Allogeneic Bone Marrow Mesenchymal Stromal Cell Transplantation Induces Dentin Pulp Complex-like Formation in Immature Teeth with Pulp Necrosis and Apical Periodontitis.

INTRODUCTION: Dental pulp regeneration is challenging in endodontics. Cellular therapy is an alternative approach to induce dental pulp regeneration. Mesenchymal stromal cells (MSCs) have the capacity to induce dental pulp-like tissue formation. In this study, we evaluated the capacity of allogeneic bone marrow MSCs (BM-MSCs) to regenerate pulp following necrosis and apical periodontitis in children's permanent immature apex teeth. METHODS: Patients aged 8 to 12 years with pulp necrosis and apical periodontitis were evaluated. The study included 15 teeth (13 incisors and 2 molars) from 14 patients (8 boys and 6 girls). Radiographic evaluation showed periapical radiolucency and immature apex teeth. There was no response to cold or electric pulp testing. The root canal of each tooth was cleaned, shaped, and Ca(OH)2 used as an interappointment medication. Cryopreserved allogeneic BM-MSCs were thawed, expanded, incorporated into preclotted platelet-rich plasma, and implanted into the tooth's pulp cavity. They were sealed with bioceramic cement and composite. Sensibility, apical foramen, calcium deposits within the root canal, and resolution of periapical lesions were evaluated in each tooth over the following 12 months. RESULTS: Based on 9 variables established for dental pulp-like tissue regeneration, all MSC-treated teeth showed evidence of successful regeneration. Clinical and radiographic evaluation of the treated teeth showed periapical lesion healing, sensitivity to cold and electricity, decreased width of the apical foramen, and mineralization within the canal space. CONCLUSIONS: Transplantation of allogeneic MSCs induces the formation of dental pulp-like tissue in permanent immature apex teeth with pulp necrosis and apical periodontitis. Implant of MSCs constitutes a potential therapy in regenerative endodontics in pediatric dentistry. Future studies incorporating a larger sample size may confirm these results.

Evaluation of a new 3D-printed tooth model allowing preoperative ICDAS assessment and caries removal.

INTRODUCTION: Teaching caries lesion management with operative care requires tooth models with highly realistic anatomical detail and caries lesions that can be assessed using ICDAS. This study aimed to develop and evaluate a new 3D-printed teeth model for ICDAS assessment and caries removal for pre-clinical hands-on education. METHODS: Printable tooth with different layers for enamel, dentin and carious lesions was designed and tested by 31 dental students. They were asked to visually and radiologically assess the ICDAS severity of the simulated carious lesions, establish the therapeutic strategy according to CariesCare 4D, and perform a qualitative assessment of the models based on five-point Likert scale items. RESULTS: Concerning carious lesions, the texture was realistic, and the shade was adequate for 94% and 97% of the participants. Ninety per cent of the participants found the model adequate to perform an ICDAS visual assessment. Seventy-four per cent of the students found the hardness adequate. Concerning the difference in shade and the noticeable hardness difference between enamel and dentin, participants have mixed agreement with a proportion of 61% and 55%, respectively. All the participants agreed these 3D-printed models provide a good caries simulation, are suitable for hands-on operative dentistry courses, and that learning outcomes better than the standard model. CONCLUSION: The present work shows that rapid prototyping paves the way for customized educational models capable of supporting operative but also preoperative skills. 3D printing opens up new opportunities by reducing the gap between pre-clinical training and clinical reality in caries management, which can positively impact the quality of patient care.

The impact of pediatric congenital heart disease on primary teeth structure: a histological study.

