Digital workflow of labial guides for alveolar ridge reduction during implant-supported full-arch rehabilitation.

This article presents a technique for fabricating two-piece labial guides using resin and cobalt-chromium for guided alveoloplasty, implant placement, and immediate full-arch implant-supported fixed complete denture placement. This technique reduces tissue damage and overcomes the negative effect of the anatomical position of the palatal neuropore and mobility of the tissue flap on the positioning and stability of the guide. The use of labial retention metal guides with improved mechanical properties of cobalt-chromium and fixation plugs allows the unilateral placement of the guide. Thus, minimally invasive implant surgery can be performed owing to the absence of large palatal flap elevation and obstruction. Such a design provides better stability of the guides and clear visual access during surgery.

The mechanical properties, tribological behaviors and color stability of a feldspar nanoceramics strengthening extrinsic stain for high-translucent zirconia.

The present work is aimed to explore the mechanical properties, tribological behaviors and color stability of nanoceramics and microceramics strengthened extrinsic stain coatings (NS and MS) upon high-translucent zirconia (TZ). The Na-rich feldspar ceramics component, microstructure and particle size of NS and MS were verified. The mechanical properties including elastic modulus and hardness of NS were enhanced compared to MS. Reciprocating wear tests under a ball-on-plate configuration manifested that the reduced coefficient of friction, wear depth and wear volume loss of NS was evaluated after 1 × 10 4 cycles and the wear scar morphology of NS characterized by microcracks while MS featured more delamination and wear debris. Post toothbrushing simulation revealed that the color stability of extrinsic stain coatings was elevated with the addition of feldspar nanoceramics. The feldspar nanoceramics strengthening extrinsic stain exhibited enhanced elastic modulus, hardness, wear resistance and color stability, especially for TZ.

Accuracy of Intraoperative Measuring Guide and Conventional Surgical Guide in Anterior Implant Surgery: A Retrospective Case-Control Study

PURPOSE: To verify a novel method that improves the accuracy of static computer-aided implant surgery (sCAIS) through intraoperative measurement. MATERIALS AND METHODS: Forty-seven patients were selected for this study, each with a missing tooth or a tooth that required extraction from the anterior area. The patients were divided into the intraoperative measuring guide (MG) and conventional guide (CG) groups. Following the preoperative implant planning, the surgical guides were designed and fabricated. In the MG group, the drill was guided by double-armed zirconia sleeves, and the axial direction of the drill was assessed using the indicator components. The implant was guided using a resin guide tube. In the CG group, the drills were guided using a metal sleeve and handles, and the implants were placed with the guidance of the metal sleeve only. The angular and linear deviations at the entry and apex between the planned and actual implant positions were measured after matching the preoperative and postoperative CBCT data. The independent-samples t test was used to compare the deviation between the MG and CG groups. RESULTS: The 3D deviations for the MG group at the entry and apex were 0.67 ± 0.44 mm and 0.93 ± 0.40 mm, respectively. The angular deviation was 2.27 ± 0.96 degrees. Statistical differences were found in the 3D deviation at the entry point and apical position between the MG and CG groups, yielding relatively smaller deviations in the MG group. CONCLUSION: The use of an intraoperative measuring guide could improve the accuracy of implant placement in sCAIS.

Application of measurable surgical guides in immediate implant placement and immediate restoration.

This article reports a case of using immediate implant placement and immediate restoration combined with measurable implant surgical guides to restore compromised maxillary incisors caused by dental trauma. Target restoration was designed in the exoCAD software preoperatively, intraoral measurements were obtained in three directions, and the correct position of virtual implants was determined in BlueSky Plan 4. Afterward, measurable implant guides were designed and fabricated by 3D printing. Under the guidance of the measurable implant surgical guides and intraoperative measurement, the entry point was determined, the axial direction was verified when drilling to half the depth, and the 3D position was verified when drilling to total depth. Implants were inserted followed by verification once again. The temporary restoration, which was designed based on the target restoration and emergence profile of the original teeth and milled preoperatively, was connected to the implant immediately after surgery. Postoperative accuracy analysis showed that the mean linear deviations between the actual implant position and the pre-planned position were (0.57±0.17) mm at the entry point and (0.82±0.27) mm at the apex, and the mean angular deviation was (1.86±0.89) °, demonstrating that precise implant placement and immediate restoration were implemented.

A digital workflow for the fabrication of an immediate implant-supported interim restoration.

Immediate interim restorations in the esthetic region are usually fabricated in situ by using the pick-up technique, which is time-consuming and has a potential for cross-infection. This article describes a rapid and precise workflow for the fabrication of an immediate implant-supported interim restoration. A cast with gingival contours and an extended tube to accommodate the implant analogs is generated preoperatively based on the virtual implant planning and a predesigned restoration. After guided osteotomy and implant insertion, the actual three-dimensional (3D) implant position is transferred precisely from the mouth to the printed cast by using the surgical guide. This technique can achieve the rapid and precise fabrication of the interim restoration with guidance immediately after the surgery, decreasing the risk of cross-infection and reducing clinical steps and time.