Reporting stAndards for research in PedIatric Dentistry (RAPID): an expert consensus-based statement.

BACKGROUND: Reporting guidelines for different study designs are currently available to report studies with accuracy and transparency. There is a need to develop supplementary guideline items that are specific to areas within Pediatric Dentistry. This study aims to develop Reporting stAndards for research in PedIatric Dentistry (RAPID) guidelines using a pre-defined expert consensus-based Delphi process. METHODS: The development of the RAPID guidelines was based on the Guidance for Developers of Health Research Reporting Guidelines. Following a comprehensive search of the literature, the Executive Group identified ten themes in Pediatric Dentistry and compiled a draft checklist of items under each theme. The themes were categorized as: General, Oral Medicine, Pathology and Radiology, Children with Special Health Care Needs, Sedation and Hospital Dentistry, Behavior Guidance, Dental Caries, Preventive and Restorative Dentistry, Pulp Therapy, Traumatology, and Interceptive Orthodontics. A RAPID Delphi Group (RDG) was formed comprising of 69 members from 15 countries across six continents. Items were scored using a 9-point rating Likert scale. Items achieving a score of seven and above, marked by at least 70% of RDG members were accepted into the RAPID checklist items. Weighted mean scores were calculated for each item. Statistical significance was set at p < 0.05 and one-way ANOVA was used to calculate the difference in the weighted mean scores between the themes. RESULTS: The final RAPID checklist comprised of 128 items that were finalized and approved by the RDG members in the online consensus meeting. The percentage for high scores (scores 7 to 9) ranged from 69.57 to 100% for individual items. The overall weighted mean score of the final items ranged from 7.51 to 8.28 (out of 9) and the difference was statistically significant between the themes (p < 0.05). CONCLUSIONS: The RAPID statement provides guidance to researchers, authors, reviewers and editors, to ensure that all elements relevant to particular studies are adequately reported.

Prospective randomized clinical trial of primary molar crowns: 36-month results.

PURPOSE: To clinically evaluate the clinical success of a primary zirconia molar crown, compared with stainless steel crowns (SSCs). METHODS: This randomized, controlled clinical trial was designed as a split-mouth study. 50 subjects ranging in age from 3-7 years were recruited to provide a total of 50 paired teeth requiring primary molar crowns, each participant receiving a SSC and zirconia crown. Restorations were evaluated at 6-, 12-, 24-, and 36-month recall appointments examining the following criteria: gingival health, estimate of the degree crown was high in occlusion, surface roughness, staining on crown surface, wear of opposing arch tooth, color match, anatomic form, marginal integrity, marginal discoloration, proximal contact area, secondary caries at crown margin and parent/guardian satisfaction with crown appearance. RESULTS: The 36-month follow up included 23 subjects (46%). 35 crowns (35%) were evaluated; of the 18 zirconia crowns and 17 SSCs, there were no failures at the 36-month evaluation. The only significant differences in the parameters evaluated were parent satisfaction, with the zirconia crown preference (P< 0.05) and gingival health, with the zirconia crowns having healthy adjacent gingiva (P< 0.01). The 36-month results indicated that zirconia primary molar crowns performed similarly to an established SSC for restoration of primary molars. CLINICAL SIGNIFICANCE: The findings from this study indicated that at 36 months, NuSmile ZR zirconia crowns clinically performed as well as stainless steel crowns.

Reporting stAndards for research in PedIatric Dentistry (RAPID): A development protocol.

Reporting guidelines can improve the quality of reports of research findings. Some specialities in health care however require guidance on areas that are not captured within the existing guidelines, and this is the case for Paediatric Dentistry where no such standards are available to guide the reporting of different types of study designs. The 'Reporting stAndards for research in PedIatric Dentistry' (RAPID) group aims to address this need by developing guidelines on reporting elements of research of particular relevance to Paediatric Dentistry. The development of RAPID guidelines will involve a five-phase process including a Delphi study, which is an explicit consensus development method designed and implemented in accordance with the Guidance on Conducting and REporting DElphi Studies. The guideline development process will be overseen by an Executive Group. Themes specific to areas in Paediatric Dentistry will be selected, and items to be included under each theme will be identified by members of the Executive Group reviewing at least five reports of experimental and analytical study types using existing reporting guidelines. For the Delphi study, the Executive Group will identify an international multidisciplinary RAPID Delphi Group (RDG) of approximately 60 participants including academics, Paediatric Dentists, parents, and other stakeholders. Each item will be evaluated by RDG on clarity using a dichotomous scale ('well phrased' or 'needs revision') and on suitability for inclusion in the Delphi study using a 9-point Likert scale (1 = 'definitely not include' to 9 = 'definitely include'). The items will then be included in an online Delphi study of up to four rounds, with participants invited from stakeholder groups across Paediatric Dentistry. Items scored 7 or above by at least 80% of respondents will be included in the checklist and further discussed in a face-to-face Delphi consensus meeting. Following this, the Executive Group will finalize the RAPID guidelines. The guidelines will be published in peer-reviewed scientific journals and disseminated at scientific meetings and conferences. All the outputs from this project will be made freely available on the RAPID website: www.rapid-statement.org.

