Predictive value of ultrasound scoring in relation to clinical and histological parameters in xerostomia patients.

BACKGROUND: Salivary gland dysfunction is one of the main clinical features of Sjögren's syndrome (SS), manifested by xerostomia with subsequent complications and well-established effects on the person's quality of life. OBJECTIVES: To determine firstly whether selected tests of salivary gland function and structure, unstimulated whole salivary flow rate (UWSFR), parotid flow rate (PFR), clinical oral dryness score (CODS) and ultrasound score (USS), can discriminate SS from non-SS sicca patients and secondly whether these tests can differentiate between patients in different subgroups of SS. METHOD: Unstimulated whole salivary flow rate, PFR, CODS and USS were determined in 244 patients comprised of SS patients (n = 118), SS patients at higher risk of lymphoma (n = 30) or with lymphoma (n = 26), and non-SS sicca disease controls (n = 70). RESULTS: All assessments showed a significant difference between the overall SS group and the disease control group, attributed mainly to the lymphoma subgroups of SS (p < 0.0001 for all parameters). There was a significant correlation (Spearman r = 0.7, p value <0.0001) and 87.3% agreement between USS and the histology focus scores of 119 patients. CONCLUSION: The results suggest that salivary gland tests including USS can aid in differentiating between SS and non-SS dry mouth, especially the subgroups of SS with lymphoma or at higher risk of developing lymphoma.

Evaluation of the efficacy of calcium silicate vs. glass ionomer cement indirect pulp capping and restoration assessment criteria: a randomised controlled clinical trial-2-year results.

OBJECTIVES: Assess calcium silicate cement (Biodentine™) vs. glass ionomer cement (Fuji IX™, control) as indirect pulp capping (IPC) materials in patients with reversible pulpitis after a 2-year follow-up. Evaluate the integrity of the overlying resin composite restorations using modified USPHS criteria and FDI criteria. Investigate the sensitivity of the modified USPHS criteria compared to the FDI criteria in the assessment of the restorations. MATERIALS AND METHODS: Seventy-two restorations (36 Biodentine™, 36 Fuji IX™) were placed randomly in 53 patients. Periapical radiographs were taken at pre-treatment (T0), 12-month (T12), and 24-month (T24) review. Restorations were assessed using the modified USPHS and FDI criteria at T12 and T24. RESULTS: At 24 months, 15 teeth had failed to maintain vitality (6 Biodentine™, 9 Fuji IX™). Clinical success rate of IPC for both materials was 72% and is related to the intensity of reversible pulpitis symptoms. No difference was found between T12 and T24 in the periapical (PA) radiographs and in the integrity of the resin composite restorations overlying Biodentine™ compared to Fuji IX™. There was no difference in the efficacy of the USPHS criteria compared to the FDI criteria in the assessment of the resin composite restorations. CONCLUSIONS: Biodentine™ and Fuji IX™ were clinically effective when used as IPC materials in teeth with reversible pulpitis at T24. Resin composite restorations overlying both materials performed well at T24. Using the USPHS or FDI criteria is equally efficient at T24; however, longer term follow-up is needed to establish whether there are sensitivity differences between these assessment criteria. CLINICAL SIGNIFICANCE: Teeth with deep carious lesions approaching the pulp and with signs of reversible pulpitis can be treated successfully by indirect pulp capping using either Biodentine™ or Fuji IX™. Using the USPHS or FDI criteria to assess restorations is equally effective at 2 years. TRIAL REGISTRATION: NCT02201641.

Alteration of palatine ruga pattern in subjects with oligodontia: A pilot study.