Congenital heart disease (CHD) is an abnormality in the structure or function of the cardio-circulatory system present at birth and the ventricular septal defect (VSD) is the most common CHD in children. This study aimed to determine any differences in the histological structure of primary teeth between both healthy children and those children with ventricular septal defects in Erbil City. Methods enrolled children were divided into two groups. Group I (control) & group II (CHD) aged between 6-10 years old. A total of 44 children were collected, (22 children) in each group. Enamel, dentin, and odontoblast layers were examined histologically. Unpaired t-test used for statistical analysis. Results: The histopathological sections showed a significant difference in enamel, dentin, and odontoblast layer thickness (255.8 ± 41.68- 406.4 ±46.39), (1156 ± 116.0 - 1320 ± 117.4) and (29.74 ± 7.66 -41.38 ± 12.06) respectively, with p values (P < 0.0001) for enamel and dentin layer, and P < 0.0004  for odontoblast layer. A study of the images in the CHD group showed that the tooth tissue lost its integrity and cohesion in some places, and the thickness of the enamel and dentin layer in this group was significantly reduced compared to group I.  Tissue loss in enamel, pulp, and dentin cell were observed. Also, connective tissue layers in the pulp were disrupted. Conclusions: CHD can alter the natural structure formation of primary teeth. Histologically, enamel, dentin, and odontoblasts layer thickness reduction are found in primary teeth in children with ventricular septal defects.

Influence of the Salivary Acquired Pellicle on the Inhibition/Progression of In Vitro Carious Dentin Treated with Silver Diamine Fluoride.

Purpose: To evaluate, in vitro, whether the presence of the acquired pellicle (AP) interferes with the effect of 38 percent silver diamine fluoride (SDF) on the inhibition or progression of carious dentin. Methods: Carious dentin specimens were divided into groups: C-no treatment control; FV-fluoride varnish; AP-acquired pellicle formation; SDF only, and APSDF-SDF plus acquired pellicle formation. After AP formation (AP and APSDF groups), all groups were subjected to pH cycling. Dentin mineral gain or loss was quantified using surface microhardness (SM). Concentrations of fluoride calcium (CaF2) and fluorapatite (FAp) fluoride retained in dentin and fluoride concentrations in de- and remineralizing solutions were determined. Results: Groups AP, FV, SDF, and APSDF showed reduced demineralization compared with the C group, but the AP group showed greater surface loss than the fluoridated groups. Groups FV, SDF, and APSDF showed greater mineral recovery than C and AP groups (P<0.05), but no differences were observed between the FV, SDF, and APSDF groups (P>0.05). The retained CaF2 and FAp were greater in the groups treated with fluoride, but there was no difference between the SDF and APSDF groups. Conclusion: The presence of the acquired pellicle reduced the progression of carious dentin lesion but did not influence its remineralization when associated with silver diamine fluoride.

Presence of host and bacterial-derived collagenolytic proteases in carious dentin: a systematic review of ex vivo studies.

Introduction and aim: The presence of host collagenases in the degradation of the protein matrix at later stages of carious dentin lesions development, as well as the potential involvement of bacterial collagenases, have been suggested but lack conclusive evidence. This study aims to conduct a systematic review to comprehensively assess the profile of host and bacterial-derived collagenolytic proteases in both root and coronal dentin carious lesions. Methods: The search was performed in eight databases and the grey literature. Studies evaluating ex vivo dentin, extracted teeth, or biofilms from natural caries lesions were included. The methodological quality of studies was assessed using the Joanna Briggs Institute tool. Synthesis of the results and the certainty of evidence were performed following the Synthesis without Meta-analysis (SWiM) checklist and GRADE approach for narrative synthesis, respectively. Results: From 935 recovered articles, 18 were included. Although the evidence was very uncertain, it was possible to suggest that 1) MMP-2, MMP-9, MMP-13, and CT-B may be increased in carious dentin when compared to sound dentin; 2) there is no difference in MMP-2 presence, while MMP-13 may be increased in root when compared to coronal carious dentin; 3) there is no difference of MMP-2 and MMP-9 expression/activity before and after cavity sealing; 4) MMP-8 may be increased in the dentin before cavity sealing compared to dentin after cavity sealing; 5) there is no difference of MMP-20 in irradiated vs. non-irradiated carious dentin. MMP-20 probably reduces in carious outer dentin when compared to carious inner dentin (moderate certainty). Genes encoding bacterial collagenolytic proteases and protein-degrading bacteria were detected in coronal and root carious lesions. Conclusion: Trends in the direction of the effect were observed for some collagenolytic proteases in carious dentin, which may represent a potential target for the development of new treatments. (Protocol register-PROSPERO: CRD42020213141).

