10-years Clinical Trial of Sealed of Margin Failures
Condition: Dental Caries Secondary to Acquired Defects of Tooth Structure
MeSH terms: Dental Caries
Study type: Observational [Patient Registry]

Summary: 
      -  Assess the effectiveness of sealing localized marginal defects of amalgam restorations
           that were initially scheduled for replacement of restorations.

        -  The hypothesis was that sealed defective margins of the amalgam restorations shows
           similar performance than replacement amalgam restorations.
    

Detailed description: 
      Study Design

      Were examined 157 patients with 586 amalgam restorations that were recruited at the Operative
      Dentistry Clinic, at the Dental School, University of Chile with the indication of amalgam
      replacements, of them, a cohort of thirty two patients (19 females and 13 males, mean age =
      27 years old), with 73 Class I amalgam restorations, that presented one or more localized
      margin defects (Bravo or Charlie according to modified United State Public Health Service,
      USPHS criteria), were included in the study. The protocol was approved by the Institutional
      Research Ethics Committee of the Dental School at the University of Chile, Investigation
      Project, School of Dentistry (0205) and all patients signed the informed consent form and
      completed the registration form. Only Faculty members were accepted to provide the treatment.

      Treatment Groups Criteria: 73 restorations with defective margins were evaluated in
      accordance with the modified USPHS criteria and assigned to either the sealant (n=26), repair
      (n=21) and control groups (n=26).

      Restorations Assessment: The quality of the restorations were evaluated using the modified
      U.S. Public Health System/Ryge criteria. Two examiners assessed the restorations
      independently and by visual and tactile (mouth mirror number 5) examination using an explorer
      (N° 23) and indirectly by radiographic, examination, for interproximal observation (Bite
      Wing). All the restorations were examined at baseline and each year during four and ten years
      after treatment. The restorations assessment was carried out by five parameters: marginal
      adaptation (MA), roughness (R), secondary caries (SC), marginal stain (MS) and teeth
      sensitivity (TS). If any difference was recorded between the 2 independent examiners, and
      they did not reach an agreement, a third clinician was called to assist with the process
      decision. If the three clinicians they did not reach an agreement, the lower score was
      recorded. All three clinicians participated in calibration exercises at the beginning and
      before the last examination took place and the inter-examiner reliability results were
      Kappa=0.74 at the baseline and Kappa=0.87 at the ten year.

      A change from Bravo to Alpha was considered an improvement and a change from Alpha to Bravo
      was considered downgrade.

      Caries risk assessment: A graphical computed program (CARIOGRAM) was used for individual´s
      patients caries risk assessed, the program weighted the interaction between the following 10
      caries related factors: Caries experience, related general disease, diet contents, diet
      frequency, plaque amount by Silness Löe Index, semi quantitative detection of mutans
      streptococci and lactobacilli in saliva by Caries Risk Test (CRT), fluoride program, amount
      of saliva stimulated secretion by CRT Buffer (Vivadent), saliva buffer capacity and clinical
      judgment. Patients were classifying in high, intermediate and low caries risk. Additionally
      the results also indicate where targeted actions to improve the situation will have the best
      effect.

      Patients were recalled ten years after the treatment, for clinical assessment by the same
      examiners, applying the same criteria used at baseline. Failed restorations were removed from
      the study and treated according to the diagnosed needs.

      Statistical analysis The ordinal dependent variable was changed in level of the modified
      USPHS criteria from the baseline value. The assigned score of each restoration reflected the
      worst result for any of the parameters. The results of each group in terms of degradation or
      upgrade were analyzed by Friedman range non-parametric test to compare the pre and
      postoperative conditions. Additionally, the performance of all groups was contrasted using
      the Mann Whitney test to determine the differences between the upgrade and downgrade of the
      restoration´s quality. The statistical significance was set at 95%, α=0.05 and β=0.80 for
      statistical analysis.
    

Intervention name(s): Sealing of amalgam margin defects; Sealing of amalgam margin defects
Intervention type(s): Other; Other
Intervention description(s): Comparison between sealing of amalgam margins defects, replacement and non treated groups.; A.Sealing of amalgam margin defects: were acid etched with 35% phosphoric acid for 15 seconds. A resin-based sealant (Clinpro Sealant, 3MESPE) was applied over the defective area. The sealant was polymerized with a photocuring unit (Curing Light 2500, 3M ESPE) for 40 seconds. Rubber dam isolation was used for this procedure. All treatments were applied by the same clinician.
B.Replacement Group: The clinician totally removed and replaces the defective restoration with a new amalgam (Tytin, Kerr Corporation, Orange, CA, USA). Rubber dam isolation was used for this procedure. All treatments were applied by the same clinician.
C.Control Group: The defective restorations did not receive any treatment.
Other intervention name(s): Use of Selant to seal amalgam margins defects
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients of the Operative Dentistry Clinics, School of Dentistry, University of Chile
      
Keywords: Sealant, Margins Defect, Amalgam