Lesion Detection in Optical Coherence Tomography with Transformer-Enhanced Detector.

Optical coherence tomography (OCT) is an emerging imaging tool in healthcare with common applications in ophthalmology for the detection of retinal diseases and in dentistry for the early detection of tooth decay. Speckle noise is ubiquitous in OCT images, which can hinder diagnosis by clinicians. In this paper, a region-based, deep learning framework for the detection of anomalies is proposed for OCT-acquired images. The core of the framework is Transformer-Enhanced Detection (TED), which includes attention gates (AGs) to ensure focus is placed on the foreground while identifying and removing noise artifacts as anomalies. TED was designed to detect the different types of anomalies commonly present in OCT images for diagnostic purposes and thus aid clinical interpretation. Extensive quantitative evaluations were performed to measure the performance of TED against current, widely known, deep learning detection algorithms. Three different datasets were tested: two dental and one CT (hosting scans of lung nodules, livers, etc.). The results showed that the approach verifiably detected tooth decay and numerous lesions across two modalities, achieving superior performance compared to several well-known algorithms. The proposed method improved the accuracy of detection by 16-22% and the Intersection over Union (IOU) by 10% for both dentistry datasets. For the CT dataset, the performance metrics were similarly improved by 9% and 20%, respectively.

The influence of mild versus severe hypodontia on facial soft tissues? A three-dimensional optical laser scanning-based cohort study.

OBJECTIVE: To determine whether there are differences in the facial soft tissue morphology between participants with mild (up to two) or severe (six or more) hypodontia. DESIGN AND SETTING: A prospective hospital-based cohort study. PARTICIPANTS AND METHODS: Ninety-two participants, aged 11-16 years, with confirmed hypodontia were recruited. Participants were sub-grouped based on the severity (mild, two or less and severe, six or more) and distribution of the missing teeth and age. They underwent a three-dimensional (3D) optical surface scan of the facial soft tissues. Facial surface scans were compared quantitatively, applying landmark measurements and surface-based analysis. RESULTS: In total, 92 participants, with an equal distribution between the mild (n=46) and severe (n=46) categories, were recruited. Patients with severe hypodontia displayed a reduced alar base, lower facial height, nasolabial angle (P = 0.02) and transgonial width (P < 0.001) compared to those with milder hypodontia. Furthermore, significant differences were observed between mild-male and severe-female groups regarding alar base, lower anterior face height and transgonial width and between mild-male and mild-female groups regarding nasolabial angle and transgonial width. CONCLUSION: Significant reductions were seen in the 3D soft tissue morphology of participants with severe hypodontia, in terms of the nasolabial angle, lower facial height, alar base and transgonial widths, emphasising the importance of using facial scanning as a relatively simple non-invasive method of assessment.

Characterisation of a Bioactive SiO2-CaO-CaF2-Na2O Glass Used in Composites.

OBJECTIVES: To characterise the ion release, pH changes and apatite formation of a phosphate free bioactive glass. METHODS: A SiO2-CaO-CaF2-Na2O glass was synthesized by a melt route with a composition close to the reactive glass in the commercial Cention N® composite. The glass was characterized after immersion in three media: Artificial Saliva pH4 (AS4) Artificial Saliva pH7 (AS7) and in a high phosphate artificial saliva at pH6.5 (AS6.5). The pH and fluoride release were measured using a pH meter and an ion selective electrode. The concentration of Ca, P, Na and Si were measured by ICP-OES. The glass powders after immersion were characterized by FTIR, X-ray powder diffraction and 19F MAS-NMR. RESULTS: The glass increased the pH in all three media. Fluoride was detected in all three media but was much higher in AS 6.5. Calcium fluoride formed in AS4 with a small amount of fluorapatite at long immersion times. Fluorapatite and calcium fluoride formed in AS7, whilst in AS6.5 fluorapatite formed. The ion concentrations in solution after immersion reflected the glass composition and the immersion media with fluorapatite being favoured by higher pHs and phosphate contents in the media. SIGNIFICANCE: The results demonstrated the ability of the glass to increase the pH and to form fluorapatite in phosphate containing media. This may explain the low incidence of secondary caries found in the commercial composite. Unlike the commercial composite evidence was found for the precipitation of fluorite, which will act to reduce the release of fluoride for preventing secondary caries.

