The change of teeth color, whiteness variations and its psychosocial and self-perception effects when using low vs. high concentration bleaching gels: a one-year follow-up.

BACKGROUND: Dental bleaching in traditional concentrations generates greater sensitivity. In this respect, new systems of lower concentration of hydrogen peroxide for tooth bleaching appeared, with color stability unknown over time. The aim of this study was to compare the change and stability of color with low-concentration (6%) hydrogen peroxide gel in an in-office bleaching setting relative to conventional 37.5% gel, including their effects on psychosocial and esthetic self-perception, after 1 year. METHODS: Patients (n = 25) were assessed at 12 months post bleaching treatment (whitening with 6% chemo-activated alkaline formula gel versus 37.5% traditional concentration gel). Color changes were measured objectively using total variation in color (ΔE), and subjectively using Vita Classical and Vita Bleached scale (ΔSGU) by calibrated evaluators (Kappa = 0.85). The Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) and Oral Health Impact Profile (OHIP-14) aesthetic questionnaires were used to measure the self-perception and the psychosocial impact of the bleaching protocols. RESULTS: The effect (ΔE) of 37.5% HP (8.37 ± 2.73) was significantly better than that of 6% HP (5.27 ± 2.53) in terms of color rebound after 1 year of follow-up. There were significant differences in psychosocial impact and esthetic self-perception measurements prior to bleaching versus one-year post-whitening time points; positive effects were maintained. CONCLUSIONS: Low concentration (6%) achieved effective bleaching with good stability after 1 year, accompanied by a positive psychosocial impact and enhanced self-perception at follow-up. TRIAL REGISTRATION: NCT03217994 (before enrollment of the first participant). Data register: July 14, 2017.

Effectiveness of Dental Bleaching With 37.5% and 6% Hydrogen Peroxide and Its Effect on Quality of Life.

OBJECTIVE:: This study investigated whether it is possible to achieve equally satisfactory results between 37.5% hydrogen peroxide (HP) gel and 6% HP gel. We also assessed the psychosocial impact and self-perception of esthetics generated by extracoronal tooth whitening. METHODS AND MATERIALS:: A prospective, double-blind, randomized clinical trial was carried out. A total of 33 patients were selected from the clinic of the Faculty of Dentistry at the University of Chile. The patients included men and women over 18 years old without prior tooth whitening treatments, tooth decay, or restorations of the maxillary anterior teeth. The patients had tooth colors of A3 or less according to the Vita Classical scale, which was determined with a Vita Easy Shade spectrophotometer. The study was carried out with a "split-mouth" design. One side of each mouth was randomly treated with 37.5% HP, and the other side was bleached with 6% HP. Each group received 3 to 12 minutes of treatment with the respective gel applications. Two sessions of bleaching were carried out each week. A spectrophotometer was used to measure the total variation of color (ΔE), and a subjective evaluation was made with Vita Classical scale (ΔSGU) between the baseline (session 1) and different measurement times. We compared ΔE and ΔSGU for both agents using the Mann-Whitney test ( α=0.05). RESULTS:: In both groups, there was variation among the initial color and the color in the different measurement times. In the month after the treatment was completed, ΔE was 9.06 in the 37.5% HP group and 5.69 in the 6% HP group. The difference between the two groups was statistically significant starting in the second session ( p=0.000). CONCLUSION:: There was a significant difference between the effectiveness of the bleaching gel concentrations of 37.5% and 6% HP according to spectrophotometer measurements and subjective evaluations. There was also a positive effect on psychosocial impact and esthetic self-perception among patients.

Does the Use of a "Walking Bleaching" Technique Increase Bone Resorption Markers?

