Clinical and radiographic outcomes of customized allogeneic bone block versus autogenous bone block for ridge augmentation: 6 Month results of a randomized controlled clinical trial.

AIM: To evaluate the efficacy of customized allogeneic bone block (CABB) for ridge augmentation compared with autogenous bone block. MATERIALS AND METHODS: Patients (N = 24) in need of ridge augmentation were randomly assigned to one of two treatment modalities: CABBs (CABB group) and autogenous bone blocks (ABB group). The primary outcome of the present study was the horizontal bone gain at 1 mm below the alveolar ridge crest (HBG1 ). Secondary outcomes were the bone gain at other levels, bone resorption rate, ridge width, operative time, postoperative pain score, and histological results. The data obtained from the current study were analysed using a generalized linear mixed effects model, two-sample t-test, or a Mann-Whitney U-test. RESULTS: Twenty-four patients completed a 6-month follow-up. One patient in the CABB group exhibited block exposure. The CABB group had significantly more horizontal bone gain (HBG1 ) and less horizontal bone resorption (HBRR1 ) at 1 mm below the alveolar ridge crest when compared with those in the ABB group (HBG1 : CABB group [4.29 ± 1.48 mm] and ABB group [1.12 ± 3.25 mm]; HBRR0 : CABB group [42.15 ± 14.03%] and ABB group [92.52 ± 55.78%], p < .05). In addition, a longer operative time was reported in the ABB group compared with the CABB group (p < .05). The histological observation indicated a new bone formation in both groups. CONCLUSIONS: The use of CABBs resulted in more horizontal bone gain and less horizontal bone resorption at 1 mm below the alveolar ridge crest at 6 months post-surgery compared with ABBs while reducing the operative time in the treatment of ridge augmentation.

An alternative method for immediate implant-supported restoration of anterior teeth assisted by fully guided templates: A clinical study.

STATEMENT OF PROBLEM: Immediate implant-supported restorations have become a common treatment strategy in the esthetic zone; however, improvements are necessary in the techniques used to fabricate interim prostheses. PURPOSE: This clinical study evaluated an alternative method for the immediate restoration of anterior teeth by using a fully guided template. MATERIAL AND METHODS: Twenty-five participants were enrolled, and 30 implants were inserted by using fully guided templates. Eleven participants and 14 implant sites were treated with immediate implant placement. Fourteen participants and 16 implant sites were treated with delayed implant placement. The same method was used for immediate restoration in all the participants. A postoperative cone beam computed tomography (CBCT) scan was compared with the preoperative planning to measure the deviation between the placed and the planned implants. The independent t test was used for the comparison of immediate and delayed implant placement (α=.05). Any complications occurring in the following 3 months were also recorded. RESULTS: None of the interim prostheses needed significant adjustments and were successfully installed on implants after the surgery. The overall mean deviations in 3D coronal, buccolingual coronal, mesiodistal coronal, 3D apical, buccolingual apical, mesiodistal apical, depth, and angle were 0.6 ±0.3 mm, 0.4 ±0.2 mm, 0.2 ±0.1 mm, 1.0 ±0.4 mm, 0.7 ±0.4 mm, 0.3 ±0.2 mm, 0.4 ±0.3 mm, and 1.9 ±1.1 degrees, respectively. The linear and angular deviations exhibited no significant differences (P>.05) between immediate and delayed implant placement. No complications developed in the follow-up period. CONCLUSIONS: In the anterior esthetic zone, this alternative method appears to be suitable for immediate restoration. The accuracy of fully guided surgery was clinically acceptable for the prefabricated interim prostheses and helped reduce postoperative chairside time.

Stability evaluation of gardenia yellow pigment in the presence of different antioxidants or microencapsulating agents.

The chemical instability of gardenia yellow pigment (GYP) limits its utilization in the food industry. In this study, the effects of different antioxidants (0.2% of tea polyphenols, sodium phytate, potassium citrate, and ascorbic acid) and microencapsulating agents (gum Arabic, maltodextrin, inulin, and gum Arabic/maltodextrin) on the degradation of GYP under different conditions (heat, light, and ferric iron) were evaluated. Then, the characteristic properties of microcapsules coated with gum Arabic/maltodextrin, gum Arabic/maltodextrin/tea polyphenols, maltodextrin, and maltodextrin/tea polyphenols were investigated. Furthermore, food models were simulated to evaluate the GYP stability of the microcapsules. The results showed that tea polyphenols, maltodextrin, and gum Arabic/maltodextrin significantly improved the GYP stability. Moreover, the presence of GYP in microcapsules was confirmed by nuclear magnetic resonance and Fourier transform infrared spectroscopy. In addition, GYP-MD/TP possessed high thermal stability under different cooking methods. PRACTICAL APPLICATION: Gardenia yellow pigment (GYP) is easily degraded under light and high-temperature conditions, which limits its applications in the food industry. This study will provide effective clues for expanding the practical applications of GYP in the natural pigment industry.

