Molar-incisor hypomineralisation: an updated view for aetiology 20 years later.

BACKGROUND: The term Molar-Incisor Hypomineralisation (MIH) was introduced in 2001 by Weerheijm, Jälevik and Alaluusua, and describes a defect of systemic origin that affects one to four first permanent molars, often associated with permanent incisors. In the past 20 years, this definition dictated the work regarding MIH prevalence, associated risk factors, association with dental caries, impact on quality of life, and therapeutic options. PURPOSE: In this report, we offer an updated and comprehensive view of MIH centred on the patient and the tooth. CONCLUSION: MIH today is globally recognized as a potential public health problem and it is not a defect of purely systemic origin but rather a condition with complex aetiology that in some instances may be the result of gene-environmental interactions.

Aesthetic perception in children with molar incisor hypomineralization.

PURPOSE: To investigate the relationship between aesthetic perception and molar incisor hypomineralization (MIH) in schoolchildren aged 8-12 years. METHODS: The study included 467 pupils enrolled in elementary schools. Once authorization was received, the students were examined for DMFT and dmft indexes (WHO criteria), and for MIH (EAPD criteria). The aesthetic perceptions were verified by the Child Perceptions Questionnaire About Tooth Appearance (CQATA), a questionnaire divided into several items, including physical, psychological and social domains; perception about tooth pleasantness, tooth alignment, tooth discoloration and tooth health; and reported pleasant colour. Data analysis was carried out using descriptive statistics, the Chi-square, the Mann-Whitney and the Kruskal-Wallis tests, and linear regression at a significance level of 0.05. RESULTS: The tooth health perception was worse when the child had MIH, and the tooth alignment and tooth discoloration perceptions, when MIH affected the incisors. The number of teeth affected by MIH was associated with higher averages in the tooth discoloration perception. CONCLUSIONS: Children with MIH showed more negative perceptions toward tooth health, tooth alignment and tooth discoloration. However, none of the clinically investigated variables negatively impacted the reported pleasant colour question.

Molar Incisor Hypomineralization in Colombia: Prevalence, Severity and Associated Risk Factors.

Aim: To determine prevalence, severity, and risk factors associated with Molar Incisor Hypomineralization (MIH) in schoolchildren between 6 and 15 years of age in Medellin, Colombia. Study design: We conducted a retrospective observational study including 1.075 children born and residing in Medellin, Colombia. A structured questionnaire addressing gestational period and first three years of child's life was administered to biological mothers. Two calibrated examiners established MIH diagnosis following the European Academy of Paediatric Dentistry criteria. Data were analyzed using descriptive statistics, bivariate analysis, and linear regression with a 5% significance. Results: Study population was predominantly male (70.7%), average age was 9.3±1.9 years. Prevalence of MIH was 11,2%. The majority of defects (85%) were mild. MIH was associated with alterations during last gestational trimester, type of childbirth and respiratory problems. Conclusion. MIH prevalence in schoolchildren between 6 and 15 years of age was 11.2%, being mild defects more frequently found. MIH was associated with different factors during pregnancy and the first three years of life.

Control of White Spot Lesions with Use of Fluoride Varnish or Chlorhexidine Gel During Orthodontic Treatment A Randomized Clinical Trial.

OBJECTIVE: To compare the effectiveness of fluoride varnish and 2% chlorhexidine gel for controlling active white spot lesions (WSLs) adjacent to orthodontic brackets. STUDY DESIGN: Thirty-five orthodontic patients (17.2 ± 2.3 years old) presenting 60 WSLs adjacent to orthodontic brackets were enrolled in this randomized, blind, 3-armed and controlled clinical trial. The patients were randomly allocated to 1 of 3 arms: (1) two applications of 5% NaF varnish- F, with one-week interval, (2) two applications of 2% chlorhexidine gel-CHX, with one-week interval and (3) usual home care-control (CO). The WSLs were scored by using a DIAGNOdent pen. An independent examiner scored the surfaces using Nyvad criteria for caries assessment. RESULTS: A total of thirty patients presenting 51 lesions completed the study. All treatments reduced the fluorescence values during the experimental period; however, F induced faster remineralization than CHX. After 3 months, 70.58 % were inactive considering all groups. DIAGNOdent pen and Nyvad presented a significant correlation. CONCLUSION: After 3 months of treatment, F, CHX and CO were capable of controlling the WSLs adjacent to the orthodontic brackets. However, the treatment with F was capable of controlling the progression of the WSLs in a shorter period of time.

Proximal caries lesion detection in primary teeth: does this justify the association of diagnostic methods?

