Clinical practice guideline of the spanish society of oral surgery for oral surgery in patients with coagulation disorders.

BACKGROUND: The number of patients treated with coagulation disorders, and more specifically with anticoagulant therapy, has increased worldwide in recent years due to increased life expectancy in developed countries. The protocols for managing this type of patient in oral surgery has varied over recent years, especially after the appearance of new direct-acting oral anticoagulants (DOACs). The assessment of risk of bleeding in this type of patient when undergoing a surgical procedure continues to be a controversial issue for patients, dentists and general practitioners. The objective of this document is to offer recommendations, based on evidence, for decision making for patients with coagulopathies who require dental surgical intervention. MATERIAL AND METHODS: Based on the indications of the "Preparation of Clinical Practice guidelines in the National Health System. Methodological manual", we gathered a group of experts who agreed on 15 PICO questions based on managing patients with coagulation disorders in dental surgical procedures, such as fitting of implants or dental extractions. RESULTS: The 15 PICO questions were answered based on the available evidence, being limited in most cases due to the lack of a control group. Two of the PICO questions were answered by the experts with a grade C recommendation, while the rest were answered with grade D. CONCLUSIONS: The results of this review highlight the need to undertake well designed clinical trials with control groups and with a representative sample size.

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.

Effect of acidity of in-office bleaching gels on tooth sensitivity and whitening: a two-center double-blind randomized clinical trial.

OBJECTIVES: The study aimed to compare the tooth sensitivity (TS) and bleaching efficacy of two hydrogen peroxide gels with different pHs (acid pH [Pola Office, SDI] and the neutral pH [Pola Office+, SDI]) used for in-office bleaching. MATERIALS AND METHODS: Fifty-four patients from Brazil and Chile, with right superior incisor darker than A2, were selected for this double-blind, split-mouth randomized trial. Teeth were bleached in two sessions, with 1-week interval. Each session had three applications of 8 min each, according to the manufacturer's instructions. The color changes were evaluated by subjective (Vita Classical and Vita Bleachedguide) and objective (Easy shade spectrophotometer) methods. Participants recorded TS with 0-10 visual analog scale. Color change in shade guide units (SGU) and ΔE was analyzed by Student's t test (α = 0.05). The absolute risk and intensity of TS were evaluated by McNemar's test and Wilcoxon-paired test, respectively (α = 0.05). RESULTS: All groups achieved the same level of whitening after 30 days of clinical evaluation. The use of a neutral in-office bleaching gel significantly decreases the absolute risk of TS (28%, 95% CI 18-41) and intensity of TS when compared to the acid bleaching gel (absolute risk of 50%, 95% CI 37-63). CONCLUSION: The use of a neutral in-office bleaching agent gel produced the same whitening degree than an acid bleaching gel but with reduced risk and intensity of tooth sensitivity. CLINICAL SIGNIFICANCE: Clinicians should opt to use in-office bleaching with a neutral gel than an acid product because the former causes a significant lower risk and intensity of tooth sensitivity.

Evaluation of scientific output in Dentistry in Spanish Universities.

BACKGROUND: The aim of this study was to assess the scientific output of Spanish universities that offer a bachelor's degree in dentistry through the use of various bibliometric indicators. MATERIAL AND METHODS: A total of 21 universities offered a bachelor's degree in dentistry in academic year 2016-2017. The search for papers published by authors associated with these institutions was carried out using the selection of journals listed in the Journal Citation Reports (JCR) and the Web of Knowledge database for the period 1986-2017. On the basis of these data, we determined the output, the h-, g- and hg-indexes, the most productive authors, international collaborations, and the most relevant journals. RESULTS: Public universities obtained better results than private universities. The University of Valencia was ranked first, followed by the Complutense University of Madrid and the University of Granada. The most productive author was José Vicente Bagán, but the author with the highest h-index was Mariano Sanz and Manuel Toledado. The universities with the greatest output and highest citation rates had more international collaborations. The most developed fields in Spanish universities were Oral surgery, Oral medicine and Dental materials. The universities had different models of production. At universities such as Barcelona or Valencia, the production was focused on very few departments and authors. At the other extreme, the University of Granada had various sources of research and authors, which meant that its output and citation rate could increase more. CONCLUSIONS: University faculties must provide suitable academic and research training, and therefore must be assessed using objective criteria and bibliometric tools. Although the number of university schools and faculties that teach dentistry has increased, and particularly the number of private universities, there is no correlation between their quality and output and the number of places offered on their courses.

