Distribution and morphology of enamel hypomineralisation defects in second primary molars

Influence of different pre-treatments on the resin infiltration depth into enamel of teeth affected by molar-incisor hypomineralization (MIH)

OBJECTIVES

This in vitro pilot study aimed to evaluate whether different pre-treatments (demineralization, deproteinization, (chemo-)mechanical reduction of the surface layer) influence the penetration depth of a resin infiltrant into MIH-affected enamel compared to initial carious lesions.

METHODS

Thirty extracted human permanent molars with non-cavitated initial carious lesions (n = 5) or MIH (n = 25) were chosen and randomly assigned to six experimental groups: IC: initial caries; M: MIH; MN: MIH, 5.25% sodium hypochlorite; MM: MIH, microabrasion; MA: MIH, air abrasion; MAN: MIH, air abrasion and 5.25% sodium hypochlorite. A modified indirect dual fluorescence staining method was adopted to assess the penetration depth (PD) of the resin infiltrant and the lesion depth (LD) by confocal laser scanning microscopy (CLSM). Exemplarily, scanning electron microscopic (SEM) images were captured. The relationship between group assignment and penetration/lesion depth was estimated using a linear mixed model incorporating the tooth as random effect (two observations/tooth). The significance level was set at p < 0.05.

RESULTS

For MIH-affected molars, the mean PD (in µm; median, [minimum-maximum]) were M (178.2 [32.5-748.9]), MN (275.6 [105.3-1131.0]), MM (48.7 [0.0-334.4]), MA (287.7 [239.4-491.7]), and MAN (245.4 [76.1-313.5]). Despite the observed differences in PD between the groups, these could not be statistically verified (Bonferroni, p = 0.322). The percentage penetration was significantly higher for IC than for MIH groups (Bonferroni, p < 0.05).

SIGNIFICANCE

Compared to IC, resin infiltration into MIH-affected enamel ist more variable. Different pre-treatments influence the resin penetration into developmentally hypomineralized enamel to a fluctuating level.

The Retention Effect of Resin-Based Desensitizing Agents on Hypersensitivity-A Randomized Controlled Trial

Recently, the development of dental materials has increased the availability of various hyperesthesia desensitizers. However, there are no studies on the duration of retreatment in terms of adherence rates. Thus, the adhesion rates of resin-based desensitizers were investigated. We used a conventional desensitizer and a recently developed desensitizer containing calcium salt of 4-methacryloxyethyl trimellitic acid (C-MET) and 10-methacryloyloxydecyl dihydrogen calcium phosphate (MDCP). These colored agents were applied to the surfaces of premolars and molars, and the area was measured from weekly oral photographs. Areas were statistically analyzed and mean values were calculated using 95% confidence intervals. A p-value of <0.05 was considered statistically significant. These rates were significantly higher on the buccal side of the maxilla and lower on the lingual side of the maxilla. In addition, the desensitizer containing C-MET and MDCP displayed significantly higher adhesion rates. It is suggested that this will require monthly follow-ups and reevaluation because both agents cause less than 10% adherence and there is almost no sealing effect after 4 weeks. In addition, the significantly higher adhesion rate of the desensitizer containing C-MET and MDCP indicated that the novel monomer contributed to the improvement in the adhesion ability.

Evaluation of a Hypersensitivity Inhibitor Containing a Novel Monomer That Induces Remineralization-A Case Series in Pediatric Patients

BACKGROUND

Recently, tooth deformities have been frequently encountered by pediatric dentists. Severe enamel hypomineralization sometimes induces pain such as hyperesthesia, but composite resin restoration is difficult because it often detaches without any cavity preparation. Resin-based hypersensitivity inhibitors for tooth physically seal the dentinal tubules. It was reported that hypersensitivity inhibitor containing novel adhesive monomers forms apatite and induces remineralization in vitro. Therefore, these case series assessed the clinical effects of remineralization and the suppression of hypersensitivity by Bio Coat Ca (Sun Medical, Shiga, Japan).

METHODS

After mechanical tooth cleaning was performed, the hypersensitivity inhibitors were applied and cured by light exposure. Changes in hypersensitivity were determined by visual analog scale (VAS). The improvement of hypomineralization was evaluated by the change in color tone based on the digital images of intraoral photographs.

RESULTS

After repeated monthly treatments, these cases showed decreased hypersensitivity after the fourth application, while the opaque white and brownish color improved on the seventh application.

CONCLUSION

This novel hypersensitivity inhibitor with calcium salt of 4-methacryloxyethyl trimellitic acid (C-MET) and 10-methacryloyloxydecyl dihydrogen calcium phosphate (MDCP) not only suppressed hypersensitivity but also improved cloudiness and brown spots in recently erupted permanent teeth in presented cases.

A Four-Year Follow-Up Case Report of Hypomineralized Primary Second Molars Rehabilitated with Stainless Steel Crowns

Hypomineralized primary second molars (HPSM) are characterized by enamel opacities accompanied by hypersensitivity and atypical caries lesion, on one to four primary second molars. The correct treatment and follow-ups of those teeth have an important impact on a correct eruption of the first permanent molars and future occlusion. Hence, this report aims to describes a case of a severe HPSM in all second molars of a four-year-old girl and subsequent four-year follow-ups. The rehabilitation involved the placement of four stainless steel crowns on all four second primary molars under general anesthesia. Concerning the available literature and the case severity of HPSM, the treatment approach proposed for the case provided good functional outcome.

Enamel opacities in all other than Molar Incisor Hypomineralisation index teeth of adolescents

BACKGROUND

There are scarce data on the hypomineralisation of other permanent teeth (HOPT) than the index teeth of Molar Incisor Hypomineralisation (MIH).

AIM

To report on the prevalence and surface pattern of HOPT and seek associations with MIH.

DESIGN

Representative samples of urban Greek 14-year-olds were examined in classroom with a dental mirror. Their enamel defects were recorded using EAPD criteria for MIH. Descriptive statistics and correlation tests for HOPT vs previously reported MIH findings in the same samples were applied.

RESULTS

HOPT prevalence in 1156 consented adolescents was 22.9%. 148 (16.2%) of 912 no-MIH children had HOPT; 117 (48.1%) of the 244 MIH children had HOPT too (OR 3.0, 95% CI 2.4-3.6). There were more HOPT teeth per child in the MIH vs no-MIH children (P < .001). HOPT tooth frequency was as follows: second molar 33.7%, canine 25.7%, first premolar 23.6%, and second premolar 17.0%. Enamel breakdown was seen in 5.3% HOPT children. Vestibular to intraoral surface defect ratio differed between jaws (maxilla 187/88, mandible 149/17, P < .05).

CONCLUSIONS

Hypomineralisation defects in the MIH non-index teeth collectively had comparable prevalence and tooth surface patterns to MIH, but much lower severity. MIH was predictor for HOPT.