Clinical SWIR and CP-OCT imaging of interproximal lesions.

BACKGROUND: Enamel is highly transparent at short wavelength infrared imaging (SWIR) wavelengths allowing the detection of dental decay without the need for ionizing radiation. The purpose of this study was to use SWIR imaging methods including cross polarization optical coherence tomography (CP-OCT), occlusal transillumination (SWIR-OT), proximal transillumination (SWIR-PT), and occlusal reflectance (SWIR-R) to image interproximal lesions in vivo and compare the sensitivity with radiography. METHODS: Participants (n = 30) aged 18-80 each with a radiopositive interproximal lesion scheduled for restoration were enrolled in the study. Studies have shown that the opposing proximal surfaces across the contact will likely also have lesions. SWIR images were acquired of the adjoining teeth at each contact with an interproximal lesion scheduled for restoration. Lesion presence and depth were assessed on each side of the contact for radiography and each SWIR imaging method. Lesions on radiographs and in CP-OCT images were identified by a single examiner while lesions in SWIR images were identified by a contrast threshold via semi-automatic image segmentation. RESULTS: All SWIR imaging methods had significantly higher sensitivity (P < 0.05) than radiographs for the detection of interproximal lesions on the teeth opposite those restored. CP-OCT and SWIR-R imaging methods had significantly higher sensitivity than the other methods. SWIR imaging methods showed significantly higher lesion contrast than radiography. CONCLUSIONS: SWIR imaging methods can be used to detect interproximal lesions on posterior teeth with higher diagnostic performance than radiographs. CP-OCT appears well suited as a potential gold standard for the detection of interproximal lesions and assessment of their severity in vivo.

Visualization of etching cycles efficacy at the resin infiltration into artificial enamel caries: in-vitro study on bovine teeth.

This study evaluated the effect of repeated etching cycles on resin infiltrant penetration. Enamel samples measuring 4 × 4 × 3 mm3 were obtained from the facial aspect of 50 extracted bovine teeth. Samples were immersed in a demineralization solution for 21 days to create artificial lesions and divided into five equal groups (n = 10). A 15% hydrochloric acid gel was administered to each group. The acid etching application time differed between groups: Group 1; 2 min, Group 2; 2 × 2 min, Group 3; 3 × 2 min, Group 4; 4 × 2 min, and Group 5; 5 × 2 min. Resin infiltration was visualized using a confocal laser scanning microscopy. The lesion, penetration and erosion depth (µm) were calculated, and data were statistically analyzed. The highest penetration depth (75.59 ± 9.42 µm) was seen in Group 5, followed by Groups 4, 3, 2 and 1. However, there were no statistically significant differences in the penetration depths between Groups 4 and 5 and between Groups 2, 3 and 4 (p > 0.05). In conclusion, a repeated etching cycle enhanced resin infiltrant penetration.

Dental student application of artificial intelligence technology in detecting proximal caries lesions.

OBJECTIVES: This study aimed to investigate the caries diagnosis performances of dental students after training with an artificial intelligence (AI) application utilizing deep learning techniques, a type of artificial neural network. METHODS: A total of 1200 bitewing radiographs were obtained from the institution's database and two specialist dentists labeled the caries lesions in the images. Randomly selected 1000 images were used for training purposes and the remaining 200 radiographs were used to evaluate the caries diagnostic performance of the AI. Then, a convolutional neural network, a deep learning algorithm commonly employed to analyze visual imagery problems, called "You Only Look Once," was modified and trained to detect enamel and dentin caries lesions in the radiographs. Forty dental students were selected voluntarily and randomly divided into two groups. The pre-test results of dental caries diagnosis performances of both groups were recorded. After 1 week, group 2 students were trained using an AI application. Then, the post-test results of both groups were recorded. The labeling duration of the students was also measured and analyzed. RESULTS: When both groups' pre-test and post-test results were evaluated, a statistically significant improvement was found for all parameters examined except precision score (p < 0.05). However, the trained group's accuracy, sensitivity, specificity, and F1 scores were significantly higher than the non-trained group in terms of post-test scores (p < 0.05). In group 2 (trained group), the post-test labeling time was considerably increased (p < 0.05). CONCLUSIONS: The students trained by AI showed promising results in detecting caries lesions. The use of AI can also contribute to the clinical education of dental students.

The effect of combined use of resin infiltration with different bioactive calcium phosphate-based approaches on enamel white spot lesions: An in vitro study.

