Dental Caries Secondary to Acquired Defects of Tooth Structure Clinical Trial
Official title:
Longitudinal Results of a 10-years Clinical Trial of Sealed Margin Failures of Amalgam Restorations
- 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.
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.
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Observational Model: Case Control, Time Perspective: Prospective