Is personality relevant in the choice of bleaching?

OBJECTIVES: The purpose was to administer the NEO-FFI personality test to patients who did and did not want to have their teeth bleached and before and after bleaching to the participants who accepted the treatment. The research question is to correlate styles and personality factors with bleaching. MATERIALS AND METHODS: There were 128 patients eligible for bleaching; 58 accepted (AB) while 70 refused (RB). The test was administered to both groups (AB-RB). The group AB was administered before and 1 week after the end of the bleaching. For each personality domain comparison, the Mann-Whitney test was used. For the group AB, the results for each domain before and after bleaching were compared using the Wilcoxon test. RESULTS: There was a significant difference between the groups (AB-RB) in the extraversion factor (p = 0.01). There was no significant difference between any of the personality items before and after bleaching (p > 0.1). The comparison between groups by sex revealed significant differences in extraversion and neuroticism factors. Males who AB scored higher in extraversion than males who RB (p < 0.05). Females scored higher in neuroticism than males who AB (p < 0.05). CONCLUSIONS: There were personality differences between people who decided to bleach compared with those who did not want the bleaching, which was mainly in the extroversion factor. This stereotypes the patients, who could be described as more sociable, extroverted, and concerned about esthetics and cleanliness. The bleaching protocol, however, cannot modify any of the personality factors. CLINICAL SIGNIFICANCE: It is important to understand a patient's behavior to meet their needs and to determine the type of patients who would like to have their teeth bleached.

Protamine/DNA/Niosome Ternary Nonviral Vectors for Gene Delivery to the Retina: The Role of Protamine.

The present study aimed to evaluate the incorporation of protamine into niosome/DNA vectors to analyze the potential application of this novel ternary formulation to deliver the pCMS-EGFP plasmid into the rat retina. Binary vectors based on niosome/DNA and ternary vectors based on protamine/DNA/niosomes were prepared and physicochemically characterized. In vitro experiments were performed in ARPE-19 cells. At 1:1:5 protamine/DNA/niosome mass ratio, the resulted ternary vectors had 150 nm size, positive charge, spherical morphology, and condensed, released, and protected the DNA against enzymatic digestion. The presence of protamine in the ternary vectors improved transfection efficiency, cell viability, and DNA condensation. After ocular administration, the EGFP expression was detected in different cell layers of the retina depending on the administration route without any sign of toxicity associated with the formulations. While subretinal administration transfected mainly photoreceptors and retinal pigment epithelial cells at the site of injection, intravitreal administration produced a more uniform distribution of the protein expression through the inner layers of the retina. The protein expression in the retina persisted for at least one month after both administrations. Our study highlights the flattering properties of protamine/DNA/niosome ternary vectors for efficient and safe gene delivery to the rat retina.

Niosomes based on synthetic cationic lipids for gene delivery: the influence of polar head-groups on the transfection efficiency in HEK-293, ARPE-19 and MSC-D1 cells.

