Comparison between two molar incisor hypomineralization detection criteria in epidemiological surveys

BACKGROUND

There is no consensus on which molar incisor hypomineralization (MIH) indices are more suitable for epidemiological surveys.

AIM

To compare the operational aspects and diagnostic ability of the MIH index (simplified/MIH_s and extended/MIH_e) with the MIH-Severity Scoring System (MIH-SSS) in classifying and diagnosing MIH.

DESIGN

This cross-sectional study assessed the indices in a homogeneous group of 680 6- to 10-year-old schoolchildren in Bauru, Brazil, who had at least one first permanent molar, ensuring consistent conditions. Followed by toothbrushing, the children seated on school chairs were examined by the two calibrated researchers under artificial lighting, using mouth mirror and WHO probe, and chronometer recording the duration of examinations.

RESULTS

The prevalence of MIH was 24.7%. The most common characteristic of MIH was demarcated opacity, with a prevalence of 81.7% and 85.45% according to the MIH_s and the MIH-SSS, respectively. A positive association was observed among the MIH_s, the MIH_e, and the MIH-SSS (chi-squared test; p < .01). The MIH-SSS demonstrated a shorter average application time than both versions of the MIH index (ANOVA/Tukey; p < .05). Additionally, fluorosis was found to be the most prevalent among other developmental defects of enamel, with a prevalence of 38.38%.

CONCLUSION

All systems effectively diagnosed MIH and its characteristics.

Revisiting the use of stainless steel crowns for treatment of molar-incisor hypomineralization: a case series

The restoration of teeth affected by molar-incisor hypomineralization (MIH) is challenging. To this end, preformed stainless steel crowns (SSCs) are a good option; however, their conventional use involves the removal of tooth structure. In the Hall technique, the SSC is seated over the primary teeth without caries removal or tooth preparation, aiming to seal carious lesions. This case series reports the use of SSCs in a similar way to the Hall technique for 3 pediatric patients with MIH. The high-caries-risk patient in case 1 lost hypomineralized enamel and developed a carious lesion immediately after eruption of a permanent first molar. The patient in case 2 complained of hypersensitivity associated with MIH of a first molar that had previously been restored. The patient in case 3 experienced atypical restoration failures in MIH-affected first molars. In all 3 cases, the use of SSCs without tooth preparation was an effective restorative treatment. Although this conservative treatment is a temporary solution, it provides good longevity and preserves tooth structure until the patient reaches physical and emotional/behavioral maturity for a definitive restoration.

Vitamin E: A potential preventive approach against dental erosion-an in vitro short-term erosive study

OBJECTIVES

This study evaluated the in vitro effect of different components of palm oil on enamel in a short-term erosive challenge.

METHODS

The acquired enamel pellicle (AEP) was previously formed in situ for 2 h. Subsequently, the bovine enamel blocks were treated in vitro according to following solutions: G1-palm oil; G2-85% tocotrienol solution; G3-oily vitamin E; G4-oily vitamin A; G5-deionized water (negative control); G6-stannous-containing solution (Elmex® Erosion Protection Dental Rinse) (positive control). After application of the treatment solutions (500 µl, 30 s), the blocks were immersed in 0.5% citric acid (pH 2.4) during 30 s (initial erosion). The response variable was the percentage of surface hardness loss. Data were analyzed by one-way ANOVA and Fisher's Test (p < 0.05).

RESULTS

The positive control (G6), palm oil (G1) and oily vitamin E (G3) groups presented the lowest percentage of surface hardness loss, and were statistically different from the negative group (G5) (p < 0.05), and no differences were found between these three groups. The 85% tocotrienol solution (G2) and oily vitamin A groups (G4) were not different to the negative control group.

CONCLUSIONS

Stannous-containing positive control (Elmex® Erosion Protection), palm oil and oily Vitamin E were able to protect enamel against the erosive challenge performed in this in vitro study. In addition, vitamin E is probably the key ingredient of palm oil responsible for preventing enamel erosion.