Survival of Zirconia Crowns in Primary Maxillary Incisors at 12-, 24- and 36-Month Follow-Up.

Purpose: The purpose of this study was to assess the survival probability of zirconia crowns (ZCs) on primary maxillary incisors placed in children diagnosed with severe early childhood caries at 12-, 24-, and 36-month follow-up visits in a university pediatric dental clinic. Methods: Ninety-four teeth in 30 healthy 24- to 60-month-olds who received ZCs under general anesthesia participated in this study (N equals 94). Data included children's demographics, dental-related variables, appointment dates, survival of crown, and type of failure (defined as replacement of lost ZCs or extraction of the treated tooth due to evidence of apical periodontitis prior to natural exfoliation). Descriptive statistics were performed to examine demographics, while Kaplan-Meier survival curves were used to estimate survival probabilities of ZCs over time. Unadjusted and adjusted hazard ratios (HR) from Cox proportional hazard regression with robust standard errors were used to compare risk of ZC failure by patient and tooth characteristics. Results: The overall survival probabilities for ZCs at 12, 24, and 36 months were 93 percent, 85 percent, and 76 percent, respectively. Conclusion: With esthetic characteristics and high survival probabilities, zirconia crowns present as a suitable alternative for reconstruction of primary maxillary incisors in young children. (Pediatr Dent 2019;41(5):385-90).

Hidden Caries: A Case Report of a 17 Years Old Male with Two Affected Mandibular Premolars.

Hidden caries is the term used to describe carious lesions that are not visualized clinically on erupted teeth but can be detected radiographically. The exact etiology remains an area of controversy. The purpose of the current case report was to discuss the diagnosis and treatment of two mandibular premolars with hidden caries. After diagnosis was established, both premolars were treated with indirect pulp caps and resin-based composite restorations. A one year follow up appointment revealed both teeth to be free from signs and symptoms of inflammation.

Early childhood caries epidemiology, aetiology, risk assessment, societal burden, management, education, and policy: Global perspective.

BACKGROUND: This paper is a summary of the proceedings of the International Association of Paediatric Dentistry Bangkok Conference on early childhood caries (ECC) held in 3-4 November 2018. AIM: The paper aims to convey a global perspective of ECC definitions, aetiology, risk factors, societal costs, management, educational curriculum, and policy. DESIGN: This global perspective on ECC is the compilation of the state of science, current concepts, and literature regarding ECC from worldwide experts on ECC. RESULTS: Early childhood caries is related to frequent sugar consumption in an environment of enamel adherent, acid-producing bacteria in a complex biofilm, as well as developmental defects of enamel. The seriousness, societal costs, and impact on quality of life of dental caries in pre-school children are enormous. Worldwide data show that ECC continues to be highly prevalent, yet infrequently treated. Approaches to reduce the prevalence include interventions that start in the first year of a child's life, evidence-based and risk-based management, and reimbursement systems that foster preventive care. CONCLUSIONS: This global perspective on ECC epidemiology, aetiology, risk assessment, global impact, and management is aimed to foster improved worldwide understanding and management of ECC.

Prospective Randomized Clinical Trial of Primary Molar Crowns: 24-Month Results.

Purpose: The purpose of this study was to evaluate the clinical success of a new primary zirconia molar crown compared with stainless steel crowns (SSCs). Methods: This randomized, controlled clinical trial was designed as a split-mouth study. Fifty three- to seven-year-old children were recruited to provide a total of 50 pairs of teeth requiring primary molar crowns, with each participant receiving a SSC and zirconia crown. Restorations were evaluated at six-month, 12-month, and 24-month recall appointments examining the following criteria: gingival health; estimate of extent the crown was high in occlusion; surface roughness; staining on crown surface; wear of opposing arch tooth; color match; anatomic form; marginal integrity; marginal discoloration; proximal contact area; secondary caries at crown margin; and parent/guardian satisfaction with crown appearance. Results: The 24-month follow-up included 39 patients (78 percent). Seventy crowns (70 percent) were evaluated; of the 36 zirconia crowns and 34 SSCs, there were no failures at the 24-month evaluation. The only significant difference in the parameters evaluated was in parental satisfaction with the zirconia crown preference (P<0.05). Conclusion: Current 24-month results indicate that zirconia primary molar crowns perform similarly to an established stainless steel crown for restoration of primary molar teeth.

