusting File (SAF; ReDent Nova, Ra'anana, Israel), Reciproc (VDW GmbH, Munich, Germany), and Revo-S (Micro-Mega, Besançon, France) systems. Then, each group was subdivided into 2 subgroups (n = 10) according to the final irrigation protocol with the SAF or EndoVac system (Discus Dental, Culver City, CA). The percentage volume and percentage reduction of AHTD after root canal preparation and final irrigation protocols were statistically compared using 1-way analysis of variance, the paired sample and the independent Student's t tests. The level of significance was set at 5%. RESULTS: Within groups, the mean percentage volume was significantly reduced after the final irrigation procedures in either the SAF (from 1.52%-1.78% to 1.01%-1.20%) or EndoVac (from 2.11%-2.23% to 1.31%-1.52%) subgroups (P < .05). In the experimental groups, the mean percentage reduction of AHTD ranged from 29.15%-39.90% after the irrigation protocols, with no statistical difference between groups (P > .05). CONCLUSIONS: None of the irrigation approaches succeeded in rendering the mesial root canal system free of AHTD. A similar percentage reduction of AHTD was achieved after final irrigation protocols using either the SAF or EndoVac system.

Comparison of accuracy between dental and skeletal age in the estimation of chronological age of Down syndrome individuals.

This study aimed to evaluate the accuracy of dental age (DA) and skeletal age (SA) methods in order to estimate chronological age (CA) in individuals with Down syndrome (DS), contributing to the Forensic Dentistry and making the identification of these individuals age possible. For this, 278 images of individuals were selected and divided in 2 groups: 216 non-DS patients and 62 with DS. At first, DA was evaluated by Nolla method, on panoramic radiographs, followed by SA, evaluated by Greulich and Pyle method. The linear correlation coefficient of Pearson was used for the analysis of concordance between the methods. Paired t-test with confidence interval was used to evaluate the accuracy and Bland and Altman method was applied to estimate limits of concordance. Complementary to this first analysis, descriptive statistics and ANOVA test were applied for comparison among chronological age (CA), dental age (DA) and skeletal age (SA), with a significance level of 95% (p≥0.05), ordering to observe the differences among them. DA, estimated by Nolla, is underestimated in both, DS and non-DS individuals, and it is more notable in DS individuals. SA estimated by Greulich and Pyle method is overestimated, except for non-DS males. The range of variance is greater in SA and DS than DA and non-DS individuals, respectively. A greater accordance was found for DA×CA if compared to SA×CA, indicating that DA, estimated by Nolla method, is more accurate than SA, evaluated by Greulich and Pyle method, for estimating CA of both, DS and non-DS individuals. However, neither method seems to be precise and more caution is required for age estimation in DS individuals.

Internal Tooth Structure and Burial Practices: Insights into the Neolithic Necropolis of Gurgy (France, 5100-4000 cal. BC).

Variations in the dental crown form are widely studied to interpret evolutionary changes in primates as well as to assess affinities among human archeological populations. Compared to external metrics of dental crown size and shape, variables including the internal structures such as enamel thickness, tissue proportions, and the three-dimensional shape of enamel-dentin junction (EDJ), have been described as powerful measurements to study taxonomy, phylogenetic relationships, dietary, and/or developmental patterns. In addition to providing good estimate of phenotypic distances within/across archeological samples, these internal tooth variables may help to understand phylogenetic, functional, and developmental underlying causes of variation. In this study, a high resolution microtomographic-based record of upper permanent second molars from 20 Neolithic individuals of the necropolis of Gurgy (France) was applied to evaluate the intrasite phenotypic variation in crown tissue proportions, thickness and distribution of enamel, and EDJ shape. The study aims to compare interindividual dental variations with burial practices and chronocultural parameters, and suggest underlying causes of these dental variations. From the non-invasive characterization of internal tooth structure, differences have been found between individuals buried in pits with alcove and those buried in pits with container and pits with wattling. Additionally, individuals from early and recent phases of the necropolis have been distinguished from those of the principal phase from their crown tissue proportions and EDJ shape. The results suggest that the internal tooth structure may be a reliable proxy to track groups sharing similar chronocultural and burial practices. In particular, from the EDJ shape analysis, individuals buried in an alcove shared a reduction of the distolingual dentin horn tip (corresponding to the hypocone). Environmental, developmental and/or functional underlying causes might be suggested for the origin of phenotypic differences shared by these individuals buried in alcoves.