The aim of this clinical study was to evaluate and compare the performance of visual exam with use of the Nyvad criteria (visual examination - (VE)), interproximal radiography (BW), laser fluorescence device (DIAGNOdent Pen-DDPen), and their association in the diagnosis of proximal lesions in primary teeth. For this purpose, 45 children (n = 59 surfaces) of both sexes, aged between 5 and 9 years were selected, who presented healthy primary molars or primary molars with signs suggestive of the presence of caries lesions. The surfaces were clinically evaluated and coded according to the Nyvad criteria and immediately afterwards with the DDPen. Radiographic exam was performed only on the surfaces coded with Nyvad scores 2, 3, 5, or 6. Active caries lesions and/or those with discontinuous surfaces were restored, considering the depth of lesion as reference standard. Sensitivity, specificity, accuracy, and area under ROC curve were calculated for each technique and its associations. Visual exam with Nyvad criteria presented the highest specificity, accuracy, and area under ROC curve values. The DDPen presented the highest sensitivity values. Association with one or more methods resulted in an increase in specificity. The performance of visual, radiographic, and DDpen exams and their associations were good; however, the clinical examination with the Nyvad criteria was sufficient for the diagnosis of interproximal lesions in primary teeth.

Assessment of a new infrared laser transillumination technology (808 nm) for the detection of occlusal caries-an in vitro study.

This study aimed to evaluate in vitro performance of near-infrared laser transillumination (NIR-LTI) for detecting early occlusal caries in permanent teeth and compare it with quantitative light-induced fluorescence (QLF), DIAGNOdent Pen (DDPen), and conventional radiography (CR). Ninety-four occlusal surfaces presenting International Caries Detection and Assessment System (ICDAS) scores ranging from 0 to 3 were selected. For the NIR-LTI examination, images were captured using a prototype, which consists of a laser beam (808 nm) and an infrared CCD camera. One occlusal site on each tooth was assessed twice by two examiners. The teeth were prepared histologically and assessed for the presence of early caries. The intraexaminer correlation showed no difference between the NIR-LTI, DDPen, and QLF analytical methods, but all these methods differed from CR. Interexaminer reproducibility was moderate for NIR-LTI, which showed sensitivity (0.68), specificity (0.85), accuracy (0.73), and area under the receiver-operating characteristic (ROC) curve (0.76) similar to those of the fluorescence method and different from those of the CR. In conclusion, the performance of NIR-LTI was comparable to that of DDPen and QLF and may therefore be considered a valid and reliable alternative for the diagnosis of incipient lesions on the occlusal surface of permanent teeth.

Aetiology of molar-incisor hypomineralisation (MIH) in Brazilian children.

AIM: To determine the potential aetiological factors related to molar-incisor hypomineralisation (MIH) in Brazilian children. METHODS: A total of 1,151 children aged 7-12 years (mean 8.86 ± 1.28), born and living in the urban area of Araraquara, Brazil, were examined by two examiners evaluating the presence of MIH according to criteria suggested by the European Academy of Paediatric Dentistry (2003). Their mothers completed a structured questionnaire about medical history, from pregnancy to the first 3 years of the children's life. Descriptive analyses of data and odds ratios (OR) with 95 % test-based confidence intervals (CI) were estimated. Chi-square test was used to evaluate the differences between groups. RESULTS: The prevalence of MIH in the children was 12.3 %. The interviewing response rate was 90.4 %. The prevalence of miscarriage history (25 vs. 15.4 %; OR = 1.21; 95 % CI 0.30-4.92) and occurrence of anaemia (23 vs. 12.4 %; OR = 2.07; 95 % CI 0.50-8.63) were higher in mothers from MIH group than those from non-MIH group. However, these associations were not statically significant. In the children's medical history, rhinitis, bronchitis (56.5 vs. 52.5 %; OR = 1.17; 95 % CI 0.82-1.68), and high fever (20.4 vs. 18.2 %; OR = 1.14; 0.73-1.76) were more prevalent in MIH group, but there were no significant differences between the groups (p > 0.05). CONCLUSIONS: No possible aetiological factor investigated was associated with MIH. Prospective studies are needed to define the aetiological factors involved with MIH.

Molar incisor hypomineralisation: possible aetiological factors in children from urban and rural areas.