INTRODUCTION: The aim of this study was to compare the palatal ruga patterns in subjects with oligodontia and normal tooth numbers. METHODS: An observational investigation was conducted by using maxillary dental study casts to compare ruga numbers, lengths, and shapes in subjects with diagnosed oligodontia or normal tooth numbers. RESULTS: A total of 32 subjects comprised both the oligodontia (mean age, 14.0 years; SD, 5.0 years) and the control (mean age, 14.5 years; SD, 5.1 years) groups. The mean number of missing teeth in the oligodontia group was 8.7. The mean number of rugae in the whole sample was 7.36 (SD, 1.16), with no significant difference between the groups (P = 0.264). For ruga pattern, no differences were found for right-sided rugae; however, on the left side, a significant difference existed in shape frequency associated with ruga 2. Specifically, a curved shape was seen more frequently in ruga 2 of the oligodontia group (P = 0.01). CONCLUSIONS: The identification of subtle differences in ruga patterns between subjects with oligodontia and normal tooth numbers suggests potentially shared pathways during the development of these oral structures. Further large-scale investigations are warranted.

Synchrotron light-based µCT to analyse the presence of dentinal microcracks post-rotary and reciprocating NiTi instrumentation.

OBJECTIVES: The purpose of this study was to determine in vitro using a synchrotron radiation-based µCT (SRCT) whether rotary and reciprocating nickel titanium (NiTi) instrumentations lead to the formation of dentine microcracks. MATERIAL AND METHODS: Fourteen extracted human molars were obtained with ethical approval. Seven distobuccal roots of the maxillary molars and seven mesial roots of the mandibular molars were assigned to two experimental groups: (A) prepared with rotary Pro Taper instrumentation (n = 6) and (B) reciprocating WaveOne (n = 6). Irrigation with 1 % NaOCl and 17 % EDTA solutions was carried out. The remaining roots served as positive control with induced fractures (group C). SRCT was used to scan all samples pre and post-operatively. An imaging software was used to determine the number and length of microcracks. Statistical analyses weighed differences between pre and post-instrumentation and between shaping methods. RESULTS: A significant increase in the number and length of microcracks was detected post-shaping. No significant difference between rotary and reciprocating instrumentation was observed. CONCLUSIONS: Within the limitations of this in vitro study, an increased number and length of microcracks was induced by mechanical instrumentation. Reciprocating and rotary instrumentation are similar in terms of effect. CLINICAL SIGNIFICANCE: Dentinal damage may occur following rotary and reciprocating instrumentation.

What do dental students know about trauma?

AIM: To assess the baseline knowledge, knowledge acquisition and retention of dental undergraduate students in dental trauma, and the impact of a lecture on their level of confidence in managing traumatic dental injuries. MATERIAL AND METHODS: A total of 145 dental undergraduate students from King's College London were invited to attend a lecture on dental trauma. The participants were asked to complete a questionnaire on dental trauma before (T0), immediately after (T1) and 6 months (T2) following a 1-h lecture. RESULTS: Seventy of the 145 students participated in the study. The level of knowledge at T0, T1 and T2 was 64.9%, 83.2% and 69.5%, respectively. The increase in score was statistically significant between T0 and T1, and between T0 and T2. A significant decrease in score was also found between T1 and T2. Sex, level of education and whether or not the participants received previous teaching in dental trauma were not significant in predicting a change in score. The level of confidence increased significantly from 2.14 at T0 to 3.13 at T2. Participants who received teaching in dental trauma previous to the lecture were significantly more confident at T0. CONCLUSIONS: Lectures are effective at improving the knowledge and retention of knowledge of dental undergraduate students in dental trauma. However, retention of the knowledge is time limited suggesting that education should be repeated after a certain period of time to ensure that a high level of knowledge is maintained.

Motivation for a career in dentistry: the views of dental students in the United Arab Emirates.

