Glass-ionomer and calcium silicate-based cements interactions with human dentine in health and disease: Two-photon fluorescence microscopy and Raman spectroscopy analysis.

OBJECTIVES: To investigate the potential mineralising effects of calcium silicate-based dentine replacement material (Biodentine™) in comparison with glass-ionomer cement (GIC) (Fuji IX™) on different human dentine substrates using a multimodal non-invasive optical assessment. METHODS: Cements were applied on artificially demineralised or naturally carious dentine and stored for 4 weeks in phosphate-rich media +/- tetracycline used for mineralisation labelling. Interfacial dentine was examined from the same sample and location before and after aging using two-photon fluorescence microscopy, fluorescence lifetime imaging (FLIM) and second harmonic generation (SHG) imaging. Additionally, Raman spectroscopy was used to detect changes in the mineral content of dentine. RESULTS: Significant changes in the fluorescence intensity and lifetime were detected in partially demineralised dentine and caries-affected dentine underneath both tested cements, after storage (p < 0.001). This was associated with a significant increase in the mineral content as indicated by the increased intensity of the phosphate Raman peak located at 959 cm-1 (p < 0.0001). Caries-infected dentine showed significant fluorescence changes under Biodentine™ after storage (p < 0.001), but not under GIC (p = 0.44). Tetracycline binding induced a reduction in the fluorescence lifetime with comparable increase in the fluorescence intensity in both cements' groups within the affected dentine (p < 0.001). Significance Two-photon fluorescence microscopy can be used efficiently for non-destructive in-vitro dentine caries characterisation providing a technique for studying the same dentine-cement interface over time and detect changes. Biodentine™ demonstrated comparable remineralising potential to GIC, in addition to inducing remineralisation of caries-infected dentine. This may suggest using Biodentine™ as part of minimally invasive operative dentistry (MID) in caries management.

Psychometric validation of a pre-existing questionnaire used to measure patient satisfaction following orthodontic treatment in a UK population.

OBJECTIVE: To determine the psychometric properties of a pre-existing orthodontic satisfaction questionnaire and to assess patient satisfaction of their orthodontic treatment. DESIGN: Psychometric assessment of a pre-existing orthodontic satisfaction questionnaire. SETTING: Two sites at King's College Hospital NHS Foundation Trust. PARTICIPANTS: Individuals aged 12-15 years who had completed fixed orthodontic treatment. METHODS: An expert panel assessed a pre-existing orthodontic treatment satisfaction questionnaire for validity and readability. As a result, revisions were made to the questionnaire and it was distributed to 103 participants aged 12-15 years, on completion of their fixed orthodontic treatment (T1). Test-retest reliability of the questionnaire was assessed through completion of a second questionnaire by 17 participants, at a two-week interval (T2). The questionnaire was assessed for reliability using item-total correlations (I-TC) and Cronbach's alpha. Factor analysis allowed exploration of the underlying factor structure of the questionnaire. Test-retest reliability was assessed using Cohen's kappa coefficient. Multiple regression analysis was used to find out the significant demographic variables that predicts the satisfaction level of treatment. RESULTS: Following validity and readability assessment by the expert panel, the questionnaire was revised. Eleven items were removed following item analysis (with I-TC ⩽ 0.3). Factor analysis was deemed uninterpretable. The overall scale demonstrated greater reliability than the underlying sub-scales. Therefore, the sub-scales were removed, resulting in one scale which assessed overall orthodontic satisfaction, comprising 37 items, with a Cronbach alpha of 0.92. The test-retest reliability of the revised 37-item scale was deemed to be poor (kappa coefficient = 0.39). Multiple regression analysis identified ethnicity as a significant predictor of orthodontic treatment satisfaction (P = 0.01). CONCLUSION: This study provides a valid measure to assess orthodontic treatment satisfaction for use in a UK population aged 12-15 years on completion of fixed orthodontic treatment.

Palatal rugae morphology is associated with variation in tooth number.