We designed niosomes based on three lipids that differed only in the polar-head group to analyze their influence on the transfection efficiency. These lipids were characterized by small-angle X-ray scattering before being incorporated into the niosomes which were characterized in terms of pKa, size, zeta potential, morphology and physical stability. Nioplexes were obtained upon the addition of a plasmid. Different ratios (w/w) were selected to analyze the influence of this parameter on size, charge and the ability to condense, release and protect the DNA. In vitro transfection experiments were performed in HEK-293, ARPE-19 and MSC-D1 cells. Our results show that the chemical composition of the cationic head-group clearly affects the physicochemical parameters of the niosomes and especially the transfection efficiency. Only niosomes based on cationic lipids with a dimethyl amino head group (lipid 3) showed a transfection capacity when compared with their counterparts amino (lipid 1) and tripeptide head-groups (lipid 2). Regarding cell viability, we clearly observed that nioplexes based on the cationic lipid 3 had a more deleterious effect than their counterparts, especially in ARPE-19 cells at 20/1 and 30/1 ratios. Similar studies could be extended to other series of cationic lipids in order to progress in the research on safe and efficient non-viral vectors for gene delivery purposes.

Minimal invasive treatment for defective restorations: five-year results using sealants.

Replacement of dental restorations has been the traditional treatment for restorations that are defective. In this five-year randomized clinical trial, restorations with localized marginal defects were treated with sealants. Thirty-two patients (mean age, 26.8 years) with 126 Class I and Class II restorations with defective margins (amalgam n=69 and resin-based composite n=57) were recruited. Treatment was seal with pit and fissure sealant on localized marginal defects (group A: n=43) and was compared with total restoration replacement (group B: n=40) and untreated restorations (group C: n=43) as negative and positive controls. Restorations were assessed by two examiners using the modified US Public Health Service criteria, observing five clinical parameters: marginal adaptation, roughness, marginal stain, teeth sensitivity, and secondary caries at baseline and at five years after treatment. At the five-year recall examination, 23 patients with 90 restorations (71.4% recall rate) were examined. A significant improvement was observed in the marginal adaptation of the restorations in group A compared with group B. None of the treated group showed trends to downgrade in any parameter. Tooth sensitivity and secondary caries showed a low frequency in all groups. No significant difference in marginal adaptation of the restorations was found between amalgam and resin-based composite restorations (p=0.191). This study demonstrated that marginal sealing of restorations is a minimally invasive treatment that may be used instead of the replacement of restorations with localized marginal defects.

Successful factorial design for the optimization of methylprednisolone encapsulation in biodegradable nanoparticles.

Due to their crystalline nature, the encapsulation of hydrophobic corticosteroids within polymeric nanoparticles by o/w solvent evaporation method is often difficult to achieve. The aim of this study was to evaluate the effect of both process and formulation parameters on the encapsulation of a model corticosteroid: methylprednisolone (MP). For this purpose, a 3(2)factorial design was performed evaluating the effects of the concentration of emulsifiers and sonication time on the manufactured nanoparticles, followed by a multiresponse optimization. The study also included the evaluation of other parameters such as the type of organic solvent used, polymer characteristics and the initial mass of drug. The optimal nanoparticle formulation using 0.25% (w/v) of emulsifying agent (Polyvinyl-alcohol, PVA) and 5 min of sonication was then characterized. The highest encapsulation was obtained with an organic phase consisting of acetone: dichloromethane (1:1), polyD,L-lactide-co-glycolide (PLGA) 50:50 as polymer and an initial mass of 6.6 mg of methylprednisolone. Nanoparticles size and ζ potential of optimized formulation were respectively around 230 nm and -14 mV. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) demonstrated that the drug was molecularly dispersed within the nanoparticles. Release study showed that MP-loaded nanoparticles sustained drug release for up to 120 h. This study reflects the importance of factorial design to optimize the manufacture of nanoparticles encapsulating hydrophobic drugs.

Effect of the calcium to phosphorus ratio on the setting properties of calcium phosphate bone cements.

