Horizontal Ridge Reconstruction of Atrophic Anterior Maxillary Ridges Using Customized Xenograft Bone Shell with 1:1 Mixture of Autogenous and Xenograft Bone Particulate (A Case Series Study).

INTRODUCTION: Different surgical procedures have been proposed to achieve successful horizontal ridge reconstruction of the anterior maxilla, most of these procedures require complex surgical stages with morbidity and are time-consuming. AIM: The purpose of this study is to evaluate the efficacy of using a customized xenograft shell with a 1:1 mixture of particulates xenograft and autogenous bone for the reconstruction of horizontally deficient anterior maxillary alveolar ridges. METHODS: Cone beam computed tomography (CBCT) images of the atrophic maxilla of eight patients were acquired and generated into 3D models. The data were transferred to a 3D printer and solid models were fabricated. During the surgery, the xenograft blocks were manually sliced and customized on the 3D printed models and fixed then the gap was augmented with a 1:1 xenograft autograft mixture. RESULTS: Clinical assessment showed no adverse effects. However, one patient exhibited wound dehiscence. The mean difference between the preoperative and the six months postoperative showed a net average bone gain by 4.06 mm at 2 mm from the crest and 4.34 mm at 5 mm from the crest, which was statistically significant. On the other hand, a statistically significant graft resorption by 1.41 mm and 2.19 mm at 2 and 5 mm from the crest was found when the mean difference between the immediate and the six months postoperative was calculated. CONCLUSIONS: Within the limitations of the study, the use of xenograft shells as a barrier for maxillary alveolar ridge reconstruction is predictable technique however, further investigations regarding the required time for graft consolidation is required.

Ridge augmentation using autologous concentrated growth factors enriched bone graft matrix versus guided bone regeneration using native collagen membrane in horizontally deficient maxilla: A randomized clinical trial.

BACKGROUND: Facial resorption of maxillary alveolar ridges is a challenging situation for implant rehabilitation, which mandates a preparatory surgery of bone augmentation. Guided bone regeneration using a 1:1 mixture of autogenous particulate and anorganic bovine bone mineral (ABBM) showed reliable outcomes in treating horizontally deficient ridges. METHODS: Twenty-eight patients were randomly assigned into two groups; in the control group, the 1:1 mixture of particulate autogenous bone and ABBM was covered with native collagen membrane, while in the study group, it was mixed with autologous fibrin glue (AFG) to make a sticky bone that was covered by concentrated growth factor (CGF) membrane. For each proposed implant site, the average bone width gain was calculated preoperatively, immediately after augmentation and after 6 months. Implants were placed after 6 months and the implant stability quotient (ISQ) was measured after insertion and after 6 more months. RESULTS: The graft consolidation period went uneventful in both groups; however, two cases in the sticky bone group showed total resorption of the graft upon re-entry. The mean horizontal bone width after 6 months was 9 mm ± 0.71 in the guided bone regeneration (GBR) group which was higher than 7.9 mm ± 0.92 for the sticky bone group. The mean primary stability was higher in the GBR group; 67.19 ± 2.23 compared to 66.7 ± 3.22 for the sticky bone group, while the mean secondary stability was higher in the sticky bone group; 72 ± 2.15 compared to 71.7 ± 2.27 for the GBR group. Results of Shapiro-Wilk's for bone width data and model residuals were both statistically not significant (p > 0.05). CONCLUSION: Comparing CGF membrane versus native collagen membrane as barriers for GBR showed no statistically significant difference regarding bone gain. However, from a clinical point of view, CGF membrane is not a predictable barrier for guided bone regeneration.

Effect of posterior span length on the trueness and precision of 3 intraoral digital scanners: A comparative 3-dimensional in vitro study.

PURPOSE: This in vitro study measured and compared 3 intraoral scanners' accuracy (trueness and precision) with different span lengths. MATERIALS AND METHODS: Three master casts were prepared to simulate 3 different span lengths (fixed partial dentures with 3, 4, and 5 units). Each master cast was scanned once with an E3 lab scanner and 10 times with each of the 3 intraoral scanners (Trios 3, Planmeca Emerald, and Primescan AC). Data were stored as Standard Tessellation Language (STL) files. The differences between measurements were compared 3-dimensionally using metrology software. Data were analyzed using 1-way analysis of variance with post hoc analysis by the Tukey honest significant difference test for trueness and precision. Statistical significance was set at P<0.05. RESULTS: A statistically significant difference was found between the 3 intraoral scanners in trueness and precision (P<0.05). Primescan AC showed the lowest trueness and precision values (36.8 µm and 42.0 µm; (39.4 µm and 51.2 µm; and 54.9 µm and 52.7 µm) followed by Trios 3 (38.9 µm and 53.5 µm; 49.9 µm and 59.1 µm; and 58.1 µm and 64.5 µm) and Planmeca Emerald (60.4 µm and 63.6 µm; 61.3 µm and 69.0 µm; and 70.8 µm and 74.3 µm) for the 3-unit, 4-unit, and 5-unit fixed partial dentures, respectively. CONCLUSION: Primescan AC had the best trueness and precision, followed by Trios 3 and Planmeca Emerald. Increasing span length reduced the trueness and precession of the 3 scanners; however, their values were within the accepted successful ranges.