Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Objective: The purpose of this study was to evaluate the influence of the pH levels of three in-office bleaching gels on the surface roughness of bovine enamel, after the bleaching protocol. Materials and methods: 36 samples of bovine enamel were obtained, which were cut and divided into three groups (n=12): 40%hydrogen peroxide (Opalescence Boost40%), 35% hydrogen peroxide (Whiteness HP AutoMixx) and 35% hydrogen peroxide (Whiteness HP Blue), receiving a 40-minute application of bleaching. The average pH values were determined using a pH meter during the initial and final application of the gel. A roughness meter was used to assess surface roughness (Ra) before and after bleaching. Data were analyzed with the Friedmann and wilcoxon test (difference between groups); the Kruskall Wallis and U Mann test (difference in each group), as well as Pearson or Spearman test for correlation. Results: There is an increase in pH values from the beginning to the end of bleaching in all groups, except for the 35% hydrogen peroxide group (Whiteness HP Automixx). For surface roughness results there is an increase in all groups. No correlation was found between pH values of the bleaching gels and the surface roughness of the enamel after bleaching. Conclusions: Hydrogen peroxide bleaching gels with high concentrations that have a high or low pH could cause alterations in the surface of the tooth enamel, such as increase in surface roughness.

Secondary caries is an important factor in the replacement of the restorations, and it is thought that fluoride-releasing materials may prevent this problem. Furthermore, the fluoride release of the materials may be increased by polishing process. Available knowledge about the effect of polishing systems (PS) on the fluoride release of materials is limited. Therefore, this study was conducted to evaluate the effect of PS on the fluoride release of fluoride-containing materials. Restorative materials were divided into 6 groups: Fuji IX GP, Fuji II, Dyract XP, Beautifil II, Beautifil-Bulk, and Filtek Ultimate. Each group was also divided into four subgroups: Mylar strip, Sof-Lex Discs, Sof-Lex Diamond, and OneGloss. Fluoride release was determined using a fluoride ion-selective electrode. Surface roughness was evaluated with a profilometer. Two-way repeated measure and one-way ANOVA tests were used for statistical analysis. The initial rapid fluoride release was observed only in Fuji IX. The PS increased the fluoride release of Fuji IX and Fuji II and Dyract XP materials while reducing the fluoride release of resin-based materials. The highest surface roughness values were obtained with OneGloss. Further, a significant relationship between fluoride release and surface roughness was found. The polishing provides an increase in fluoride release, especially in glass-ionomer-based materials. This article revealed that there is a relationship between fluoride release and surface roughness. Proper PS must be chosen according to the material to provide the best clinical benefits in terms of fluoride release and surface roughness.

The present study analyzed the utilitary arch of Ricketts made with TMA and Elgiloy alloys, evaluating the forces that each one presented at different activation lengths. METHODS: A total of 30 arches (15 per alloy) 17x25 caliber were assessed. An acrylic model that simulated the jaw was used with tubes welded to the bands located on the first molars where the arches were attached and brackets were bonded to the lower incisors. The Ricketts arches had a total length of 100 mm and were activated in their distal branch, obtaining the lengths of 5, 10 and 15 mm measured from the slot of the anterior brackets in the midline. A Digital Universal Testing Machine CMT-5L was used to measure the bending force and the statistical analysis was carried out with the Student's T and Mann-Whitney U test. RESULTS: The TMA alloys had a significantly lower strength in each of the activations 5, 10, 15 mm (13,53; 31,61 and 42,01grams respectively) compared to Elgiloy (31.41; 62,61 y 93,00 grams respectively). While increasing the activation length, the flexural forces increased significantly for both alloys. CONCLUSION: The suggested forces for the intrusion of lower incisors were reached by the Elgiloy arches.

The aim of this study was to evaluate the shear bond strength (SBS) of two universal adhesives (Universal Single Bond and All Bond Universal) and a two-step self-etch adhesive system (Clearfil SE Bond) to dentine at various temperatures. Materials and Methods: One hundred and twenty dentin specimens were divided randomly to 12 groups, according to adhesive systems (Universal Single Bond and All Bond Universal, Clearfil SE Bond)  and temperature  ( 4ºC, 20 ºC, 36ºC, 55ºC) used. Dentin specimens were prepared (n :10, adhesives were applied, and composite cylinders were polymerized. Statistical analysis of the SBS data was performed using Two-way analysis of variance (ANOVA) and Tukey’s Honestly Significant Differences post-hoc test. Results: The Clearfil SE Bond was shown to have higher SBS than the universal adhesives at all temperatures; however, there was no statistically significant difference (P>0.05). In both groups, the lowest SBS values were observed in the samples at 4°C while the highest SBS values were observed in the samples at 55°C. In this case, there was a statistically significant difference (P<0.05). Conclusions: The results suggest that the effectiveness of an adhesive may increase if it is preheated at 36°C or above before use instead of being used immediately after removal from the refrigerator or at room temperature.