OBJECTIVE: This randomized clinical trial evaluated the effect of 35% hydrogen peroxide in comparison with 37% carbamide peroxide in a nonvital bleaching technique of "walking bleaching" (four sessions of treatment) on periodontal markers: nuclear factor kappa B-ligand (RANK-L-process of root resorption marker) and interleukin 1ß (IL-1ß-inflammatory response marker). METHODS AND MATERIALS: Fifty volunteers presenting with discoloration of nonvital teeth and endodontic treatment in good condition participated. Fifty teeth were randomly divided into two study groups according to bleaching gel: HP = 35% hydrogen peroxide (n=25) and 37% carbamide peroxide (n=25). Nonvital bleaching was performed with a walking bleaching technique consisting of four sessions of bleach application. Gingival crevicular fluid samples were taken in order to quantify the RANK-L and IL-1ß levels by enzyme-linked immunosorbent assay. Samples were obtained from six periodontal sites for each bleached tooth: three vestibular and three palatine (mesial, middle, and distal) at seven time periods: baseline, after each of the four sessions of nonvital bleaching, at one week, and at one month after nonvital bleaching. Tooth color variations were analyzed in each session by VITA Bleachedguide 3D-MASTER (ΔSGU). RESULTS: Significant increments in the RANK-L and IL-1ß levels were detected in each evaluated time compared with baseline ( p<0.05); however, no differences were detected between hydrogen peroxide and carbamide peroxide on increments of the biomarkers studied. The change of color was effective for both nonvital bleaching therapies ( p<0.05). CONCLUSIONS: Nonvital bleaching induced a significant increment in the RANK-L and IL-1ß levels in periodontal tissues around bleached, nonvital teeth.

[Kinship determination using DNA markers]. / Estudios de parentesco mediante marcadores del ADN: Experiencia en resolución de casos en los últimos seis años.

BACKGROUND: Autosomal and Y chromosome short tandem repeats (STRs) and mitochondrial DNA polymorphisms are the most commonly used molecular tools for determination of kinship. AIM: To report a revision of 1,120 kinship cases (paternity and others) analyzed in our laboratory. MATERIAL AND METHODS: Revision of all kinship cases analyzed between years 2001-2006. Autosomal and Y chromosome STRs and mitochondrial DNA polymorphisms were analyzed in DNA extracted from blood samples. RESULTS: Paternity was excluded in 27.2% of cases. This figure did not change significantly along years. Most paternity exclusions were confirmed by the discordance in 5 genetic markers (30.5%), followed by exclusion of 4 and 6 genetic markers (20.3 and 20% respectively). Two studied cases were paternal and maternal exclusions, corresponding to a change of children between two families. In one case, the paternal line was assessed through Y chromosome markers, studying 16 STRs of this chromosome, positively confirming this paternal relationship. Another case was analyzed for maternal line using mitochondrial DNA analysis. In six cases, a genetic marker with a paternal-sibling mutation, was observed. The criteria for the determination of mutation was the finding of only one discordant marker between at least thirteen markers analyzed in each case. Also, an increase or decrease in one unit repeated in tandem (tetranucleotide) between the alleged father and the son was also required. One subject had a double mutation. In this case, paternity was confirmed analyzing thirteen autosomic STRs and five Y-STRs. CONCLUSIONS: The authors have acquired great expertise in kinship analysis and had established criteria to solve complex kinship cases.

Estudios de parentesco mediante marcadores del ADN: Experiencia en resolución de casos en los últimos seis años / Kinship determination using DNA markers

Autosomal and Y chromosome short tandem repeats (STRs) and mitochondrial DNA polymorphisms are the most commonly used molecular tools for determination of kinship. Aim: To report a revision of 1,120 kinship cases (paternity and others) analyzed in our laboratory. Material and methods: Revision of all kinship cases analyzed between years 2001-2006. Autosomal and Y chromosome STRs and mitochondrial DNA polymorphisms were analyzed in DNA extracted from blood samples. Results: Paternity was excluded in 27.2 percent of cases. This figure did not change significantly along years. Most paternity exclusions were confirmed by the discordance in 5 genetic markers (30.5 percent), followed by exclusion of 4 and 6 genetic markers (20.3 and 20 percent respectively). Two studied cases were paternal and maternal exclusions, corresponding to a change of children between two families. In one case, the paternal line was assessed through Y chromosome markers, studying 16 STRs of this chromosome, positively confirming this paternal relationship. Another case was analyzed for maternal line using mitochondrial DNA analysis. In six cases, a genetic marker with a paternal-sibling mutation, was observed. The criteria for the determination of mutation was the finding of only one discordant marker between at ¡east thirteen markers analyzed in each case. Also, an increase or decrease in one unit repeated in tandem (tetranucleotide) between the alleged father and the son was also required. One subject had a double mutation. In this case, paternity was confirmed analyzing thirteen autosomic STRs and five Y-STRs. Conclusions: The authors have acquired great expertise in kinship analysis and had established criteria to solve complex kinship cases.