OBJECTIVES: This in vitro study aimed to evaluate the effect of resin infiltration combined with casein phosphopeptide-amorphous calcium phosphate with fluoride (CPP-ACPF) or bioactive glass (BAG) on the stability of enamel white spot lesions (WSLs) treatment. MATERIALS AND METHODS: Eighty-four enamel blocks were prepared from the buccal surfaces of sound human premolars. All enamel blocks were placed in a demineralisation solution for 3 days to establish the artificial enamel WSLs. Enamel blocks with WSLs were randomly divided into three groups (n = 28 each group): RI/B: one-off resin infiltration followed by twice daily BAG treatment; RI/C: one-off resin infiltration followed by twice daily CPP-ACPF treatment; RI: one-off resin infiltration treatment only (as control) and subjected to pH cycling for 7 days. Surface morphology, elemental analysis, crystal characteristics, surface roughness and microhardness of enamel surfaces were investigated by scanning electron microscopy and energy-dispersive spectrometry observation, X-ray diffraction (XRD), atomic force microscope and Vickers' hardness testing, respectively. RESULTS: Mean values of the surface roughness (mean±standard deviation (nm)) were 24.52±5.07, 27.39±5.87 and 34.36±4.55 for groups RI/B, RI/C and RI respectively (p = 0.003). The calcium to phosphate ratios were 1.32±0.16, 1.22±0.26 and 0.69±0.24 for groups RI/B, RI/C and RI respectively (p < 0.001). XRD revealed apatite formation in all three groups. The mean enamel surface microhardness (kg/mm2) of the groups were 353.93±28.49, 339.00±27.32 and 330.38±22.55 for groups RI/B, RI/C and RI respectively (p = 0.216). CONCLUSIONS: Resin infiltration combined with CPP-ACPF or BAG remineralisation appears to improve the surface properties of WSLs. CLINICAL SIGNIFICANCE: The combination of resin infiltration and CPP-ACPF/BAG remineralisation may be a potential treatment for the management of the WSLs.

Remineralisation of enamel and dentine with stabilised stannous fluoride dentifrices in a randomised cross-over in situ trial.

OBJECTIVES: To compare the remineralisation efficacy and ion bioavailability of two novel SnF2-containing dentifrices in a blinded, cross-over, randomised in situ clinical study. METHODS: Six participants wore removal palatal appliances holding human enamel and dentine blocks with subsurface lesions. Appliances were worn for two treatment periods of 14 consecutive days each, with a one-week washout period in-between. Participants were randomly allocated to rinse with a 1:5 diluted coded slurry of one of two dentifrices containing either 5 % casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) +1100 ppm F as SnF2 [MIPOP], or 1100 ppm F as SnF2 [CT], for 1 min, four times a day. Saliva was collected post-treatment and analysed for tin, calcium, inorganic phosphate and fluoride ions using atomic absorption spectrophotometry and ion chromatography. Enamel and dentine lesions were analysed for percent remineralisation (%R) using transverse microradiography and percent surface microhardness recovery (%SMHR). RESULTS: MIPOP released significantly higher F (3.00 ± 0.27 mM), Ca (15.23 ± 3.23 mM) and Sn (1.18 ± 0.13 mM) into saliva whereas CT released 2.89 ± 0.32 mM F and only 0.84 ± 0.11 mM Ca and 0.28 ± 0.10 mM Sn. MIPOP produced significantly higher %R than CT: 25.6 ± 1.5 % compared to 15.2 ± 0.7 % in enamel, and 33.6 ± 3.1 % compared to 20.6 ± 1.1 % in dentine. Additionally, MIPOP produced significantly higher %SMHR (18.2 ± 7.9 %) compared to CT (4.1 ± 0.6 %). CONCLUSIONS: Both dentifrices promoted remineralisation, but the MIPOP dentifrice with added CPP-ACP and the ion-stabilising effects of CPP released higher amounts of bioavailable tin and produced significantly higher remineralisation and surface microhardness recovery. CLINICAL SIGNIFICANCE: Modern dentifrices contain SnF2 for a range of oral health benefits. Challenges associated with stability of these formulations can affect ion bioavailability, reducing efficacy. Two dentifrices with SnF2 promoted remineralisation in situ, however the dentifrice with the added saliva biomimetic CPP-ACP was superior and therefore may produce greater health benefits.

Linear enamel hypoplasia in Homo naledi reappraised in light of new Retzius periodicities.

OBJECTIVES: Among low-latitude apes, developmental defects of enamel often recur twice yearly, linkable to environmental cycles. Surprisingly, teeth of Homo naledi from Rising Star in South Africa (241-335 kya), a higher latitude site with today a single rainy season, also exhibit bimodally distributed hypoplastic enamel defects, but with uncertain timing and etiology. Newly determined Retzius periodicities for enamel formation in this taxon enable a reconstruction of the temporal patterning of childhood stress. METHODS: Using high resolution casts of 31 isolated anterior teeth from H. naledi, 82 enamel defects (linear enamel hypoplasia [LEH]) were identified. Seventeen teeth are assigned to three individuals. Perikymata in the occlusal wall of enamel furrows and between the onsets of successive LEH were visualized with scanning electron microscopy and counted. Defects were measured with an optical scanner. Conversion of perikymata counts to estimates of LEH duration and inter-LEH interval draws upon Retzius periodicities of 9 and 11 days. RESULTS: Anterior teeth record more than a year of developmental distress, expressed as two asymmetric intervals centered on 4.5 and 7.5 months bounded by three LEH. Durations, also, show bimodal distributions, lasting 3 or 12 weeks. Short duration LEH are more severe than long duration. Relative incisor/canine rates of formation are indistinguishable from modern humans. DISCUSSION: We invoke a disease and dearth model, with short episodes of distress reflecting onset of disease in young infants, lasting about 3 weeks, followed by a season of undernutrition, possibly intensified by secondary plant compounds, spanning about 12 weeks, inferably coincident with austral winter.