Dentin and enamel demineralization inhibition at restoration margins of Vitremer, Z 100 and Cention N.

PURPOSE: To examine the in vitro caries inhibition of a resin-modified glass-ionomer cement, and a fluoride and calcium releasing resin-based composite. METHODS: Standardized Class V preparations were placed in 30 molars, the gingival margin placed below the cemento-enamel junction. Randomly, 10 Vitremer, 10 Z 100 and 10 Cention N restorations were placed according to manufacturer's instructions, in 30 teeth. The Z 100 non fluoride-releasing resin-based composite group acted as the control. All teeth had an acid-resistant varnish placed to within 1 mm of restoration margins and they were placed into artificial saliva for 2 weeks, the saliva being replenished every 48 hours. All teeth were subjected to thermocycling each day and to an artificial caries challenge (pH 4.4) for one hour twice a day. Sections of 100 µm were obtained, photographed under polarized light microscopy and then demineralized areas adjacent to restorations were quantitated. RESULTS: The mean (± S.D.) area (µm 2) demineralization 100 µm from the enamel and dentin margins were: Vitremer 1,554 ± 1,153, 4,125 ± 301; Cention N 3580 ± 1,518, 6,246 ± 630; Z 100 13,257 ± 3,794, 8,842 ± 1,799. A Mann-Whitney Rank Sum Test indicated that Vitremer had significantly less enamel demineralization then Cention N (P< 0.003) and Z 100 (P< 0.001) and Cention N had significantly less enamel demineralization than Z 100 (P< 0.001) and Z 100 (P< 0.001). Vitremer also had significantly less dentin demineralization than Cention N (P< 0.001) and Cention N had significantly less dentin demineralization than Z 100 (P< 0.001). CLINICAL SIGNIFICANCE: Recurrent caries remains a concern and this in vitro research indicates that Cention N, as well as Vitremer may clinically inhibit caries at restoration margins.

Fluoride release and re-release from a bioactive restorative material.

PURPOSE: To compare the amount of fluoride release and re-release of three different restorative materials. METHODS: The three restorative materials included a resin-based composite (Z100TM, 3M-ESPE), a resin-modified glass ionomer cement (VitremerTM, 3M-ESPE) and a bioactive material (Activa Bioactive-RestorativeTM, Pulpdent,). Ten disks were fabricated from each material. The disks were immersed in deionized water and stored. Samples were taken from each vial on Days 1, 7, 14 and 30 for fluoride ion analysis. Each disk was then exposed to 2.0% neutral sodium fluoride gel (0.9% fluoride ion, Dentsply), immersed in deionized water and stored. Samples were taken on Days 1, 7, 14 and 30 for fluoride ion analysis utilizing a fluoride-specific ion-analyzer. RESULTS: Z100 released less fluoride on Days 1 (P< 0.001), 7 (P= 0.001) and 14 (P< 0.022) for Phase I (initial release) than Phase II (re-release). Vitremer and Activa released less fluoride on Days 7, 14 and 30 (P< 0.001) for Phase II than Phase I. For all intervals of Phase I, Vitremer released the most fluoride, Activa released the second most, and Z100 released the least. These results were the same for Days 7, 14 and 30 of Phase II. The level of fluoride release from Activa was less than that of Vitremer, and greater than that of Z100 for all intervals of Phase I. The results were the same for all but one interval of Phase II. CLINICAL SIGNIFICANCE: This in vitro study evaluated the fluoride release and subsequent re-release of fluoride following a topical fluoride treatment to analyze if the materials were truly bioactive. The results indicate the bioactive material does uptake fluoride and re-release it which could offer inhibition to caries at restoration margins.

Fluoride release and re-release from various esthetic restorative materials.