AIM: To analyse factors potentially associated with molar incisor hypomineralisation (MIH) development. METH¬ODS: A population-based study was carried out with 903 children aged from 6-12 years old, born and residing in rural and urban areas of the town of Botelhos, State of Minas Gerais, Brazil. Their mothers completed a structured medical history questionnaire, from pregnancy to the child's 3rd year of life. Two examiners evaluated children for MIH according to criteria suggested by the European Academy of Paediatric Dentistry. Descriptive analyses of the data and odds ratios (OR) with 95% test-based confidence intervals (CI) were estimated. Chi-square test was used to evaluate the differences between groups. RESULTS: The prevalence of MIH in children from rural area (RA) was significantly higher than those from the urban area (UA) (24.9% versus 17.8%, p= 0.01). In urban children, neither significant associations with MIH nor medical problems were found. In rural children, however, MIH was significantly more common among those whose mothers had experienced medical problems during pregnancy (OR=2.11; 1.01-4.37 CI 95%; p=0.04), who had throat infections (OR=2.93; 1.47-5.87 CI 95%; p=0.01), who had high fever (OR=1.91; 1.07-3.39 CI 95%; p=0.02), and who had used amoxicillin associated with other antibiotics (OR=1.92; 1.02-3.62 CI 95%; p=0.04) during the first 3 years of life. CONCLUSION: This study suggests a link between MIH and health problems during pregnancy, as well as environmental factors.

Influence of cutting instruments and adhesive systems on hybrid layer formation.

Influence of cutting instruments and The aim of this study was to analyze the hybrid layer in noncarious dentin prepared by different cutting instruments and restored with composite resin. The cavities were randomly prepared in 40 specimens using a high-speed diamond bur (KG Sorensen 1013) and an ultrasonic tip (CVDentus C22). The cavities were restored with composite resin by varying the adhesive system between the Adper™ Single Bond (2 x 1 system, primer+adhesive) and the Prompt L-Pop™ (3 x 1 system, self-etching). The restorations were hemisected longitudinally and analyzed in the SEM (Scanning electron microscopy) in order to evaluate the hybrid layer and resinous tags characteristics, using scores ranging from 1 to 6. The Pearson test revealed a high correlation coefficient and good significance levels for both intra- and inter-raters values (r=0.90). The data were statistically analyzed using the Mann-Whitney test (P≤0.05). A larger proportion of regular hybrid layers with numerous tags were observed in the dentin prepared using the high-speed diamond burs and restored with a 2 × 1 adhesive system. Alternatively, the 3 × 1 adhesive system promoted the generation of a thin hybrid layer with few tags. After preparation using an ultrasonic tip revealed few or no tags after the preparation and 2 × 1 or 3 × 1 adhesive system application. The high-speed diamond burs produced a dentin surface that was more favorable to restorative material adhesion than the ultrasonic tips, regardless of the adhesive system used.

Evaluation of the dentin-pulp complex after cavity preparation with ultrasonic diamond tip.

AIM: The aim of this paper was to compare the dentin-pulp complex response to cavity preparation in human teeth using ultrasonic chemical vapor deposition (CVD) diamond tip and high-speed diamond bur. METHODS: Class V buccal cavities were randomly prepared in 40 premolars from 14 patients aged 11 to 15 years. The cutting time was recorded and the cavities had the axial walls protected with gutta-percha and were filled with glass ionomer cement. The teeth were extracted at intervals of 0, 5, 10 and 20 days, and were decalcified, sectioned and stained by Hematoxylin & Eosin, Masson's Trichrome and Brown & Brenn techniques. The inflammatory response and cell disorganization were blindly evaluated by two examiners. The remaining dentin thickness (RDT) was measured by a linear scale using computer software. Statistical analysis by one-way ANOVA showed no statistically significant difference (P≤0.05) among the cavities prepared with either type of instrument, with mean RDT of 1132.50 mm. Cutting time and the pulp-dentin complex responses were analyzed statistically by Kruskal-Wallis and Dunn tests (P≤0.05). RESULTS: The ultrasonic CVD diamond tip took 5 times longer to prepare the cavities and there were no typical inflammatory pulp responses in cavities prepared with either type of cutting instrument, only mild to moderate cell disorganization was present. CONCLUSION: Even taking longer to cut the dental substrate, the ultrasonic CVD diamond tip produced similar pulp response compared to the conventional high-speed diamond bur.

Comparative cutting effectiveness of an ultrasonic diamond tip and a high-speed diamond bur.

