Survival of pre-formed zirconia crowns in primary teeth: a prospective practice-based cohort study.

BACKGROUND: This study aimed to investigate the (1) survival probabilities of prefabricated zirconia crowns (PZCs) placed on primary teeth and (2) identify demographic and tooth-related factors that might affect survival probability. METHODS: This study prospectively followed children treated under general anaesthesia by a single practitioner between 2012 and 2020. Demographic variables including the age at treatment, gender and tooth-related variables including FDI tooth number, crown size used and any procedural complications at postoperative reviews were collected. RESULTS: A total of 155 children involving 319 teeth with PZCs were followed up between 12 and 78 months postoperatively with a mean of 38 months. Of the 319 crowns followed, five failures were observed in three patients requiring extraction. Other procedural complications noted included fracture (n = 3), overhangs (n = 3), internal resorption (n = 5) and 24% of crowns showed signs of radiographic changes on postoperative radiographs when these were taken. Age at treatment, tooth type and need for pulp therapy were not statistically associated with clinical success (P > 0.1). CONCLUSIONS: PZCs provide an aesthetic and durable solution in the management of children with early childhood caries. This study shows very good clinical success and survival extending up to 78 months for PZCs placed on primary teeth under general anaesthesia.

Acidity, fluoride and silver ion concentrations in silver diamine fluoride solutions: a pilot study.

BACKGROUND: There has been renewed interest in the use of silver diamine fluoride (SDF) for the management of carious lesions in high-risk groups. Previous studies have found a difference in clinical efficacy among different concentrations of SDF and discrepancies between ionic concentrations of fluoride (F) and silver (Ag) in SDF preparations. The aim of this study was to measure the free F, Ag ion concentrations and pH of a variety of commercially available SDF preparations. METHODS: Seven SDF products used globally were evaluated for F and Ag ion concentrations using a calibrated ion-selective electrode and optical emission spectrometry respectively. Acidity was determined with a pH electrode. RESULTS: The 30% SDF solution contained almost half the F concentration and a much higher Ag concentration than expected (16 343 ppmF and 246 000 ppmAg). Comparatively, the mean F concentration of the remaining six 38% solutions was 74 802 ppm (expected mean 44 800 ppm) ranging from 36 457 ppm to 120 760 ppm. The mean Ag concentration was 326 000 ppm (expected mean 253 870 ppm) and ranged from 246 000 ppm to 425 451 ppm. All solutions were found to be neutral or mildly alkaline in nature (pH 7-10.3). CONCLUSIONS: Wide variations between claimed and measured F and Ag ion concentrations exist among the different brands of commercially available SDF products.

Knowledge, experiences and attitudes of dental health professionals towards reporting child abuse in Western Australia.

BACKGROUND: Up to 50% of child abuse (CA) victims exhibit evidence of traumatic facial or intraoral injuries. Dental health professionals (DHPs) are therefore well-positioned to detect and report incidences of CA. This study aimed to assess the knowledge and attitudes of Western Australian DHPs towards identifying and reporting CA. METHODS: General dentists, specialists, hygienists and oral health therapists completed an online questionnaire which assessed their knowledge and experience in identifying and reporting CA. RESULTS: A total of 228 participants completed the questionnaire (representing 7% of DHPs, 60% of paediatric dentists and 11% of all dental hygienists and therapists in Western Australia). The majority of participants (66.2%, P < 0.05) felt that they were unlikely to recognize a patient with physical abuse, or detect signs of sexual abuse (90.8%, P < 0.001). Uncertainty around diagnosing abuse was a barrier towards reporting cases (86.4%, P < 0.05) and most participants (78.0%, P < 0.05) felt that they did not have adequate safeguarding training to report CA. CONCLUSIONS: Self-reported confidence in identifying and reporting CA cases was low; with the majority of the dental professionals participating in this study unlikely to recognize signs of CA. Inadequate training and knowledge around correct reporting protocols were identified as barriers, which warrants an appropriate change to improve child safeguarding.

Correlating spacing in the primary dentition and caries experience in preschool children.