α-Tricalcium phosphate (α-TCP) has become the main reactant of most experimental and commercial ceramic bone cements. It has calcium-to-phosphorus (Ca/P) ratio of 1.50. The present study expands and reports on the microstructures and mechanical properties of calcium phosphate (CP) cements containing sintered monolithic reactants obtained in the interval 1.29 < Ca/P < 1.77. The study focuses on their cement setting and hardening properties as well as on their microstructure and crystal phase evolution. The results showed that: (a) CP-cements made with reactants with Ca/P ratio other than 1.50 have longer setting and lower hardening properties; (b) CP-cements reactivity was clearly affected by the Ca/P ratio of the starting reactant; (c) reactants with Ca/P < 1.50 were composed of several phases, calcium pyrophosphate and α- and ß-TCP. Similarly, reactants with Ca/P > 1.50 were composed of α-TCP, tetracalcium phosphate and hydroxyapatite; (d) only the reactant with Ca/P = 1.50 was monophasic and was made of α-TCP, which transformed during the setting into calcium deficient hydroxyapatite; (e) CP-cements developed different crystal microstructures with specific features depending on the Ca/P ratio of the starting reactant.

Ultrasound monitoring of the setting of calcium-based bone cements.

In this study, the setting of calcium-sulphate (CS) and -phosphate (CP) based bone cements (BCs) was monitored by ultrasound. The objective was to link acoustic and material properties of ceramic-based BCs from the early stages of the cement curing process. The powder phase of the CS-cement consisted of CS hemihydrate; the CP-cement was a mixture of alpha-tricalcium phosphate, CS dihydrate and hydroxyapatite. For the CS-cement, the acoustic impedance z (c)(t), the speed of sound c (c)(t) and the density ρ(c)(t) were measured at the interval of liquid-to-powder ratios LPRs from 0.20 to 3.00 ml/g. For the CP-cement, the acoustic characteristics obtained were the z (c)(t) and the reflection coefficient R (p,c)(t), and the LPRs ranged from 0.30 to 0.40 ml/g. The resulting acoustic properties indicated that CP- and CS-cements exhibited distinctly different curing behaviour; while CS-cement expanded, CP-cement shrank with time.

Effect of Different Irrigants on the Adhesive Interface and Influence on the Push Out Strength of Fiber Posts.

PURPOSE: The aim of this study was to evaluate the effects of a new irrigant solution on the post space cleaning and the adhesive resistance of fiber posts. METHODS AND MATERIALS: Eighty roots of bovine teeth were randomly allocated into eight groups (n=10 for each group). Evaluations were performed in two different time points for each irrigant. The irrigants included a control group with distilled water (DW), 2.5% NaOCl and 17% EDTA (SH), 1% peracetic acid (PA), and 5% boric acid and 1% citric acid (EX). The time points were 24 hours (I-immediate) and 6 months (D-delayed). The push-out test was performed using a universal testing machine with a 5 kN load cell operating at a crosshead speed of 0.5 mm/minute. The dentinal cementation system was analyzed using a laser confocal microscope (LSM5, Zeiss, Jena, Germany), and incidence of residue on radicular dentin was evaluated by scanning electron microscopy (SEM). The incidence of residue was evaluated by the Kruskal-Wallis test and push-out bond strength and dentin penetrability were evaluated via a one-way analysis of variance (ANOVA) and Tukey tests (α=0.05). RESULTS: The EX irrigation protocol demonstrated the lowest incidence of residue on the dentin surface (p<0.05), independently of the evaluated third. In the cervical and the middle post thirds, EXI, EXD, SHI, and SHD groups exhibited similar push-out bond strength values (p>0.05). EXI, EXD, PAI, and PAD exhibited the greatest dentinal penetrability of the cementation system in all the post thirds (p<0.05). CONCLUSIONS: A solution containing 5% boric acid and 1% citric acid can be a promising irrigant for radicular post space cleaning. It has adequate potential for cleaning the dentin surface without interfering with the adhesive interface between the dentin and the cementation system.

Customized Fiber Post Improves the Bond Strength and Dentinal Penetrability of Resin Cementation System to Root Dentin.