Use of micro-computed tomography and scanning electron microscopy with energy-dispersive spectroscopy to distinguish natural white spot enamel lesions from sound enamel in human premolars.

PURPOSE: The aim of the present study was to develop a novel method for distinguishing white spot lesions (WSLs) from sound enamel in human premolars using micro-computed tomography (micro-CT) and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), and to examine differences in surface morphology, chemical composition, and mineral density (MD) between these two areas. METHODS: Fourteen premolars with natural WSLs on the enamel surface of the crowns were examined. After sectioning the teeth, each specimen containing WSLs adjacent to intact enamel was examined for MD, surface morphology, and atomic percentages (At%) of chemical components using micro-CT and SEM/EDS, respectively. Differences between these areas of the same specimen were analyzed statistically using paired t-test. RESULTS: SEM images highlighted increased roughness and irregularity in the lesion area. EDS analysis revealed significant reductions in calcium (Ca), phosphorus (P), fluorine (F), chlorine (Cl), and sodium (Na) levels at the lesion surface in comparison to intact enamel (P < 0.05). The decreases in the MD of the lesions were statistically significant in comparison to sound enamel (P < 0.05). CONCLUSION: These findings provide standard measurements for evaluating the essential characteristics of WSLs and intact enamel, being vital for assessment of treatment outcomes and development of innovative biomaterials for management of hypo-mineralized enamel lesions.

Dual-species biofilm of Streptococcus mutans and Candida albicans produces subsurface caries lesions on bovine enamel.

OBJECTIVES: To develop a protocol for forming subsurface caries lesions on bovine enamel by dual-species biofilms of Streptococcus mutans and Candida albicans in vitro. DESIGN: Biofilms were grown on bovine enamel specimens in artificial saliva (AS) for seven days. After 24 h of formation, the AS was supplemented or not with fluoride (F) using sodium fluoride (0.005 or 0.008 ppm F), and the biofilms were exposed or not to a 20 % sucrose solution (reproducing a cariogenic challenge) once/day. On the seventh day, the biofilms were harvested and had their extracellular polysaccharides (EPS) and inorganic components analyzed. The specimens were subjected to computed X-ray microtomography analysis to determine their mineral concentration. Data were compared using two-way analyses of variance, followed by Fisher's LSD or Student-Newman-Keuls tests (p < 0.05). RESULTS: Biofilms exposed to the cariogenic challenge had significantly higher EPS concentrations than those not exposed, regardless of the presence of F. For biofilms grown with 0.008 ppm F, those exposed to the cariogenic challenge had lower F levels than those not exposed. For biofilms exposed to the cariogenic challenge, those grown with 0.008 ppm F had lower lesion depths and integrated mineral loss, and higher outer layers than those grown without F. CONCLUSIONS: The dual biofilm model assessed was able to create subsurface caries lesions in bovine enamel in vitro, which was influenced by the presence of F in the culture medium and exposure to sucrose.

Reliability of impedance spectroscopy versus digital radiograph and ICDAS-II in occlusal caries detection: a prospective clinical trial.

The traditional methods in early caries detection had many limitations. So, this study aimed to evaluate the clinical performance of alternating current impedance spectroscopy ACIST in comparison with digital radiograph and ICDAS-II in detection of occlusal carious lesions. Occlusal surfaces of molar and premolar teeth from 40 adult participants were examined by two observers using three diagnostic methods: (1) international caries detection and assessment system (ICDAS-II) (2) digital radiograph (DR) and (3) Cariescan Pro device (ACIST). Agreement analysis and the difference in sensitivities and specificities were evaluated. The results showed an excellent agreement in the different groups. The difference from the visual tactile against ACIST scoring for enamel caries detection, was statistically significant (p = 0.012) and the agreement was moderate (k = 0.509). For dentinal caries the difference was not statistically significant (p > 0.05) and the agreement was similarly moderate (k < 0.6). The difference from the digital radiograph against ACIST scoring, for enamel caries, digital radiography had significantly higher sensitivity and specificity than ACIST (p < 0.001) while for dentinal caries detection and overall, ACIST had higher sensitivity and digital radiography had higher specificity and the difference was statistically significant (p < 0.001). Visual-tactile examination is a considered as feasible and valid technique for occlusal caries detection, digital radiography is superior to ACIST in diagnosing enamel caries, but it could underestimate the caries depth, ACIST is a reliable tool for detecting occlusal caries in dentin.

Optical coherence tomography and gray scale digital analysis as noninvasive techniques for evaluating molar-incisor hypomineralization severity: A comparative study with microcomputed tomography.

