The purpose of this study is to compare the effectiveness of the conservative (pulpectomy) versus non-conservative treatment (tooth extraction) of primary molars affected with severe dental caries associated to oral health-related quality of life, anthropometric and clinical outcomes.

Treatment: evaluate two interventions for treating severe dental caries in primary molared of preschool children.

SAMPLE: preschool children aged 3 to 5 years with severe dental caries (SDC) in primary molars. SDC will be indicated by the Pufa index. The Pufa index records the presence of severely decayed teeth with visible pulp involvement (p), ulceration of the oral mucosa owing to root fragments (u), fistula (f) and abscess (a). Children with pufa-score > 0 in primary molars will be included in the study. All children aged 3 to 5 years, who sought dental screening at the Dental School, University of São Paulo (USP) in August to October 2013 can be initially eligible.

CLINICAL GROUPS RANDOMLY ASSIGNED:

• Group A: Conservative treatment represented by pulpectomies + teeth restoration with composite resin crown.

• Group B: Dental extraction

  • Treatment of carious teeth with pufa score =0 will receive dental fillings (01 occlusal surface affected: ART; 02 surfaces affected: composite resin; ≥ 03 surfaces affected: composite resin crown).
  • One operator (specialists in paediatric dentistry) blinded to the outcomes will carry out the treatments.

FOLLOW-UP: 4, 8 and 12 months.

OUTCOMES: All outcomes will be assessed by a single person interviewer/examiner blinded to the oral treatments groups.

1. Oral Health-Related Quality of Life:

   • Brazilian SOHO-5
   • Brazilian ECOHIS

2. Anthropometric measures:

   • Weight-for-age Z-score (WAZ)
   • Height-for-age Z-score (HAZ)
   • BMI-for age Z-score (BAZ)

3. Dental anxiety (Facial Image Scale).

4. Dental pain (Wong-Baker Scale)

5. Problems in the developing occlusion: loss of space

Inclusion Criteria:

• Preschool children with severe dental caries (SDC) in primary molars.
• SDC will be indicated by the Pufa index
• The Pufa index records the presence of severely decayed teeth with visible pulp involvement (p), ulceration of the oral mucosa owing to root fragments (u), fistula (f) and abscess (a). Children with a pufa-score > 0 will be included in the study.

Exclusion Criteria:

• Children with severe crowding of anterior teeth
• Severe arch length deficiencies
• Children with systemic and neurological diseases or those with illnesses that adversely affect growth according to parents reports
• Children on regular nutrition supplements
• Children who had undergone dental treatment in the last three months and who were not willing to participate in the study. Tooth with anomalies, extensive crown destruction and impossibility of absolute isolation in the conservative intervention group.