The FiCTION trial: Child oral health-related quality of life and dental anxiety across three treatment strategies for managing caries in young children.

OBJECTIVES: The FiCTION trial compared co-primary outcomes (dental pain and/or infection) and secondary outcomes (child oral health-related quality of life [COHRQOL], child dental anxiety, cost-effectiveness, caries development/progression and acceptability) across three treatment strategies (Conventional with Prevention [C + P]; Biological with Prevention [B + P]; Prevention Alone [PA]) for managing caries in children in primary care. COHRQOL and child dental anxiety experiences are reported upon here. METHODS: A multi-centre, 3-arm, parallel-group, unblinded patient-randomized controlled trial of 3- to 7-year-olds treated under NHS contracts was conducted in 72 general dental practices in England, Wales and Scotland. Child participants (with at least one primary molar with dentinal caries) were randomized (1:1:1) to one of three treatment arms with the intention of being managed according to allocated arm for 3 years (minimum 23 months). Randomization was via a centrally administered system using random permuted blocks of variable length. At baseline and final visit, accompanying parents/caregivers completed a parental questionnaire including COHRQOL (16 item P-CPQ-16), and at every visit, child- and parental-questionnaire-based data were collected for child-based dental trait and state anxiety. Statistical analyses were conducted on complete cases from the modified intention-to-treat (mITT) analysis set. RESULTS: A total of 1144 children were randomized (C + P: 386; B + P: 381; PA: 377). The mITT analysis set included the 1058 children who attended at least one study visit (C + P: 352; B + P: 352; PA: 354). Median follow-up was 33.8 months (IQR: 23.8, 36.7). The P-CPQ-16 overall score could be calculated after simple imputation at both baseline and final visit for 560 children (C + P: 189; B + P: 189; PA: 182). There was no evidence of a difference in the estimated adjusted mean P-CPQ-16 at the final visit which was, on average, 0.3 points higher (97.5% CI: -1.1 to 1.6) in B + P than C + P and 0.2 points higher, on average, (97.5% CI: -1.2 to 1.5) in PA than for C + P. Child dental trait anxiety and child dental state anxiety, measured at every treatment visit, showed no evidence of any statistically or clinically significant difference between arms in adjusted mean scores averaged over all follow-up visits. CONCLUSIONS: The differences noted in COHRQOL and child-based dental trait and dental state anxiety measures across three treatment strategies for managing dental caries in primary teeth were small, and not considered to be clinically meaningful. The findings highlight the importance of including all three strategies in a clinician's armamentarium, to manage childhood caries throughout the young child's life and achieve positive experiences of dental care.

Best-practice prevention alone or with conventional or biological caries management for 3- to 7-year-olds: the FiCTION three-arm RCT.

