BackgroundTo evaluate the changes in the peri-implant soft tissues of convergent collar implants with biologically oriented preparation technique (BOPT) crowns, 10 months after loading.Material and MethodsA pilot study was carried out from January 2016 to October 2017 involving 14 patients with one or two implants in the posterior mandibular sector. A total of 32 convergent collar implants were placed using a non-submerged protocol. Three months later the provisional cemented crowns were fitted using the BOPT approach with the finish line 1-1.5 mm below the gingival margin, simulating coronal emergence of a natural tooth. The soft tissue changes were measured with an intraoral scanner at two different timepoints: a) on the day of provisionalization, before prosthetic loading; and b) 10 months later without the provisional prosthesis. The STL files were superimposed and the soft tissue changes were recorded using a color scale with measurement of the volumetric changes in mm3.ResultsA mean increase in peri-implant mucosal volume of 64.7 mm3 was observed in 29 implants. The zones with the greatest increase in soft tissue volume were the papillae of implants with adjacent teeth and the peri-implant buccal margin. Three implants showed a mean decrease in soft tissue volume of -25.1 mm3.ConclusionsThe fitting and design of crowns using the biologically oriented preparation technique (BOPT) over convergent collar implants affords a significant increase in peri-implant soft tissue volume both at the level of the papillae and in the buccal margin. Key words:Dental implants, one-piece dental implants, convergent collar implants, soft tissue volume, peri-implant mucosa, BOPT, vertical preparation, shoulderless abutments, emergence profile, intraoral scanner, profilometric analysis.

The Biologically Oriented Preparation Technique (BOPT), developed by Ignacio Loi and published in 2008, is a consolidated concept in the modeling and preservation of pericoronal soft tissues. The present study describes the analogical and digital methods allowing adequate design and preparation of the emergence profile of BOPT crowns in the working model, with a view to comparing the workflow and advantages of each method. At present, not all the digital procedures have been fully optimized to completely replace the traditional analogical methods. Nevertheless, it is only a matter of time until dental digitalization technology totally replaces the analogical clinical methods. The digital workflow for this procedure is quickly implemented and optimized, and represents the most realistic option, with possibilities for further development in the immediate future.

Background Hemostasis is of critical importance in endodontic surgery. Studies on bleeding control in maxillary molars are scarce. The present study compares the efficacy of two hemostatic techniques in controlling bleeding in endodontic surgery. Material and Methods A randomized two-arm pilot study involving 30 patients with peri-radicular lesions in maxillary molars (first and second molars) was carried out including the following hemostatic agents: polytetrafluoroethylene (PTFE) strips as an adjunct to epinephrine impregnated gauze (test group; n = 15) and aluminum chloride (Expasyl™) (control; n = 15). Bleeding control was independently assessed by the surgeon and by two blinded observers before and after application of the hemostatic agent, and was classified as either adequate (complete bleeding control) or inadequate (incomplete bleeding control). Results Bleeding control was similar in both groups. Simple binary logistic regression analysis failed to identify variables affecting bleeding control. Only the height of the keratinized mucosal band (≥ 2 mm) suggested a decreased risk of inadequate bleeding control of up to 89% (OR=0.11; p =0.06). Conclusions No difference in the efficacy of bleeding control was observed between PTFE strips as an adjunct to epinephrine impregnated gauze and aluminum chloride in maxillary molars. Key words: PTFE-strips, aluminum chloride, endodontic surgery, epinephrine, hemostasis, hemostatic agent, molars.

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This report describes a prosthetically-driven implant planning method, guided by the alignment procedures between the cone beam computed tomography, intraoral digital scans, and digitized maxillary and mandibular interim complete dentures using intraoral composite resin markers as a common reference. The markers were attached to the keratinized oral mucosa of the edentulous ridges using cyanoacrylate and kept in place during the digitizing procedures. The technique provides a simpler and more economical alternative to conventional prosthetically-driven static implant planning methods.