Subjective versus objective, polymer bur-based selective carious tissue removal: 2-year randomized clinical trial.

OBJECTIVES: We aimed to compare subjective (S) selective carious tissue removal using hand instruments versus objective (O) removal using a self-limiting polymer bur in a single-blind cluster-randomized controlled superiority trial. METHODS: 115 children (aged 7-8 years) with ≥1 vital primary molar with a deep dentin lesion (>1/2 dentin depth) were included and randomized (60 S/55 O); all eligible molars in a child were treated identically (91 S/86 O). Cavities were prepared and carious tissue on pulpal walls selectively removed using hand instruments (S) or a self-limiting polymer bur (Polybur P1, Komet), followed by restoration using a glass hybrid material (Equia Forte, GC). Treatment time and satisfaction data have been reported in a 1-year-interim report. We here report on 2 year survival (tooth retained with or without further retreatments being needed, or tooth exfoliated), analyzed using multi-level Cox-regression analysis, as well as success (ART criteria 0/1, no pulpal complications, no re-intervention needed, or tooth extraction). RESULTS: 71 restorations in S and 65 in O were examined after a mean (SD, range) of 22 (11; 3-31) months, of which 50 S and 48 O restorations were successful and 70 S and 65 O survived. The majority of failures were restorative, not pulpal, and distribution of ART codes was not significant different between groups. Risk of failure was not significantly associated with the removal protocol (HR; 95 % CI: 0.95; 0.51-1.78), and also not age, sex or dental arch, while single surfaced restorations showed significantly lower hazard (0.14; 0.06-0.37). CONCLUSION: There was no significant difference in success or survival between objective and subjective carious tissue removal. CLINICAL SIGNIFICANCE: In primary teeth, subjective selective excavation had no disadvantage compared with objective excavation, which required a separate instrument (polymer-based bur) for carious tissue removal. Polymer-based burs may be particularly useful when standardized excavation is needed.

Genome-wide association study identifies novel caries-associated loci showing sex-specificity-A study on the Northern Finland Birth Cohort 1966.

A genome-wide association study was performed in sex-stratified groups representing three different caries phenotypes among adults. The study sample consisted of 46-year-old participants of the Northern Finland Birth Cohort 1966 study (n = 1481). The phenotypes for analyses were the dentin caries phenotype (persons having at least one tooth with dentin caries lesion), and the enamel caries phenotype (those having teeth with more than 10 enamel caries lesions), while the control group had <10 enamel caries lesions and no teeth with dentin caries, respectively. A third phenotype dubbed the caries severity phenotype had a below-average number of teeth with initial lesions and at least one extensive dentin caries lesion; their controls had an above-average number of teeth with initial caries lesions and no teeth with extensive dentin caries lesions. All analyses were performed for the whole group and for sex-stratified subgroups. In females, loci in chromosomes 2, 5, and 15 showed a statistically significant association with caries severity. In males, there was a novel association between chromosome 5 and dentin caries. The results of this study may suggest a genetic background of caries among adults. In the future, the detection of genetic predisposing variants may allow the identification of patients at risk for caries, even in the absence of behavioral and environmental risk factors.

[Recognition on dentin dysplasia type â ¡].

Dentin dysplasia type Ⅱ (DD-Ⅱ) is a subtype of hereditary dentin disorders. The dentin sialophosphoprotein (DSPP) gene has been revealed to be the causative gene, whose mutations could affect the normal tooth development process. The lesions involve both deciduous and permanent dentition, mainly manifested as tooth discoloration, attrition and even the subsequent malocclusion. If not treated in time, it will significantly affect the physical and psychological health of patients. The disease is difficult to be diagnosed in clinic accurately as its low incidence and hidden manifestations. The present article aims to discuss the clinical and radiographic characteristics, diagnosis, treatment of DD-Ⅱ, in order to improve the overall understanding on DD-Ⅱ for clinicians.