Molar-incisor hypomineralization (MIH) is a qualitative defect of dental enamel characterized by demarcated opacities present in permanent first molars and other teeth. It is considered a major clinical challenge in dentistry because it makes affected teeth more susceptible to fractures and dental caries. Its diagnosis is mainly clinical and there are few technological resources that allow for a more accurate diagnosis, especially with respect to the depth of the defect in the dental enamel. In this context, optical coherence tomography (OCT), which is routinely used in ophthalmology, can produce images of the depth of the dental enamel, making it a promising method. In this study, 33 teeth with different MIH severities were evaluated using OCT and microcomputed tomography (microCT). Semi-quantitative methods of grayscale pattern analysis were used to compare images obtained from different severities of MIH with the mineral density obtained through microCT. MicroCT evaluation revealed that hypomineralized enamel had a significantly lower mineral density than intact enamel. However, this difference was not observed between the mild and severe MIH lesions. In the OCT evaluation, significant differences were observed between the intact and hypomineralized enamel, and the gray value comparison provided a method for quantitative differentiation between the two. This study suggests that OCT could be a useful adjunct to traditional diagnostic methods for MIH, offering a noninvasive approach to evaluate enamel defects. RESEARCH HIGHLIGHTS: Combining optical coherence tomography with grayscale digital analysis shows potential as a promising method for diagnosing molar-incisor hypomineralization and assessing its level of severity.

The effect of silver diammine fluoride on In Vitro Enamel caries lesion remineralization and staining as a function of lesion baseline mineral distribution.

OBJECTIVES: to investigate whether baseline mineral distribution modulates the ability of silver diammine fluoride (SDF) to remineralize and stain enamel caries lesions. METHODS: This laboratory study followed a 3 [treatment: SDF/fluoride varnish (FV)/deionized water (DIW)] ×3 [lesion protocol: methylcellulose (MeC)/hydroxyethylcellulose (HEC)/Carbopol 907 (C907)] factorial design. Lesions were created in bovine enamel specimens (n = 20). Treatments were applied and lesions remineralized in artificial saliva. Digital transverse microradiography (TMR-D) was used to analyze lesions. Lesion color was monitored spectrophotometrically. The effects of lesion protocol and treatment on changes in lesion depth (ΔLD), mineral loss (ΔΔZ), maximum mineral density at the surface zone (ΔSZmax), and color changes related to remineralization (ΔL*remin) were analyzed using two-way ANOVA. RESULTS: The treatment×lesion protocol interaction was significant for ΔΔZ (p < 0.01) and ΔL*remin (p < 0.01), however not for ΔLD (p = 0.23) or ΔSZmax (p = 0.91). There were no differences in ΔΔZ between treatments in HEC and C907 lesions. However, DIW resulted in more remineralization than both SDF (p < 0.01) and FV (p = 0.01) in MeC lesions. Considering changes from lesion baseline after remineralization in MeC lesions, SDF treatment resulted in the highest mineral gain in the surface zone. However, DIW revealed the highest mineral gain after remineralization in the lesion body. SDF stained lesions with the intensity increasing after remineralization in C907 lesions, whereas staining decreased in MeC and HEC lesions. CONCLUSION: High fluoride treatments can interfere with continuous remineralization of caries lesions due to partial arrest. Baseline lesion mineral distribution affects SDF's ability to enhance remineralization and the staining caused by SDF. CLINICAL SIGNIFICANCE: SDF is being used to arrest active caries lesions extending into dentin and to treat dentin hypersensitivity. This study shed light on SDF's effect on an isolated process in dental caries only, remineralization. It achieved this by examining enamel caries lesions with differing mineral distributions and assessing their staining properties.

External validation of an artificial intelligence-based method for the detection and classification of molar incisor hypomineralisation in dental photographs.

OBJECTIVES: This ex vivo diagnostic study aimed to externally validate an open-access artificial intelligence (AI)-based model for the detection, classification, localisation and segmentation of enamel/molar incisor hypomineralisation (EH/MIH). METHODS: An independent sample of web images showing teeth with (n = 277) and without (n = 178) EH/MIH was evaluated by a workgroup of dentists whose consensus served as the reference standard. Then, an AI-based model was used for the detection of EH/MIH, followed by automated classification and segmentation of the findings (test method). The accuracy (ACC), sensitivity (SE), specificity (SP) and area under the curve (AUC) were determined. Furthermore, the correctness of EH/MIH lesion localisation and segmentation was evaluated. RESULTS: An overall ACC of 94.3 % was achieved for image-based detection of EH/MIH. Cross-classification of the AI-based class prediction and the reference standard resulted in an agreement of 89.2 % for all diagnostic decisions (n = 594), with an ACC between 91.4 % and 97.8 %. The corresponding SE and SP values ranged from 81.7 % to 92.8 % and 91.9 % to 98.7 %, respectively. The AUC varied between 0.894 and 0.945. Image size had only a limited impact on diagnostic performance. The AI-based model correctly predicted EH/MIH localisation in 97.3 % of cases. For the detected lesions, segmentation was fully correct in 63.4 % of all cases and partially correct in 33.9 %. CONCLUSIONS: This study documented the promising diagnostic performance of an open-access AI tool in the detection and classification of EH/MIH in external images. CLINICAL SIGNIFICANCE: Externally validated AI-based diagnostic methods could facilitate the detection of EH/MIH lesions in dental photographs.