PURPOSE: To evaluate the correlation between spacing in the primary dentition and caries experience. METHODS: One hundred seventy-four clinical records, including photographs during 2017-2019 were assessed for primate, generalised and interdental spaces. The mean of decayed, missing or filled teeth and surfaces (dmft and dmfs) were recorded to quantify the caries experience. Linear regression analyses were used to ascertain correlations between spacing and dental caries. The strength of the associations was quantified using odds ratio (OR) and 95% confidence interval (CI). RESULTS: Ninety-seven boys and 77 girls were included in the final analysis. Approximately 41% of children had primate space in all four quadrants, and 15% of children had no primate spaces in all four quadrants. 50% of children did not exhibit generalised spacing, while 39% of children showed interdental spacing. Children with no primate space had approximately five surfaces higher dmfs score compared to those with primate space in all four quadrants (95% CI - 9.27 to - 1.23; p < 0.05). Similarly, children with no primate space in the mandible had 6.12 surfaces higher dmfs score compared to those with primate space in the mandibular arch (95% CI - 10.07 to - 2.17; p < 0.05). CONCLUSIONS: Preschool children with no primate space exhibited a 50% increase in dmfs scores compared to children with primate space.

Root canal morphology of hypomineralised first permanent molars using micro-CT.

AIM: To investigate the root canal morphology of hypomineralised first permanent molars (FPMs) using micro-CT (µCT). METHODOLOGY: Twenty-four hypomineralised FPMs and five clinically sound FPMs were scanned using µCT and assessed using the following parameters: (i) root canal configuration, (ii) connecting canal frequency, (iii) enamel, dentin, and pulp volumes, (iv) cusp tip to pulp horn distance, root canal length, root canal width, and dentin thickness, and (v) the influence of the root canal system landmarks on access cavity outline forms and canal curvature. A two-way repeated-measures analysis of variance was employed with the statistical significance set at p < 0.05. RESULTS: The frequency of accessory and connecting canals was higher in hypomineralised FPMs. Mesio-buccal cusp horn was found to be the closest to its corresponding cusp tip in both groups. There was no significant difference between the root lengths, dentine widths, and pulp space measurements of hypomineralised FPMs compared to clinically sound FPMs. The best angulation to access FPMs was straight-line radicular, along the pulp horn. CONCLUSIONS: This study illustrates some variations in the root canal morphology in hypomineralised FPMs compared to clinically sound FPMs. Future studies should focus on assessing these parameters in larger samples.

Correction to: Biodentine™ material characteristics and clinical applications: a 3 year literature review and update.

Owing to a misunderstanding on the part of the authors, the name of the last author, Prof. R. M. H. Verbeeck, was omitted from this article.

Pre-maxillary hypohyperdontia: a report of two cases.

BACKGROUND: Hypodontia and hyperdontia are considered to be at opposite ends of the dental development spectrum. Nevertheless, these anomalies may occur concomitantly (hypohyperdontia). CASE REPORT: This clinical report describes two case of hypohyperdontia occurring exclusively in the premaxillary region, and the difficulties associated with its diagnosis and management. Following 24 months of follow-up examinations, Case 1 developed a sequential supernumerary tooth in the tooth 35 region. CONCLUSION: Cases of hypohyperdontia can occur exclusively in the premaxillary region and may be difficult to diagnose. Multidisciplinary treatment planning is essential to facilitate appropriate management, and long-term follow-up is necessary as sequential supernumerary teeth may develop.

Biodentine™ material characteristics and clinical applications: a 3 year literature review and update.

