New
articles / Nuevos artículos
Actualizado
/ Updated January 7, 2005
Partial
caries removal and cariostatic materials in carious primary molar teeth:
a randomised controlled clinical trial
This paper determines the durability and effectiveness of a
black copper cement and a conventional glass ionomer cement when used
to restore primary molars following partial caries removal. It also
compares these results with conventional cavity preparation and restoration
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The aim of the current investigation is to evaluate optimal pontic and retainer fiber positions for Polyethylene fiber-reinforced composite (FRC) restorations. In series I notch disc specimens were used to mimic loading cuspal regions of pontics. Four groups (n=15/group; codes A to D) were prepared from Artglass composite. Groups A to C were reinforced with polyethylene fibers, and group D was an unreinforced control. Fibers were positioned either around (A), beneath the notch (B), or at the disc base (C). Specimens were stored in distilled water at 37ºC for 24 h before testing to failure (CHS=1mm/min) in a universal testing machine. Mean torque to failure values ranked [P< 0.05; one-way analysis of variance (ANOVA)] as follows A = B > C = D. In series II five groups of three unit bridges (n =5/group; codes A to E) were prepared from Artglass dental composite without (group A) or with (groups B to E) different Connect fiber reinforcement locations/techniques. Bridges were cemented using 2 bond resin cement to a standardized substructure. After storage, as per series I, bridges were loaded mid-pontic region to failure. One-way ANOVA showed no significant (P=0.08) difference between test groups. The research hypothesis was that notched disc and 3 unit bridge test techniques would discriminate equally between fiber-reinforced specimens and an unreinforced composite control was rejected.
Autotransplantation of mandibular third molars in a precocious phase of development is indicated when a substitute for adjacent compromised or missing molars is needed, and when mesial movements of the posterior teeth, the resultant loss of space, and overeruption of opposing teeth and consequent changes in the occlusion must be avoided.
Provided that the apices of the mandibular third molar are immature, the immediate replacement of a lost or compromised tooth usually ensures a good outcome. Transplantation of third molars helps to maintain alveolar bone and enables endosseous implantation without requiring bone regeneration.
We present examples of transplantation of mandibular third molars and review the factors that affect the success or failure of this procedure, such as atraumatic extraction and adequate immobilization of the transplanted tooth and root development after transplantation. Sex or age seem to have no effect on the final outcome.
The
effectiveness of fissure sealants
How effective are fissure sealants in preventing occlusal caries in children
and adolescents?
Data sources Sources were Medline, the Cochrane Library,
reference lists of identified articles and selected textbooks.
Study selection Selected studies were randomised clinical trials (RCT), quasi-RCT or controlled clinical trials that compared fissure sealing with no treatment or another preventive treatment, in children of up to 14 years of age at the beginning of study, with clearly described diagnostic criteria, and with at least 2 years follow-up. Studies reported in Danish, English, French, German, Italian, Norwegian, Spanish or Swedish were considered.
Data extraction and synthesis Inclusion decisions and grading of the studies was done independently by two of the authors. The main outcome was caries increment and the measure of treatment effect was either relative risk (RR) reduction or prevented faction. A pooled estimate was calculated for studies using resin-based materials.
Results Thirteen studies were included, eight of which used resin-based material and were selected for meta-analysis. The pooled estimate of effect for a single application of resin-based sealant on first permanent molars showed the RR of developing caries in sealed teeth relative to controls was 0.67 (95% confidence interval, 0.55-0.83), a reduction in RR of 33%. For repeated applications, the reduction in RR varied from 69 to 93%.
Conclusions The review provides limited evidence that fissure sealing of first permanent molars with resin-based materials has a caries-preventive effect. The evidence is incomplete for second permanent molars, premolars and primary molars and for glass ionomer cements. Overall, there remains a need for further trials of high quality, particularly in child populations of both low and high caries risk.
Streptococcus
mutans Strains Harboring Collagen-binding Adhesin
A previously
unidentified 120-kDa protein was detected in Streptococcus mutans strain
Z1 and was involved in the cold-agglutination of the strain. We have identified
the gene, designated cnm, as being involved in the agglutination of strain
Z1 following random mutagenesis. The amino acid sequence of the deduced
Cnm protein exhibited high similarity to those of collagen-binding adhesins
from staphylococci and other organisms. To confirm whether the protein
is involved in collagen-binding, we cloned a cnm gene fragment, overexpressed
it in E.coli, and prepared crude extracts. The extracts containing recombinant
protein exhibited binding to immobilized collagen and laminin but not
to fibronectin. Compared with the parental strain Z1, the cold-agglutination-negative
mutant 05A02 exhibited reduced binding to collagen and laminin but retained
that to fibronectin. This gene was detected in some strains of S. mutans.
Therefore, the cnm gene encoded a new strain-specific member of the collagen-binding
adhesin family.
Ultimas publicaciones en el area odontologia del British Journal of Medicine
Background
Clinical (normative) and subjective (self-assessment) evaluation of caries and periodontal diseases have been reported to demonstrate a significant disparity. The dental public health team is obligated to recognize and understand this gap. The objectives of the study were to investigate the practical values of using questionnaires (self–perceived assessment) as compared to clinical examinations (normative assessment) and to evaluate the implications of the results in understanding the public's perception of oral health.
Methods
The investigation was performed on 4920, 21 year-old Israeli adults upon release from compulsory military service between 1996 and 1998. Participants were asked to fill in a questionnaire inquiring how they would rate their personal dental and periodontal health levels. Clinical examinations, employing the DMFT and CPITN indices, were performed to determine normative oral health status. Perceived and normative assessments were compared for sensitivity, specificity, positive and negative predictive values and overall proportions using the clinical examinations as a gold standard.
Results
The sensitivity (disease perception) for dental status was found to be 0.34, while the specificity (health perception) was found to be 0.83. The positive predictive value for perceived dental status was found to be 0.68, whereas the negative predictive value was found to be 0.54. The sensitivity for perceived periodontal status was found to be 0.28, while the specificity was found to be 0.83. The positive predictive value for perceived periodontal status was found to be 0.05, whereas the negative predictive value was found to be 0.97. Regarding the overall proportions, a large discrepancy was found between self–assessment and professional assessment for both dental and periodontal health status.
Conclusions
Self-assessment questionnaires were of low value in evaluating oral health status both in the individual and public levels, though perception levels of health were higher than that of disease. Findings reflects a low level of awareness of the public that may influence care-seeking behavior and highlight the importance of oral health promotion and the crucial need for public health action.