Polydopamine-mediated graphene oxide and nanohydroxyapatite-incorporated conductive scaffold with an immunomodulatory ability accelerates periodontal bone regeneration in diabetes.

Regenerating periodontal bone tissues in the aggravated inflammatory periodontal microenvironment under diabetic conditions is a great challenge. Here, a polydopamine-mediated graphene oxide (PGO) and hydroxyapatite nanoparticle (PHA)-incorporated conductive alginate/gelatin (AG) scaffold is developed to accelerate periodontal bone regeneration by modulating the diabetic inflammatory microenvironment. PHA confers the scaffold with osteoinductivity and PGO provides a conductive pathway for the scaffold. The conductive scaffold promotes bone regeneration by transferring endogenous electrical signals to cells and activating Ca2+ channels. Moreover, the scaffold with polydopamine-mediated nanomaterials has a reactive oxygen species (ROS)-scavenging ability and anti-inflammatory activity. It also exhibits an immunomodulatory ability that suppresses M1 macrophage polarization and activates M2 macrophages to secrete osteogenesis-related cytokines by mediating glycolytic and RhoA/ROCK pathways in macrophages. The scaffold induces excellent bone regeneration in periodontal bone defects of diabetic rats because of the synergistic effects of good conductive, ROS-scavenging, anti-inflammatory, and immunomodulatory abilities. This study provides fundamental insights into the synergistical effects of conductivity, osteoinductivity, and immunomodulatory abilities on bone regeneration and offers a novel strategy to design immunomodulatory biomaterials for treatment of immune-related diseases and tissue regeneration.

Evaluation of Immediate Implantation and Provisionalization Combined with Guided Bone Regeneration by a Flap Approach in the Maxillary Esthetic Zone: A Retrospective Controlled Study.

The aim of this research was too compare the thickness change of labial contour and bone tissues, as well as some biological complications of immediate implantation with and without immediate provisionalization for a single anterior maxilla presenting a vertical defect on labial bone with the need of guided bone regeneration (GBR) by a flap approach. A total of 40 single implants were placed in 40 patients into fresh extraction sockets of the anterior maxilla with a vertical defect on the labial bone (<4 mm). Simultaneously, GBR was conducted at the sites by a flap approach, and the implants were given immediate or delayed provisionalization. The thickness change of bone tissues during six-month evaluation and labial contour during three and six-month follow-up were measured. Complications such as implant and restoration survival rates, infection as well as wound exposure were also evaluated at six months postoperatively. After six months, the mean thickness losses in labial bone were 0.9040, 0.8050, 0.7165, 0.5285 and 0.5335 mm at five different sites in immediate provisionalization group, and 0.8780, 0.8605, 0.7560, 0.5900 and 0.6300 mm, respectively, in delayed provisionalization group, showing no significant difference between the groups at all measurement sites. Although the labial contour changes of the two groups were similar at most sites, the values at 1 and 2 mm above the implant neck remained significantly lower in the immediate provisionalization group at three and six months postoperatively. No complications occurred during the follow-up time. Based on the limitation of this study, the immediate implantation combined with GBR, flap operation and immediate provisionalization obtained acceptable outcomes for a single anterior maxilla with vertical defect on the labial bone, but more long-term research with a larger sample are urgently needed in the future.

Lateral Ridge Augmentation with Guided Bone Regeneration Using Particulate Bone Substitutes and Injectable Platelet-Rich Fibrin in a Digital Workflow: 6 Month Results of a Prospective Cohort Study Based on Cone-Beam Computed Tomography Data.

This study aimed to test whether or not a digital workflow for GBR with particulate bone substitutes and injectable platelet-rich fibrin improved the thickness of the hard tissue compared to the conventional workflow. 26 patients in need of lateral bone augmentation were enrolled. GBR with particulate bone substitutes and injectable platelet-rich fibrin was performed in all patients. Patients were divided into two groups: control (conventional workflow; n = 14) and test (digital workflow; n = 12). CBCT scans were performed before surgery, immediately after wound closure, and 6 months post-surgery, and the labial thickness of the hard tissue (LT) was assessed at 0-5 mm apical to the implant shoulder (LT0-LT5) at each time point. A total of 26 patients were included in this study. After wound closure, the test group showed significantly greater thickness in LT0-LT2 than the control group (LT0: test: 4.31 ± 0.73 mm, control: 2.99 ± 1.02 mm; LT1: test: 4.55 ± 0.69 mm, control: 3.60 ± 0.96 mm; LT2: test: 4.76 ± 0.54 mm, control: 4.05 ± 1.01 mm; p < 0.05). At 6 months, significant differences in LT0-LT1 were detected between the groups (LT0: test: 1.88 ± 0.57 mm, control: 1.08 ± 0.60 mm; LT1: test: 2.36 ± 0.66 mm, control: 1.69 ± 0.58 mm; p < 0.05). Within the limitations of this study, the use of digital workflow in GBR with particulate bone substitutes and i-PRF exerted a positive effect on the labial thickness of hard tissue in the coronal portion of the implant after wound closure and at 6 months.