Estudio de tres loci hipervariables en población mixta chilena / Study of 3 hypervariable loci in a mixed chilean population

Background: Genetic markers are useful to study evolution parameters in populations and to determine kinship. Aim: To characterize three short tandem repeat loci in a sample of Chilean subjects and compare them with Caucasian and Hispanic populations. Material and methods: Three hundred ninety three unrelated subjects that were sent for genetic studies from courts of justice, were studied. The loci FESFPS, F13A01 and vWA in blood samples, were typified amplifying DNA by polymerase chain reactions. Results: The three studied loci were highly polymorphic. F13A01 and FESFPS were in Hardy-Weinberg genetic equilibrium. A significant excess of heterozygotes was detected for vWA locus. There were no differences in allele frequencies, according to ethnic origins of last names. Allele frequencies for F13A01 and vWA loci were similar to those of Hispanic populations of Unites States and FESFPS loci was different. Conclusions: All three loci had a high efficiency for genetic identification tests according to the estimated a priory exclusion probability

Análisis de paternidad utilizando cuatro marcadores de DNA amplificados mediante la reacción en cadena de polimerasa / Paternity analysis using 4 DNA markers amplified by polymerase chain reaction

Background: DNA typing in forensic analysis is a useful tool to analyze paternity due to its high discrimination power. Aim: To report the experience of Servicio Medico Legal in Santiago, resolving cases of dubious paternity. Subjects and methods: Four highly polymorphic loci, amplified by polymerase chain reactions, were analyzed in 153 cases of uncertain paternity. The paternity index was calculated for each case. Results: The four genetic markers analyzed provided an exclusion probability of 0.933 for the general population in Santiago. Thirty seven cases were excluded as parents. In 31 cases, the paternity index ranged from 19 to 100, considered as probable paternity and 77 cases had an index of over 100, considered as almost certain paternity. Eight cases had an index between 0.5 and 19, considered as inconclusive. All loci met Hardy-Weinberg expectations and their frequencies were similar to other data from people living in Santiago. Conclusions: The use of these genetic markers proved to be very useful, reliable and with a high exclusion power for paternity analysis

Paternity analysis in cases of father-daughter incest using multiallelic loci.

The inclusion of DNA polymorphism into paternity analysis represents a major advance since it allows one to achieve a high probability of exclusion. This is of particular importance in paternity cases in which the mother and the alleged father are close relatives. The purpose of this article is to demonstrate an approach to calculate the probability of exclusion and to compute the paternity index in case of father-daughter incest using data from multiallelic loci that can be obtained with a single locus probe. The global probability of exclusion achieved at a multiallelic locus, in cases of father-daughter incest, is lower than the one obtained when both parents are not relatives. The probability of exclusion of each mother-offspring pair is different from that obtained when the parents are not close relatives. Among mother-offspring pairs having the same genotype, the probability of exclusion is zero, and in such a condition, the locus is not informative. To obtain a high exclusion capability, it is necessary to analyze several independent loci in which both the mother and the child have different genotypes. Expressions to obtain the paternity index for all the possible combinations of mother-offspring-alleged father in cases of father-daughter incest are derived and discussed.

Análisis de paternidad en casos de incesto, utilizando polimorfismo del ADN de loci multialélicos / Paternity analysis in incest cases using DNA polymorphisms of multiallelic loci

The analysis of genetic markers in man allows to efficiently resolve cases of dubious paternity. Lately, the use of genetic markers derived from DNA analysis allows high exclusion probabilities. A particular case are those consultations whom the progenitors are closely related, in which the criteria to attribute paternity are modified. The present report explains the analysis methods and interpretation of results in situations of doubtful paternity in cases of incest between father and daughter, using monolocus DNA polymorphisms. The method is illustrated through the analysis of 4 cases seen at the Servicio Médico Legal of Santiago. To be able to determine paternity in these cases of incest, at least three multiallelic loci in which mother and son have different genotypes must be examined