Cytotoxicity evaluation of Chlorhexidine and Blue®M applied to a human gingival fibroblast (HGF-1) and keratinocytes (NOK-SI): In vitro study.

Chlorhexidine (CHX) is a prime choice to control the oral microbiota. However, it's a chemical agent leading to side effects such as teeth strains, taste disturbance, and desquamation of oral mucosa. Alternatively, the lactoferrin and oxygen-based Blue®M has been introduced as an alternative to the CHX, not disturbing tissue repair. Therefore, the study aimed to evaluate the effects of Blue®M and CHX on oral human fibroblasts (HGF-1) and keratinocytes (NOK-SI). Cell cultures using HGF-1 and NOK-SI evaluated cell proliferation, cell cycle, apoptosis and necrosis, and migration. In the dose-effect test, Blue®M reduced the HGF-1 sample in a 4-fold concentration than CHX (CHX: 173.07 ±10.27; Blue®M: 43.86 ±3.04). The proliferation test revealed an eightfold reduction of the sample for CHX, while for Blue®M, the proliferation rate was eighteen times lower. The apoptosis and necrosis rates increased by 25% (p<0.0001) for HGF-1 for both substances. In NOK-SI, the apoptosis rates increased by 10% (p=0.02) and 15% (p=0.001) for CHX and Blue®M, respectively. Furthermore, the fibroblast had a lower capacity for wound closure in the Scratch Assay (monolayer cell migration) for Blue®M. Despite the limitations of this in vitro study, the results of the lactoferrin and oxygen-based Blue®M demonstrated cytotoxicity in doses over the Minimum inhibitory concentration and Minimum bactericidal concentration for Oral fibroblasts (HGF- 1) and Keratinocytes (NOK-SI).

Postsurgical Volumetric Airway Changes in Class III Patients Receiving Bimaxillary Orthognathic Surgery.

The purpose of the present study was to investigate the pharyngeal airway space (PAS) changes in class III patients receiving bimaxillary orthognathic surgery and correlate the PAS volume and minimum axial section changes with the magnitude of the surgical movement. This research involved a retrospective sample composed of 38 patients with class III skeletal occlusions. Three-dimensional measurements of the PAS volume and minimum axial section were conducted. Cephalometric points were used to verify the extent of jaw-hyoid bone movement. No significant differences were found between pre and postoperative total PAS volume (P = 0.280), nasopharyngeal volume (P = 0.545), oropharyngeal volume (P = 0.297), and minimum axial section (P = 0.568). Anterior movement of point A and posterior nasal spine were significantly associated with an increase in total PAS volume, oropharyngeal volume, and minimum axial section (P < 0.05). However, the posterior movement of menton was significantly associated with a decrease in total PAS volume, oropharyngeal volume, and minimum axial section (P < 0.05). The results of the present study indicated that PAS is not negatively affected by bimaxillary surgery in class III patients. However, the planning of class III patients who are prone to the development of airway problems should be done carefully.

Titanium Mesh Exposure After Bone Grafting: Treatment Approaches-A Systematic Review.

Study Design: A systematic review according to PRISMA statement has been designed to answer the preliminary question: "In titanium mesh exposures, is there a treatment alternative which leads to an increased graft maintenance?" and fill the PICO assessment out. Objective: To review studies published in the past 20 years (1999-2019) in which mesh exposure has occurred, detecting the suitable approaches to treat exposure allowing the graft maintenance. Methods: Initial search on PUBMED, SCOPUS, and COCHRANE databases resulted in 777 articles, and hand-searching identified 6 articles. After removing duplicates and unrelated articles, eligibility criteria were applied, and 31 studies were selected (randomized clinical trials, retrospective/prospective clinical trials, and case series). Results: A total of 677 surgical sites and 225 cases of mesh exposure were identified. Eleven treatments have been identified. Chlorhexidine was the primary approach in 46% of cases, followed by oral hygiene instructions and follow-up with 22.5% of occurrences. In 21% of clinical situations, titanium mesh removal was the treatment of choice, associated with other measures (i.e., antibiotic prescription). There seems to be a consensus in cases of infection. When this complication was associated with tissue dehiscence, the primary treatment was mesh removal. The same does not occur when the site needs to be cleaned for long-term periods. Conclusion: In 2 decades of use of titanium meshes, the available treatments do not seem to have evolved, and there is not enough data to establish a guideline.