PURPOSE: To measure the amount of fluoride release and re-release after re-charge from two commonly used esthetic restorative materials and compare it to a new experimental material. METHODS: 30 standardized disc-shaped specimens were fabricated using resin-based composite (Z100), resin-modified glass-ionomer cement (Vitremer) and a new experimental material which is a self-curing resin-based composite with light curing option. 10 specimens were made from each material. The specimens of each group were immersed separately in 10 ml distilled water. Fluoride release was measured after 1, 7, 14 and 30 days using a fluoride-specific ion electrode and an ion-analyzer. The specimens were then exposed to 2.0% neutral sodium fluoride foam (0.9% fluoride ion). The amount of fluoride re-released was measured at Days 1, 7, 14 and 30. RESULTS: An ANOVA indicated a statically significant variance among the groups (P< 0.001). The experimental group demonstrated significantly less fluoride release at Day 1 compared to Day 31 (first day after 2% sodium fluoride application). At Days 7, 14 and 30 there was significantly more fluoride release than Day 7, 14 and 30 after the topical fluoride application (P< 0.001). There was significantly more fluoride release from Vitremer than the experimental material at Days 1 and 7. However, similar release was observed at Days 14 and 30 for Vitremer and experimental material, but not for Z100. Both Vitremer and the experimental material showed significantly more release of fluoride compared to Z100 at all time points. CLINICAL SIGNIFICANCE: This study demonstrates that the new experimental material released fluoride, re-charged and re-released fluoride at a level comparable to Vitremer but more than Z100.

Dentin sialoprotein facilitates dental mesenchymal cell differentiation and dentin formation.

Dentin sialoprotein (DSP) is a dentin extracellular matrix protein. It is involved in dental mesenchymal cell lineages and dentin formation through regulation of its target gene expression. DSP mutations cause dentin genetic diseases. However, mechanisms of DSP in controlling dental mesenchymal cell differentiation are unknown. Using DSP as bait, we screened a protein library from mouse odontoblastic cells and found that DSP is a ligand and binds to cell surface receptor, occludin. Further study identified that the C-terminal DSP domainaa 363-458 interacts with the occludin extracellular loop 2aa 194-241. The C-terminal DSP domain induced phosphorylation of occludin Ser490 and focal adhesion kinase (FAK) Ser722 and Tyr576. Coexpression of DSP, occludin and FAK was detected in dental mesenchymal cells during tooth development. Occludin physically interacts with FAK, and occludin and FAK phosphorylation can be blocked by DSP and occludin antibodies. This DSP domain facilitates dental mesenchymal cell differentiation and mineralization. Furthermore, transplantation and pulp-capping procedures revealed that this DSP domain induces endogenous dental pulp mesenchymal cell proliferation, differentiation and migration, while stimulating blood vessel proliferation. This study elucidates the mechanism of DSP in dental mesenchymal lineages and implies that DSP may serve as a therapeutic agent for dentin-pulp complex regeneration in dental caries.

Dentin Sialoprotein is a Novel Substrate of Matrix Metalloproteinase 9 in vitro and in vivo.

Dentin sialoprotein (DSP) is essential for dentinogenesis and processed into fragments in the odontoblast-like cells and the tooth compartments. Matrix metalloproteinase 9 (MMP9) is expressed in teeth from early embryonic to adult stage. Although MMP9 has been reported to be involved in some physiological and pathological conditions through processing substrates, its role in tooth development and whether DSP is a substrate of MMP9 remain unknown. In this study, the function of MMP9 in the tooth development was examined by observation of Mmp9 knockout (Mmp9-/-) mouse phenotype, and whether DSP is a substrate of MMP9 was explored by in vitro and in vivo experiments. The results showed that Mmp9-/- teeth displayed a phenotype similar to dentinogenesis imperfecta, including decreased dentin mineral density, abnormal dentin architecture, widened predentin and irregular predentin-dentin boundary. The distribution of MMP9 and DSP overlapped in the odontoblasts, the predentin, and the mineralized dentin, and MMP9 was able to specifically bind to DSP. MMP9 highly efficiently cleaved DSP into distinct fragments in vitro, and the deletion of Mmp9 caused improper processing of DSP in natural teeth. Therefore, our findings demonstrate that MMP9 is important for tooth development and DSP is a novel target of MMP9 during dentinogenesis.

Establishment of Immortalized BMP2/4 Double Knock-Out Osteoblastic Cells Is Essential for Study of Osteoblast Growth, Differentiation, and Osteogenesis.

Bone morphogenetic proteins 2 and 4 (BMP2/4) are essential for osteoblast differentiation and osteogenesis. Generation of a BMP2/4 dual knock-out ((ko/ko)) osteoblastic cell line is a valuable asset for studying effects of BMP2/4 on skeletal development. In this study, our goal was to create immortalized mouse deleted BMP2/4 osteoblasts by infecting adenoviruses with Cre recombinase and green fluorescent protein genes into immortalized murine floxed BMP2/4 osteoblasts. Transduced BMP2/4(ko/ko) cells were verified by green immunofluorescence and PCR. BMP2/4(ko/ko) osteoblasts exhibited small size, slow cell proliferation rate and cell growth was arrested in G1 and G2 phases. Expression of bone-relate genes was reduced in the BMP2/4(ko/ko) cells, resulting in delay of cell differentiation and mineralization. Importantly, extracellular matrix remodeling was impaired in the BMP2/4(ko/ko) osteoblasts as reflected by decreased Mmp-2 and Mmp-9 expressions. Cell differentiation and mineralization were rescued by exogenous BMP2 and/or BMP4. Therefore, we for the first time described establishment of an immortalized deleted BMP2/4 osteoblast line useful for study of mechanisms in regulating osteoblast lineages.

