Salivary Markers of Oxidative Stress in Patients Undergoing Orthodontic Treatment with Clear Aligners versus Self-Ligating Brackets: A Non-Randomized Clinical Trial.

The aim of this work was to determine advanced the oxidative protein products (AOPPs), total antioxidant capacity (TAC), and myeloperoxidase activity (MPO) in the saliva of patients undergoing orthodontic treatment with clear removable aligners in comparison with another group in treatment with fixed passive self-ligating brackets applying light forces, before treatment, after 30 days, and after 90 days of treatment. This non-randomized clinical trial recruited patients consecutively, all of which were over 18 years of age and due to undergo orthodontic treatment. They were divided into two groups according to treatment type: Group A, 48 patients treated with clear aligners (Invisalign®); and Group B, 19 patients treated with Damon System® 0.22″ self-ligating brackets applying light forces. Saliva samples were collected by a single clinician following the same protocol and underwent three analyses-AOPPs, TAC, and MPO levels-at baseline before placing the apparatus, after 30 days, and after 90 days treatment. Orthodontic treatment, whether with clear aligners or fixed self-ligating brackets and light forces, increased AOPPs after the first 30 days of treatment. During the initial phases of orthodontic treatment, neither clear aligners nor fixed self-ligating brackets applying light forces showed changes in TAC and MPO. Orthodontic treatment with both clear aligners and fixed apparatus self-ligating brackets applying light forces increases oxidative stress (AOPPs) after the first 30 days of treatment. There are no differences in AOPP levels between treatment with clear aligners and self-ligating brackets during the first 90 days of treatment. The antioxidative capacity of saliva during the initial phases of orthodontic treatment, whether with self-ligating brackets or clear aligners, does not undergo significant changes. With either orthodontic technique, the patients' salivary antioxidant capacity is similar.

The antibiotic of choice determined by antibiogram in maxillary sinus elevation surgery: a clinical study.

OBJECTIVES: This study set out to make antibiograms of positive bacteria cultures in samples collected when performing maxillary sinus elevations to determine a specific and effective antibiotic in each case. MATERIAL AND METHODS: A total of 174 patients (90 women and 84 men) with a mean age of 55.92 years underwent 227 sinus elevations. As the membrane was lifted, a sample was collected from the maxillary sinus floor with a cotton swab and placed on a blood agar and chocolate agar culture to incubate for 48 h at 37°; the samples then underwent microbiological analysis. Antibiograms were made for each positive culture to identify the most sensitive antibiotic, which were regrouped according to their mechanism of action as: beta-lactam (penicillins), beta-lactam (cephalosporins), macrolides, quinolones, fosfomycin, aminoglycosides, or trimethoprim-sulfamethoxazole. RESULTS: Of 227 cultures, 18.1% were bacteria-positive. Of the germs, 45% were of the Streptococcus genus, most of which belonged to the Streptococcus viridans group (61.1%). The germs studied showed greater resistance to macrolides and greater sensitivity to penicillins, cephalosporins, and ciprofloxacin. The antibiotics that showed the greatest efficacy were as follows: ampicillin, amoxicillin-clavulanate, and ciprofloxacin. CONCLUSIONS: On the basis of antibiograms of positive cultures, the antibiotics presenting the greatest efficacy against possible complications were as follows: ampicillin, amoxicillin-clavulanate, and ciprofloxacin. Clinically, the antibiograms proved useful as they allowed the prescription of specific antibiotics to resolve possible postoperative sinus infections.

Update of Surgical Techniques for Maxillary Sinus Augmentation: A Systematic Literature Review.

OBJECTIVE: A wide range of surgical techniques are available for maxillary sinus augmentation. This review aimed to determine which techniques have achieved the highest success rates and so offer the greatest predictability. MATERIALS AND METHODS: A systematic literature review was performed using the PubMed, MEDLINE, and Scopus databases, identifying clinical trials that assessed different surgical techniques for maxillary sinus augmentation, and registered the success rates of subsequent implant placement. RESULTS: A total of 40 articles described clinical studies involving different maxillary sinus augmentation procedures with follow-up periods of at least 6 months after dental implant placement. Implant success rates varied between 94% and 100% during the follow-up periods. CONCLUSION: A wide variety of clinical techniques are available for maxillary sinus augmentation; the choice of the technique will depend chiefly on the characteristics of the edentulous site, which will permit or prevent the placement of the implant at the moment of sinus augmentation surgery.

Bacterial influence on consolidation of bone grafts in maxillary sinus elevation.

OBJECTIVES: The aim of this study was to identify microorganisms present on the maxillary sinus floor at the moment of sinus elevation surgery and, using tomography, to investigate the repercussions these might have for regenerated bone 9 months after the procedure. MATERIALS AND METHODS: 174 patients (90 women and 84 men) with a mean age of 55.92 years underwent 227 sinus elevations (120 left sinus, 107 right sinus). As the membrane was lifted, a sample of the maxillary sinus floor was collected with a cotton swab, and placed on a blood agar and chocolate agar culture to incubate for 48 h at 37°C; the samples then underwent microbiological analysis. Orthopantomographs and computerized tomographs were made immediately after the sinus grafting and after 9 months to measure the amount of remaining and regenerated bone in vertical and transversal direction. RESULTS: 18.1% of 227 cultures were bacteria-positive. 45% of the germs were of the Streptococcus genus, most of which belonged to the S. viridans group (61.1%). Patients presenting negative cultures had 5% more regenerated bone than patients with bacteria-positive cultures, which represents an additional 2.28 mmof vertical bone (with a confidence interval between 0.83 mm and 3.73 mm). CONCLUSIONS: Patients with bacteria-positive cultures obtained previously to the sinus grafting procedure have greater risk of bone height loss after 9 months, which indicates that bacterial contamination may influence bone graft regeneration.