This observational study compared palatal rugae morphology in adolescent subjects with normal tooth number and tooth agenesis. Maxillary dental study casts were used to compare rugae number, length and shape. Each study group contained 60 subjects (30 females and 30 males) mean age 13.4 (SD, 1.55) in control and 13.56 (SD, 1.54) years in tooth agenesis groups (p = 0.576). Mean number of missing tooth units in the tooth agenesis group was 2.1. Mean number of primary rugae in the whole sample was 4.35 (SD, 0.98) on the right and 4.33 (SD, 0.92) on the left with no significant differences (p = 0.236 and p = 0.404, respectively). However, the number of secondary rugae on the left (p = 0.006) and fragmentary rugae on the right (p = 0.004) was significantly increased in the tooth agenesis group. The shape of left primary rugae 2 and 3 also differed between groups, tending towards a wavy pattern in the control group and curved in the tooth agenesis group (p = 0.012 and p = 0.004, respectively). In addition, primary rugae 3 was more convergent (p = 0.008) whilst left primary rugae 3 and 5 were orientated in an antero-posterior direction (p = 0.04 for both rugae) in the tooth agenesis group. Subgroup analysis also identified significant associations between patterns of tooth agenesis and rugae number, in addition to shape of primary rugae. The identification of significant differences in rugae pattern between subjects with normal tooth number and agenesis suggests potential commonality in signal pathway disruption during establishment of these structures.

A systematic review of interventions after restoring the occluding surfaces of anterior and posterior teeth that are affected by tooth wear with filled resin composites.

OBJECTIVES: The aim of this systematic review was to assess intervention rates of direct composite restorations in the worn dentition based on data published in clinical trials. METHODS: Searches of electronic data bases, grey Literature and hand searches were completed, and selection criteria were applied at the title, abstract and full paper stages. Unavailable full papers or papers with unsuitable data were excluded. A reference search was conducted, and a final set of papers were selected for data analysis. Data were extracted and noted as any intervention required or performed, or intervention free. Descriptive statistics were used to summarise the findings and the odds ratios were calculated. RESULTS: 1683 titles were found in the initial searches. On application of selection criteria, 140 abstracts were selected (Kappa 0.885), 17 papers were chosen by 3 reviewers (Kappa 0.914 - 0.942) and 12 selected for statistical analysis (Kappa 0.924). A total of 3540 composites in 386 participants were analysed, with 1919 in the anterior region, and 1044 in the posterior region of these 11.7 % required intervention. Annual Intervention Rates (AIR) ranged from 0.8 to 17.9% reflecting the variation in reporting. CONCLUSION: There was wide variation between studies on the type of intervention. Overall the intervention rate of 11.6 % shows a favourable outcome but suggests some form intervention may be needed. CLINICAL SIGNIFICANCE: Direct composites remain a viable option to treat tooth wear but the outcome varies. Provided patients appreciate that some maintenance may be needed they are an effective intervention.

A comparison of conventional vs automated digital Peer Assessment Rating scoring using the Carestream 3600 scanner and CS Model+ software system: A randomized controlled trial.

INTRODUCTION: A prospective randomized study was undertaken to compare conventional study model-based manual Peer Assessment Rating (PAR) scoring with computer-based automated scoring using scanned study models or intraoral scanning. METHODS: The sample consisted of 67 patients, mean age 15.03 (range 11-37) years. Sixty-seven patients underwent alginate impression-taking and intraoral scanning (CS 3600; Carestream Dental, Stuttgart, Germany) at a single appointment in a randomized order. For each patient, a weighted PAR score was calculated manually by a calibrated examiner using study models and a PAR ruler (conventional group), and automatically using Carestream Dental CS Model+ software and data from scanned study models (indirect digital group) or intraoral scans (direct digital group). All procedures were timed, and each patient completed a binary questionnaire relating to their experience. RESULTS: There were no significant differences between methods for calculated mean weighted PAR score (P = 0.68). Mean (standard deviation) chairside time for impression-taking was 5.35 (± 1.16) minutes and for intraoral scanning, 7.76 (± 2.76) minutes (P <0.05). Mean (standard deviation) times taken to calculate weighted PAR scores were 2.86 (± 0.96), 5.58 (± 2.33), and 4.58 (± 2.18) minutes for conventional, indirect digital, and direct digital groups, respectively (P >0.05). A total of 61 patients (91%) preferred intraoral scanning to impression-taking. CONCLUSIONS: Automated PAR scoring using cast study models or intraoral scanning is valid, though both methods take longer than conventional scoring. Patients prefer intraoral scanning to impression-taking. REGISTRATION: ClinicalTrials.gov (NCT03405961). PROTOCOL: The protocol was not published before study commencement.

