Regenerative endodontic therapy: a follow-up of 47 anterior traumatised teeth.

PURPOSE: To collect long-term survival data in anterior traumatised teeth on the outcome of Regenerative Endodontic Treatments (RET) with a network of dentists working in different clinics to overcome the problem of anecdotical evidence. METHODS: The seven dentists from Paediatric REsearch Project (PREP) performed RET treatments following the same protocol in five different secondary dental care clinics in the Netherlands. Treatment resulting in pain, apical problems, sinus tracts, resorption or fracture were considered as failure of treatment. RESULTS: 47 teeth in 38 children were treated between January 2009 and September 2017 and had at least 6 month follow-up (mean 35 months). Apical closure was seen in 27 teeth (25 cases) and root length growth in 6 teeth (6 cases). Thickening of the root walls was seen in 20 teeth (20 cases) and obliteration of the root canal in 30 teeth (25 cases). Of 38 teeth with apical inflammation at the start of treatment, no radiographic sign of apical inflammation was visible at 3 months in 13 of 28 teeth; taking up to 42 months for radiographic signs of apical inflammation to be not visible. Nineteen of 35 teeth showed discoloration at the beginning of treatment. After 18 months two teeth showed signs of ankylosis, but were still functional. After 36 months one more tooth showed signs of new apical inflammation and 2 months later it was extracted. CONCLUSIONS: With three failures in 47 treated teeth, RET seems to be a promising treatment for difficult to treat anterior traumatised teeth with an open apex.

Molar incisor hypomineralisation (MIH) training manual for clinical field surveys and practice.

BACKGROUND: Despite clear assessment criteria, studies of molar incisor hypomineralisation (MIH) and hypomineralised second primary molars (HSPM) are marked by inconsistency in outcome measurements. This has detracted from meaningful comparisons between studies and limited interpretation. AIM: To provide a comprehensive manual as a companion to assist researchers in planning epidemiological studies of MIH and HSPM, with particular reference to outcome measurement. METHODS: This manual begins with a succinct review of the clinical problems and evidence for management of the conditions. The subsequent sections guide researchers through diagnosis of MIH and HSPM and implementation of both the long and short forms of a recently proposed grading system. MIH and HSPM can often be confused with fluorosis, enamel hypoplasia, amelogenesis imperfecta, and white spot lesions but can be distinguished by a number of unique clinical features. Based on the grading system, a standardised protocol is proposed for clinical examinations. Intra and inter-examiner reliability is of key importance when outcome measurement is subjective and should be reported in all epidemiological studies of MIH. The manual concludes with an exercise forum aimed to train examiners in the use of the grading system, with answers provided. CONCLUSION: The use of a standardised protocol, diagnostic and grading criteria will greatly enhance the quality of epidemiological studies of MIH.

Association between Bone Mass and Dental Hypomineralization.

The aim of this study was to examine the association between the bone mass (bone mineral content [BMC]) and hypomineralized second primary molars (HSPMs)/molar incisor hypomineralization (MIH) in 6-y-old children. This cross-sectional study was embedded in the Generation R Study, a population-based prospective cohort study, starting from fetal life until adulthood in Rotterdam, Netherlands. The European Academy of Pediatric Dentistry criteria were used to score the intraoral photographs on the presence or absence of HSPMs and MIH. Bone mass was measured with a dual-energy x-ray absorptiometry (DXA) scan. Intraoral photographs and DXA scans were available in 6,510 6-y-old children. Binary logistic regression models were used to study the association between the bone mass and HSPMs/MIH. In total, 5,586 children had their second primary molars assessed and a DXA scan made; 507 children were diagnosed with HSPM. Of 2,370 children with data on their permanent first molars, 203 were diagnosed with MIH. In the fully adjusted model, children with lower BMC (corrected for bone area) were more likely to have HSPMs (odds ratio, 1.13; 95% confidence interval, 1.02 to 1.26 per 1-standard deviation decrease). A lower BMC (corrected for bone area) was not associated with MIH (odds ratio, 1.02; 95% confidence interval, 0.87 to 1.20 per 1-standard deviation decrease). We observed a negative association between BMC (corrected for bone area) and HSPMs. No association was found between BMC (corrected for bone area) and MIH. Future research should focus on investigating the mechanism underlying the negative association between the bone mass and HSPMs. Our study, in a large population of 6-y-old children, adds the finding that BMC (corrected for bone size) is associated with HSPMs but not with MIH in childhood.