Underlying Dentin Shadows (ICDAS 4) in Occlusal Surface of Permanent Teeth Have Low Progression Rate after 1-2 Years.

The aim of this prospective cohort study was to assess the radiographic progression of underlying dentin shadows (UDS) on the occlusal surfaces of permanent posterior teeth of adolescents and young adults over 1-2 years and to identify possible risk factors. A total of 149 UDS lesions (from 101 individuals) were included at baseline. Each participant had to present at least one UDS to be considered eligible for the study. Data collection included the application of a questionnaire, clinical examination, and bilateral bitewing radiographs, performed at baseline and after 1-2 years. The association between possible predictors and UDS progression (defined radiographically as an increase in the radiographic score from baseline to follow-up) was assessed using Weibull regression models. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were estimated. A total of 81 individuals (mean age: 24.0, standard deviation: 8.03) were reexamined after 1-2 years (742 occlusal surfaces, of which 118 were UDS). The overall progression rate was 8.6% after 1-2 years, being 12.6% for UDS without baseline radiolucency and 20% for UDS with baseline radiolucency. The risk analysis showed that UDS without radiolucency at baseline had a similar likelihood of progression (adjusted HR = 1.71, 95% CI = 0.68-4.32, p = 0.26) while UDS with radiolucency at baseline were more likely to progress (adjusted HR = 2.96, 95% CI = 1.06-8.26, p = 0.04) than the reference category (sound occlusal surfaces without radiolucency). These estimates were adjusted for caries prevalence, tooth type, and arch. This study showed low progression rates of UDS after 1-2 years. The presence of radiolucency at baseline was found to predict UDS progression.

Iron level participates in the pathological damages of dental caries in infant rats by affecting enamel mineralization.

Iron deficiency anemia (IDA) is a common nutritional disease associated with early childhood caries. This study aimed to explore the role of iron levels in pathological changes of dental caries in childhood. Rats were divided into four groups based on their iron content: IDA, positive control (PC), high iron (HI), and negative control (NC). Except for the rats in the NC group, rats in the other groups were inoculated with Streptococcus mutans and fed cariogenic high-sugar fodder to induce caries. Three months later, the caries status of the molars was evaluated at both the smooth and sulcal surfaces according to Keyes scores. Scanning electron microscopy (SEM) was performed to reveal microstructural changes in caries. Energy-dispersive spectroscopy (EDS) was used to determine the elemental composition of the enamel and dentin. In addition, the histopathology of the salivary gland was detected using hematoxylin and eosin (HE) staining.The results showed that rats in the PC group exhibited obvious carious lesions. The carious score was significantly higher in the IDA group than in the PC group but was lower in the HI group. SEM revealed complete destruction of the enamel and damage to the middle dentin in the IDA group. In contrast, the molars in the HI group exhibited some degree of enamel demineralization, but the underlying dentin was almost intact. In addition, the elemental compositions of the enamel and dentin were similar among the four groups, and iron was detected only in the HI group. No differences were observed in the morphological structures of the salivary glands of rats from the different groups. In conclusion, ID enhanced the pathological damage of caries, whereas HI weakened it. Iron may participate in the pathological damage caused by childhood caries by affecting enamel mineralization.

Chapter 3: Pathological Features of Coronal Caries.

Pathology is the science of how a tissue changes during the process of the disease. The pathology is of important knowledge for understanding subsequent treatment concepts of a disease. In the cariology field, pathological features of caries are often presented using tooth sections, whereby the sequence and spread can be monitored. It is optimal to describe such changes using thin undecalcified tooth sections as an overview can be given of both enamel demineralization and pulp-dentine reactions. Also, an optimal understanding is achieved if the clinical status of carious lesion activity is known. Different studies using human teeth have shown the principle changes in progressive stages of carious lesions; the growth of the enamel lesion reflects the growth condition of the cariogenic biofilm. Surprisingly, the pulp (the odontoblast) is aware of the cariogenic stimuli even before mineral alteration has taken place within the dentine. The microorganisms mainly invade the dentine during enamel cavitation. In this chapter, the current improvement of knowledge on advanced carious lesions has been assessed in detail both histologically and radiographically. From a radiographic point of view, well-defined deep and extremely deep carious lesions and their difference are presented. Recent advances in artificial intelligence (AI) in medicine have raised the possibility of increasing the accuracy and speed of histopathological examination techniques. However, the literature involving AI-based histopathological features of hard and soft dentinal tissue pathologic changes is still scarce.