The effect of viewing idealised smile images versus nature images via social media on immediate facial satisfaction in young adults: A randomised controlled trial.

INTRODUCTION: The objective of this randomised controlled trial (RCT) is to investigate the effect of a social networking site (SNS) on body dissatisfaction, facial and smile dissatisfaction, and face-related discrepancy, and whether these effects differ from the use of appearance-neutral Instagram images. We also aimed to investigate whether there are trends in increased self-reported use of social media and increased body dissatisfaction, facial and smile dissatisfaction, and face-related discrepancy. METHODS: Undergraduate students were randomly allocated to an experimental group with idealised smile images or to a control group with neutral nature images. They completed pre-exposure questionnaires, then perused for 5 min their allocated images on individual Apple iPads via the Instagram application. Participants then completed the post-exposure surveys. The main outcome was facial dissatisfaction. Body dissatisfaction and total facial and body dissatisfaction were secondary outcomes. Simple randomisation was achieved with a computerised random number generator. Data were analysed using repeated measures ANOVA and multivariate regression analyses. RESULTS: A total of 132 participants (mean age = 20.50 ± 2.21 years) were randomised to either the experimental group with idealised smile images (n=71) or the control group with neutral nature images (n=61). Baseline characteristics were similar between groups and no participants were lost. Exposure to 'ideal' facial images on social media decreases facial satisfaction (95% confidence interval [CI] = 0.85-1.05; P < 0.0001). Individuals with high baseline self-discrepancy scores are less satisfied with their facial features and body appearance (95% CI = 0.04-1.16; P = 0.036). CONCLUSION: This study shows that viewing SNSs with high visual media reduces satisfaction with facial appearance in the short term in men and women. This effect is greater in those with high self-discrepancy scores. Increased media usage was not correlated with increased dissatisfaction. Wearing braces or having had braces was shown not to influence post-exposure dissatisfaction.

Embarking on a professional career: social advantage in dentistry and medicine. UK dental and medical student applications and admissions, 1996-2011.

Objectives The objectives of this research were to compare trends in applications and admissions to dentistry and medicine by sociodemographic status, country/region, academic experience and attainment, for UK domiciled students, and also to compare the odds of gaining admission to each course.Methods Secondary analysis of student data from University and College Admissions Services (UCAS) for focused, successful, UK domiciled applicants whose preferred subject was medicine or dentistry from 1996-2011. Trends for both programmes were examined using univariate and multivariate analysis including logistic regression, both with and without tariff scores.Results Admission ratios to dentistry and medicine are similar, fluctuating over this period. These professions attracted more applications from females, people of Asian ethnicity, direct entrants to university, pupils from selective schools and Londoners. Males, students of White and Black ethnicity, those from England (excluding London), and from lower social groups, were under-represented. The odds of applicants gaining admission were lowest if male, mature (>20 years), of Black ethnicity, from a lower socioeconomic classification, or domiciled in England. When tariff was included in the model, the odds of acceptance for dentistry and medicine were higher for applicants achieving high tariff scores.Discussion This analysis highlights geographic disparities and demonstrates how certain groups remained under-represented, with social inequalities clearly reflected in admissions. The complexity of the societal challenge in accessing these courses must not be underestimated. Social status, geographic region and selective schools remain important determinants of entry, emphasising the importance of educational reform.

Information retention of orthodontic patients and parents: A randomized controlled trial.

