In the field of oral rehabilitation, the combined use of 3D imaging technologies and computer-guided approaches allows the development of reliable tools to be used in preoperative assessment of implant placement. In particular, the accurate transfer of the virtual planning into the operative field through surgical guides represents the main challenge of modern dental implantology. Guided implant positioning allows surgical and prosthetic approaches with minimal trauma by reducing treatment time and decreasing patient’s discomfort. This paper aims at defining a CAD/CAM framework for the accurate planning of flapless dental implant surgery. The system embraces three major applications: (1) freeform modelling, including 3D tissue reconstruction and 2D/3D anatomy visualization, (2) computer-aided surgical planning and customised template modelling, (3) additive manufacturing of guided surgery template. The tissue modelling approach is based on the integration of two maxillofacial imaging techniques: tomographic scanning and surface optical scanning. A 3D virtual maxillofacial model is created by matching radiographic data, captured by a CBCT scanner, and surface anatomical data, acquired by a structured light scanner. The pre-surgical planning process is carried out and controlled within the CAD application by referring to the integrated anatomical model. A surgical guide is then created by solid modelling and manufactured by additive techniques. Two different clinical cases have been approached by inserting 11 different implants. CAD-based planned fixture placements have been transferred into the clinical field by customised surgical guides, made of a biocompatible resin and equipped with drilling sleeves

Background/Purpose This study compared maintenance of canal anatomy, occurrence of apical transportation, and working time observed after instrumentation with One Shape New Generation rotary system (Micro-Mega), with those observed after instrumentation with Reciproc (VDW) and WaveOne (Dentsply-Maillefer) reciprocating systems. Materials and methods The mesial canals of 45 mandibular molars (curvature angles between 35° and 45°) were selected. Specimens were randomly divided into three groups, and canal preparations were performed using One Shape, Reciproc, or WaveOne systems (size #25). A digital double radiographic technique was used to determine apical transportation and change in angle of curvature. Also, working time and instrument failures were recorded. Data were statistically analyzed. Results During preparation, no file fractured. No statistically significant differences were found among groups. No system showed a significantly faster preparation time than others (P > 0.05). All instruments maintained the original canal curvature well and were safe to use. Conclusion Both continuous rotary instrument and reciprocating systems did not have any influence on the presence of apical transportation or caused an alteration in angle of canal curvature.

BackgroundNeutral zone (NZ) is a specific area in the oral cavity where muscular opposite forces are null. NZ represents the ideal zone for prosthesis placement. In this study, we compared digital implant planning using conventional technique and using NZ registration through piezography.MethodsSixty‐tree implants were digitally planned. Angular deviation differences between traditional planned and NZ‐planned implants were calculated. In addition, interferences with soft tissues (i.e., tongue and cheeks) were evaluated.ResultsWe observed a significant difference between traditional technique and piezographic approach in terms of implants angulation (p = .003), independent of site. A 4.7% of the planned abutments with traditional technique were placed outside the NZ, causing conflict with soft tissues in the digital model.ConclusionsCompared with traditional technique, piezography allows a significantly different exploitation of the nonconflict area, which potentially translates into better management of soft tissues and improved functionality of the implants.

The method, even if it requires further validation, seems to be a valid aid in solving lower edentulous clinical cases, and appears less complex and with more indications of other proposals presented in the current clinical literature. Our case report differs from the current technique All-on-Four, which uses four implants in the mandible to support over-denture prosthesis, assuring a very promising clinical result.

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