Horizontal ridge augmentation using xenogenous bone graft-systematic review.

PURPOSE: This study aimed to perform a systematic review about the use of xenogenous bonegraft in horizontal ridge augmentation to answer the following question: In implant patients, treated with xenografts for horizontal ridge augmentation, what would be the outcomes in terms of bone gain, bone resorption, implant survival, and complication rates? METHODS: The main search was performed at PubMed, Cochrane, and Scopus databases, and found 2610 articles. After selection and duplicate removal, 29 studies were included in the final review. The collected data were sample size, number and type of graft, site, horizontal gain, resorption rate, and complications. RESULTS: A total of 610 patients were submitted to 853 bone grafts, both in the maxilla and mandible. Most studies (n = 26) used particulate grafts, isolated or associated with autogenous bone, and covered by collagen membrane or titanium mesh. The mean of horizontal bone gain was 4.44 mm. In addition, the augmented ridges allowed placement of 1325 successful dental implants. The complication rate was 7.85%, and membrane exposure was the most reported complication. CONCLUSIONS: Although the autogenous bone graft remains as the gold standard for alveolar reconstruction, this review suggests that xenogenous bone graft is a feasible alternative for horizontal bone augmentation.

Effect of zirconia substructure thickness on the mechanical properties and adhesion of veneering porcelain

Aim: This study investigated the influence of yttrium-stabilized tetragonal zirconia polycrystals (Y-TZP) thickness on fracture load of porcelain-veneered crowns (FL), fracture toughness of porcelain (FT), and the shear bond strength zirconia/porcelain (SBS). Methods: Artificial first molar was prepared for full crown (N=45) with different occlusal reduction. Y-TZP cores were made with different thickness at the occlusal face (1mm, 2mm and 3mm) (n=15). The cores were veneered with VM9 ­ Vita porcelain with 1.0 mm layer. For FL testing, axial load was applied to the mesiolingual cusp of the crowns. For FT testing, flat Y-TZP plates (5X5 mm) with 1, 2 or 3 mm thickness were veneered with 1.0 mm porcelain layer (n=10). FT by indentation fracture technique was measured close to the interface and at the top surface. For SBS by knife-edge shearing rod, cylindrical porcelain with 5 mm in diameter and 3 mm was applied on flat Y-TZP plates (1, 2 and 3 mm thickness) (n = 10). Results: Data analyzed by 1-Way ANOVA for FL of crowns and SBS between Y-TZP and porcelain were not significant. Two-way ANOVA for FT was significant for zirconia thickness and measurement area. The post-hoc test showed higher values for the groups with 2 and 3mm, and higher values at the interface, irrespectively of Y-TZP thickness. Conclusion: The zirconia thickness did not affect the FL of veneered crowns and the SBS between the ceramics, but FT of porcelain was lower in thinner zirconia substructure and close to the interface Y-TZP/Porcelain

Hemocyanin facilitates lignocellulose digestion by wood-boring marine crustaceans.

Woody (lignocellulosic) plant biomass is an abundant renewable feedstock, rich in polysaccharides that are bound into an insoluble fiber composite with lignin. Marine crustacean woodborers of the genus Limnoria are among the few animals that can survive on a diet of this recalcitrant material without relying on gut resident microbiota. Analysis of fecal pellets revealed that Limnoria targets hexose-containing polysaccharides (mainly cellulose, and also glucomannans), corresponding with the abundance of cellulases in their digestive system, but xylans and lignin are largely unconsumed. We show that the limnoriid respiratory protein, hemocyanin, is abundant in the hindgut where wood is digested, that incubation of wood with hemocyanin markedly enhances its digestibility by cellulases, and that it modifies lignin. We propose that this activity of hemocyanins is instrumental to the ability of Limnoria to feed on wood in the absence of gut symbionts. These findings may hold potential for innovations in lignocellulose biorefining.

Atrophic Maxilla Reconstruction With Autogenous Iliac Graft and Guided Dental Implants.

Oral rehabilitation with osseointegrated implants is frequently the best alternative for replacement of lost teeth. Several techniques and materials allow achievement of excellent function and esthetics. In the case of maxillary or mandibular atrophy, extensive grafting may be necessary before implants can be properly placed. This is a case of maxillary reconstruction with autogenous iliac crest bone grafts, followed by placement of guided implants. After integration of the grafts, planning and insertion of implants allowed installation of an implant-supported prosthesis, recovering the morphology, function, and esthetics.