INTRODUCTION: A randomized controlled trial was undertaken to compare the efficacy of 3 methods of delivering information on short- and long-term recall of information in orthodontic patients and parents. METHODS: Participants who received an audiovisual presentation on orthodontic treatment were randomly allocated to 1 of 3 written information groups (leaflets, generic mind map, or participant's customized mind map). A questionnaire was used to assess short- and long-term retention of information (maximum score 30). RESULTS: Eighty-eight patients (94.6%) and 77 parents (86.5%) completed the study. The average knowledge scores at baseline for the patient groups were 17.71 95 CI 16.28-19.14), 16.58 (14.67-18.49), and 17.37 (15.92-18.81), respectively. The parents' knowledge scores for the 3 groups were 19.06 (17.51-20.62), 19.39 (17.44-21.35), and 18.76 (17.19-20.33), respectively. The short- and long-term knowledge scores improved over baseline in all 3 groups (P <0.0001). The parents achieved higher scores than the patients (P = 0.002) and their rate of forgetting information was less. The knowledge scores of the mind map groups were higher than that of the leaflet group for all cohorts (P = 0.025). No statistical difference was found between the type of mind map. The correlation between patient and parent knowledge scores was significant (P <0.0001) at all 3 time points. CONCLUSIONS: Provision of an audiovisual presentation supplemented with 1 of 3 written information methods is an effective way of delivering information. There was a significant improvement in the retention of information with the use of mind maps compared with leaflets. The generic mind map is equally as effective, more consistent in information delivered, and less labor intensive than the individual customized mind map and therefore would be our recommendation. Participation of parents is important because they comprehend and retain information better. In this study, 100% of parents shared information with their children, perhaps improving the patients' recall.

Survival probability of dental autotransplantation of 366 teeth over 34 years within a hospital setting in the United Kingdom.

INTRODUCTION: The purpose of this retrospective study was to evaluate 34 years' experience of autotransplantation of teeth during orthodontic treatment. METHODOLOGY: Treatment was completed at Queen Mary's Hospital, Sidcup, Kent, UK, during the period 1969-2003. A total of 366 teeth were transplanted in 314 patients. RESULTS: Canines totalled 78 per cent of all autotransplanted teeth; mean age of patient was 19.4 years. Survival probability for the first 5 years post-autotransplantation was 95 per cent, 94 per cent for the subsequent 5 years, and 88 per cent after 15 years. The maximum observation period was 34 years, the median was 2.0 years, and the mean was 3.51 (standard deviation = 3.68) years. Of the observed teeth, 10 failed and these were lost due to unsuccessful periodontal ligament regeneration and persistent mobility grade III (or greater). Apical pathology was observed in 16 per cent of all autotransplanted teeth. In 79 per cent of this subgroup, apical pathology was evident in the first 3 years post-operatively. Seventy per cent of all external resorption also occurred within the first 3 years. Internal resorption was rare but its occurrence was mostly observed between the second and sixth year post-transplantation. A minority of autotransplanted teeth [14 per cent (n = 51)] needed root canal therapy, and this was completed within the first 6 months post-transplantation. CONCLUSIONS: Autotransplantation can be a justified procedure with good survival probability. It can be considered an alternative to other treatments, such as prosthodontic replacement of teeth.

Expressing Uncertainty in Dental Age Estimation: A Comparison between Two Methods of Calculating the "Average" Standard Deviation.

The expression of uncertainty is defined by the standard deviation and is usually expressed in multiples of the standard deviation (±1sd, ±2sd, and ±3sd). The objective was to use weighting of the sd calculation by the number or count of subjects for each tooth development stage. A comparison shows the difference between the range of uncertainty using the unweighted sd and the weighted sd. The range of uncertainty related to Dental Age Estimation is statistically significantly greater (p < 0.001) for the weighted sd compared to the unweighted sd. It is concluded that the number of subjects for each Tooth Development Stage in the Reference Data set should be included in the calculation for a single Dental Age Estimation using the Simple Average Method when presenting the uncertainty associated with the point estimate of the "mean" for Dental Age Estimation of a single subject of unknown age.

The impact of dental phobia on care planning: a vignette study.

Introduction A high percentage of people with dental phobia have poor oral health. This may be the result of delayed treatment or differences in care planning by the oral health care team.Aim This study sought to determine the effect, if any, of dental phobia and complexity of dental care on the proposed care plan devised by clinicians for patients.Design An experimental analogue study with independent variables of the presence of phobia and complexity of treatment need. Dependent variables included frequency of care planning elements such as periodontal treatment, prevention, restorations, root canal treatment, extraction and provision of crowns, bridges and prostheses.Participants Seventy-nine UK-based dental practitioners.Analysis The association between the case status (phobic versus non-phobic, simple versus complex) and the outcome variables were assessed using a chi-square test for association. Logistic regression analyses were also used to determine the predictors of care planning elements.Results There were no differences in care planning for phobic and non-phobic patients. Complexity of treatment need had significant effects on advanced periodontal treatment, restorations anterior and posterior, root canal treatment, provision of crowns, and extractions.Conclusions Care planning is influenced by patients' dental needs and not their phobic status.