Chapter 9.3: Current Concepts of Caries Removal in Daily Practice.

Although the discussion about the amount of carious dentin to be removed during cavity preparation is quite old, concepts for caries removal have evolved and changed considerably over the last decades. The antiquate understanding that it was necessary to eliminate the microbial contamination of a cavity before placing the restoration was replaced by the current knowledge that maintaining contaminated dentin beneath restorations is inevitable and is not associated with treatment failure. This chapter brings together the body of evidence behind carious dentin removal to indicate a conservative treatment, aiming to preserve both tooth vitality and structure. Studies that evaluated the effects of sealing contaminated dentin are described, which are focused on different outcomes, such as microbiological counts, clinical characteristics, laboratory analysis, and radiographic findings. Long-term studies and randomized clinical trials also support the current recommendations. After addressing the available literature on this topic, this chapter concludes that (1) the amount of carious dentin to be removed should be defined by lesion depth; (2) sealing and/or selective caries removal to firm dentin is recommended for the management of shallow and moderate lesions; (3) the selective caries removal to soft dentin in a single session is indicated for deep caries lesions aiming to preserve tooth vitality; and (4) the use of a cavity liner after selective caries removal seems to be an unnecessary clinical step.

Gaze patterns of dentists while evaluating bitewing radiographs.

OBJECTIVES: Understanding dentists' gaze patterns on radiographs may allow to unravel sources of their limited accuracy and develop strategies to mitigate them. We conducted an eye tracking experiment to characterize dentists' scanpaths and thus their gaze patterns when assessing bitewing radiographs to detect primary proximal carious lesions. METHODS: 22 dentists assessed a median of nine bitewing images each, resulting in 170 datasets after excluding data with poor quality of gaze recording. Fixation was defined as an area of attentional focus related to visual stimuli. We calculated time to first fixation, fixation count, average fixation duration, and fixation frequency. Analyses were performed for the entire image and stratified by (1) presence of carious lesions and/or restorations and (2) lesion depth (E1/2: outer/inner enamel; D1-3: outer-inner third of dentin). We also examined the transitional nature of the dentists' gaze. RESULTS: Dentists had more fixations on teeth with lesions and/or restorations (median=138 [interquartile range=87, 204]) than teeth without them (32 [15, 66]), p<0.001. Notably, teeth with lesions had longer fixation durations (407 milliseconds [242, 591]) than those with restorations (289 milliseconds [216, 337]), p<0.001. Time to first fixation was longer for teeth with E1 lesions (17,128 milliseconds [8813, 21,540]) than lesions of other depths (p = 0.049). The highest number of fixations were on teeth with D2 lesions (43 [20, 51]) and lowest on teeth with E1 lesions (5 [1, 37]), p<0.001. Generally, a systematic tooth-by-tooth gaze pattern was observed. CONCLUSIONS: As hypothesized, while visually inspecting bitewing radiographic images, dentists employed a heightened focus on certain image features/areas, relevant to the assigned task. Also, they generally examined the entire image in a systematic tooth-by-tooth pattern.

Axin2-CreERT2 mediated knockout of bone morphogenetic protein receptor type 1A caused abnormal secondary dentine and altered cell fate of Axin2-expressing odontogenic cells.

