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STATEMENT OF PROBLEM: In patients with a completely edentulous maxilla, the variability in resilience and mucosal thickness and the lack of teeth and rigid supporting structures may lead to poor adaptation of the surgical guide and significant variation in the definitive implant position. Whether a modified double-scan technique with overlap of surfaces will improve implant placement is unclear. PURPOSE: The purpose of this prospective clinical study was to evaluate the 3-dimensional position and the correlation of 6 dental implants in participants with a completely edentulous maxilla using a mucosa-supported flapless surgical guide designed with 3 matched digital surfaces obtained with a modified double-scan protocol. MATERIAL AND METHODS: Dental implants were installed with an all-on-6 protocol in the edentulous maxilla of participants at the Santa Cruz Public Hospital, Chile. A stereolithographic mucosa-supported template was fabricated from a cone beam computed tomography (CBCT) scan made with a prosthesis with 8 radiopaque ceramic spheres inserted and by scanning the same prosthesis with an intraoral scanner. The mucosa was obtained by digitally casting the relining of the removable complete denture in the design software program. After 4 months, a second CBCT scan was obtained to evaluate the position of the installed implants measured at 3 locations: apical, coronal, platform depth, and angulation. Differences in position between the 6 implants in the completely edentulous maxilla and their linear correlation at the measured points were compared with the Kruskal-Wallis and Spearman correlation tests (α=.05). RESULTS: Sixty implants were installed in 10 participants (age 54.3 ±8.2 years; 7 women). The average deviation in the apical axis was 1.02 ±0.9 mm, coronal 0.76 ±0.74 mm, platform depth 0.92 ±0.8 mm, and the major axis angulation of the 6 implants was 2.92 ±3.65 degrees. The implant in the maxillary left lateral incisor region had the most significant deviation in apical and angular points (P<.05). A linear correlation between apical-to-coronal deviations and apical-to-angular deviations was observed for all implants (P<.05). CONCLUSIONS: A stereolithographic mucosa-supported guide designed with the overlap of 3 digital surfaces had average dental implant position values similar to those reported by systematic reviews and meta-analyses. In addition, implant position varied based on the location of the implant installation in the edentulous maxilla.
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Chlorhexidine (CHX) is one of the most widely used antiseptics in the oral cavity due to its high antimicrobial potential. However, many authors have stated that the effect of CHX in nonsurgical periodontal therapy is hampered by its rapid elimination from the oral environment. The aim of this study was to determine the antibacterial efficacy of a new compound of chlorhexidine 0.20% + cymenol (CYM) 0.10% on a multispecies biofilm. For this, an in vitro study was designed using a multispecies biofilm model of Streptococcus mutans, Fusobacterium nucleatum, Prevotella intermedia, and Porphyromonas gingivalis. Quantification of the microbial viability of the biofilm was performed using 5-cyano-2,3-ditolyl tetrazolium-chloride (CTC) to calculate the percentage of survival, and the biofilms were observed using a a confocal laser scanning microscopy (CLSM). It was observed that the bactericidal activity of the CHX + cymenol bioadhesive gel was superior to that of the CHX bioadhesive gel, in addition to higher penetrability into the biofilm. Therefore, there was greater elimination of bacterial biofilm with the new compound of chlorhexidine 0.2% plus cymenol 0.1% in a bioadhesive gel form compared to the formulation with only chlorhexidine 0.2% in a bioadhesive gel form.
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BACKGROUND: The efficacy of mouth-rinses strongly depends upon their substantivity. The use of natural and non-toxic products that avoid secondary effects is gaining interest in preventive dentistry. The purpose of this study was to evaluate the substantivity of two formulations of mouth-washing solutions based on cetylpyridinium (CPC) and O-cymen-5-ol. METHODS: This was a randomized, double-blind, crossover trial conducted at the Faculty of Medicine and Health Sciences of the University of Barcelona. Bacterial re-colonization was followed by live/dead (SYTOTM9 + propidium iodide) bacterial staining and measured by confocal laser scanning microscopy and fluorometry. Unstimulated saliva samples were collected from 16 healthy individuals at baseline saliva and then, at 15 min, 30 min and 1, 2, 3, and 4 h after the following mouth-rinses: (i) a single, 1-min mouth-rinse with 15 ml of placebo (negative control); (ii) a single, 1-min mouth-rinse with 15 ml of CPC (0.05%) ; (iii) a single, 1-min mouth-rinse with 15 ml of O-cymen-5-ol (0.09%); (iv) a single, 1-min mouth-rinse with 15 ml of CPC (0.05%) + O-cymen-5-ol (0.09%). RESULTS: Proportion of dead bacteria was significantly higher for all mouthrinses during the first 15 min compared to baseline (CPC = 48.0 ± 13.9; 95% CI 40.98-56.99; p < 0.001, O-cymen-5-ol = 79.8 ± 21.0; 95% CI 67.71-91.90; p < 0.05, CPC + O-cymen-5-ol = 49.4 ± 14; 95% CI 40.98-56.99; p < 0.001 by fluorometry and 54.8 ± 23.0; 95% CI 41.50-68.06; p < 0.001, 76.3 ± 17.1; 95% CI 66.36-86.14; p < 0.001, 47.4 ± 11.9; 95% CI 40.49-54.30; p < 0.001 by confocal laser scanning microscopy, respectively). Nevertheless, after 4 h, CPC + O-cymen-5-ol was the only one that obtained significant values as measured by the two quantification methods used (80.3 ± 22.8; 95% CI 67.15-93.50; p < 0.05 and 81.4 ± 13.8; 95% CI 73.45-89.43; p < 0.05). The combined use of CPC + O-cymen-5-ol increased the substantivity of the mouthrinse with respect to mouthrinses prepared with either of the two active products alone. CONCLUSION: The synergistic interaction of CPC and O-cymen-5-ol prolongs their substantivity. The resulting formulation may be as effective as other antimicrobials, such as triclosan or chlorhexidine, but without their undesirable secondary effects. Thus, mouthrinsing products based on Combinations of CPC and O-cymen-5-ol may replace in the near future Triclosan and Chlorhexidine-based mouthrinses.