Standardised studies on Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM): a need.

In November 2014, a review of literature concerning prevalence data of Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) was performed. A search of PubMed online databases was conducted for relevant articles published until November 2014. The reference lists of all retrieved articles were hand-searched. Studies were included after assessing the eligibility of the full-text article. Out of 1078 manuscripts, a total of 157 English written publications were selected based on title and abstract. Of these 157, 60 were included in the study and allocated as 52 MIH and 5 HSPM, and 3 for both MIH and HSPM. These studies utilised the European Academy of Paediatric Dentistry judgment criteria, the modified index of developmental defects of enamel (mDDE) and self-devised criteria, and demonstrated a wide variation in the reported prevalence (MIH 2.9-44 %; HSPM 0-21.8 %). Most values mentioned were representative for specific areas. More studies were performed in cities compared with rural areas. A great variation was found in calibration methods, number of participants, number of examiners and research protocols between the studies. The majority of the prevalence studies also investigated possible aetiological factors. To compare MIH and HSPM prevalence and or aetiological data around the world, standardisation of such studies seems essential. Standardisation of the research protocol should include a clearly described sample of children (minimum number of 300 for prevalence and 1000 for aetiology studies) and use of the same calibration sets and methods whereas aetiological studies need to be prospective in nature. A standardised protocol for future MIH and HSPM prevalence and aetiology studies is recommended.

Mineral content in teeth with deciduous molar hypomineralisation (DMH).

OBJECTIVES: We report the mineral (hydroxyapatite) density of sound and opaque areas in DMH molars with sound parts of (carious) deciduous teeth serving as controls. METHODS: Twenty-nine extracted second primary molars obtained from 15 children were studied. Thirteen of these molars were DMH molars with yellow opacities, seven were DMH molars with white opacities, three DMH molars with brown opacities and eleven were molars without DMH. Prior to microCT scanning, the teeth were mounted in impression material (Impregum(®)) and stored in water with a thymol crystal. Spot analysis and line scans were performed in areas with opacities and in sound areas. An ANOVA test and t-tests were used to test if there were significant differences between the groups. RESULTS: The average densities of the hydroxyapatite in yellow and brown opacities (1368mg HA/cm(2) and 1407mg HA/cm(2), respectively) were significantly lower than in clinically unaffected enamel (1747mg HA/cm(2)) of DMH molars or of sound molars (1758mg HA/cm(2)). The mineral density in white opacities (1737mg HA/cm(2)) was not different from that in the enamel of sound molars. The mineral density values in yellow and brown enamel opacities were in between those of dentine (1018mg HA/cm(2)) and enamel. CONCLUSIONS: DMH molars with yellow or brown opacities had a 20-22% lower mineral density in the hypomineralised enamel compared with sound molars. White opacities do not show a lower mineral content. The reduction in enamel mineral content in DMH molars stressed the need for a preventive approach in DMH.

Deciduous molar hypomineralization and molar incisor hypomineralization.

This study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life until young adulthood. This study focused on the relationship between Deciduous Molar Hypomineralization (DMH) and Molar Incisor Hypomineralization (MIH). First permanent molars develop during a period similar to that of second primary molars, with possible comparable risk factors for hypomineralization. Children with DMH have a greater risk of developing MIH. Clinical photographs of clean, moist teeth were taken with an intra-oral camera in 6,161 children (49.8% girls; mean age 74.3 mos, SD ± 5.8). First permanent molars and second primary molars were scored with respect to DMH or MIH. The prevalence of DMH and MIH was 9.0% and 8.7% at child level, and 4.0% and 5.4% at tooth level. The Odds Ratio for MIH based on DMH was 4.4 (95% CI, 3.1-6.4). The relationship between the occurrence of DMH and MIH suggests a shared cause and indicates that, clinically, DMH can be used as a predictor for MIH.

Validity of scoring caries and primary molar hypomineralization (DMH) on intraoral photographs.