BACKGROUND: Historically, lack of evidence for effective management of decay in primary teeth has caused uncertainty, but there is emerging evidence to support alternative strategies to conventional fillings, which are minimally invasive and prevention orientated. OBJECTIVES: The objectives were (1) to assess the clinical effectiveness and cost-effectiveness of three strategies for managing caries in primary teeth and (2) to assess quality of life, dental anxiety, the acceptability and experiences of children, parents and dental professionals, and caries development and/or progression. DESIGN: This was a multicentre, three-arm parallel-group, participant-randomised controlled trial. Allocation concealment was achieved by use of a centralised web-based randomisation facility hosted by Newcastle Clinical Trials Unit. SETTING: This trial was set in primary dental care in Scotland, England and Wales. PARTICIPANTS: Participants were NHS patients aged 3-7 years who were at a high risk of tooth decay and had at least one primary molar tooth with decay into dentine, but no pain/sepsis. INTERVENTIONS: Three interventions were employed: (1) conventional with best-practice prevention (local anaesthetic, carious tissue removal, filling placement), (2) biological with best-practice prevention (sealing-in decay, selective carious tissue removal and fissure sealants) and (3) best-practice prevention alone (dietary and toothbrushing advice, topical fluoride and fissure sealing of permanent teeth). MAIN OUTCOME MEASURES: The clinical effectiveness outcomes were the proportion of children with at least one episode (incidence) and the number of episodes, for each child, of dental pain or dental sepsis or both over the follow-up period. The cost-effectiveness outcomes were the cost per incidence of, and cost per episode of, dental pain and/or dental sepsis avoided over the follow-up period. RESULTS: A total of 72 dental practices were recruited and 1144 participants were randomised (conventional arm, n = 386; biological arm, n = 381; prevention alone arm, n = 377). Of these, 1058 were included in an intention-to-treat analysis (conventional arm, n = 352; biological arm, n = 352; prevention alone arm, n = 354). The median follow-up time was 33.8 months (interquartile range 23.8-36.7 months). The proportion of children with at least one episode of pain or sepsis or both was 42% (conventional arm), 40% (biological arm) and 45% (prevention alone arm). There was no evidence of a difference in incidence or episodes of pain/sepsis between arms. When comparing the biological arm with the conventional arm, the risk difference was -0.02 (97.5% confidence interval -0.10 to 0.06), which indicates, on average, a 2% reduced risk of dental pain and/or dental sepsis in the biological arm compared with the conventional arm. Comparing the prevention alone arm with the conventional arm, the risk difference was 0.04 (97.5% confidence interval -0.04 to 0.12), which indicates, on average, a 4% increased risk of dental pain and/or dental sepsis in the prevention alone arm compared with the conventional arm. Compared with the conventional arm, there was no evidence of a difference in episodes of pain/sepsis among children in the biological arm (incident rate ratio 0.95, 97.5% confidence interval 0.75 to 1.21, which indicates that there were slightly fewer episodes, on average, in the biological arm than the conventional arm) or in the prevention alone arm (incident rate ratio 1.18, 97.5% confidence interval 0.94 to 1.48, which indicates that there were slightly more episodes in the prevention alone arm than the conventional arm). Over the willingness-to-pay values considered, the probability of the biological treatment approach being considered cost-effective was approximately no higher than 60% to avoid an incidence of dental pain and/or dental sepsis and no higher than 70% to avoid an episode of pain/sepsis. CONCLUSIONS: There was no evidence of an overall difference between the three treatment approaches for experience of, or number of episodes of, dental pain or dental sepsis or both over the follow-up period. FUTURE WORK: Recommendations for future work include exploring barriers to the use of conventional techniques for carious lesion detection and diagnosis (e.g. radiographs) and developing and evaluating suitable techniques and strategies for use in young children in primary care. TRIAL REGISTRATION: Current Controlled Trials ISRCTN77044005. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 1. See the NIHR Journals Library website for further project information.