OBJECTIVE: This study aimed to evaluate the effect of fiber post customization on the bond strength (24 hours and 6 months), resin cement thickness, and dentinal penetrability of Adper Scotchbond Multi-Purpose - RelyX ARC (AS-RA), RelyX U200 (R2), and Scotchbond Universal - RelyX Ultimate (SU-RU) cementation systems to root dentin from the cervical-, middle-, and apical-thirds of the post space. METHODS: One hundred twenty bovine incisors were endodontically treated. After post space preparation, the roots were divided into six groups, according to the luting protocols (AS-RA, R2, SU-RU) and the type of fiber post [noncustomized post (NC) and customized post (C)]. Customization procedures were peformed using a resin composite (Z350 XT). 24 hours (n=60) or 6 months later (n=60), specimens from the cervical-, middle-, and apical-thirds of the post space were submitted to cementation system thickness measurement, bond strength evaluation, and dentinal penetrability analysis with Confocal Laser Scanning Microscopy (CLSM). Failure mode was classified as adhesive, cohesive, or mixed. Data were submitted to ANOVA and Tukey tests (α=0.05). RESULTS: Cementation protocols with customized fiber posts presented the lowest cementation system thickness, regardless of the cementation system or post space-third (p<0.05), and the highest bond strength values (p<0.05), regardless of the third space (p>0.05), for both periods (24 hours or 6 months). The comparison of push-out bond strength values between 24 hours and 6 months showed a reduction in all groups for the cervical-third (p<0.05). For the middle-third, only noncustomized groups showed reduction (p<0.05). For the apical-third, no reduction was observed (p>0.05). CONCLUSIONS: Anatomical customization favored both the bond strength of cements to dentin and the dentinal penetrability, but with lower cementation system thickness, regardless of cement composition and adhesive strategy.

Bladder augmentation using the gastrointestinal tract. Indication, follow up and complications.

UNLABELLED: The purpose of bladder augmentation using the gastrointestinal tract is to create a low-pressure and high-capacity reservoir, permitting suitable continence and voiding, preserving the upper urinary tract. OBJECTIVE: To analyze the indications, complications and results of our series of augmentation enterocystoplasties. METHOD: We retrospectively reviewed patients undergoing augmentation enterocystoplasty in our department between 1997 and 2010, both included. The indications were: Interstitial cystitis, neurogenic bladder and inflammatory bladder retraction. In all cases a cystography, urethrocystoscopy, urodynamic study and studies of each condition. Bladder release is performed by means of medial laparotomy and an extraperitoneal approach with bivalve opening to the urethral orifices. The bladder augmentation is performed with a 15-20 cm segment of detubularized ileum obtained at 20 cm from the ileocecal valve; in cases of kidney failure, a 7-cm gastric body wedge is added. The bladder catheter was removed following cystogram after 15 days. Monitoring was performed by means of ultrasound with postvoid residual, blood analyses, urine culture and voiding diary. We performed a descriptive study of the demographic characteristics, postoperative complications according to the Clavien classification and in the long term. RESULTS: We included 24 patients, 19 women and 5 men with a mean age of 48.5 years and a median of 47 (21-77). Mean follow up was 7.5 years with a median of 8 (1-11). The indications were: 7 interstitial cystitis, 8 bladder retraction and 7 neurogenic bladder. There were no intraoperative complications. The postoperative complications were 3 Clavien I, 2 type II, 2 IIIA and 1 IIIB. In the long term, 3 patients presented urinary incontinence, 2 mild metabolic acidosis, 5 required self-catheterization, 6 bladder stones, 2 febrile urinary tract infections and 1 stricture of the anastomotic mouth. In three cases, an ileogastrocystoplasty was performed without hydroelectrolytic impairment or impairment of kidney function. CONCLUSIONS: In selected patients, augmentation enterocystoplasty constitutes an efficacious therapeutic option in the treatment of lower urinary tract dysfunction with scant morbidity and few complications.

A new inertial navigation system for guiding implant placement. An in-vitro proof-of-concept study.