Progression of proximal caries in primary molars using the radiographic ICDAS: a retrospective cohort study.

PURPOSE: To evaluate the proximal caries progression in primary molars using the radiographic International Caries Detection and Assessment System (ICDAS). METHODS: A study was conducted on 196 children aged 3-9 years old who underwent the clinical examination and bitewing radiography during baseline and 6-month (and over) follow-up visits. The primary molars bitewing radiographs with initial enamel caries (RA1 and RA2) or outer dentine caries (RA3) of proximal surfaces were included. Caries advancement was scored using ICDAS criteria and statistical analyses with the chi-square test. Median survival time was evaluated using Kaplan-Meier survival curves and log-rank tests. RESULTS: A total of 439 surfaces of primary molars were included in this study and an averaged follow-up period of enamel and dentine caries group were 18.3 ± 9.6 months and 16.5 ± 9.5 months respectively. The progression of proximal enamel lesions significantly differed between primary maxillary and mandibular molars (p = 0.002) and among each patient's primary mandibular second molar and the others (p = 0.002). On the contrary, the outer dentine caries of each group of primary molars was not different. The median survival time of the initial enamel proximal caries (23.30 months) was non-significantly longer than that of the dentine (20.80 months). CONCLUSIONS: Progressions of the initial enamel proximal caries were significantly different among primary molars at the average 18.3-month follow-up. The median survival period of the enamel proximal caries was more extended than that of dentine but without statistical difference. These results provide essential information for dentists regarding an appropriate appointment for bitewing examinations.

Clinical, Radiographic, and Histological Changes in Enamel and Dentin, According to Caries Care International™ Evaluation, In Permanent Posterior Teeth: An Observational Study / Cambios Clínicos, Radiográficos e Histológicos en Esmalte y Dentina, Según Evaluación de Caries Care International™, en Dientes Posteriores Permanentes: Un Estudio Observacional

SUMMARY: CariesCare International ™ practical guide is a tool for the comprehensive assessment and treatment of caries that synthesizes clinical and radiographic diagnosis and risk factors, classifying the severity, progression, and activity of lesions. The objective of this study was to analyze the validity and prediction characteristics of the proposed dental caries classification in the CariesCare International ™ practical guide as a reference through clinical and radiographic evaluation versus histological evaluation. Ninety-seven permanent posterior teeth were evaluated, and clinical and radiographic diagnoses were determined according to parameters defined in the CariesCare International™ guide as a reference. Subsequently, histological evaluation was performed to compare each stage of dental caries progression, and statistical analysis was applied. When comparing the validity and prediction values between radiographic and clinical diagnoses in relation to histological evaluation, a low sensitivity and high specificity relationship was found. The sensitivity and specificity percentages between the clinical and radiographic methods show that the clinical method has a lower number of false negatives. Histological changes in dental tissue were evident from the earliest stages of lesions, even in those not related to the caries process, indicating that the dentist should be careful when deciding on a treatment plan and take into account all variables involved in the caries process, as proposed by the CariesCare International ™ guide.

La guía práctica CariesCare International™ es una herramienta para la evaluación y tratamiento integral de la caries que sintetiza el diagnóstico clínico y radiográfico y los factores de riesgo, clasificando la gravedad, progresión y actividad de las lesiones. El objetivo de este estudio fue analizar la validez y características de predicción de la clasificación de caries dental propuesta en la guía práctica CariesCare International™ como referencia a través de la evaluación clínica y radiográfica versus la evaluación histológica. Se evaluaron noventa y siete dientes posteriores permanentes y se determinaron diagnósticos clínicos y radiográficos según parámetros definidos en la guía CariesCare International™ como referencia. Posteriormente se realizó una evaluación histológica para comparar cada etapa de progresión de la caries dental y se aplicó análisis estadístico. Al comparar los valores de validez y predicción entre los diagnósticos radiológicos y clínicos en relación con la evaluación histológica, se encontró una relación de baja sensibilidad y alta especificidad. Los porcentajes de sensibilidad y especificidad entre el método clínico y radiográfico muestran que el método clínico tiene un menor número de falsos negativos. Los cambios histológicos en el tejido dental fueron evidentes desde las primeras etapas de las lesiones, incluso en aquellas no relacionadas con el proceso de caries, lo que indica que el odontólogo debe tener cuidado al decidir un plan de tratamiento y tener en cuenta todas las variables involucradas en el proceso de caries, tal como propone la guía CariesCare International™.