WHAT WAS THE QUESTION?: Tooth decay is common; it can lead to pain, days off school for children and days off work for parents and is a financial burden to the NHS. There is uncertainty about the best way of managing decay in young children. This trial aimed to find out whether or not there was a difference in the amount of pain and/or infection suffered by children having their decay treated with one of the following: fillings, having decay sealed in or using preventative treatment alone. Which method represented the best value was also explored. WHAT DID WE DO?: For young children with decay, the Filling Children's Teeth: Indicated Or Not? (FiCTION) trial compared the difference between fillings, sealing in the decay and using preventative treatment alone over 3 years in NHS dental practices in Scotland, England and Wales. We recruited 1144 children aged 3­7 years with one or more holes in their baby back teeth (molars), but without pain/infection, and placed them at random into one of three groups: (1) tooth numbing, removing decay and filling(s) with preventative treatment; (2) sealing in decay with fillings or caps and preventative treatment but no numbing; or (3) preventative treatment alone. WHAT DID WE FIND?: Recruitment was challenging but was achieved. There was no evidence of a difference in children's experience of pain or infection, quality of life or dental anxiety between groups. All three ways of treating decay were acceptable to children, parents and dental professionals. Sealing in with preventative treatment was most likely to be considered the best way of managing children's decay if we are willing to pay a minimum of £130 to avoid an episode of pain or infection. WHAT DOES THIS MEAN?: As there was no evidence of a difference between the three treatment groups in pain/infection experienced, treatment choice should continue to be based on shared decision-making between the child, parent and clinician to agree the best option for the individual child.

A randomized clinical trial comparing Hall vs conventional technique in placing preformed metal crowns from Sudan.

Despite the high success rates of preformed metal crowns (PMCs) in children no randomized clinical trials compare methods of placement and none describe its use in Africa. Our aim was to compare survival and cost-effectiveness of PMCs placed by conventional techniques (CT) and biological Hall techniques (HT) using a prospective randomized control trial in a general dental practice from Khartoum. One hundred and nine and 103 PMCs were placed in randomly selected children (5-8years) with 1-2 carious primary molars using HT and CT respectively and followed for 2 years. Socioeconomic status, periodontal health, occlusion, anxiety, and procedure time were compared using student t-test. Kaplan-Meier survival rates and incremental cost effectiveness ratio (ICER) were compared between CT and HT. CT and HT groups were similar for age, gender, socio-economic status. Survival rates were high (over 90%) for both study arms and not statistically different (p>0.05). Anxiety scores were significantly higher in CT arm after 12 months compared to HT (p<0.001). Clinically, gingival and plaque indices were similar between groups (p>0.05) but occlusions were raised in nearly all subjects in the HT arm (p<0.05). Periodontal health improved, and occlusions adjusted over time in both arms. There were 3 (2.7%) and 6 (5.8%) minor failures, 7 (6.4%) and 6 (5.8%) major failures in HT and CT arms respectively. Mean procedure time was lower in HT (9.1 min) than CT (33.9 min); p<0.001. Mean PMC cost was US$2.45 and US$7.81 for HT and CT respectively. The ICER was US$136.56 more for each PMC placed by CT per life year. We show that PMCs have high survival outcomes in disadvantaged populations similar to results from developed countries. As HT can be carried out by less experienced dental operators and therapists, this biological approach provides a promising cost-effective option to manage caries in developing countries with limited resources. Trial registration: The trial is registered at clinicaltrials.gov. ClinicalTrial.gov Trial Registration: NCT03640013.

Estimating age using permanent molars and third cervical vertebrae shape with a novel semi-automated method.

Estimating chronological age accurately in young adults is difficult and additional methods are required to increase the accuracy. This study explored a new semi-automated method to assess shape change of third cervical vertebra (C3) with age in the living; comparing this as a method to determine whether individuals could be categorised into being less than 18 years of age (<18), or at least 18 years of age (≥18) with tooth formation of the second and third mandibular molars (M2 and M3). The sample was panoramic and lateral skull radiographs of 174 dental patients (78 males, 96 females aged 15-22 years). Twelve variables were compared in two age categories: younger than 18 and at least 18 years of age in males and females separately using a t-test. Tooth formation of M2 and M3 was assessed. Mean values of eight variables of C3 in males and one variable in females were significantly different between the two age categories (p < 0.05). Results for males showed that the best age indicator for age ≥18 was the ratio between height and width of C3 and for females, the ratio between diagonals. Results for molars showed that M2 was mature in 69% of males and 83% of females, within the expected age range of 14-16 years. M3 was highly variable ranging from stages 6-14 for both; M3 was missing in 24% of males and 28% of females and mature in 14% of males and 15% of females. The conclusion was that shape change of C3 has potential as an additional method to group individuals <18 and ≥ 18 years of age.