The effect of air-abrasion on the susceptibility of sound enamel to acid challenge.

OBJECTIVE: To evaluate the effect of air-abrasion using three abrasive powders, on the susceptibility of sound enamel to an acid challenge. METHODS: 40 human enamel samples were flattened, polished and assigned to 4 experimental groups (n=10); a: alumina air-abrasion, b: sodium bicarbonate air-abrasion, c: bioactive glass (BAG) air-abrasion and d: no surface treatment (control). White light confocal profilometry was used to measure the step height enamel loss of the abraded area within each sample at three stages; after sample preparation (baseline), after air-abrasion and finally after exposing the samples to pH-cycling for 10 days. Data was analysed statistically using one-way ANOVA with Tukey's HSD post-hoc tests (p<0.05). Unique prismatic structures generated by abrasion and subsequent pH cycling were imaged using multiphoton excitation microscopy, exploiting strong autofluorescence properties of the enamel without labelling. Z-stacks of treated and equivalent control surfaces were used to generate non-destructively 3-dimensional surface profiles similar to those produced by scanning electron microscopy. RESULTS: There was no significant difference in the step height enamel loss after initial surface air-abrasion compared to the negative control group. However, a significant increase in the step height enamel loss was observed in the alumina air-abraded samples after pH-cycling compared to the negative control (p<0.05). Sodium bicarbonate as well as BAG air-abrasion exhibited similar enamel surface loss to that detected in the negative control group (p>0.05). Surface profile examination revealed a deposition effect across sodium bicarbonate and BAG-abraded groups. CONCLUSION: This study demonstrates the importance of powder selection when using air abrasion technology in clinical dentistry. Pre-treating the enamel surface with alumina air-abrasion significantly increased its susceptibility to acid challenge. Therefore, when using alumina air-abrasion clinically, clinicians must be aware that abrading sound enamel excessively renders that surface more susceptible to the effects of acid erosion. BAG and sodium bicarbonate powders were less invasive when compared to the alumina powder, supporting their use for controlled surface stain removal from enamel where indicated clinically.

The use of low-level laser therapy for controlling the gag reflex in children during intraoral radiography.

The current literature suggests that low-level laser stimulation of the PC 6 acupuncture points may prevent gagging. This study aimed to determine if low-level laser therapy (LLLT) can reduce the gag reflex in children undergoing intraoral maxillary radiography. This randomized, controlled, double-blind clinical trial was conducted with 25 children with moderate-to-very severe gag reflexes who required bilateral periapical radiographic examination of the maxillary molar region. Children's anxiety levels were initially evaluated using Corah's Dental Anxiety Scale (DAS) to identify any possible relationship between gagging and anxiety. A control radiograph was taken of one randomly selected side in each patient after simulated laser application so that the patient was blinded to the experimental conditions (control group). Laser stimulation was then performed for the experimental side. A laser probe was placed on the Pericardium 6 (PC 6) acupuncture point on each wrist, and laser energy was delivered for 14 s (300 mW, energy density 4 J/cm(2)) at a distance of 1 cm from the target tissue. Following laser stimulation, the experimental radiograph was taken (experimental group). Gagging responses were measured using the Gagging Severity Criteria for each group. Data were analyzed using Spearman's rho correlations and Mann-Whitney U tests. Both mean and median gagging scores were higher in the control group than in the experimental group. Patients who were unable to tolerate the intraoral control radiography were able to tolerate the procedure after LLLT. Differences between gagging scores of the control and experimental groups were statistically significant (P = .000). There was no significant correlation between gagging severity and anxiety score (P > .05). A negative correlation was found between age and gagging score in the control group (P ˂ .05). Within the limitations of this study, LLLT of the PC 6 acupuncture points appears to be a useful technique for controlling the gag reflex in children during maxillary radiography.