Enfoque de Tratamiento de una Adolescente con Amelogénesis Imperfecta / Treatment Approach for an Adolescent with Amelogenesis Imperfecta

La amelogénesis imperfecta (AI) es un grupo de tras-tornos hereditarios, clínica y etiológicamente hete-rogéneos, derivados de mutaciones genéticas, que se caracterizan por anomalías cualitativas y cuanti-tativas del desarrollo del esmalte, pudiendo afectar la dentición primaria y/o permanente. El tratamiento del paciente con AI es complejo y multidiscliplinario; supone un desafío para el odontólogo, ya que por lo general están involucradas todas las piezas dentarias y afecta no solo la salud buco dental sino el aspecto emocional y psicológico de los pacientes. Con el obje-tivo de describir el tratamiento integral y rehabilita-dor realizado en una paciente con diagnóstico de AI tipo III, se reporta el caso de un adolescente de sexo femenino de 13 años, que concurrió en demanda de atención a la Cátedra de Odontología Integral Niños de la Facultad de Odontología de la Universidad de Buenos Aires (FOUBA), cuyo motivo de consulta fue la apariencia estética y la hipersensibilidad de sus pie-zas dentarias. Durante el examen clínico intraoral, se observó que todas las piezas dentarias presentaban un esmalte rugoso, blando, con irregularidades y una coloración amarronada, compatible con diagnóstico de Amelogénesis Imperfecta tipo III hipomineralizada. Conclusión: El tratamiento rehabilitador de la AI en los pacientes en crecimiento y desarrollo estará diri-gido a intervenir de manera integral y temprana para resolver la apariencia estética y funcional, evitar las repercusiones sociales y emocionales, y acompañar a los pacientes y sus familias (AU)

Amelogenesis imperfecta (AI) is a group of clinically and etiologically heterogeneous hereditary disorders, derived from genetic mutations, characterized by qualitative and quantitative anomalies of enamel development, which can affect primary and/or permanent dentition. The treatment of patients with AI is complex and multidisciplinary, it is a challenge for the dentist, since in general all the teeth are involved and it affects not only oral health but also the emotional and psychological aspect of the patients. Objective: To describe the comprehensive and rehabilitative treatment carried out in an adolescent patient with a diagnosis of type III AI. Case report: The case of a 13-year-old female patient, who required dental attention at the Department of Dentistry for Children of the School of Dentistry of the University of Buenos Aires, whose reason for consultation was esthetic appearance and hypersensitivity of her teeth. In the intraoral clinical examination, it was observed that all the teeth had rough, soft enamel, with irregularities and a brownish color, compatible with the diagnosis of type III hypomineralized Amelogenesis Imperfecta. Conclusion: Rehabilitative treatment of AI in growing and developing patients will be aimed at early and comprehensive intervention to resolve esthetic and functional appearance, avoid social and emotional repercussions and accompany patients and their families (AU)

Association between demarcated enamel hypomineralization on second primary molars and dental caries in childhood / Associações entre hipomineralização demarcada de esmante nos segundos molares decíduos e cárie dentària na infância

ABSTRACT Hypomineralized Second Primary Molars (HSPM) is the name used to describe the presence of demarcated enamel hypomineralization in second primary molars. HSPM has been compared with Molar Incisor Hypomineralization (MIH) as regards its clinical appearance and consequences. The aim of this study was to investigate associations between HSPM and dental caries in childhood. It was a cross-sectional population-based study that included 216 children aged 4-6 years from public schools in Botelhos, Brazil. Children with all second primary molars erupted were eligible for participation. Clinical examination was performed by one calibrated examiner. HSPM was recorded according to modified European Academy of Paediatric Dentistry criteria. The main outcome was dental caries experience as indicated by the dmft index (%dmft>0) according to WHO criteria. Chi-square test and Logistic Regression Model were used to adjust the results for effects of covariates Among the 216 children examined, 22.2% presented HSPM. After adjustment for logistic regression, children with HSPM were found to have a 2.28 times greater chance of presenting dental caries. Our results reinforce the importance of HSPM in caries development in children, which should be considered by public health dentists in the process of planning actions aimed at this population.

RESUMO A hipomineralizacao de segundo molar deciduo (HSMD) é de-nominação utilizada para descrever a presenga de hipomineralização demarcada do esmalte nos segundos molares decídus. A HSMD foi comparada com a hipomineralização de molares e incisivos (HMI) no que diz respeito á aparencia e as conse-quencias clínicas. O objetivo deste estudo foi investigar asso-ciações entre HSMD e cárie na infáncia. Foi realiza um estudo transversal de base populacional, composto por 216 criangas de 4 a 6 anos de idade de escolas públicas de Botelhos, Brasil. As criangas com todos os segundos molares deciduos foram elegíveis para participação. O exame clínico foi realizado por um examinador calibrado. A HSMD foi registrada de acordo com os critérios modificados da European Academy of Paediatric Dentistry. O desfecho principal foi a experiencia de cárie dentària nos dentes deciduos conforme o índice ceo (% ceo> 0), segundo os critérios da OMS. Os testes de Qui-quadrado e o modelo de regressao logística foram utilizados para ajustar os resultados dos efeitos das covariáveis. Verificou-se que entre as 216 criangas examinadas, 22,2% apresentaram HSMD. Após o ajuste da regressao logística, as criangas com HSMD tiveram 2,28 vezes mais chances de apresentar cárie dentària. Nossos resultados reforgam a importáncia do HSMD no desenvolvimento da cárie em criangas, fato que deve ser considerado pelos dentistas de saúde pública no processo de planejamento de ações voltadas a essa população.