INTRODUCTION: Biodentine™ has frequently been acknowledged in the literature as a promising material and serves as an important representative of tricalcium silicate based cements used in dentistry. AIM: To provide an update on the physical and biological properties of Biodentine™ and to compare these properties with those of other tricalcium silicate cements namely, different variants of mineral trioxide aggregate (MTA) such as ProRoot MTA, MTA Angelus, Micro Mega MTA (MM-MTA), Retro MTA, Ortho MTA, MTA Plus, GCMTA, MTA HP and calcium enriched mixture (CEM), Endosequence and Bioaggregate™. STUDY DESIGN: A comprehensive literature search for publications from November 20, 2013 to November 20, 2016 was performed by two independent reviewers on Medline (PubMed), Embase, Web of Science, CENTRAL (Cochrane), SIGLE, SciELO, Scopus, Lilacs and clinicaltrials.gov. Electronic and hand search was carried out to identify randomised control trials (RCTs), case control studies, case series, case reports, as well as in vitro and animal studies published in the English language. CONCLUSIONS: The enhanced physical and biologic properties of Biodentine™ could be attributed to the presence of finer particle size, use of zirconium oxide as radiopacifier, purity of tricalcium silicate, absence of dicalcium silicate, and the addition of calcium chloride and hydrosoluble polymer. Furthermore, as Biodentine™ overcomes the major drawbacks of MTA it has great potential to revolutionise the different treatment modalities in paediatric dentistry and endodontics especially after traumatic injuries. Nevertheless, high quality long-term clinical studies are required to facilitate definitive conclusions.

Tooth mineral density of different types of hypomineralised molars: a micro-CT analysis.

AIM: This study sought to evaluate the tooth mineral density (TMD) for the different lesion types in hypomineralised first permanent molars (FPMs) and compare them to unaffected enamel in clinically sound FPMs. DESIGN: Eighteen FPMs with varying degrees of hypomineralised enamel were grouped into brown, yellow/creamy and white lesion types. Micro-CT was used to determine the TMD for each lesion type, and for unaffected enamel at different locations in the outer, middle, and inner-third of the enamel. RESULTS: The average TMD for brown, yellow/creamy, white and unaffected enamel was 1.79, 2.21, 2.43 and 2.46 g/cm3, respectively. Brown and yellow/creamy lesions exhibited a statistically significant difference when compared to white lesions and unaffected enamel. However, no statistical difference was evident in TMD between white lesions and unaffected enamel. The TMD increased from the outer-third to inner-third for brown and yellow/creamy lesions (p < 0.05), while in white lesions and unaffected enamel, the TMD decreased from the outer-third to inner-third (p < 0.05). CONCLUSION: TMD was lowest for brown lesions followed by yellow/creamy lesions while the TMD for white lesions was similar to unaffected enamel.

Is there sufficient evidence to support an optimum time for the extraction of first permanent molars?

AIM: To evaluate whether the literature contains evidence, of an appropriate quality, to support the fundamental belief that there is an "optimal time" for extraction of FPMs with a poor prognosis. METHODS: A comprehensive search, limited to human studies, was performed using five databases. PICO based inclusion and exclusion criteria were employed to facilitate article selection. Three independent reviewers assessed the quality of included studies using STROBE and GRADE criteria. RESULTS: Initially, 56 articles were selected, of which 9 were included for final assessments. None of the included studies obtained moderate or high GRADE level rating and neither did they meet all of the STROBE requirements with only one study satisfying 95%, and another study satisfying 73%, of the requirements. The inter-observer agreement was excellent. CONCLUSION: There is no scientific evidence, of an appropriate quality, to support the "optimal time" for extraction of FPMs with a poor prognosis.

Bilateral supplemental maxillary central incisors with double-tooth like appearance.

BACKGROUND: Supplemental teeth refer to extra teeth that resemble the normal tooth series. Bilateral supplemental central incisors in a healthy individual are rare and bilateral supplemental incisors with double-tooth like appearance are exceptionally rare and has not been previously reported in the dental literature. CASE REPORT: This clinical report describes an 8-year old healthy Indian boy referred for the management of delayed eruption of his permanent maxillary incisor teeth. Following clinical and radiographic examination the two supplemental incisors closer to the midline were extracted under local analgesia and both of them exhibited double-tooth like appearance. CONCLUSIONS: The present case refutes the conventional wisdom that "supplemental teeth are usually smaller than the normal tooth type they resemble and occur distal to the normal tooth series", illustrates that the unusual can occur and that the clinician should be aware of such variations.

Reliability of horizontal and vertical tube shift techniques in the localisation of supernumerary teeth.

