Oxalic acid may offer a novel approach to improve the reduction of dentin postoperative sensitivity after placement of resin-bonded restorations. SUMMARYThe aim of this double-blind randomized controlled clinical trial was to evaluate the reduction of dentin sensitivity using an oxalatebased compound, placed under adhesive restorations, during a four-month period. One hundred three preoperatively sensitive teeth, on 36 patients aged 25 to 66 years (mean, 40.367), were included in the study. Group A (experimental) was treated with oxalic acid (BisBlock) before resin-based composite (RBC) restorations (n¼52), and group B (control) was treated with distilled water before RBC restorations (n¼51). The first tooth in each patient was randomly assigned to group A, and the second tooth received group B. Clinical evaluation was made by a thermal/ evaporation test with an air syringe and measurement by visual analog scale (VAS) at baseline and four months after treatment. The results showed sensitivity reduction during the evaluation period (expressed in VAS values): group A, 7.6 to 0.8; group B, 7.3 to 2.6. We concluded from this study that both treatments reduced dentin sensitivity during the

One of the most effective and studied measures in the prevention of caries is the use of fluoride, which has the property to reduce their incidence and severity. In Chile, 75 % of the population receives it the drinking water. In 1984, WHO recommended the use of milk as an alternative vehicle. In Chile, the Fluoridated School Feeding Program (FSFP) was introduced in 1994, using this alternative in rural areas without fluoride in water. The objective of the study was to compare prevalence and severity of dental caries and dental fluorosis in 8-year-old children of four state schools: two with fluoride supplementation in drinking water or milk and two without any fluoride program. Epidemiological, descriptive, comparative, observational and cross-sectional study with a sample of 140 8-year-old children, with no systemic diseases and who had lived in the same place since birth: 50 schoolchildren from an area with fluoridated water; 40 from an area with fluoridated milk and 50 from a zone without supplementation of F. The percentage of caries-free children was obtained with the methodology described by the WHO, for severity the dmft and DMFT indexes were used. To quantify the prevalence and severity of dental fluorosis, Dean Index was used. 38 % of the children were caries-free in the community with fluoridated water (CFW); 0 % in the community with fluoridated milk (FSFP) and 10 % in the community with no fluoride program established (CNF). The difference between CFW with CNF is statistically significant (p<0.05). The prevalence of fluorosis is significantly higher for CFW (48.8 %) than FSFP (35 %) and CNF (16 %). Conclusion: The contribution of fluoride in drinking water causes a decrease in the prevalence and severity of dental caries in children of 8 years of age, and an increase in the prevalence of dental fluorosis.

La Poliposis Adenomatosa Familiar (PAF) es un síndrome hereditario autosómico dominante causado por la mutación del gen APC. En su forma clásica se desarrollan más de 100 pólipos adenomatosos intestinales que progresan a cáncer colorrectal en casi el 100% de los casos no tratados. Dentro de las manifestaciones extracolónicas de PAF, se encuentran las maxilofaciales, como: osteomas y alteraciones dentales, que pueden preceder por años al desarrollo de poliposis colónica. A pesar de que en Chile hay estudios de PAF y cáncer de colon, son escasos los reportes de manifestaciones maxilofaciales en estos pacientes. En la familia en estudio se encontró manifestaciones descritas previamente como: odontoma, osteomas y malformaciones de incisivos; adicionalmente tags mucosos que no se han asociado previamente al síndrome. ABSTRACTFamilial adenomatous polyposis (FAP) is an autosomal dominant hereditary syndrome caused by the mutation of the APC gene. In its classic form, more than 100 intestinal adenomatous polyps progress to colorectal cancer in almost 100% of cases if they are not treated. Within the extracolonic manifestations of FAP are the maxillofacial, such as: osteomas and dental alterations, which may precede the development of colonic polyposis. Although studies of colonic adenomatous polyposis and colon cancer exist in Chile, there are few reports of maxillofacial manifestations in these patients. In the family under study, previously described manifestations were found, such as: odontoma, osteomas and dental malformations; mucosal tags were also observed, with no previous association with the syndrome.