OBJECTIVES: To investigate final-year dental students' perceived motivation for choosing dentistry as a professional career at one dental school in the United Arab Emirates (UAE). METHOD: Final-year dental students of Ajman University (n = 87) completed a questionnaire. Univariate and multivariate analysis of the data were undertaken using statistical software. RESULTS: A response rate of 82% (n = 71) was achieved, 65% of whom were female. Students ranged from 21 to 29 years of age. Motivation to study dentistry was led by a 'desire to work in health care' (93%), 'wish to provide a public service' (88.7%) and because 'degree leads to a recognised job' (84.5%). Males were significantly more likely to report 'high income' (84% vs. 67%; P = 0.01) and females 'influence of family' (80% vs. 60%; P = 0.02) as motivating influences. The reliability and internal consistency of the instrument as calculated by Cronbach's alpha was 0.82. Eight factors explaining the 71% of the variation were: 'professional job factors' (11.7%), 'experience and advice' (9.8%), 'business and financial with independence' (9.7%), 'careers, advice and possibilities' (8.9%), 'knowledge and job security' (8.8%), 'health care, people and public service' (8%), 'family and friends' (7.2%) and 'career in dentistry' (6.9%). Gender was a significant predictor of 'business and financial' factor (b = -0.76; P = 0.003) and age for 'careers in dentistry' (b = -0.18; P = 0.03). CONCLUSION: Students are motivated by a wide range of factors similar to those found in other studies; however, business features and family influences were significantly associated with gender.

Retrospective evaluation of sensory neuropathies after extraction of mandibular third molars with confirmed "high-risk" features on cone beam computed topography scans.

OBJECTIVES: The objective of this study was to identify the incidence of inferior alveolar nerve (IAN) injury after extraction of mandibular third molars with confirmed "high-risk" features on cone beam computed topography scans and establish any risk factors that significantly increase the chances of sustaining an IAN injury. STUDY DESIGN: This study is a retrospective analysis of outcomes after surgical extraction of 500 mandibular third molars over a 5-year period. All teeth showed signs of contact with or compression of the IAN on cone beam computed topography scans. RESULTS: The overall incidence of IAN injury was 6.6%, with permanent neuropathies accounting for 1.8% within this high-risk cohort. Statistically significant factors shown to increase the risk of nerve injury included increasing age (P = .002), compression of the nerve evident on cone beam computed topography scan (P = .005), and buccal or interradicular position of the nerve (P = .042). CONCLUSIONS: Results indicate a low incidence of IAN injury, particularly given the high-risk nature of all teeth that were extracted. It highlights the benefits of cone beam computed topography scans in surgical planning. These data are an important contribution to the existing literature and valuable in the consent procedure for patients undergoing surgical removal of mandibular third molars in contact with the IAN.

The physical characteristics of resin composite-calcium silicate interface as part of a layered/laminate adhesive restoration.

OBJECTIVES: To compare in-vitro micro-shear bond strengths (µSBS) of resin composite to calcium silicate cement (Biodentine™) vs. glass ionomer cement vs. resin modified glass ionomer cement (RM-GIC) using an adhesive in self-etch (SE)/total etch (TE) mode after aging three substrates and bond and characterizing their failure modes. METHODS: Resin composite was SE/TE bonded to 920 standardized disks of Biodentine™, GIC & RM-GIC. Dividing samples into two groups, the first underwent early (t=0min, 5min, 20min, 24h) or delayed (t=2wk, 1 month, 3 months, 6 months) substrate aging before bonding and µSBS (t=24h) testing. In the second, adhesive was applied after either early (t=5min) or delayed (t=2wk) substrate aging and then tested after bond aging (t=2wk, 1 month, 3 months, 6 months). The failure modes were identified using stereomicroscope. SEM images of selected samples were analyzed. RESULTS: No significant differences were observed between (SE)/(TE) bonding modes (P=0.42). With substrate aging, a significant reduction in µSBS occurred between early and delayed time intervals for Biodentine™ (P=0.001), but none for the GIC/RM-GIC (P=0.465, P=0.512 respectively). With bond aging, there was no significant difference between time intervals for all groups, except at 6 months for the GIC (P<0.05). Modes of failure were primarily cohesive within all the substrates (68.82%) followed by adhesive failure at the resin-substrate interface (21.71%). SIGNIFICANCE: Biodentine™ is a weak restorative material in its early setting phase. Placing the overlying resin composite as part of the laminate/layered definitive restoration is best delayed for >2wk to allow sufficient intrinsic maturation to withstand contraction forces from the resin composite. A total-etch or self-etch adhesive may be used.