The Influence of Different Guided Bone Regeneration Procedures on the Contour of Bone Graft after Wound Closure: A Retrospective Cohort Study.

The aim of this study was to evaluate the impact of different guided bone regeneration (GBR) procedures on bone graft contour after wound closure in lateral ridge augmentation. A total of 48 patients with 63 augmented sites were included in this study. Participants were divided into 4 groups (n = 12 in each group) based on different surgical procedures: group 1: particulate bone substitute + collagen membrane; group 2: particulate bone substitute + collagen membrane + healing cap, group 3: particulate bone substitute + injectable platelet-rich fibrin (i-PRF) + collagen membrane; group 4: particulate bone substitute + i-PRF + surgical template + collagen membrane. After wound closure, the thickness of labial graft was measured at 0-5 mm apical to the implant shoulder (T0-T5). At T0-T2, the thickness of labial graft in group 4 was significantly higher than the other three groups (p < 0.05). And group 4 showed significantly more labial graft thickness than group 1 and group 2 at T3-T5 (p < 0.05). Within the limitations of this study, the use of i-PRF in combination with the surgical template in GBR may contribute to achieving an appropriate bone graft contour after wound closure.

Accuracy of Full-Guided and Half-Guided Surgical Templates in Anterior Immediate and Delayed Implantation: A Retrospective Study.

Computer-aided implantology has developed rapidly in recent years, this study aimed to compare the accuracy of guided-surgery between anterior immediate and delayed implantation, and simultaneously assess the effect of full-guided and half-guided templates on accuracy values. Seventy-six implants were inserted in 63 patients using full-guided or half-guided template in the anterior zone. Postoperative cone beam computed tomography (CBCT) was matched with preoperative planning to evaluate the deviation between actual and planned implants. No statistical difference was found in any deviation between immediate and delayed implantation (p > 0.05). In anterior immediate implantation, the global coronal, apical, depth and angular deviations of full-guided templates were all significantly lower than those of half-guided templates (0.66 ± 0.26 vs. 1.10 ± 0.76 mm, 0.96 ± 0.41 vs. 1.43 ± 0.70 mm, 0.46 ± 0.24 mm vs. 0.93 ± 0.79 mm and 1.69° ± 0.94° vs. 2.57° ± 1.57°). While in delayed implantation, full-guided templates only perform better with statistical significance on global apical and depth deviation (1.01 ± 0.42 vs. 1.51 ± 0.55 mm and 0.32 ± 0.26 vs. 0.71 ± 0.47 mm). After excluding the influence of depth deviation, the coronal and apical deviations between the two systems in immediate implantation and the apical deviations in delayed implantation had no statistical difference. Within the limit of this study, the results suggested the accuracy of guided-surgeries for anterior immediate and delayed implantations was comparable, and full-guided template was more accurate for immediate and delayed implantation.

Three-dimensional finite element analysis of different designs of residual posterior root restored with a new titanium alloy post / 口腔疾病防治

Objective @#To compare the stress distribution of residual posterior root restored with a new titanium alloy post of different diameter and taper, and discuss the rational design of posterior tooth post by the three-dimensional finite element method. @*Methods @#Mandibular second premolar image data was obtained by CBCT, and the mandibular second premolar post models with different diameter and taper were established with the help of Mimics data conversion, Geomagic Studio image processing technology and Creo/Parametric software. Then Abaqus was used to simulate the load condition of prosthesis and analyze the Von Mises stress of the cervical and apical regions.@*Results@#With the same diameter, the influence of the different post tapers on the peak stress of the root cervical area was irregular. When the taper was the same, the peak stress of the root apex area decreased firstly and then increased as the diameter increased. When the diameter was 1 mm, the peak stress of the root cervical and apex area was the lowest.@*Conclusion @#The effect of diameter on the stress distribution of dentin is more important than that of taper. To select the reasonable diameter and taper of the post is helpful to reduce the peak stress of the root cervical and apex area.