CLINICAL SIGNIFICANCE

Vitamin E presented similar preventive effect to a commercial mouthwash stannous-containing solution (Elmex® Erosion Protection) against initial erosion and, it can be considered as a promising natural alternative for the formulations of solutions aiming to prevent erosive tooth wear.

Simplified occlusal replica adapted technique with glass ionomer cement for molar-incisor hypomineralization-affected molars: An 18-month follow-up

BACKGROUND AND OVERVIEW

Molar-incisor hypomineralization (MIH) is a qualitative developmental defect of enamel, which has been a daily concern in clinical practice owing to its difficult treatment.

CASE DESCRIPTION

An 11-year-old girl was admitted to the pediatric dental clinic with a symptom of severe hypersensitivity in the permanent molars owing to MIH. The treatment consisted of a simplified occlusal replica adapted technique with conventional glass ionomer cement in the MIH-affected molars, which involved laboratory and clinical stages. The patient was reexamined every 3 months, and after 18 months there was no additional tooth structure loss, restoration failure, or pain. This technique may be considered a feasible alternative to restore hypomineralized teeth owing to its reduced procedure time and good performance in the follow-up period of 18 months.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The technique successfully restored the function and shape of the affected teeth, decreasing the sensitivity by means of covering the demarcated MIH opacities.

Influence of mandibular and palatal intraoral appliances on erosion in situ study outcome

The standardization of in situ protocols for dental erosion is important to enable comparison between studies.

Impact of a simplified in situ protocol on enamel loss after erosive challenge

This study investigated the effect of the period of use and location of intraoral appliances on enamel surface loss. This randomized, single blind in situ study was conducted in 2 crossover phases based on the period of use, in which maxillary and mandibular appliances were simultaneously worn. Bovine enamel blocks (n = 120) were randomly divided among the studied groups by surface hardness. In each phase, fifteen volunteers used one maxillary appliance and two mandibular appliances for 5 days. Erosive challenge was performed 4X/day by immersion in 0.01 M HCL for 2 minutes. In the continuous phase, the intraoral appliances were worn for 20 hours. In the intermittent phase the appliances were worn for 8 hours and 30 minutes. Enamel loss was determined profilometrically. The discomfort of use of the appliances were evaluated in a questionnaire. Data were analyzed by two-way ANOVA/Tukey’s test and chi-square test (p<0.05). The maxillary appliance promoted higher enamel loss compared to the mandibular one (p<0.001). Intermittent use of appliances resulted in similar enamel loss to the continuous one (p = 0.686). All volunteers preferred to use the maxillary appliance in an intermittent regimen. The intermittent use of maxillary appliance is a simplified reliable protocol appropriated for in situ erosion studies in enamel.

Effect of different salivary exposure times on the rehardening of acid-softened enamel

This in situ study assessed the effect of different times of salivary exposure on the rehardening of acid-softened enamel. Bovine enamel blocks were subjected in vitro to a short-term acidic exposure by immersion in 0.05 M (pH 2.5) citric acid for 30 s, resulting in surface softening. Then, 40 selected eroded enamel blocks were randomly assigned to 10 volunteers. Intraoral palatal appliances containing 4 enamel blocks were constructed for each volunteer, who wore the appliance for 12 nonconsecutive hours: initial 30 min, followed by an additional 30, and then by an additional 1 hour. For the last additional 10 hours the appliances were used at night, during the volunteers' sleep. Surface hardness was analyzed in the same blocks at baseline, after erosion and after each period of salivary exposure, enabling percentage of surface hardness recovery calculation (%SHR). The data were tested using repeated measures ANOVA and Tukey's test (α = 0.05). Increasing periods of salivary action promoted a progressive increase in the surface hardness (p < 0.001). However a similar degree of enamel rehardening (p = 0.641) was observed between 2 hours (49.9%) and 12 hours (53.3%) of salivary exposure. Two hours of salivary exposure seems to be appropriate for partial rehardening of the softened enamel surface. The use of the intraoral appliance during sleep did not improve the enamel rehardening after erosion.