A Novel Kinetic Method to Measure Apparent Solubility Product of Bulk Human Enamel.

Introduction: Tooth enamel mineral loss is influenced by its solubility product value, which is fundamental to the understanding of de- and remineralization resulting from a carious or erosive challenge. Published pKsp values for human enamel and hydroxyapatite range from 110 to 126 suggesting a heterogeneous nature of enamel solubility. However, this range of values may also result from the variety of methods used, e.g., some authors reporting values for suspensions of enamel powder and others for bulk enamel. The aim of this study was to develop a method to measure the solubility of bulk human enamel under controlled in vitro conditions simulating demineralization behavior of enamel within the oral environment using scanning microradiography (SMR). SMR was used to monitor real-time changes in enamel demineralization rates at increasing calcium concentrations in a caries simulating demineralization solution until the concentration at which thermodynamic equilibrium between enamel and solution was achieved. Method: 2 mm thick caries free erupted human enamel slabs with the natural buccal surfaces exposed were placed in SMR cells exposed to circulating caries-simulating 2.0 L 0.1 M pH = 4.0 acetic acid, at 25°C. SMR was used to continuously measure in real-time the decrease in mineral mass during the demineralization at 5 different points from on each slab. Demineralization rates were calculated from a linear regression curve of projected mineral mass against demineralization time. Changes in the demineralization rates were monitored following a series of successive increases in calcium (and phosphate at hydroxyapatite stoichiometric ratios of Ca:P 1.67) were added to the demineralizing solution, until demineralization ceased. The pH was maintained constant throughout. Results: Demineralization halted when the calcium concentration was ~30 mM. At higher calcium concentrations, mineral deposition (remineralization) occurred. By comparison with results from speciation software calculations for the calcium phosphate ternary system, this result suggests that the bulk solubility product of enamel (pKspBEnamel) under the conditions used is 121. Discussion: The apparent pKspBEnamel under these conditions was higher than many previous reported values, and much closer to those previously reported for HAp. However, this is a bulk value, and does not reflect that enamel is a heterogeneous material, nor the influence of ionic inclusions.

How do foster carers manage the oral health of children in foster care? A qualitative study.

OBJECTIVES: This qualitative study explored how the foster family environment influenced children's oral health. It also aimed to better understand foster carers' oral health knowledge, attitudes and experiences of managing foster children's oral health behaviours and oral health care. METHODS: An interpretative phenomenological analysis (IPA) study design was used to recruit a purposive sample of foster carers in Tower Hamlets, United Kingdom, from a range of backgrounds (maximum variation sampling). Participants were aged 21 years and older and provided full-time foster care for children for a minimum of 1 year. The foster carers took part in focus groups that were audio-recorded and transcribed verbatim. Data analysis followed a five-step IPA process, which included reading the transcripts, note taking, identifying emerging themes, connecting related themes and writing up the final themes. Iterative data gathering and analysis continued to reach thematic saturation. RESULTS: Three focus groups were conducted, involving a total of 12 foster carers. Eight of the 12 participants had fostered children for more than 10 years and they were currently fostering 22 children aged five to 18 years old. Four themes emerged from within the context of the supportive and nurturing foster family environment that described how foster carers' responded to and managed the oral health of their foster children. Foster carers had adopted an oral health caregiving role, "in loco parentis" responding to the poor oral health of their vulnerable foster children. They were hypervigilant about establishing and monitoring children's oral health routines and taking their children to see a dentist; these were seen as an integral part of being good foster carers. They were knowledgeable about the causes of children's oral ill health, gained from their own dental experiences and from looking after their own children. Foster carers had experienced tensions while adopting this oral health caregiving role with dentists who had refused to see younger children. Foster carers had also experienced tensions with teenage foster children who questioned their parental authority and legitimate right to set rules about smoking and healthy eating. CONCLUSIONS: This is the first study to explore foster carers' oral health perspectives and the foster family environment within the oral health context. It highlights the unrecognized and important role that foster carers have in improving the oral health of vulnerable children. Further research is needed to explore the relationship between foster carers and dentists and to support the development of health and social care interventions to improve foster children's oral health.

