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.

Comparison of the accuracy of immediate implant placement using static and dynamic computer-assisted implant system in the esthetic zone of the maxilla: a prospective study.

PURPOSE: This study aimed to compare the accuracy of fully guided between dynamic and static computer-assisted implant surgery (CAIS) systems for immediate implant placement in the esthetic zone. METHODS: A total of 40 qualified patients requiring immediate implant placement in the esthetic zone were randomly and equally assigned to either static CAIS group (n = 20) or dynamic CAIS groups (n = 20). Global deviations at entry, apex, and angular deviation between placed and planned implant position were measured and compared as primary outcomes. Secondary outcomes were the deviation of implant placement at mesial-distal, labial-palatal, and coronal-apical directions. RESULTS: For the immediate implant placement, the mean global entry deviations in static and dynamic CAIS groups were 0.99 ± 0.63 mm and 1.06 ± 0.55 mm (p = 0.659), while the mean global apex deviations were 1.50 ± 0.75 mm and 1.18 ± 0.53 mm (p = 0.231), respectively. The angular deviation in the static and dynamic CAIS group was 3.07 ± 2.18 degrees and 3.23 ± 1.67 degrees (p = 0.547). No significant differences were observed for the accuracy parameters of immediate implant placement between static and dynamic CAIS systems, except the deviation of the implant at entry in the labial-palatal direction in the dynamic CAIS group was significantly more labial than of the static CAIS (p = 0.005). CONCLUSIONS: This study demonstrated that clinically acceptable accuracy of immediate implant placement could be achieved using static and dynamic CAIS systems. Trial registration ChiCTR, ChiCTR2200056321. Registered 3 February 2022, http://www.chictr.org.cn/showproj.aspx?proj=151348.

3D printing of Ti3C2-MXene-incorporated composite scaffolds for accelerated bone regeneration.

Grafting of bone-substitute biomaterials plays a vital role in the reconstruction of bone defects. However, the design of bioscaffolds with osteoinductive agents and biomimetic structures for regeneration of critical-sized bone defects is difficult. Ti3C2MXene-belonging to a new class of 2D nanomaterials-exhibits excellent biocompatibility, and antibacterial properties, and promotes osteogenesis. However, its application in preparing 3D-printed tissue-engineered bone scaffolds for repairing bone defects has not been explored. In this work, Ti3C2MXene was incorporated into composite scaffolds composed of hydroxyapatite and sodium alginate via extrusion-based 3D printing to evaluate its potential in bone regeneration. MXene composite scaffolds were fabricated and characterized by SEM, XPS, mechanical properties and porosity. The biocompatibility and osteoinductivity of MXene composite scaffolds were evaluated by cell adhesion, cell counting kit-8 test, quantitative real-time polymerase chain reaction, alkaline phosphatase activity and alizarin red S tests of bone mesenchymal stem cells (BMSCs). A rat calvarial defect model was performed to explore the osteogenic activity of the MXene composite scaffoldsin vivo. The results showed the obtained scaffold had a uniform structure, macropore morphology, and high mechanical strength.In vitroexperimental results revealed that the scaffold exhibited excellent biocompatibility with BMSCs, promoted cell proliferation, upregulated osteogenic gene expression, enhanced alkaline phosphatase activity, and promoted mineralized-nodule formation. The experimental results confirmed that the scaffold effectively promoted bone regeneration in a model of critical-sized calvarial- bone-defectin vivoand promoted bone healing to a significantly greater degree than scaffolds without added Ti3C2MXene did. Conclusively, the Ti3C2MXene composite 3D-printed scaffolds are promising for clinical bone defect treatment, and the results of this study provide a theoretical basis for the development of practical applications for tissue-engineered bone scaffolds.

Clinical outcomes of immediate implantation and provisionalization combined with guided bone regeneration for a single anterior maxillary tooth with a thin facial bone phenotype / 口腔疾病防治

Objective@#To study the postoperative soft and hard tissue changes and aesthetic effect of immediate implantation and provisionalization (IIPP) combined with guided bone regeneration (GBR) for a single anterior maxillary tooth with a thin facial bone phenotype.@*Methods @# A total of 34 patients with thin facial bone (<1 mm) were categorized into two groups: a flapped GBR group and a flapless group. Tooth extraction and IIPP were conducted at the sites in both groups. Implant survival rates, dimensional changes in soft and hard tissues during the six- and twelve-month follow-ups, the pink esthetic score (PES) and patient satisfaction scores at the twelve-month follow-up were measured.@*Results @#The implant survival rates were 100% in both groups, and no complications occurred during the 12 months after surgery. The facial bone thickness remained over 2 mm on all measured sides, and the height of the facial bone crest remained at 1.39 mm at the 12-month follow-up in the flapped GBR group, while the facial bone thickness remained less than 2 mm on all measured sides, and the height of the facial bone crest remained at 1.03 mm at the 12-month follow-up in the flapless group. The absorption of facial bone at all measured sides in the flapped GBR group was greater than that in the flapless group (P<0.05). There was no significant difference between the two groups in the dimensional changes of labial soft tissues during the six- and twelve-month follow-ups (P>0.05). The mean PES scores were 10.29 ± 2.34 for the flap GBR group and 10.12±1.78 for the flapless group (P = 0.807). The mean patient satisfaction scores were 8.65 ± 1.27 in the flapped GBR group and 8.76 ± 1.25 in the flapless group, and the patients in both of the groups were satisfied with the esthetic outcomes (P = 0.787). @*Conclusion @#IIPP combined with GBR might be a prospective treatment strategy for a single anterior maxillary tooth with a thin facial bone phenotype, but the esthetic risks should never be ignored.

A prospective cohort study of immediate implantation and delayed implantation for a labial bony dehiscence defect in the maxillary aesthetic area / 口腔疾病防治

Objective @# To investigate the effect of immediate and delayed implant placement on dimensional changes in hard and soft tissues as well as esthetic outcomes. @*Methods @# A total of 40 maxillary single anterior teeth with a dehiscence defect on the labial bone (≤4 mm) were categorized into two groups according to the timing of implant placement: immediate implant placement (n = 20) or delayed implant placement (n = 20). Guided bone regeneration (GBR) was conducted at the sites using a flap approach, and the implants were given immediate provisionalization. Implant survival rates, dimensional changes in hard and soft tissues during the six- and twelve-month follow-ups, and pink esthetic scores (PESs) were measured. @*Results @# The implant survival rates in both groups were 100%, and no complications occurred during the follow-up time. There was no significant difference between the two groups at the measurement sites in the dimensional change of hard and soft tissues during the six- and twelve-month follow-ups. The largest resorption was observed at the implant neck, with a loss of (1.29 ± 0.71) mm in the immediate implant placement group and (1.43 ± 0.19) mm in the delayed implant placement group. The mean PES scores were (10.95 ± 1.51) for the immediate implant placement group and (11.05 ± 1.23) for the delayed implant placement group. @*Conclusion@# Immediate implantation or delayed implantation combined with GBR and immediate provisionalization might both be a prospective treatment strategy for a maxillary single anterior tooth with a dehiscence defect on the labial bone.

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.