Canonical Wnt pathway gene expression and their clinical correlation in oral squamous cell carcinoma.

AIM: The aim of this study is to explore the prognostic significance and clinicopathological correlations of the Wnt pathway genes in a cohort of surgically treated patients with oral squamous cell carcinoma (OSCC) patients. SETTINGS AND DESIGN: A prospective genetic study on patients with OSCC was carried out during the period from July 2014 to January 2016. Informed consent from patients and institutional ethical approval for the study was obtained and the guidelines were strictly followed for collection of samples. SUBJECTS AND METHODS: Clinical data and mRNA expression analysis of ten genes in the canonical Wnt pathway were evaluated and their relationships with clinical and demographic variables were studied in 58 tissue samples. Wnt-3a, ß-catenin, secreted frizzled-related proteins sFRP-1, sFRP-2, sFRP-4, sFRP-5, Wnt inhibitory factor 1, dickkopf-1, c-MYC, and cyclin-D1 from cancer (n = 29) and normal (n = 29) tissue samples were investigated using quantitative reverse transcription-polymerase chain reaction. STATISTICAL ANALYSIS: Descriptive statistics were used to summarize the sample characteristics and clinical variables. If the data were normal, then parametric tests were used; otherwise, nonparametric alternatives were used. All the analyses were carried out using SPSS version 23.0 (IBM SPSS Inc., USA). RESULTS: Expression of sFRP-1, sFRP-2, and sFRP-5 in control samples and expression of c-MYC and cyclin D1 in cancer samples showed statistical significance. Significant expression of Wnt3A was observed among patients who had recurrence and were deceased. CONCLUSION: Wnt3A, ß-catenin, and cyclin D1 are recognized as key components of Wnt/ß-catenin signaling. However, in this study, there was no significant expression of all the three genes in OSCC. The proto-oncogene c-MYC showed statistically significant upregulation in cancer tissue samples suggesting that the OSCC among South Indian population is primarily not mediated by the canonical Wnt signaling pathway.

An up to 50-year follow-up of crown and veneer survival in a dental practice.

STATEMENT OF PROBLEM: Indirect restorations are an important treatment in dental practice, but long-term survival studies are lacking. PURPOSE: The purpose of this retrospective study was to report on the outcome of indirect restorations, which were followed up annually for up to 50 years in a dental practice. MATERIAL AND METHODS: A retrospective survival study was undertaken at a mixed National Health Service (NHS)/private dental practice in London, UK. Data were collected for restorations placed between 1966 and 1996 by 1 experienced operator. It was a requirement that patients had been followed up annually with clinical and radiographic examinations for up to 50 years. Patients were enrolled on a strict preventive policy and had excellent oral hygiene. Oral hygiene, restoration location, sensitivity, occlusion, and other details (preparation design, taper, cement used) were recorded. Restoration outcome was recorded as successful and surviving, unknown, or failed. The data were described descriptively. Kaplan-Meier survival curves and hazard curves were used to assess the survival of crowns and the probability of failure over time. RESULTS: A total of 223 restorations were placed in 47 patients between 1966 and 1996 and reviewed annually for up to 50 years (until 2016). These restorations included 154 metal-ceramic crowns (101 posterior and 53 anterior), 25 posterior gold crowns, 22 anterior ceramic veneers, and 22 anterior ceramic crowns. Restorations were in occlusion. The mean survival for metal-ceramic crowns was estimated as 47.53 years (95% confidence interval [CI]: 45.59-49.47 years). Failures in metal-ceramic crowns (n=6, 3.9%) were due to periapical periodontitis. The remaining restoration types had 100% survival at 50 years. CONCLUSIONS: This study showed that the survival of crowns and veneers is high over 50 years in clinical practice with annual follow-up and good oral hygiene. The proportion of teeth with loss of vitality, confirmed clinically and with radiographs, was minimal.

Reduced statherin in acquired enamel pellicle on eroded teeth compared to healthy teeth in the same subjects: An in-vivo study.