Influence of the bracket on bonding and physical behavior of orthodontic resin cements.

The aim of the study is to determine the influence of the type of bracket, on bond strength, microhardness and conversion degree (CD) of four resin orthodontic cements. Micro-tensile bond strength (µTBS) test between the bracket base and the cement was carried out on glass-hour-shaped specimens (n=20). Vickers Hardness Number (VHN) and micro-Raman spectra were recorded in situ under the bracket base. Weibull distribution, ANOVA and non-parametric test were applied for data analysis (p<0.05). The highest values of ή as well as the ß Weibull parameter were obtained for metallic brackets with Transbond™ plastic brackets with the self-curing cement showing the worst performance. The CD was from 80% to 62.5%.

Morphological integration of mandible and cranium: orthodontic implications.

OBJECTIVES: This study aimed at clarifying the morphological interactions among the cranial base, face, and mandible, to improve the assessment and treatment of skeletal malocclusions involving the mandible. DESIGN: Untreated adult subjects (n=187) were grouped according to standard cephalometric criteria of vertical and sagittal relationships. Geometric morphometrics were used to test the null hypothesis that integration patterns between the mandible and its associated basicranial and upper midfacial counterparts would be similar among various vertical and sagittal facial patterns. RESULTS: The null hypothesis was rejected for vertical groups, because the dolicho- and brachyfacial subjects showed significantly different integration patterns, but was accepted for sagittal groups, which showed identical covariation patterns. The morphological integration between the cranium-face and mandible were similarly high in the three skeletal classes, which explained the similarly large covariance between the two structures (57.80% in Class II to 60% in Class III). CONCLUSIONS: Dolicho- and brachi-facial subjects showed specific and different cranium-face and associated mandible configurations. The cranium-face configuration may have an important influence (∼60%) on the generation of sagittal (anteroposterior) skeletal malocclusions. The remaining morphological component of the skeletal malocclusion (∼40%) would be independent of this particular integration (PLS1) between the cranium-face and mandible.

Demineralization effects of hydrogen peroxide on bovine enamel and relation to shear bond strength of brackets.

PURPOSE: To measure the demineralization capacity of 37% phosphoric acid and shear bond strength (SBS) of brackets attached on bovine enamel at different times after bleaching with 30% hydrogen peroxide. MATERIALS AND METHODS: Four equally-sized pieces of each crown from 18 bovine incisors were randomly distributed among 7 groups (n = 10). After bleaching with 30% hydrogen peroxide for 1 h, specimens were stored in artificial saliva for 0 h, 24 h, or 1, 2, 3, or 4 weeks before bonding specimens to brackets. An unbleached group of specimens served as controls. Shear bond strength (SBS in MPa) was measured with a universal testing machine. Adhesive Remnant Index (ARI) scores were determined after failure of bracket bonds. To measure demineralized Ca2+, four 4 x 4 mm sections from each of 15 bovine incisors were randomly distributed among 4 groups (n = 15). Specimens were stored in artificial saliva for 0 h, 24 h or 7 days after bleaching and then immersed in 37% phosphoric acid solution. After 15 s, 30 s, and 60 s, 5-ml aliquots of solution were removed for spectrophotometry. Unbleached specimens served as controls. RESULTS: Larger amounts of Ca2+ were extracted from the enamel by phosphoric acid up to 24 h after application of hydrogen peroxide, when there was also a significant decrease in bracket-enamel SBS. After 1 week, there were no changes in amounts of Ca2+ extracted, and SBS values returned towards unbleached values. CONCLUSION: Lower bracket-enamel SBS values at 24 h after bleaching are closely correlated with the larger amounts of Ca2+ extracted from the enamel.

A new approach to endodontic treatment and operative procedure in nonendodontically treated posterior crown root fractures.

We report a case of nonendodontically treated first upper premolar crown root fracture in which the palatal cusp fracture extended below the cementoenamel junction. Reattachment of the palatal cusp in its original position by acid-etch and flowable composite allowed the creation of a standard access opening as in an intact tooth, avoiding apex location errors and contamination of the root canal. During crown-lengthening surgery, the palatal cusp fragment was hollowed out and used as a natural individual matrix for placement of the core material.

Activity of jaw muscles in unilateral cross-bite without mandibular shift.

OBJECTIVES: To evaluate and compare electromyographic activity of jaw muscles at rest and during maximal voluntary clenching in maximal intercuspation between growing individuals with unilateral posterior cross-bite without functional mandibular lateral shift during closure and matched individuals with normal occlusion. These findings may help elucidate the impact of this occlusal condition on jaw muscle function and the therapeutic implications. DESIGN: 30 growing children (10-12 years) with unilateral cross-bite without functional mandibular lateral shift during closure (cases) and 30 age- and sex-matched children with normal occlusion (controls) were consecutively selected applying highly restrictive criteria. Electromyographic activity coming from the areas of right and left anterior temporalis, posterior temporalis, masseter, and supra-hyoid muscles was evaluated at rest and during clenching. The asymmetry index was calculated for each muscle area to quantify the degree of asymmetry between sides. The masseter/anterior temporalis ratio during clenching was also recorded. RESULTS: No significant differences were found between groups at rest. During clenching, activity of the cross-bite side masseter area was significantly lower in cases versus controls but no difference was found between cross-bite and non-cross-bite sides of this muscle. CONCLUSIONS: Unilateral posterior cross-bite without functional mandibular lateral shift is associated with a lower electromyographic activity of masseter muscle area of the cross-bite side during maximal clenching in maximal intercuspation, compared to the children with normal occlusion. This result could suggest a functional adaptation that should be carefully considered. Long-term studies are needed to determine future repercussions and to evaluate the benefit of an early treatment.