A new primary dental care service compared with standard care for child and family to reduce the re-occurrence of childhood dental caries (Dental RECUR): study protocol for a randomised controlled trial.

BACKGROUND: In England and Scotland, dental extraction is the single highest cause of planned admission to the hospital for children under 11 years. Traditional dental services have had limited success in reducing this disease burden. Interventions based on motivational interviewing have been shown to impact positively dental health behaviours and could facilitate the prevention of re-occurrence of dental caries in this high-risk population. The objective of the study is to evaluate whether a new, dental nurse-led service, delivered using a brief negotiated interview based on motivational interviewing, is a more cost-effective service than treatment as usual, in reducing the re-occurrence of dental decay in young children with previous dental extractions. METHODS/DESIGN: This 2-year, two-arm, multicentre, randomised controlled trial will include 224 child participants, initially aged 5 to 7 years, who are scheduled to have one or more primary teeth extracted for dental caries under general anaesthesia (GA), relative analgesia (RA: inhalation sedation) or local anaesthesia (LA). The trial will be conducted in University Dental Hospitals, Secondary Care Centres or other providers of dental extraction services across the United Kingdom. The intervention will include a brief negotiated interview (based on the principles of motivational interviewing) delivered between enrollment and 6 weeks post-extraction, followed by directed prevention in primary dental care. Participants will be followed up for 2 years. The main outcome measure will be the dental caries experienced by 2 years post-enrollment at the level of dentine involvement on any tooth in either dentition, which had been caries-free at the baseline assessment. DISCUSSION: The participants are a hard-to-reach group in which secondary prevention is a challenge. Lack of engagement with dental care makes the children and their families scheduled for extraction particularly difficult to recruit to an RCT. Variations in service delivery between sites have also added to the challenges in implementing the Dental RECUR protocol during the recruitment phase. TRIAL REGISTRATION: ISRCTN24958829 (date of registration: 27 September 2013), Current protocol version: 5.0.

Canine Gouging: A Taboo Resurfacing in Migrant Urban Population.

Cosmopolitan cities have become a pool of migrants from different parts of the world, who carry their cultural beliefs and superstitions with them around the globe. Canine gouging is a kind of infant oral mutilation (IOM) which is widely practiced among rural population of Africa where the primary tooth bud of the deciduous canine is enucleated. The belief is that the life threatening illnesses in children like vomiting, diarrhoea, and fevers are caused by worms which infest on tooth buds. This case report is of a 15-year-old Somalian born boy, who presented at the dental institute with intermittent pain in his lower right permanent canine which was associated with a discharging intra oral buccal sinus. The tooth was endodontically treated and then restored with composite. General dental practitioners need to be vigilant when encountered with tooth presenting unusual morphology, unilateral missing tooth, and shift in the midline due to early loss of deciduous/permanent canines. Identification of any such dental mutilation practice will need further counselling of the individual and family members. It is the duty of every dental professional to educate and safeguard the oral and dental health of general public.

A novel frameshift MSX1 mutation in a Saudi family with autosomal dominant premolar and third molar agenesis.