The aim of this in-vivo study was to compare total protein and four key salivary proteins present in the acquired enamel pellicle (AEP) on eroded and non-eroded surfaces in participants with erosive tooth wear. Participants with erosive tooth wear of dietary non-intrinsic origin, present on the occlusal surfaces of the lower first molars and an unaffected posterior occlusal surface in the same quadrant were recruited from restorative dental clinics at King's College London Dental Institute (n = 29, REC ref 14/EM/1171). Following removal of the salivary film, AEP samples were collected from the eroded occlusal surfaces (EP, n = 29) and the non-eroded occlusal surfaces (NP, n = 29) using 0.5% sodium dodecyl sulfate (SDS) soaked filter papers. Total protein concentration was analysed using bicinchoninic acid assay (BCA). Protein fractions were separated using SDS-PAGE and immunoblotted against: mucin5b, albumin, carbonic anhydrase VI (CA VI) and statherin antibodies. Amounts were quantified using ImageLab software against purified protein standards of known concentration. ANOVA followed by paired t-test and Wilcoxon's matched-pair signed-rank test were used to test statistical significance. The difference was considered to be significant at a P value < 0.05. The total protein on eroded surfaces was significantly lower compared to the total protein on non-eroded surfaces [0.41mg/mL (0.04) and 0.61 mg/mL (0.11)] respectively (p< 0.05). The median (min, max) amount of statherin was also significantly lower on eroded occlusal surfaces [84.1 (20.0, 221.8) ng] compared to AEP from non-eroded teeth in the same subjects [97.1(30.0, 755.6) ng] (p = 0.002). No statistical differences were observed for mucin 5b, albumin or CA VI. The total protein and statherin in the in-vivo AEP were different between eroded and non-eroded tooth surfaces of the same patient.

Quantitative Swept-Source Optical Coherence Tomography of Early Enamel Erosion in vivo.

Swept-source optical coherence tomography (SS-OCT) shows potential for the in vivo quantitative evaluation of micro-structural enamel surface phenomena occurring during early erosive demineralization. This randomized controlled single-blind cross-over clinical study aimed to evaluate the use of SS-OCT for detecting optical changes in the enamel of 30 healthy volunteers subjected to orange juice rinsing (erosive challenge) in comparison to mineral water rinsing (control), according to wiped and non-wiped enamel surface states. Participants were randomly allocated to 60 min of orange juice rinsing (pH 3.8) followed by 60 min of water rinsing (pH 6.7) and vice versa, with a 2-week wash-out period. In addition, the labial surfaces of the right or left maxillary incisors were wiped prior to SS-OCT imaging. An automated ImageJ algorithm was designed to analyse the back-scattered OCT signal intensity (D) after orange juice rinsing compared to after water rinsing. D was quantified as the OCT signal scattering from the 33 µm sub-surface enamel, normalised by the total OCT signal intensity entering the enamel. The back-scattered OCT signal intensity increased by 3.1% (95% CI 1.1-5.1%) in the wiped incisors and by 3.5% (95% CI 1.5-5.5%) in the unwiped incisors (p < 0.0001). Wiping reduced the back-scattered OCT signal intensity by 1.7% (95% CI -3.2 to -0.3%; p = 0.02) in comparison to the unwiped enamel surfaces for both rinsing solutions (p = 0.2). SS-OCT detected OCT signal changes in the superficial sub-surface enamel of maxillary central incisor teeth of healthy volunteers after orange juice rinsing.

Dental Age Estimation-Root Pulp Visibility (RPV) patterns: A reliable Mandibular Maturity Marker at the 18 year threshold.

The purpose of this paper was to explore the potential application of Root Pulp Visibility (RPV) to determine whether or not a subject of unknown date of birth is under or over the 18year threshold. PATIENTS, MATERIALS AND METHODS: Two thousand Dental Panoramic Radiographs comprising equal numbers of females and males evenly distributed between the ages of 16 and 26 years were examined. All third molars were scored using the Anglo-Canadian 8 Stage Tooth Development system [1]. The Lower Left Third Molar was censored to avoid redundant data being included in the data array for the Age at Attainment of Stage H, the final stage of tooth development (Roberts et al., 2015 [2]). A filter cascade was applied to the data to select the data array for 1. Teeth in the final stage of development, 2. Female or male gender, 3. The definitive stage of RPV: RPV-A, RPV-B, RPV-C, or RPV-D. RESULTS: The summary data for each of these stages was derived and the minimum value for each was used to determine the relationship of the minimum value of A, B, C or D to the 18 Year threshold. It was found that for both females and males the minimum value for RPV-A and RPV-B indicated that subjects displaying this could be under 18 years old. For RPV-C and RPV-D, the minimum values show unequivocally that for both females and males the subject was over 18 years old. CONCLUSION: RPV has an important role in unambiguously determining whether a subject is below or above the 18year threshold.