Space loss following premature loss of primary second molars.

This study was designed to evaluate the amount of space loss (SL) caused by premature loss of primary second molars, determine whether the eruption status of permanent first molars is an important factor in the amount of SL, and evaluate the effectiveness of space maintainers (SMs) in SL prevention. SL associated with 100 prematurely extracted primary second molars was evaluated in 87 healthy patients. Teeth were divided into groups based on the use of SMs (36 with SM and 64 without SM). Bitewing and periapical radiographs taken before extraction and 6, 12, 24, 36, and 48 months after extraction were used to determine the amount of SL. Not every patient attended every recall appointment, so the sample size varied at different evaluation times. The most significant amount of SL occurred in the first 12 months after extraction. In patients who did not use an SM, at 6 months there was a mean SL of 2.12 mm (SD, 1.65 mm) and at 12 months there was a mean of 4.02 mm (SD, 1.65), with significantly more SL in the first 6 months (P < 0.001). There was no statistically significant difference in the amount of SL found at 12 and 24 months (P > 0.05). When patients without an SM were grouped by the eruption status of the permanent first molar, there was significantly more SL in the groups with unerupted first molars than there was in the groups with erupted first molars at both 6 months (P < 0.001) and 12 months (P < 0.05). At both 6 and 12 months, the amount of SL in patients who had an SM (n = 13 and n = 14, respectively) was not significantly different from the amount of SL in those who did not have an SM (n = 33 and n = 23, respectively). SMs should be placed as soon as possible following tooth extraction to prevent undue SL. Placement of an SM a year or more after extraction has minimal benefit, since most SL takes place within the first year. SL does occur even when SMs are used.

Establishment of Immortalized Mouse Bmp2 Knock-Out Dental Papilla Mesenchymal Cells Necessary for Study of Odontoblastic Differentiation and Odontogenesis.

Bmp2 is essential for dentin formation. Bmp2 cKO mice exhibited similar phenotype to dentinogenesis imperfecta, showing dental pulp exposure, hypomineralized dentin, and delayed odontoblast differentiation. As it is relatively difficult to obtain lot of primary Bmp2 cKO dental papilla mesenchymal cells and to maintain a long-term culture of these primary cells, availability of immortalized deleted Bmp2 dental papilla mesenchymal cells is critical for studying the underlying mechanism of Bmp2 signal in odontogenesis. In this study, our goal was to generate an immortalized deleted Bmp2 dental papilla mesenchymal (iBmp2(ko/ko)dp) cell line by introducing Cre recombinase and green fluorescent protein (GFP) into the immortalized mouse floxed Bmp2 dental papilla mesenchymal (iBmp2(fx/fx)dp) cells. iBmp2(ko/ko)dp cells were confirmed by GFP and PCR. The deleted Bmp2 cells exhibited slow cell proliferation rate and cell growth was arrested in G2 phase. Expression of tooth-related marker genes and cell differentiation were decreased in the deleted cells. Importantly, extracellular matrix remodeling was impaired in the iBmp2(ko/ko)dp cells as reflected by the decreased Mmp-9 expression. In addition, with exogenous Bmp2 induction, these cell differentiation and mineralization were rescued as well as extracellular matrix remodeling was enhanced. Therefore, we for the first time described establishment of iBmp(ko/ko) cells that are useful for study of mechanisms in regulating dental papilla mesenchymal cell lineages.

Dental sealants guidelines development: 2002-2014.

The purpose of this paper was to review the chronology of dental sealant guideline developments and changes in recommendations regarding sealant usage by various state, national, and international organizations between 2002 and 2014. More specific objectives include: (1) review and summarize the findings of systematic evidence-based reviews and recommendations regarding the use of pit and fissure sealants published since the 2002 American Academy of Pediatric Dentistry Pediatric Restorative Dentistry Consensus Conference; (2) identify consistencies and changes in conclusions or recommendations regarding the use of pit and fissure sealants, and differences in the methods used to develop recommendations/guidelines over time; and (3) describe the purpose and scope of current efforts to update American Dental Association 2008 Evidence-based Clinical Recommendations for the Use of Pit and Fissure Sealants. A summary of recommendations based on experts' synthesis of published evidence and recommendations is included.