AIM: The aim of this in vitro study was to compare an ultrasonic diamond tip to a high-speed conventional diamond bur regarding the cutting effectiveness in enamel and dentin of human teeth. METHODS: Twenty permanent molars were longitudinally sectioned in the buccal-lingual plane giving 40 specimens, 20 for enamel and 20 for dentin groups. One cavity was performed in each specimen using a spherical diamond tip (83231, CVDentus(R), CVDVale, São José dos Campos, SP, Brazil) coupled with an ultrasound device or a conventional spherical diamond bur (1013, KG Sorensen, São Paulo, Brazil)) coupled with a high-speed turbine. A modified measurement analysis using the Radiocef 4.0 software (Radiocef Memory) was applied to determine the width and the depth of the cavities on scanning electron microscopy (SEM) at x50 magnification micrographs. The features of the cavities and the characteristics of the cutting instruments were also examined under different magnifications by SEM. RESULTS: Statistical analysis by Kruskal-Wallis non-parametric and Dunn post hoc tests (P < or = 0.05) showed that cavities prepared in enamel and dentin with the ultrasonic diamond tip were shallower and narrower than those prepared with conventional diamond bur. The internal walls of cavities prepared in dentin by the ultrasonic diamond tip reproduced the superficial aspect of the diamond, however, scratches were observed in the internal walls of the dentin cut by high-speed conventional diamond bur. CONCLUSIONS: Both instruments were effective in enamel and dentin cutting; however, cavities prepared with a high-speed conventional diamond bur showed more invasive characteristics.

The effectiveness of alumina powder on carious dentin removal.

This study determined the size of aluminum oxide particles used in an air abrasion system that is able to remove carious dentin tissue with maximum preservation of sound structure. Thirty extracted and carious-free third molars were used in this study. The dentin sample was obtained by sectioning the middle of the crown longitudinal to the long axis of the tooth in a mesio-distal direction. One half of the crown corresponded to the sound dentin group (SD), while the other half was used to develop artificial caries, constituting the carious dentin group (CD). The specimens were air abraded for 15 seconds. The SD and CD groups were each randomly divided into three subgroups (N=10) according to the particle diameter employed (27, 50 and 125 microm). The prepared cavity was perpendicularly cut in half, and the profiles of all hemi-fragments were observed using SEM microscopy. The cavity measurements were made using a modified cephalometric analysis. The 27, 50 and 125 microm aluminum oxide particles did not present selectivity in the removal of carious dentin. However, when using the air abrasive technique for carious dentin treatment, the use of 27 and 50 microm aluminum oxide particles is recommended, due to their capacity to remove less sound tissue than the 125 microm particles.

Evaluation of the microtensile bond strength of composite resin restoration in dentin prepared with different sizes of aluminum oxide particles, using the air abrasion system.

AIM: The purpose of this in vitro study was to evaluate the influence of the abrasive technique on the microtensile bond strength of composite resin restorations. In addition, any differences in the microtensile bond strength were observed when different aluminum oxide particle sizes were used. METHODS: Flat coronal dentin surfaces were randomly distributed into 3 groups, according to surface treatment: Group A27 Air-abraded dentin with 27 microm aluminum oxide particles; Group A50-Air-abraded dentin with 50 microm aluminum oxide particles; Group HS cut dentin with a #1013 diamond bur in high-speed rotary instrument. After the bonding procedure (Single Bond/Z100), the teeth were stored in distilled water at 37 masculineC for 48 h prior to sectioning. Then, each bonded tooth was longitudinally sectioned producing sticks with a cross-sectional area of 0.81 mm2. The tensile load was applied at a crosshead speed of 0.5 mm/min, until the stick fractured. The data were analyzed by one-way ANOVA and post hoc multiple comparisons using Tukey's test. RESULTS: No difference was observed in composite bond strength when 27 and 50 microm aluminum oxide particles were used for dentin surface preparation using an air abrasion system. However, air-abraded dentin, using 27 microm aluminum oxide particles, demonstrated a higher bond strength when compared to dentin prepared by the conventional method (bur in high-speed). CONCLUSIONS: The air-abraded dentin, using 27 microm alumina powder, demonstrated higher composite bond strength when compared to bur-cut dentin, raising the possibility that this method may increase restoration longevity.

Restoration of severely decayed primary incisors using indirect composite resin restoration technique.

Caries of primary incisors is a common problem in paediatric dentistry in some countries. The restoration of primary incisors which have been severely damaged by early childhood caries or trauma is also a difficult challenge for clinicians. This case report describes an indirect technique for the restoration of primary anterior teeth using composite resin reinforced with a fibre-glass post. Over a one-year period, the crowns have demonstrated good retention and aesthetic results. The restorations were provided in two short chair-side sections, with satisfactory patient cooperation.

In vitro evaluation of probiotics microorganisms adhesion to an artificial caries model.