AIM: To assess the reliability of the vertical tube shift technique (VTST) and horizontal tube shift technique (HTST) for the localisation of unerupted supernumerary teeth (ST) in the anterior region of the maxilla. METHODS: A convenience sample of 83 patients who attended a major teaching hospital because of unerupted ST was selected. Only non-syndromic patients with ST and who had complete clinical and radiographic and surgical records were included in the study. Ten examiners independently rated the paired set of radiographs for each technique. Chi-square test, paired t test and kappa statistics were employed to assess the intra- and inter-examiner reliability. RESULTS: Paired sets of 1660 radiographs (830 pairs for each technique) were available for the analysis. The overall sensitivity for VTST and HTST was 80.6 and 72.1% respectively, with slight inter-examiner and good intra-examiner reliability. Statistically significant differences were evident between the two localisation techniques (p < 0.05). CONCLUSIONS: Localisation of unerupted ST using VTST was more successful than HTST in the anterior region of the maxilla.

Hypodontia of all primary canines.

BACKGROUND: Several hypotheses have been proposed to explain hypodontia of the various tooth types with evolutionary and anatomic models. Hypodontia of all primary canines in a healthy individual is exceptionally rare and has not been previously reported in the dental literature. CASE REPORT: This clinical report describes a 4-year-old southern Chinese female with the congenital absence of the primary canines in all quadrants. Furthermore, all of the permanent tooth germs excluding the third molars were evident on a panoramic radiograph and were developing consistent with the subject's chronological age. CONCLUSION: This case serves as an excellent example to refute the conventional wisdom that "all primary canines can never go missing" and that all of the currently proposed hypotheses to explain hypodontia have limitations.

Remineralizing potential of CPP-ACP applied for 1 min in vitro.

AIM: To evaluate (1) the remineralizing potential of Tooth Mousse(®) (TM) on artificial carious lesions, when applied for 1 min, and (2) the benefit of a fluoridated dentifrice prior to TM application. METHODS: Demineralisation caries-like lesions 120-200 µm deep were produced by placing molars in demineralizing solution for 96 h, sections 100-150 µm thick were then randomly assigned to four groups. Specimens were treated thrice daily with a non-fluoridated (Group A), or fluoridated dentifrice (1000 ppm) (Group B), or TM (Group C), or a fluoridated dentifrice followed by TM (Group D) then subjected to a 10-day pH cycling model. Lesion evaluation involved polarizing light microscopy and microradiography. RESULTS: Application of TM in isolation (Group C) for 1 min resulted in significant increase in lesion depth (LD), however, an increase in mineral content deposition (V max) was not significant. Post treatment LD increases were greatest in Group A, then Group C and Group B respectively. A decrease in LD (by 19.9 %) was noted only after fluoridated dentifrice and TM (Group D) were applied consecutively for 1 min each (p < 0.05). Mineral content deposition was also greatest in this group (Group D) and both V max and LD changes were statistically significant when compared to other groups. CONCLUSIONS: TM alone failed to remineralize carious lesions when applied for 1 min. However, remineralization occurred after a prior application of a fluoridated dentifrice.

Caries burden and efficacy of a referral pathway in a cohort of preschool refugee children.

BACKGROUND: This study aimed to assess the early caries experience and the efficacy of a community based dental referral pathway in preschool refugees in Western Australia. METHODS: Preschool refugee children referred to the Western Australian paediatric hospital Refugee Health Clinic were prospectively screened for caries by a paediatric dentist before being referred to community dental clinics. Dental forms and medical records were audited to assess decayed, missing and filled teeth (dmft), medical data and dental services engagement. Poisson regression analysis determined the contribution of count variables to the final model. RESULTS: Among the 105 screened children (54% male, median age 3.2 years, 41% Burmese), community dental clinic engagement was low (46%, n=48). Of the 62% with caries (n=65/105, mean dmft 5.2, SD 4.1), 45% were recommended for specialist dental services and 48% were treated. After adjustment for age, gender and total number of teeth, caries incidence was significantly associated with BMI-for-age Z score (p=0.02). CONCLUSIONS: Preschool refugee caries burden was high. The community dental referral pathway was ineffective compared to co-located intersectorial dental screening. Specialist dental service needs are high in this cohort and require a targeted approach.