Oscar González-Martín

Zygomatic implants: indications, techniques and outcomes, and the Zygomatic Success Code

The zygoma implant has been an effective option in the management of the atrophic edentulous maxilla as well as for maxillectomy defects. Brånemark introduced the zygoma implant not only as a solution to obtain posterior maxillary anchorage but also to expedite the rehabilitation process. The zygoma implant is a therapeutic option that deserves consideration in the treatment-planting process. This paper reviews the indications for zygoma implants and the surgical and prosthetic techniques (including new developments) and also reports on the clinical outcome of the zygomatic anatomy-guided approach. An overview of conventional grafting procedures is also included. Finally, a Zygoma Success Code, describing specific criteria to score the success of rehabilitation anchored on zygomatic implants, is proposed.

Lingualized flapless implant placement into fresh extraction sockets preserves buccal alveolar bone: a cone beam computed tomography study.

The use of immediate placement and loading protocols in implant dentistry has increased during the past several years. However, limited information related to the response of the osseous architecture has been reported. The purpose of this study was to evaluate the fate of the buccal alveolar plate with cone beam computed tomography (CBCT) following lingualized placement of implants into fresh extraction sockets using a flapless surgical approach and immediate nonocclusal loading. A total of 14 patients who required extraction of a single maxillary incisor were selected for this study. CBCT was performed preextraction, at the time of implant placement, and 6 months following implant surgery. The results of this study indicate that resorption of the buccal alveolar plate was not significant. It was therefore concluded that with strict patient selection and appropriate technique, predictable healing can be achieved with lingualized implant placement into fresh extraction sockets and immediate loading.

CBCT fractal dimension changes at the apex of immediate implants placed using undersized drilling

OBJECTIVES To evaluate, on the base of cone beam computed tomography (CBCT) fractal dimension, bone quality changes surrounding the apical portion of immediate implants placed under higher insertion torque utilizing an undersized drilling technique. MATERIALS AND METHODS Three patients were enrolled in this study. Single implants were placed into fresh extraction sockets in the anterior maxilla and provisionalized immediately. Adequate stability was ensured on all the implants by a 28.5% undersizing of the apical portion of the osteotomy. Bone quality at the most apical 1.15 mm peri-implant bone portion were measured by CBCT at placement and after 6 months. This analysis was carried out by evaluating the box counting fractal dimension of 15 consecutive CBCT slices related to the most apical part of each implant. RESULTS All the three implants were successful after an 18-month follow-up period. The mean fractal dimension at the implant apex exhibited a 3% increase 6 months following placement. CONCLUSIONS Within the limitations of an explorative study, an undersized drilling resulting in high insertion torque would seem to induce no adverse changes in radiographic bone quality after 6 months of follow-up. The most favorable entity of drilling undersizing and its effect on peri-implant bone remodeling, should be evaluated on a larger patient population.

Quantitative three-dimensional methodology to assess volumetric and profilometric outcome of subepithelial connective tissue grafting at pontic sites: a prospective pilot study

The aim of this study was to describe a technique for the assessment of soft tissue volumetric and profilometric changes. The technique has been applied at the alveolar contour of mild to moderate horizontal ridge defects after soft tissue augmentation at pontic sites. A quantitative three-dimensional (3D) analysis based on laser scanning was used for the measurement of volume gain and horizontal changes of alveolar profile 5 months after a subepithelial connective tissue graft using a pouch approach in five patients. All the surgical sites healed uneventfully. A mean soft tissue volume increase of 35.9 mm3 was measured 5 months after the grafting procedure. The linear measurements showed that, in the area where the augmentation was performed, the distance between the preoperative vestibular profile and the postoperative one ranged from 0.16 to 2 mm. The described quantitative measurements based on 3D laser scanning appear to be an effective method for assessment of soft tissue changes in future studies. Additionally, within the limitation of a small sample size, the present data suggest that the investigated surgical technique can be considered when corrections of mild to moderate alveolar horizontal ridge atrophies at maxillary lateral incisor edentulous gaps are necessary.

Position Accuracy of Implant Analogs on 3D Printed Polymer versus Conventional Dental Stone Casts Measured Using a Coordinate Measuring Machine: Accuracy of Implant Analogs on 3D Printed Models

PURPOSE To compare the accuracy of implant analog positions on complete edentulous maxillary casts made of either dental stone or additive manufactured polymers using a coordinate measuring machine (CMM). MATERIAL AND METHODS A completely edentulous maxillary model of a patient with 7 implant analogs was obtained. From this model, two types of casts were duplicated, namely conventional dental stone (CDS) using a custom tray impression technique after splinting (N = 5) and polymer cast using additive manufacturing based on the STL file generated. Polymer casts (N = 20; n = 5 per group) were fabricated using 4 different additive manufacturing technologies (multijet printing-MJP1, direct light processing-DLP, stereolithography-SLA, multijet printing-MJP2). CMM was used to measure the correct position of each implant, and distortion was calculated for each system at x-, y-, and z-axes. Measurements were repeated 3 times per specimen in each axis yielding a total of 546 measurements. Data were analyzed using ANOVA, Sheffé tests, and Bonferroni correction (α = 0.05). RESULTS Compared to CMM, the mean distortion (μm) ranged from 22.7 to 74.9, 23.4 to 49.1, and 11.0 to 85.8 in the x-, y-, and z-axes, respectively. CDS method (x-axis: 37.1; z-axis: 27.62) showed a significant difference compared to DLP on the x-axis (22.7) (p = 0.037) and to MJP1 on the z-axis (11.0) (p = 0.003). Regardless of the cast system, x-axes showed more distortion (42.6) compared to y- (34.6) and z-axes (35.97). Among additive manufacturing technologies, MJP2 presented the highest (64.3 ± 83.6), and MJP1 (21.57 ± 16.3) and DLP (27.07 ± 20.23) the lowest distortion, which was not significantly different from CDS (32.3 ± 22.73) (p > 0.05). CONCLUSION For the fabrication of the definitive casts for implant prostheses, one of the multijet printing systems and direct light processing additive manufacturing technologies showed similar results to conventional dental stone. CLINICAL SIGNIFICANCE Conventional dental stone casts could be accurately duplicated using some of the additive manufacturing technologies tested.

Extraction Socket Management with Buccal Plate Expansion: Preliminary Results of a Novel Technique.

The primary objective of this pilot study was to evaluate a new socket preservation technique involving the intentional expansion of the extraction socket buccal plate using a flapless internal corticotomy and biomaterials. A total of 11 patients requiring tooth extraction were enrolled in this study. The aim of this technique was to maintain or improve the hard and soft tissue contour of the ridge after tooth extraction. All surgical sites healed uneventfully. Significant alveolar bone dimension changes were observed in the coronal region of the ridge (-1.4 ± 0.9 mm); however, it was only slightly lower at the medium (-0.35 ± 0.7 mm) and apical levels (-0.3 ± 0.8 mm) (P > .05). The ridge dimensional changes were significantly higher in the buccal aspect than in the palatal aspect in all patients. Vertical bone resorption was not significant. Concerning the soft tissue contour, the horizontal distance between the preoperative and postoperative buccal profiles ranged from 0.94 to -2.88 mm. The proposed ridge preservation technique may help maintain the volume of the healed ridge but cannot completely prevent contour changes after tooth extraction.