Dental caries in three-year-old preschool children in Lima, Peru assessed according to the CAST instrument / Caries dental en niños prescolares de 3 años en Lima-Perú evaluados con el instrumento CAST

ABSTRACT The aim of this study was to determine the caries situation of three-year-old preschool children residing in low socioeconomic status districts in Lima, Peru. The study is a crosssectional analysis of the caries situation of suburban areas of Lima. A stratified sampling procedure by geographical distribution, considering healthcare centers with a motherand- child health clinic and surrounding preschools as factors, identified 45 randomly selected preschools, of which 17 accepted to participate. Children from 3-year-old classrooms were examined by two independent calibrated dentists using the Caries Assessment Spectrum and Treatment (CAST) instrument at their premises using artificial light, sterile examination mirrors and gauze for drying each tooth before evaluation. ANOVA and the Tamhane method were used to analyze the data. 308 children, mean age 3.4 years (min: 3 years; max: 3 years, 7 months), were examined. The sample prevalence of enamel and dentine carious lesions (CAST code 3-7) was 91.2% while the prevalence of dentine carious lesions (CAST code 4-7) was 58.8%. The mean number of teeth with cavities that had reached the pulp and those that had an abscess or fistula were 2.0% and 0.5% respectively. The majority of enamel and dentine carious lesions were observed in molars. The CAST severity score was 7.0. Mean examination time was 57 seconds. The burden of dental caries of the children at this young age was high.

RESUMEN El objetivo del presente estudio fue determinar la prevalencia de caries dental en niños en edad preescolar de 3 años residentes en áreas suburbanas de Lima, Perú. Se trata de un análisis transversal de la situación de caries de áreas periféricas de Lima. Un procedimiento de muestreo estratificado por distribución geográfica consideraba a los centros de salud materno-infantiles y centros educativos preescolares de la jurisdicción como factores, identificando 45 centros prescolares aleatoriamente, de los cuales 17 aceptaron la invitación para participar del presente estudio. Dos odontólogas independientes, calibradas examinaron a los niños de las aulas de 3 años utilizando el instrumento Caries Assessment Spectrum and Treatment (CAST) en las instalaciones de cada jardín de infancia, utilizando luz artificial, instrumental estéril y gasas para el secado de las superficies a evaluar. Los datos fueron analizados utilizando ANOVA y el método Tamhane. Se evaluaron 308 niños, quienes tenían una edad media de 3.4 años (min: 3 años; max: 3 años, 7 meses). La prevalencia de lesiones de caries de esmalte y dentina (código CAST 3-7) fue del 91,2%, mientras que la prevalencia de lesiones de caries en dentina (código CAST 4-7) fue de 58,8%. El número promedio de dientes afectados por caries dental con compromiso pulpar y que tenían un absceso o fístula fue de 2.0% y 0.5% respectivamente. La mayoría de las lesiones de caries en esmalte y dentina se observaron en los molares. La valoración de severidad CAST fue 7.0. El tiempo promedio de examinación fue de 57 segundos. La carga de la enfermedad caries dental a estas edades tan tempranas ya es alta en la infancia suburbana de Lima.

Alteración del gen AMELX en amelogénesis imperfecta. Una breve revisión / Alteration of the AMELX gene in amelogenesis imperfecta. A brief review

Resumen La amelogénesis imperfecta es un grupo de trastornos de desarrollo del esmalte dental asociados principalmente con mutaciones en el gen AMELX. Clínicamente presenta diferentes fenotipos que afectan la estructura y función del esmalte, tanto de la dentición primaria como secundaria. El objetivo de este estudio fue realizar una revisión bibliográfica de las funciones y mutaciones de AMELX relacionadas con amelogénesis imperfecta. Se llevó a cabo una revisión bibliográfica en dos bases de datos: PubMed y Web of Science, usando las palabras clave “AMELX”, “amelogenina”, “amelogénesis imperfecta” y “mutación de AMELX”. Fueron revisados 40 artículos y se encontró que AMELX es el gen predominante en el desarrollo del esmalte dental y de la amelogénesis imperfecta, alterando la estructura de la amelogenina. En los últimos años se han descrito las características en el proceso de amelogénesis imperfecta con diferentes fenotipos de esmalte hipoplásico o hipomineralizado y se han reportado diferentes mutaciones, con lo que se ha determinado la secuenciación del gen y las posiciones de las mutaciones.

Abstract Amelogenesis imperfecta is a group of developmental disorders of the dental enamel that is mainly associated with mutations in the AMELX gene. Clinically, it presents different phenotypes that affect the structure and function of dental enamel both in primary and secondary dentition. The purpose of this study was to conduct a literature review on the AMELX functions and mutations that are related to amelogenesis imperfecta. A literature search was carried out in two databases: PubMed and Web of Science, using the keywords “AMELX”, “amelogenin”, “amelogenesis imperfecta” and “AMELX mutation”. Forty articles were reviewed, with AMELX being found to be the predominant gene in the development of dental enamel and amelogenesis imperfecta by altering the structure of amelogenin. In the past few years, the characteristics of the amelogenesis imperfecta process have been described with different phenotypes of hypoplastic or hypo-mineralized enamel, and different mutations have been reported, by means of which the gene sequencing and the position of mutations have been determined.