Micro-computed tomography and histomorphometric analysis of human alveolar bone repair induced by laser phototherapy: a pilot study.

Immediate dental implant placement in the molar region is critical, because of the high amount of bone loss and the discrepancy between alveolar crest thickness and the implant platform. Laser phototherapy (LPT) improves bone repair. The aim of this study was to evaluate the human alveolar bone repair 40 days after molar extraction in patients submitted to LPT. Twenty patients were selected for this randomized controlled clinical trial; 10 underwent LPT (laser group) with a GaAlAs diode laser (808 nm, 100 mW, 0.04 cm(2), 75 J/cm(2), 30s per point, 3 J per point, at five points). The control group patients (n=10) were not irradiated. Forty days later, the tissue formed inside the sockets was analyzed by micro-computed tomography and histomorphometry. Data from the two groups were compared with Student's t-test and Pearson's correlation test. The relative bone volume was significantly higher in the laser group (P<0.0001). The control group showed negative correlations (P<0.01) between number and thickness, and between number and separation of trabeculae, and a positive correlation between thickness and separation of trabeculae. The laser group showed a significant negative correlation between the number and thickness of trabeculae (P<0.01). The results suggest that LPT is able to accelerate alveolar bone repair after molar extraction, leading to a more homogeneous trabecular configuration represented by thin and close trabeculae.

Technical quality of root canal treatment of posterior teeth after rotary or hand preparation by fifth year undergraduate students, The University of Jordan.

The aim of this study was to investigate the technical quality of root canal treatment provided by the undergraduate students as their first experience in molar endodontics using nickel-titanium (NiTi) files in a crown-down approach compared with stainless steel standard technique. This study was carried out by the fifth year undergraduate students attending peer review sessions as a part of their training programme, using two different questionnaires to assess the overall technical quality and potential problems regarding endodontic complications after root canal preparation with these two techniques. The overall results indicated a statistically significant difference in the performance of the two instrument techniques in difficult cases showing better performance of the NiTi system and mean rotary preparation time (P < 0.001). Under the conditions of this study, novice dental students, using NiTi ProTaper rotary files, were able to prepare root canals faster with more preparation accuracy compared with canals of same teeth prepared with hand instruments.

Brief communication: Comparative patterns of enamel thickness topography and oblique molar wear in two Early Neolithic and medieval population samples.

Enamel thickness has been linked to functional aspects of masticatory biomechanics and has been demonstrated to be an evolutionary plastic trait, selectively responsive to dietary changes, wear and tooth fracture. European Late Paleolithic and Mesolithic hunter-gatherers mainly show a flat wear pattern, while oblique molar wear has been reported as characteristic of Neolithic agriculturalists. We investigate the relationships between enamel thickness distribution and molar wear pattern in two Neolithic and medieval populations. Under the assumption that dietary and/or non-dietary constraints result in directional selective pressure leading to variations in enamel thickness, we test the hypothesis that these two populations will exhibit significant differences in wear and enamel thickness patterns. Occlusal wear patterns were scored in upper permanent second molars (UM2) of 64 Neolithic and 311 medieval subadult and adult individuals. Enamel thickness was evaluated by microtomography in subsamples of 17 Neolithic and 25 medieval individuals. Eight variables describing enamel thickness were assessed. The results show that oblique molar wear is dominant in the Neolithic sample (87%), while oblique wear affects only a minority (42%) of the medieval sample. Moreover, in the Neolithic molars, where buccolingually directed oblique wear is dominant and greatest enamel lost occurs in the distolingual quadrant, thickest enamel is found where occlusal stresses are the most important-on the distolingual cusp. These results reveal a correlation between molar wear pattern and enamel thickness that has been associated to dietary changes. In particular, relatively thicker molar enamel may have evolved as a plastic response to resist wear.