OBJECTIVE: This in vitro study compared the adhesion of two probiotics microorganisms (Lactobacillus casei Shirota and Lactobacillus acidophilus) to an artificial caries model. METHOD: In total, 30 bovine teeth were longitudinally sectioned, excluding the lingual half surface. The specimens were covered with nail varnish, except for an area of 3 by 5 mm in dentin, suspended in an artificial caries solution promoted by Streptococcus mutans, and incubated at 37 degrees C. After 14 days, the specimens were separated equally into two groups and transferred to a brain heart infusion culture media containing L. acidophilus (group A) and L. casei Shirota (group S), at 37 degrees C. After 48 h, the exposed area of dentin was washed with 1 ml of distilled water and the caries dentin was removed and dispersed in 1 ml of saline solution. The samples of distilled water and caries dentin were diluted and inoculated in Rogosa selective Lactobacillus agar. The results in CFU/ml were analysed by the Mann-Whitney test. RESULTS: There was no significant difference between Groups A and S for the lactobacilli count in samples of distilled water (P = 0.237). CONCLUSIONS: The amount of L. acidophilus in the artificially caries dentin was significantly superior compared to L. casei Shirota (P = 0.047), suggesting an inferior adhesion potential for this microorganism.

Takayasu's arteritis: what should the dentist know?

Takayasu's arteritis is a chronic inflammatory disease that affects large blood vessels, especially the aorta and/or its major branches. The condition presents with segmental lesions adjacent to normal, apparently unaffected, areas. The lesions include stenosis, occlusion, dilatations or aneurysm formations along the path of the affected artery. Because of the severity of the disease and the possibility of cardiovascular complications, patients with Takayasu's arteritis require medical treatment based on immunosuppressive and antihypertensive drugs, as well as regular follow up and surgical intervention in many instances. The aim of this paper was to describe the characteristics of Takayasu's arteritis, to report dental treatment carried out on an affected patient, and to discuss the main implications and care required during routine treatment for children in the dental office.

Evaluation of cutting patterns produced with air-abrasion systems using different tip designs.

This study assessed cavity preparations produced with different air abrasion tip parameters. Twelve test groups of extracted teeth were prepared to evaluate the parameters of 80 degrees or 45 degrees nozzle angles and 0.38 or 0.48 mm inner tip diameters. All other factors were held constant. A device was made to hold the specimen and air abrasion handpiece that standardized the distance and position relative to the tooth and time of application. The cavities were evaluated by assessing the rounding of the cavosurface margins and cavity floor. Measurements of cavosurface angles and the angle of concavity were made at the deepest portion of the abraded surface using scanning electron micrographs. The cavosurface angles were compared using paired t-test, and the effects of the tip design parameters were analyzed by ANOVA and Duncan's Multiple Range test. From the cavity patterns found in this study, the authors suggest that 80 degrees angle tips are more appropriate than 45 degrees angle tips for making narrow, deep cuts for preventive resin restorations. Conversely, when shallow preparations are needed, as in the case of Class V cavity preparations, cutting patterns of 45 degrees angle tips are more suitable.

Effect of handpiece tip design on the cutting efficiency of an air abrasion system.

PURPOSE: The aim of this study was to evaluate the effect of nozzle angle and tip diameter on the cutting efficiency of an air abrasion system. MATERIALS AND METHODS: Thirty-six extracted human third molars were air-abraded with the PrepStar microabrasion machine using a handpiece with either 80 degrees or 45 degrees nozzle angles with 0.38 or 0.48 mm tip orifice diameters. The following parameters were held constant: abrasive particle size (27 microm), air pressure (80 psi), distance (2 mm) and duration (15 seconds). The cutting efficiency was compared using enamel, dentin and cementum substrates. Width and depth of the cutting patterns were analyzed and measured using scanning electron micrographs. RESULTS: Statistical analysis using three-way ANOVA and Duncan's Multiple Range test revealed that the width of the cuts was significantly greater when the cavities were prepared using the 45 degrees nozzle angle. Significantly deeper cavities were produced with the 80 degrees nozzle angle. The tip orifice of the nozzle influenced the cutting efficiency in softer substrates, dentin and cementum. Precise removal of hard tissue is best accomplished using the 80 degrees angle nozzle tips for all types of tooth surfaces, enamel, dentin and cementum.

Fenestration gingival defect in erupting permanent mandibular incisors: a case report.

Bilateral fenestration of the labial gingival tissue of the permanent mandibular central incisors is described. The situation was followed over a 2-year period with no treatment other than prophylaxis and oral hygiene instruction. The final outcome was an apical positioning of the gingival margin, which was lower than that of the adjacent uninvolved teeth.