The aim of this study was to assess the potential use of a new advanced inertial navigation system for guiding dental implant placement and to compare this approach with standard stereolithographic template guiding. A movement processing unit with a 9-axis absolute orientation sensor was adapted to a surgical handpiece and wired to a computer navigation interface. Sixty implants were placed by 10 operators in 20 jaw models. The 30 implants of the test group were placed in 10 models guided by the new inertial navigation prototype. The 30 implants of the control group were placed in another 10 models using a CAD-CAM template. Both groups were subdivided into experienced and non-experienced operators. Pre- and postoperative computer tomography images were obtained and matched to compare the planned and final implant positions. Four deviation parameters (global, angular, depth, and lateral deviation) were defined and calculated. The primary outcome was the angular deviation between the standard stereolithographic approach and the new inertial navigation system. Results showed no significant differences between both groups, suggesting that surgical navigation based on inertial measurement units (IMUs) could potentially be useful for guiding dental implant placement. However, more studies are still needed to translate this new approach into clinical practice.

Challenging the Concept that OptiBond FL and Clearfil SE Bond in NCCLs Are Gold Standard Adhesives: A Systematic Review and Meta-analysis.

PURPOSE: The following PICO (Patient/Population, Intervention, Comparison, and Outcomes) question was proposed: "Are retention rates of composite resin restorations in noncarious cervical lesions (NCCLs) when using adhesives considered "gold standard" (OptiBond FL and Clearfil SE Bond) higher than those obtained with other adhesives brands"? METHODS: A search was performed in February 2019 (updated in November 2019) in the PubMed/MEDLINE, EMBASE, LILACS, BBO, Web of Science, Cochrane Library, Grey Literature, and IADR abstracts (1990-2018); unpublished and ongoing trial registries, dissertations, and theses were also searched. Only randomized clinical trials (RCTs) conducted in NCCLs that compared either OptiBond FL or Clearfil SE Bond adhesive with other commercially available adhesives were included. The risk of bias (RoB) was applied by using the Cochrane Collaboration tool. A meta-analysis was performed for retention rates at different follow-up times using a random effects model for both the adhesives. Heterogeneity was assessed with the Cochran Q test and I2 statistics. Grading of Recommendations: Assessment, Development and Evaluation (GRADE) assessed the quality of evidence. RESULTS: After removal of duplicates and noneligible articles, 25 studies remained for qualitative synthesis, as one study was common to the two adhesives, of which 9 studies were used for the OptiBond FL meta-analysis and 14 for the Clearfil SE Bond meta-analysis. No significant differences were observed for retention rates in follow-up periods of 12-24 months (p=0.97), 36-48 months (p=0.72), or 108-156 months (p=0.73) for OptiBond FL; and for 12-24 months (p=0.10) and 36-48 months (p=0.17) for Clearfil SE Bond. A significant difference was only found for OptiBond FL at 60-96 months (p=0.02), but only three studies were included in this meta-analysis. CONCLUSIONS: The evidence from available RCTs conducted in NCCLs that compared OptiBond FL or Clearfil SE Bond does not support the widespread concept that these adhesives are better than any other competitive brands available in the dental market.

Evaluation of Tooth Sensitivity of In-office Bleaching with Different Light Activation Sources: A Systematic Review and a Network Meta-analysis.

OBJECTIVES: A systematic review and network meta-analysis were performed to answer the following research question: Are there differences in the risk and the intensity of tooth sensitivity (TS) among eight light activation systems for in-office bleaching in adults? METHODS: Randomized controlled trials (RCTs) that compared at least two different in-office bleaching light activations were included. The risk of bias (RoB) was evaluated with the RoB tool version 1.0 from the Cochrane Collaboration tool. A random-effects Bayesian mixed treatment comparison (MTC) model was used independently for high- and low-concentration hydrogen peroxide. The certainty of the evidence was evaluated using the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) approach. A comprehensive search was performed in PubMed, Bridge Base Online (BBO), Latin American and Caribbean Health Sciences Literature database (LILACS), Cochrane Library, Scopus, Web of Science, and grey literature without date and language restrictions on April 23, 2017 (updated on September 26, 2019). Dissertations and theses, unpublished and ongoing trials registries, and IADR (International Association for Dental Research) abstracts (2001-2019) were also searched. RESULTS: After title and abstract screening and the removal of duplicates, 32 studies remained. Six were considered to be at low RoB, three had high RoB, and the remaining had an unclear RoB. The MTC analysis showed no significant differences among the treatments in each network. In general, the certainty of the evidence was graded as low due to unclear RoB and imprecision. CONCLUSION: There is no evidence that the risk and intensity of TS are affected by light activation during in-office bleaching.