AIM: Inducing odontogenic differentiation and tubular dentine formation is extremely important in dentine repair and tooth regeneration. Bone morphogenic proteins (BMPs) signalling plays a critical role in dentine development and tertiary dentine formation, whilst how BMPR1A-mediated signalling affects odontoblastic differentiation of Axin2-expressing (Axin2+ ) odontogenic cells and tubular dentine formation remains largely unknown. This study aims to reveal the cellular and molecular mechanisms involved in the formation of secondary dentine. METHODOLOGY: Axin2lacZ/+ mice harvested at post-natal 21 (P21) were used to map Axin2+ mesenchymal cells. Axin2CreERT2/+ ; R26RtdTomato/+ mice and Axin2CreERT2/+ ; R26RDTA/+ ; R26RtdTomato/+ mice were generated to observe the tempo-spatial distribution pattern of Axin2-lineage cells and the effect of ablation of Axin2+ cells on dentinogenesis, respectively. A loss-of-function model was established with Axin2CreERT2/+ ; Bmpr1afl/fl ; R26RtdTomato/+ (cKO) mice to study the role of BMP signalling in regulating Axin2+ cells. Micro-computed tomography, histologic and immunostainings, and other approaches were used to examine biological functions, including dentine formation, mineralization and cell differentiation in cKO mice. RESULTS: The results showed rich expression of Axin2 in odontoblasts at P21. Lineage tracing assay confirmed the wide distribution of Axin2 lineage cells in odontoblast layer and dental pulp during secondary dentine formation (P23 to P56), suggesting that Axin2+ cells are important cell source of primary odontoblasts. Ablation of Axin2+ cells (DTA mice) significantly impaired secondary dentine formation characterized with notably reduced dentine thickness (Mean of control: 54.11 µm, Mean of DTA: 27.79 µm, p = .0101). Furthermore, malformed osteo-dentine replaced the tubular secondary dentine in the absence of Bmpr1a with irregular cell morphology, abnormal cellular process formation and lack of cell-cell tight conjunction. Remarkably increased expression of osteogenic markers like Runx2 and DMP1 was detected, whilst DSP expression was observed in a dispersed manner, indicating an impaired odontogenic cell fate and failure in producing tubular dentine in cKO mice. CONCLUSIONS: Axin2+ cells are a critical population of primary odontoblasts which contribute to tubular secondary dentine formation, and BMP signalling pathway plays a vital role in maintaining the odontogenic fate of Axin2+ cells.

Evaluation of the remineralization and antibacterial effect of natural versus synthetic materials on deep carious dentin: A randomized controlled trial.

BACKGROUND: A variety of natural and synthetic agents have recently been used in clinical trials to arrest dentin caries. OBJECTIVES: The aim of the present study was to explore the remineralization and antibacterial effect of natural (propolis, hesperidin) vs. synthetic (silver diamine fluoride (SDF)) agents on deep carious dentin. MATERIAL AND METHODS: A total of 64 human molar teeth with Class I caries were randomly distributed into 4 groups: control group; propolis group; hesperidin group; and SDF group. The cavities were prepared using the stepwise caries removal technique, and then covered with the materials to be tested. The samples were taken from the carious lesions before and after treatment to evaluate the antibacterial effect. Then, the teeth were restored with a glass ionomer cement (GIC). Digital X-rays were taken to assess remineralization and the antibacterial effect after 6 and 12 weeks. RESULTS: The highest value of radiodensity was observed in the propolis group (46.44 ±9.65 HU), while the lowest value was noted in the hesperidin group (12.62 ±5.86 HU). The bacterial count in the propolis group was 1,280.00 ±1,480.54 CFU/mL at baseline, which was not significantly higher than the value measured after 6 weeks (574.00 ±642.48 CFU/mL; p = 0.153), whereas in the hesperidin group, the mean value of the bacterial count at baseline (3,166.67 ±1,940.79) was not much higher as compared to the value obtained at 6 weeks (2,983.33 ±1,705.77) (p = 0.150). CONCLUSIONS: In comparison with SDF, propolis and hesperidin agents showed promising effects in terms of remineralization of carious dental tissue and hindering the progression of caries.