Dental age estimation: periodontal ligament visibility (PLV)-pattern recognition of a conclusive mandibular maturity marker related to the lower left third molar at the 18-year threshold.

The purpose of this study was to explore the applicability of periodontal ligament visibility (PLV) at the 18-year threshold. This mandibular maturity marker is graded into four separate age related stages, PLV-A, PLV-B, PLV-C, and PLV-D. These are discernible on a dental panoramic tomograph (DPT). The sample comprised a total of 2000 DPTs evenly divided into half yearly age bands from 16.00 to 25.99 years with 50 females and 50 males in each age band. It was found that PLV-A and PLV-B had minimum values below the 18-year threshold. PLV-C and PLV-D in females had minimum values of 18.08 and 18.58 years, respectively. In males, the minimum values for PLV-C was 18.10 years and PLV-D was 18.67 years. It was concluded that the presence of PLV-C or PLV-D indicates that a subject is over 18 years with a very high level of probability.

Dental Age Estimation: Pattern Recognition of Root Canal Widths of Mandibular Molars. A Novel Mandibular Maturity Marker at the 18-Year Threshold.

The final stage of third molar development is used to assign a subject to above the 18-year threshold. Some subjects exhibiting this final stage are less than 18 years. Radiographs from 1000 females and 1000 males age 16.00-25.99 years were examined. Each half-year age band comprised 50 females and 50 males. Three categories of root canal widths (RCW) of the LL6, LL7, and LL8 [FDI 36, 37, and 38] were defined. Reproducibility was achieved by re-assessing the same subjects 12 months apart. For females, the minimum value for RCW-A was 16.33 years, RCW-B 17.23 years, and RCW-C 18.45 years. For males, the minimum values were RCW-A 17.16 years, RCW-B 18.29 years, and RCW-C 18.16 years. The presence of RCW-C in a female, and the presence of RCW-B or RCW-C in a male is compelling evidence that the subject is above the 18-year threshold.

A systematic review and meta analysis of the longevity of anterior and posterior all-ceramic crowns.

BACKGROUND: Clinical experience suggests that there is a difference in survival between anterior and posterior all ceramic restorations. OBJECTIVES: This systematic review compared the difference in survival for full coverage all-ceramic materials used in adults to restore anterior or posterior vital teeth, not involved with fixed dental prostheses, but opposed by teeth. DATA AND SOURCES: Searches using Medline, Embase, and the Cochrane Library, including hand searches, with the inclusion criteria containing all-ceramic full coverage crowns in human adults over 17 years of age, prospective and retrospective studies, opposed by teeth, periodontal pocketing ≤5mm, but not involving implant supported crowns or non-vital teeth. All papers were published between 1980 and March 2014 and available in English. From the selected studies a meta analysis was undertaken. The chi square test, I2, Begg's and Egger's test were analysed and the publication bias was assessed using a Funnel plot. The, Kappa scores were 0.63, 0.88, and 0.81 at each selection stage. STUDY SELECTIONS: Pooled data produced 1112 anterior crowns with 73 failures (6.5%) and 1821 posterior crowns with 166 failures (9.1%) with a follow up time from 36 to 223 months. Relative risk meta-analysis of the 14 selected papers demonstrated that anterior all-ceramic crowns were 50% less likely to fail than posterior all-ceramic crowns (p=0.001). CONCLUSION: These results indicate that there were differences in failure between anterior and posterior all ceramic crowns but the difference was only 3%. Although this has clinical relevance and some caution is needed when prescribing all ceramic posterior crowns the difference was relatively small. CLINICAL SIGNIFICANCE: The clinically relevant results of this review, based on currently available data, demonstrate a need for some caution when considering posterior all-ceramic crowns. Lithium disilicate restorations were observed to have higher failures on anterior restorations and more research is needed to investigate why.