AIM: The aims of this study were to assess whether intraoral photographs could be used to score caries and hypomineralization on primary molars (Using adapted Molar Incisor Hypomineralization (MIH)-criteria), and also to assess the reliability and validity in 3-7 year-old Dutch children of these scores by comparing them to direct clinical scorings. STUDY DESIGN: Cross-sectional study. METHODS: In this study 62 children (38.7% girls) with a mean age of 4.96 years (SD 1.27) participated. The children were rated clinically by their own dentist (authors JV or ME) for caries reaching the dentine in their primary molars (WHO criteria) and also for primary molar hypomineralization using the adapted MIH-criteria. For the intraoral photographs, a digital intraoral camera was used. The two paediatric dentists rated all the intraoral photographs on caries and hypomineralizations on the second primary molars, using the same criteria for the clinical scoring as for the scoring of the photographs. They scored independently, at least 2 weeks after the initial clinical scoring to avoid observational bias with the clinical scoring. STATISTICS: This clinical observation was used as the gold standard from which sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) and the Positive and Negative Likelihood Ratio were computed. To test the intra-observer agreement 25 % of the photographs were scored again, at least 2 weeks after the initial scoring of the images. Inter- and intra-observer agreement were tested using Cohen's Kappa. RESULTS: The mean prevalence of clinically detected caries at tooth level was 46.7% and the mean prevalence of clinically detected hypomineralizations in second primary molars at tooth level was 21.8%. The sensitivity of assessing caries using intraoral photographs was 85.5%, the specificity 83.6%, the positive likelihood ratio 5.2 and the negative likelihood ratio was 0.17. For Primary Molar Hypomineralization (DMH) the sensitivity was 72.3%, the specificity 92.8%, the positive likelihood ratio 10.1 and the negative likelihood ratio was 0.30. The inter-observer agreement yielded the following Cohen's Kappa scores: for caries 0.76 and for DMH 0.62. The intra-observer agreement was for caries 0.80 (ME) and 0.72 (JV) and for DMH 0.95 (both ME and JV). CONCLUSIONS: From this investigation it was concluded that the sensitivity, specificity and the likelihood ratio of scoring caries and DMH on photographs made with an intraoral camera were good. The inter- and intra-observer reliability for caries and DMH were good to excellent. These findings suggest that intraoral photographs may be used in clinical practice and large epidemiological studies.

Hypomineralized second primary molars: prevalence data in Dutch 5-year-olds.

The aim of this cross-sectional observational study was to report on the prevalence of hypomineralizations in second primary molars in 5-year-old Dutch children. In the study 386 (45% girls) 5-year-old Dutch children, all insured by a Health Insurance Fund, participated. Scoring criteria for molar incisor hypomineralization molars were adapted to score second primary molars. The prevalence of hypomineralized second primary molars (HSPM) was 4.9% at child level and 3.6% at tooth level. Most HSPMs (87%) showed demarcated opacities, followed by posteruptive enamel loss (40%).

Caries pattern in primary molars in Dutch 5-year-old children.

AIM: The aim of this study was to investigate the difference in caries prevalence based on quadrant dmfs data between first and second primary molars in 5-year-old Dutch children. STUDY DESIGN: Cross-sectional observational study. METHODS AND STATISTICS: For this study 692 children, all insured by a "Health Insurance Fund", living in one of four selected cities in The Netherlands were asked to participate in the study. From the original cohort 435 children (49% girls) participated. Clinical examinations were performed and only carious lesions with involvement of the dentine were reported. Lesions on the occlusal, buccal, palatinal/lingual, mesial and distal surfaces as well as lesions in buccal and palatinal pits and fissures were reported separately. No radiographs were taken. Systematic differences in dmfs between first and second molars in the same quadrant of each primary dentition were tested with the Wilcoxon signed rank test. RESULTS: Second primary molars, even after correction for caries in pits and buccal/palatinal fissures, had a statistically significant higher total dmfs than the first primary molars. The differences were mainly found on the occlusal surfaces. On proximal surfaces, the first primary molars had significant more caries than the second primary molars. The d-component constituted the major part of the caries index. CONCLUSIONS: Second primary molars, corrected for decay in the pits and buccal/palatinal fissures of this molar, are more affected by caries than first primary molars and that the differences in caries prevalence are the largest on the occlusal surface. The specific site of the caries found suggests that developmental disturbances in second primary molars may attribute to their prevalence.