Burning mouth syndrome (BMS) is a chronic intraoral pain state that has been described as burning pain, tingling or numbness in the oral mucosa, in the absence of any organic disease. Most often affecting the tongue, anterior palate, and/or lips. The diagnosis of primary BMS is purely clinical and based on patients’ description of typical subjective symptoms as well on the exclusion of any systemic or local factors that may give rise to secondary burning pain sensations within the oral mucosa. Relevant studies links BMS to a peripheral neuropathy and BMS patients have revealed distinct abnormalities within the trigeminofacial large and small fiber systems and the trigeminal brainstem complex. Therefore, treatment approach should involve a multidisciplinary character similar to the treatment for neuropathic pain including factors that might also play a role on the BMS etiology and pathophysiology.

The objective of this article was to analyze the indications for the proper selection of  Onlay adhesive ceramic restorations, providing a step-by-step clinical protocol. Biomechanical principles based on morphological considerations and geometric terms must be present for the careful preparation of Onlay-type cavities. Concepts about cavitary preparations are discussed under essential conditions in the preservation of healthy dental tissue, without compromising the functional and aesthetic results over time. The author's suggestion is to respect and follow in a timely manner each of the steps applied in this restorative clinical protocol, to improve the final outcome of the restoration.

Maxillary sinus floor elevation has been extensively documented as a safe and predictable procedure for gaining vertical bone height in the atrophic posterior maxilla. Even though, complications have been reported, which can potentially jeopardize the outcome of the regeneration and implant therapy. Therefore, the purpose of this literature review is to present, debate and analyze the different complications that can occur during a sinus floor elevation.

Objective: Determine sexual dimorphism precision via palatal vault morphometric analysis in craniums sourced from the Laboratorio de Investigación Forense del Equipo Forense Especializado (EFE) de Ayacucho del Ministerio Público - Perú. Materials and Methods: Cross-sectional design consisting of a sample of 43 skulls with pre-established biological gender, (24 males and 19 females). Sexual dimorphism was established by means of the method proposed by Meera Jacob and co., based on palatal width and length measurements, after which the palatal index was calculated, establishing the method’s precision and accuracy. The inferential analysis was made with a level of significance of 5% through the T student test, Shapiro Wilk and Pearson’s coefficient. Results: Palatal width had a mean of 3.43 (+0.31cm) for males and 3.62 (+0.25) for females and in palatal length a mean of 5.07 (+0.44) cm. for males and 4.79 (+0.41) cm. for females is established; on palatal index, 100% of the male skulls correspond to hard narrow palate and on females 73.7% to narrow, 21% to intermediate and 5.3% to wide. Furthermore, it was determined that there were statistically significant differences between width and length of palatal vault for both genders, and a discriminating analysis formula was proposed. Conclusion: Morphometric analyses of palatal vaults establish an 83.72% precision on the estimation of sexual dimorphism.

Amaranth, due to its nutritional composition (carbohydrates 50-66%, lipids 1.9-9.7% and proteins 12-22%) has been selected by FAO as the best food of vegetable origin, it has also been reported that amaranth exerts beneficial effects on health such as lowering the blood cholesterol level, stimulating the immune system, having antioxidant activity as well as protecting against cancer. In some researches, it has been mentioned that thermal pre-treatments such as roasting, extrusion and explosion, applied to amaranth grain before flour processing, have an impact on nutrient content and bioavailability of nutrients. The high content of proteins makes amaranth an attractive substrate for the growth of probiotic lactic acid bacteria, which would complement the benefits provided by the nutrients of amaranth and would be an alternative of probiotic consumption for those people who cannot consume them regularly (lactose intolerant, allergic to milk protein, gluten or soy). Therefore, the objective of this research was to evaluate the effect of pretreatments on the functionality of amaranth seed extracts as a substrate for the growth of probiotic lactic acid bacteria. To achieve this goal, extracts of amaranth flour were prepared from: without treatment, washed, cooked and burst seeds. The protein content, reducing sugars and total carbohydrates were determined to the extracts. Growth kinetics of Lactobacillus plantarum were developed by the pouring plate method. The results show that amaranth extracts are functional for the culture of L. plantarum and that only the explosion of the seeds seems to affect the availability of nutrients since it was in the only extract where a significantly lower maximum cell growth was observed (1.44 ± 0.04 Log UFC/UFC0), Nevertheless the rate of growth was not affected.

The effect of different levels of maralfalfa meal (Pennisetum purpureum) (5, 10, 15 and 20%), in the diet of New Zealand rabbits (Oryctolagus cuniculus) from weaning to the beginning of the reproductive life, was evaluated. 4 treatments with 5 repetitions to be compared with a control treatment. A completely randomized design was applied in combinatorial arrangement of two factors, where the, factor A, were the levels of maralfalfa flour and the B factor, the sex of the animal. The results of the present investigation show that the use of maralfalfa flour supplied to rabbits improves the productive parameters, which is reflected in a reduction of costs and an increase in profitability, observing that when applying 20% of maralfalfa flour, better final weight (4.51kg), higher weight gain (3.63kg) with a total feed intake of 3.63 kg / MS (Dry matter) were recorded; feed conversion (4.20); weight to the carcass (2.61kg) and yield to the carcass (58.53%).