OBJECTIVES: In this study, the aim was to investigate a consanguineous Saudi family with non-syndromic premolars and third molars agenesis and to identify the causal mutation(s) using whole exome sequencing. DESIGN: Family phenotype and family pedigree were constructed from clinical and radiographic examinations. Whole exome sequencing was performed in two affected members of the Saudi family using the SureSelect Human all Exon 50 Mb kit (Agilent Technologies, Inc., Santa Clara, CA) and then sequenced on an Illumina HiSeq. SNP and indel calling were performed using samtools version 0.18 and were annotated using the software ANNOVAR. RESULTS: The family pedigree showed that the inheritance was autosomal dominant. Whole exome sequencing revealed that the affected members in this family were heterozygous with a novel frameshift mutation in exon 2 of the MSX1 gene, (NM_002448:c.750_751insACCGGCTGCC, p.F251PfsX92). CONCLUSIONS: The novel MSX1 frameshift mutation was linked to a family with moderate to severe tooth agenesis phenotype affecting second premolars and third molars in both arches. This expands the genotype-phenotype of MSX1 associated conditions.

Synthesis and characterizations of a fluoride-releasing dental restorative material.

The aim was to develop an obturating material which has the tendency to release fluoride and minimize interfaces with tooth. Nano-fluorapatite (nFA) powder was synthesized by sol-gel. The composite based on polyurethane (PU) was obtained by chemically binding the nFA (10, 15, 20%wt/wt) to the diisocyanate component by utilizing in-situ polymerization. The procedure involved stepwise addition of monomeric units of PU, and optimizing the reagent concentrations to synthesize composite. The structural, phase and morphological analysis of nFA was evaluated. The structural, fluoride release and in-vitro adhesion analysis with tooth structure of PU/nFA was conducted. For fluoride release analysis the samples were stored in artificial saliva and deionized water for periodical time intervals. Bond strength of composites was analyzed by push-out test. Chemical linkage was achieved between PU and nFA without intermediate coupling agent. The insignificant difference of fluoride release pattern was observed in artificial saliva and (p≥0.05) deionized water. The PU/nFA composite provided sustained release of fluoride over a long period of time. The composite showed more adhesion toward tooth structure with the increase in concentration of nFA. Bond strength of composite was in accordance with root canal filling material, hence, the material with anti-cariogenic properties can be used as an obturating material.

A comparison of the mechanical properties of a modified silorane based dental composite with those of commercially available composite material.

OBJECTIVES: The aim of this study was to compare the mechanical properties of the nano-hydroxyapatite incorporated silorane composite material with the commercially available dental composites. METHODS: Filtek Silorane resin composite was incorporated with 5% and 10% nano-hydroxyapatite crystals and then mechanically tested in comparison along with the commercially available Filtek Silorane and Filtek Supreme XT after 1, 14, 30 and 90 days period. RESULTS: The mechanical tests revealed that the modified silorane based dental composite had a significant increase in the mechanical properties than the commercially available Filtek Silorane and Filtek Supreme XT. SIGNIFICANCE: The collected data suggests that nano-hydroxyapatite crystals modified silorane may provide the clinicians with a better composite materials having a longer life especially in the posterior restorations where the masticatory forces are very much high.

Structural and in vitro adhesion analysis of a novel covalently coupled bioactive composite.

The interfacial adhesion between a restorative composite and tooth is one of the major factors that determine the ultimate performance of composite restoration. A novel polyurethane (PU) composite material was prepared by chemically binding the nano-hydroxyapatite (nHA) to the diisocyanate component in the PU backbone by utilizing solvent polymerization. The procedure involved stepwise addition of monomeric units of the PU and optimizing the reagent concentrations. The resultant materials were characterized structurally (Raman Spectroscopy) and in vitro bioactive analysis was conducted in modified-simulated body fluid for periodical time intervals. The in vitro study evaluated the push-out bond strength of existing obturating material and novel covalently linked PU/nHA composites to dentin after long-term storage in deionized water and artificial saliva. Human extracted molar roots were filled with experimental samples and analyzed at predetermined time intervals. The shear bond strength of samples was measured and surface morphologies were evaluated. Covalent bond formation was achieved between PU and nHA without intermediate coupling agent. With the increase in concentration of nHA, the composite showed more bioactivity and adhesion toward tooth structure. Bond strength of this new composite were in accordance with obutrating material, therefore, the material can be used as an obturating material because of its direct adhesion with tooth structure.

