First Permanent Molars and Permanent Incisors Teeth by Tooth Prevalence of Molar-Incisor-Hypomineralisation in a Group of Spanish Schoolchildren

Background

Molar-incisor-hypomineralisation (MIH) is a disturbance in dental development that commonly involves first permanent molars but permanent incisors may also be compromised. The prevalence of MIH in the literature varies between 2.5% and 40% of the world child population. Little information is gained on the prevalence of MIH among children in Spain.

Aim

The aim of this study was to investigate the prevalence of MIH among school children from Barcelona, Spain.

Material and methods

A cross-sectional study which included 705 children, aged 6 -14 years and 11 months was carried out. Full mouth examinations were performed using the European Academy of Paediatric Dentistry (EAPD) criteria for the diagnosis of MIH.

Results

A total of 56 cases of MIH were found, 22 (39.3%) boys and 34 (60.7%) girls. The prevalence was 7.94% (6.39% for boys and 9.41% for girls). MIH lesions were seen more often in girls than boys (χ² = 4.9, p= 0.023) the male/female ratio being 1:1.54. Upper teeth were more prevalent than lower teeth in both genders with an upper/lower ratio of 1.86/1 for boys and 1.68/1 for girls.

Conclusion

Considered either by gender or by teeth, upper teeth and girls were ahead in our sample.

Oral focal fibrous hyperplasia and squamous cell papilloma treated with an erbium laser. Case presentation

Mouth and oropharynx cancer constitute 5% of all malignancies; 95% of them are head and neck squamous cell carcinomas. Carcinogenesis is a multifactor process. Mutagenesis is also determined by the human papilloma virus which has recently been found to be etiologically associated with 20 to 25% of head and neck squamous cell carcinomas, mostly in the oropharinx. Focal fibrous hyperplasia of the connective tissue comes up as an answer to a chronic irritation in which a big amount of collagen can be found. As there exist certain clinical resemblance between squamous cell papilloma, fibrous focal hyperplasia and other mesenchimal tumors it is recommended to proceed, always, with removal and study. Two cases, one of an oral papilloma and another of a focal fibrous hyperplasia in pediatric patients, treated with an Er,Cr:YSGG laser wave length (mu) of 2780 nm are presented.

Laser-assisted treatment of a dentigerous cyst: case report

Dentigerous cysts are benign maxillary odontogenic cysts associated with the crown of an unerupted tooth. They can expand the cortical bone to such an extent that they cause displacement of teeth and root resorption in the adjacent teeth. The purpose of this report was to describe the clinical case of a dentigerous cyst in a mandibular permanent molar of a 6-year-old child. The cyst caused the displacement of the bud of the permanent second molar and root resorption of the primary second molar. The cyst was treated by: (1) mucous fenestration using an erbium laser: (2) drainage of the fluid content; and (3) curettage of the bone cavity. The injury was successfully resolved in just 5 months with: (1) bone regeneration; (2) the repositioning of the displaced bud; and (3) correct eruption of the affected tooth.

Eruption cyst treated with a laser powered hydrokinetic system

Eruption cysts are benign cysts that appear on the mucosa of a tooth shortly before its eruption. The majority disappear on their own. If they hurt, bleed or are infected they may require surgical treatment to expose the tooth and drain the content. Here we present a clinical case of a six-year-old child with an eruption cyst on the permanent maxillary central left incisor, which was handled using treatment with an Er,Cr-YSGG laser. It did not require suture, there was no haemorrhage, swelling, infection or postoperative pain. The treatment of eruption cysts with this technique facilitates obtaining the cooperation of pediatric patients and makes behavior management by the pediatric dentist easier.

Bond strength and micro morphology of a self-etching primer versus a standard adhesive system with varying etching times in primary teeth

AIMS

These were to firstly evaluate the shear bond strength of a composite resin to primary dental enamel treated with a standard adhesive system but with varying phosphoric acid etching times along with a self-etching prime, secondly to analyse the etching patterns using SEM.

METHODS

Forty primary molars were used. In the first three groups, following acid etching, a layer of Prime & Bond NT adhesive was employed, and in group 4 the self-etching adhesive system (Prompt-L-Pop) was used. A composite cylinder (Spectrum, Denstply, Germany) was then applied. After processing of the samples, the teeth were subjected to shear stress using an Instrom universal machine. The study of primary enamel morphology after etching for different time periods and using different etching systems was carried out with a scanning electron microscope.

STATISTICS

Data were analysed using one way ANOVA, followed by Scheffé, test to determine differences between groups.

RESULTS

In the groups subjected to acid etching for 5 and 15 seconds significant differences were recorded versus the self-etching group (p<0.0001). Regarding the SEM study of primary enamel morphology, there was predominately a clear and marked type 2 etching pattern.

CONCLUSIONS

Longer acid etching times for primary enamel do not appear necessary, as 15 seconds suffice to obtain retentive etching patterns, and the bonding strengths obtained with the traditional etching technique followed by two-step adhesive application are sufficient to ensure good composite resin bonding to the enamel surface. However, the self-etching adhesive system employed yields less than optimum bonding strength to primary enamel surfaces.

Effect of different prophylaxis methods on sealant adhesion

The objective of this study was to evaluate the retention of a light-cured sealant using previously different prophylaxis methods and two different etching times, thirty and fifteen seconds. Eighty, third molars surgically extracted were sectioned into two halves (buccal and lingual). The teeth were divided into 8 groups of 20 samples each, according to prophylaxis type: pumice powder, fluoridated paste, sodium bicarbonate spray, and control (no prophylaxis); and etching time: 30 and 15 seconds. Tensile bond strengths were studied using a universal Instron testing machine. A statistical test ANOVA was used. No statistical differences were found when comparing both etching times, but when prophylaxis methods were compared a statistically significant higher retention was found in the sodium bicarbonate and fluoridated paste groups.