Identification of DSPP novel variants and phenotype analysis in dentinogenesis dysplasia Shields type II patients.

OBJECTIVES: To investigate the genetic causes and teeth characteristics of dentin dysplasia Shields type II(DD-II) in three Chinese families. MATERIALS AND METHODS: Data from three Chinese families affected with DD-II were collected. Whole-exome sequencing (WES) and whole-genome sequencing (WGS) were conducted to screen for variations, and Sanger sequencing was used to verify mutation sites. The physical and chemical characteristics of the affected teeth including tooth structure, hardness, mineral content, and ultrastructure were investigated. RESULTS: A novel frameshift deletion mutation c.1871_1874del(p.Ser624fs) in DSPP was found in families A and B, while no pathogenic mutation was found in family C. The affected teeth's pulp cavities were obliterated, and the root canals were smaller than normal teeth and irregularly distributed comprising a network. The patients' teeth also had reduced dentin hardness and highly irregular dentinal tubules. The Mg content of the teeth was significantly lower than that of the controls, but the Na content was obviously higher than that of the controls. CONCLUSIONS: A novel frameshift deletion mutation, c.1871_1874del (p.Ser624fs), in the DPP region of the DSPP gene causes DD-II. The DD-II teeth demonstrated compromised mechanical properties and changed ultrastructure, suggesting an impaired function of DPP. Our findings expand the mutational spectrum of the DSPP gene and strengthen the understanding of clinical phenotypes related to the frameshift deletion in the DPP region of the DSPP gene. CLINICAL RELEVANCE: A DSPP mutation can alter the characteristics of the affected teeth, including tooth structure, hardness, mineral content, and ultrastructure.

Three-Dimensional Assessment of Radiographic Changes after Indirect Pulp Capping Using Silver Diamine Fluoride with or without Potassium Iodide in Young Permanent Teeth (12-Month RCT).

The aim of this study was to conduct a three-dimensional (3D) evaluation of radiographic changes after indirect pulp capping (IPC) with silver diamine fluoride (SDF) with or without potassium iodide (KI) and resin-modified glass ionomer cement (RMGIC) in deep carious young permanent molars using cone-beam computed tomography (CBCT). 108 first permanent molars with deep occlusal cavitated caries lesions, in forty-nine 6- to 9-year-old children, were randomly allocated to one of 3 groups (n = 36) and treated with SDF+KI, SDF, and RMGIC as IPC materials. CBCT scans were taken at 0 and 12 months to assess tertiary dentin formation (volume and grey level intensity), increase in root length, and pathological changes such as secondary caries, periapical radiolucency, internal resorption, and obliteration of the pulp. The 3D image analysis procedures were performed using ITK-SNAP and 3D Slicer CMF. Comparisons were made using analysis of variance with a fixed effect for treatment and random effects for patient and patient-by-treatment to account for within-patient correlations. A two-sided 5% significance level was used. There were no significant differences among the three groups regarding tertiary dentin volume (p = 0.712) and grey level intensity (p = 0.660), increase in root length (p = 0.365), prevention of secondary caries (p = 0.63), and periapical radiolucency (p = 0.80) in the analysed 69 CBCT scans. The study did not find differences among the groups regarding quality and quantity of tertiary dentin formed, increase in root length, absence of secondary caries, and other signs of failure as shown by CBCT. Clinical Significance: The results show no significant differences in radiographic outcomes (quality and quantity of tertiary dentin formed, increase in root length, absence of secondary caries, and other signs of failure) when using SDF+KI, SDF, and RMGIC in IPC. The results of this study can help guide treatment decision-making regarding use of SDF and SDF+KI as IPC materials in deep cavitated lesions.

Time-dependent structural changes and hypermineralisation of artificially demineralised dentine following treatment with silver diammine fluoride and glass ionomer cement.