Comparison of the visco-elastic behavior of a pre-impregnated reinforced glass fiber composite with resin-based composite.

OBJECTIVES: The visco-elastic behavior of a pre-impregnated reinforced glass fiber composite (everStick) was compared with a resin-based particulate composite (Filtek P60) by using dynamic mechanical analysis (DMA) to determine their storage modulus (E') and damping ratio (tandelta). METHODS: These materials were subjected to three-point bend tests using a PerkinElmer DMA7. In temperature mode, the temperature was increased from 26 to 140 degrees C at 1 Hz. In frequency mode, the range was 1-10 Hz at a constant temperature of 37 degrees C. RESULTS: In both temperature and frequency modes, E' for everStick was significantly higher and tandelta was significantly lower than those for Filtek P60, indicating that the stiffness of the pre-impregnated glass fiber composite was higher and its damping property was lower than those for resin-based particulate composite. SIGNIFICANCE: The glass fiber restorative composite appears to absorb less energy in repeated stress and is less likely to retain external energy as residual stress.

The cost of treating children and adolescents with injuries to their permanent incisors at a dental hospital in the United Kingdom.

The aim was to estimate the total cost, including the direct costs (outpatient costs) and indirect costs (missed working day) of treating children and adolescents with traumatic injuries to their incisors. Factors such as the number of treatment visits and the success of outcome were also investigated. The sample was taken from patients who attended the dental trauma clinic at a London teaching hospital between 1990 and 2001. Eighty-one patients, with 111 traumatized incisors were included in this study. The mean age was 9.9 (SD = 2.33) years and the male:female ratio was 3:2. The median number of visits and median treatment duration were eight visits and 21 months, respectively. Sixty-two per cent of the patients lived >5 miles and 25% lived >10 miles from the hospital; 44% of the patients had uncomplicated and 56% had complicated trauma to their incisors. Accidental falls, falls involving a second person, sport-related injuries and road accidents accounted for 30, 22, 22 and 17% of the total injuries. For uncomplicated trauma, 97% of the patients had a successful outcome but this was reduced to 58% for complicated trauma. The average total cost of treating a patient with one traumatic injury was 856 pounds. The best predictor for higher number of visits and unsuccessful outcome was complicated trauma with odd ratios of 4.5 and 24 (95% CI 1.5-13.7 and 2.9-194.2), respectively. It was concluded that the indirect cost was a considerably large proportion (39%) of the total cost. More specialists in paediatric dentistry are needed to improve access to care locally and thus reducing the indirect travelling cost.

The relationship between problem behaviour and traumatic dental injury amongst children aged 7-15 years old.

AIM: The aim of this study was to test whether dental injuries are related to problem behaviour. In addition, it aimed to confirm the relationship between dental injuries and size of overjet and type of lip coverage. METHODS: A hospital-based matched (age and sex) case-control design was adopted. Data were collected through clinical examinations and interviews. The informant-rated version of the Strengths and Difficulties Questionnaire (SDQ) was used to identify problem behaviour. One parent of the child, most often the mother, was interviewed. Hierarchical modelling using conditional logistic regression was used to test the relationship between the five problem behaviours and traumatic dental injuries. RESULTS: The Odds ratio of having a dental injury increased 3.14 times if children have peer relationship problems (P = 0.032), whilst a prosocial behaviour showed a tendency to have a protective effect (OR = 0.25; P = 0.064). Emotional symptoms, conduct disorder and hyperactivity behaviours were not related to dental injury (P > 0.75). Results were adjusted by father's level of education, size of overjet and type of lip coverage, and these variables were significantly related to dental injury (P < 0.05). CONCLUSION: Problem behaviour may play an important role in the occurrence of traumatic dental injury.