Immunohistochemical study of amelogenin binding proteins in an amelogenin point mutation mouse / Estudio inmunohistoquímico de proteínas de unión de la amelogenina en un ratón con mutación puntual de amelogenina

Amelogenin is one of the enamel matrices secreted by ameloblasts. A mutation of the amelogenin gene can cause hereditary dental enamel defects known as amelogenesis imperfecta (AI). Since lysosome-associated membrane protein-1 (LAMP-1), -3 (LAMP-3), and 78kDa glucose-related protein (Grp78) were identified as binding proteins of amelogenin, several studies have suggested the involvement of these binding proteins with the cell kinetics of ameloblasts in normal or abnormal conditions. The purpose of this study is to investigate the distribution of these amelogenin binding proteins in the ameloblast cell differentiation of mice with a point mutation of the amelogenin gene (Amelx*). The incisors of Amelx* mice had a white opaque color and the tooth surface was observed to be rough under a scanning electron microscope. Among the sequential ameloblast cell differentiation in the Amelx* mice, the shape of ameloblasts at the transition stage was irregular in comparison to those in wild-type (WT) mice. Immunostaining of Grp78 revealed that the whole cytoplasm of the transition stage ameloblasts was immunopositive for Grp78 antibody, while only the distal part of cell was positive in the WT mice. Furthermore, in the Amelx* mice, the cytoplasm of the transition stage ameloblasts was immunopositive for LAMP-1 and LAMP-3. These results suggest that Amelx* may cause the abnormal distribution of amelogenin binding proteins in the cytoplasm of ameloblasts.

La amelogenina es una de las matrices de esmalte secretadas por los ameloblastos. Una mutación del gen de amelogenina puede causar defectos hereditarios del esmalte dental conocidos como amelogénesis imperfecta (AI). Dado que la proteína de membrana asociada a lisosoma-1 (LAMP-1), -3 (LAMP-3) y la proteína relacionada con la glucosa de 78 kDa (Grp78) se identificaron como proteína de unión a amelogenina, varios estudios han sugerido la participación de estas proteínas con la cinética celular de los ameloblastos en condiciones normales o anormales. El objetivo del estudio fue investigar la distribución de LAMP-1, LAM-3 y Grp78 durante la diferenciación celular de ameloblastos de ratones con una mutación puntual del gen de amelogenina (Amelx*). Los incisivos de los ratones Amelx* presentaron un color blanco opaco y se observó en microscopio electrónico de barrido que la superficie del diente era áspera. La diferenciación celular secuencial y la forma de los ameloblastos en la etapa de transición en los ratones Amelx* fue irregular en comparación con los ratones silvestres (RS). La inmunotinción de Grp78 reveló que todo el citoplasma de los ameloblastos en etapa de transición fue inmunopositivo para el anticuerpo Grp78, mientras que solo la parte distal de la célula fue positiva en los ratones RS. Además, en ratones Amelx*, el citoplasma de los ameloblastos en etapa de transición fue inmunopositivo para LAMP-1 y LAMP-3. Estos resultados sugieren que Amelx* puede causar distribución anormal de proteínas de unión a amelogenina en el citoplasma de los ameloblastos.

Diversity of clinical, radiographic and genealogical findings in 41 families with amelogenesis imperfecta

Abstract Amelogenesis imperfecta (AI) is a group of enamel development disorders that alter the structure and chemical composition of the tissue. There is great variability in the clinical presentation; according to Witkop, AI can be categorized into 14 subtypes, which makes its diagnosis extremely complex. Objective: This study aimed to describe and determine the frequency of clinical and radiographic features and inheritance patterns found in 41 Chilean families diagnosed with diverse types of AI. Material and Methods: We analyzed the clinical records, photographs, pedigrees and radiographs of 121 individuals recruited between 2003 and 2016. All of the information was included in a database that was analyzed using the application Stata 14. Results: The 72 affected individuals had average age of 16 years, and no sex association with the presence of AI was found. The most frequent clinical subtypes were as follows: 43% hypomature, 25% hypoplastic, 21% hypomature/hypoplastic, 7% hypocalcified and 4% hypocalcified/hypoplastic. The number of severely affected teeth was 22, which occurred in the patients with hypocalcified and hypocalcified/hypoplasic AI who presented the highest number of damaged teeth. Caries and periodontal disease were found in 47 and 32% of the patients, respectively. Malocclusions were observed in 43% of the individuals with AI, with open bite being the most frequent. Radiographically, the thickness of the enamel decreased in 51% of the patients, and 80% showed decreased radiopacity of the enamel compared to that of dentin. Autosomal dominant inheritance pattern was found in 37% of the families with hypoplastic AI, and autosomal recessive pattern was present in 56% of the other clinical subtypes, but more frequently in those affected with hypomature and hypocalcified AI. Conclusion: Of the five clinical subtypes, autosomal recessive hypomature, autosomal dominant hypoplastic and autosomal recessive hypomature/hypoplastic AI were the most prevalent subtypes in this group.