Success of root fillings with zinc oxide-ozonated oil in primary molars: preliminary results.

AIM: To evaluate the success rate of mixture of ozonated oil and zinc oxide as a primary teeth root filling material. STUDY DESIGN: Prospective randomised clinical study. METHODS: The study included 60 infected primary mandibular molars which were equally divided into study group (ozonated oil-ZnO) and control group (zinc oxide-eugenol). Pulpectomy procedure was performed and the children were followed at regular intervals. All the children were available for evaluation at the end of 12 months. The teeth were evaluated for success or failure based on clinical and radiographic criteria by a blinded investigator. STATISTICS: The proportional values were compared using χ(2) test. RESULTS: Clinical and radiographic evaluation suggested that teeth obturated with ozonated oil-zinc oxide demonstrated good success rate (93.3%) as compared to zinc oxide eugenol (63.3%). However, no statistically significant variation (p = 0.408) was observed between the groups. CONCLUSION: Ozonated oil-ZnO demonstrated a good clinical and radiographic success at 12 months follow-up and it can be considered as an alternative obturating material in infected primary teeth.

Hierarchical modelling of elastic behaviour of human enamel based on synchrotron diffraction characterisation.

Human enamel is a hierarchical mineralized tissue with a two-level composite structure. Few studies have focused on the structure-mechanical property relationship and its link to the multi-scale architecture of human enamel, whereby the response to mechanical loading is affected not only by the rod distribution at micro-scale, but also strongly influenced by the mineral crystallite shape, and spatial arrangement and orientation. In this study, two complementary synchrotron X-ray diffraction techniques, wide and small angle X-ray scattering (WAXS/SAXS) were used to obtain multi-scale quantitative information about the structure and deformation response of human enamel to in situ uniaxial compressive loading. The apparent modulus was determined linking the external load and the internal strain in hydroxyapatite (HAp) crystallites. An improved multi-scale Eshelby model is proposed taking into account the two-level hierarchical structure of enamel. This framework has been used to analyse the experimental data for the elastic lattice strain evolution within the HAp crystals. The achieved agreement between the model prediction and experiment along the loading direction validates the model and suggests that the new multi-scale approach reasonably captures the structure-property relationship for the human enamel. The ability of the model to predict multi-directional strain components is also evaluated by comparison with the measurements. The results are useful for understanding the intricate relationship between the hierarchical structure and the mechanical properties of enamel, and for making predictions of the effect of structural alterations that may occur due to the disease or treatment on the performance of dental tissues and their artificial replacements.

Should pulp chamber pulpotomy be seen as a permanent treatment? Some preliminary thoughts.

AIM: To investigate the benefits of pulpotomy (to the level of the floor of the pulp chamber) as an endodontic treatment for teeth with vital pulps. METHODOLOGY: Seventeen patients, aged 7-54 years (mean of 37.2 year), were treated by pulpotomy and filling with ProRoot MTA(®) in premolar or molar teeth with vital pulps and without clinical evidence of irreversible pulpitis. The patients were then followed up for 12 to 24 months and the teeth then assessed by clinical and radiographic examination. Statistical analysis was performed with Kaplan-Meier survival probability statistics to estimate the survival of the treated teeth. RESULTS: At 24 months, the survival rate without any complementary treatment was estimated to be 82%. Two of the 17 treated teeth required root canal treatment for pain control and one for prosthetic reasons. CONCLUSIONS: Under the conditions of this study, pulpotomy offered a viable alternative to root canal treatment for teeth with vital pulps in the short term. However, there is insufficient clinical evidence to consider this technique for the treatment of every permanent tooth. Nevertheless, it should be considered as a potential alternative approach to be further developed for future applications.