OBJECTIVES: This study aimed to evaluate the change of mineral content in dentine lesions over time and examine the effectiveness of the combined treatment with silver diammine fluoride (SDF) and glass ionomer cement (GIC). METHODS: Sixty bovine dentine specimens were divided into 4 groups: cont, Fuji, Safo, and Safo+Fuji. The specimens were imaged and measured using microcomputed tomography (microCT) at 7 time points: pre-demineralisation, after demineralisation for two weeks, immediately after treatment, 1 week, 2 weeks, 1 month, and 3 months after treatment. The 3-month group was evaluated with a light microscope, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and scanning electron microscope (SEM)/energy-dispersive X-ray spectroscopy (EDS). Data were analysed by Dunn's test and Wilcoxon signed rank test with Bonferroni correction for microCT, and Kruskal-Wallis test and two-way analysis of variance for EDS characterisation. RESULTS: MicroCT images showed high mineral density beneath dentine lesions in Safo+Fuji. The mineral density at 600 µm in Safo+Fuji increased significantly over time, while Safo showed an opposite trend (adjusted p<0.005). In Safo+Fuji, EDS revealed significantly high energy of fluorine (p<0.05, at 300 µm) and a tendency towards high energy of calcium (p>0.05). However, Safo+Fuji showed lower energy of silver compared to Safo (p<0.001). ATR-FTIR revealed that phosphate groups had the highest peak at a depth between 300 and 400 µm in Safo+Fuji. CONCLUSIONS: Safo+Fuji was effective in remineralising the deep lesion in dentine after one and three months, and a hypermineralisation zone generated beneath the lesion demonstrated additional benefit in this study. CLINICAL SIGNIFICANCE: This long-term in vitro study showed that SDF+GIC treatment could strengthen the structure of decayed teeth when applied in the treatment of patients with advanced rampant caries.

Minimally invasive selective caries removal: a clinical guide.

An evolving understanding of the carious process, along with new research in adhesive restorative materials, has led to a more conservative, minimally invasive and biologically-based approach to managing dental carious lesions. The growing volume of literature has also demonstrated prognostic success in the selective caries excavation technique, subsequently preventing excessive tooth structure removal and injury to the dentine-pulp complex, which maintains pulp vitality and improves the long-term prognosis of the tooth. However, at present, there remains a limited volume of high-quality evidence to support selective caries removal, which subsequently could partly explain some resistance to its use in clinical practice. This clinical technique guide aims to demonstrate the management of carious lesions of moderate-to-deep depth in permanent teeth based on current minimally invasive dental literature.

Dentine Mineral Changes Induced by Polyalkenoate Cements after Different Selective Caries Removal Techniques: An in vitro Study.

This study aimed at evaluating the mineral variation induced by polyalkenoate cements in residual dentine after different caries removal methods. Ten extracted sound molars were selected, and five cavities were prepared on the occlusal surface of each specimen. Carious lesions were generated using a microbial protocol, while the caries removal was performed using bur, hand excavator, or two papain-based chemo-mechanical agents. One cavity was left unexcavated in each tooth. Cavities were restored using a zinc polycarboxylate cement (ZPC; n = 25), or a glass ionomer cement (GIC) was used (n = 25). Subsequently, the specimens were stored under simulated pulpal pressure for 45 days. Micro-CT scanning was performed after caries formation, removal, and restoration. Cavity volumes (mm3) and mineral density (MD) changes were calculated. Remineralisation ability was investigated by scanning electron microscopy (SEM) and Fourier-transformed infrared spectroscopy (FTIR). Statistical analysis was performed (5% significance level). Baseline caries, cavity volume, and MD increase after caries removal were similar to all excavation groups (p > 0.05). MD was higher in ZPC compared to GIC (p < 0.05). SEM revealed that the chemo-mechanical techniques produced a smoother dentine surface compared to mechanical methods. FTIR showed silicon-based minerals in GIC-treated dentine, while ZPC-treated presented mineral deposits characterised by amorphous calcium phosphate. In both cases, the presence of carbonates was detected on dentine surfaces. All caries removal techniques performed similarly in terms of carious dentine excavation. ZPC can be used as dentine replacement material after caries removal as it may induce higher MD increase in residual dentine via deposition of calcium phosphates, compared to GIC.