Six-month Follow-up of the Effect of Nonvital Bleaching on IL-1ß and RANK-L: A Randomized Clinical Trial.

OBJECTIVES: It has been reported that bleaching generates an increase in the activity of osteoclasts in vitro. We quantified the RANK-L and IL-1ß biomarkers in a double-blind, randomized clinical trial evaluating the in vivo effect of hydrogen peroxide (35%) and peroxide carbamide (37%) six months after whitening. METHODS AND MATERIALS: Fifty volunteers participated, each with color change in a nonvital tooth. Fifty teeth were randomly divided into two groups (n=25), and the teeth were bleached using either 35% hydrogen peroxide (G1) or 37% carbamide peroxide (G2). Intracoronal bleaching was carried out by a technical "walking bleach" over four sessions. Gingival crevicular fluid samples were collected and used to quantify the IL-1ß and RANK-L secreted levels. Samples of six periodontal sites (three vestibular and three palatal) were collected for up to six months (at the beginning of the study [baseline] and at one week, one month, and six months posttreatment). The color change was visually monitored using the Vita Bleached Guide (ΔSGU). RESULTS: Comparing each time to baseline assessment, a significant increase in the levels of IL-1ß and RANK-L across time points was detected (p<0.05). The color change was 4 in G1 and G2, and a statistically significant difference (p<0.05) was found at the month time point between the groups. Using the Spearman test, a strong correlation (>0.8) between the IL-1ß and RANK-L levels in both groups at all time points was detected. CONCLUSIONS: Nonvital bleaching using a technical walking bleach induces an increase in the IL-1ß and RANKL production in periodontal tissues, which persists for six months after treatment. Both biomarkers were highly correlated in both groups and at all time points.

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.

Color Regression and Maintenance Effect of Intracoronal Whitening on the Quality of Life: RCT-A One-year Follow-up Study.

OBJECTIVE:: This randomized clinical study evaluated two parameters: 1) the clinical color rebound of whitening patients' tooth discoloration using the walking bleaching technique and 2) the impact on psychological and aesthetic self-perception at the one-year follow-up of patients who underwent bleaching of nonvital teeth. METHODS AND MATERIALS:: Fifty study participants with nonvital tooth discoloration were recruited. Teeth were assigned randomly into one of two groups: 1) 35% hydrogen peroxide (n=25) and 2) 37% carbamide peroxide (n=25). Intracoronal bleaching was carried out over the course of four sessions using the walking bleach technique. Tooth color was evaluated after each session in order to measure the total color variation (ΔE). The guide was arranged from highest (B1) to lowest values (C4) for evaluating color, and color changes using Vita Classical Shade (ΔSGUs) units were calculated. Subjective and objective assessments were compared with the counterpart of the tooth. Aesthetic perception and psychosocial factors were evaluated before and after treatment by the Oral Health Impact Profile (OHIP) and Psychological Impact of Dental Impact Questionnaire (PIDAQ) surveys. RESULTS:: Color changes (ΔE) were 15.48 ± 5.17 and 14.02 ± 4.85 for carbamide and hydrogen peroxide groups, respectively. There were no significant differences ( p>0.05) between these two groups at the one-year follow-up. There was a decrease in the PIDAQ scores after treatment compared to baseline values ( p<0.05). The majority of OHIP values regressed to baseline values. CONCLUSION:: The technique of walking bleaching was highly effective and showed minimal color rebound in nonvital teeth and had a positive effect on patients' psychological impact at the one-year follow-up.