Implant site development using titanium plate and platelet-rich fibrin for congenitally missed maxillary lateral incisors: A case report.

BACKGROUND: Bone deficiency and soft tissue atrophy in the absence of maxillary lateral incisors are among the most challenging problems for implant clinicians. Autologous bone grafting is the gold standard for bone augmentation, but not without limitations. Platelet-rich fibrin (PRF), a biodegradable autologous biomaterial, has been widely used for bone and soft tissue management. Moreover, titanium plate is an advantageous barrier due to its good space-maintaining ability. However, there is a lack of literature on implant site development using titanium plate and PRF for congenitally missing maxillary lateral incisors. CASE SUMMARY: The patient was a 19-year-old girl with a congenitally missing tooth (#12). She underwent implant placement and simultaneous autologous bone grafting with titanium plate and PRF. At the follow-up visit 15 d post-procedure, the vascularization of soft tissue was visible. There was no swelling or pain after the surgery. Six months postoperatively, bone regeneration was evident. Subsequently, the definitive restoration was placed, and the patient was satisfied with the esthetic outcomes. CONCLUSION: Implant site development using titanium plate and PRF for congenitally missing maxillary lateral incisors is a feasible procedure. In this case, the labial bone plate was displaced but remained connected to the base bone, ensuring blood supply. The titanium plate fixed the labial bone plate and maintained the osteogenic space, while the PRF provided growth factors and leukocytes for bone and soft tissue regeneration. Furthermore, the procedure reduced the surgical complexity and adverse reactions, displaying outstanding esthetic outcomes.

Immediate implant placement in combination with platelet rich-fibrin into extraction sites with periapical infection in the esthetic zone: A case report and review of literature.

BACKGROUND: In this case, platelet-rich fibrin (PRF) was added to guided tissue regeneration as a biomaterial in proper order for immediate planting in aesthetic area with periapical infection. CASE SUMMARY: With the history of endodontic failure in maxillary central incisor, a 34-year-old female patient required the extraction of maxillary anterior residual root and immediate implantation. Cone beam computed tomography and clinical observation were used to assess the regeneration of soft and bone tissue. Before operation, cone beam computed tomography showed the anterior residual root had serious periapical periodontitis with insufficient labial bone in the aesthetic zone. The patient underwent immediate implant placement and reconstruction of the bone substitution by modified guided bone regeneration. The barrier was a three-layer structure of PRF-collagen membrane-PRF that covered the mixture of PRF and Bio-Oss to promote both osteogenesis and soft tissue healing. At 6 mo postoperatively, the definitive crown was placed after accomplished finial impression. One-year follow-up showed a satisfactory aesthetic effect with no obvious absorption of the labial bone and soft tissue. CONCLUSION: The use of PRF in combination with guided bone regeneration can serve as a reliable and simple adjuvant for immediate implanting in infected socket and result in a stable osteogenic effect with good aesthetic outcome.

[Effects of scaffold microstructure and mechanical properties on regeneration of tubular dentin].

Tubular dentin is of great significance in the process of tooth tissue and tooth regeneration, because it is not only the structural feature of primary dentin, but also can affect the tooth sensory function, affect the differentiation of dental pulp cells and provide strong mechanical support for teeth. Scaffold is one of the three elements of tissue engineering dentin regeneration. Most experiments on dentin regeneration involve the study of the microstructure and mechanical properties of the scaffold. The microstructure and mechanical characteristics of scaffold materials have important effects on the differentiation and adhesion of odontoblast, it can directly affect the tissue structure of regenerated dentin.

[Development of tilted implant for free end of maxillary posterior teeth].

Vertical bone insufficiency in the maxillary posterior teeth is a common clinical situation. At present, the bone insufficiency in the maxillary posterior teeth is mainly overcome by bone grafting through maxillary sinus floor elevation. Compared with traditional axial implantation, tilted implantation can better avoid bone grafting, reduce complications, shorten the treatment cycle, reduce the treatment cost for patients, and gradually be promoted in clinical settings. This article reviews the concept, biomechanics, clinical evaluation, and digital trend of tilted implants of maxillary posterior teeth.

Minimally invasive maxillary sinus augmentation with simultaneous implantation on an elderly patient: A case report.

BACKGROUND: In this case study, a minimally invasive transalveolar approach using platelet-rich fibrin and bone substitute with simultaneous implantation was carried out in an elderly patient. We analyzed the cone-beam computed tomography (CBCT) findings to evaluate bone regeneration. CASE SUMMARY: A 65-year-old female with no contraindications for dental implants and loss of maxillary bilateral molars is described. Examination by CBCT showed the available vertical bone height in the bilateral posterior maxilla was 0.5-6.8 mm in the left and 2.8-6.5 mm in the right. The patient underwent a transalveolar approach using platelet-rich fibrin and bone substitute with simulataneous placement of an implant 10 mm in length. Six months post-surgery, the implant showed excellent osseointegration with the bone graft. Thereafter, full-ceramic crowns were fitted. Follow-up at 2 years demonstrated satisfactory prognosis. CONCLUSION: Platelet-rich fibrin and bone substitute can be used to augment the maxillary sinus with a vertical bone height less than 4 mm.

Flapless immediate implant placement into fresh molar extraction socket using platelet-rich fibrin: A case report.

BACKGROUND: There are some challenges concerning immediate implant placement in the molar region. Platelet-rich fibrin (PRF), an autologous biomaterial, has been used widely for periodontal intra-bony defects, sinus augmentation, socket preservation, and gingival recession. However, the literature remains scarce for reports on immediate implants with PRF, particularly in the case of fresh molar extraction socket. CASE SUMMARY: The patient was a 43-year-old woman with maxillary molar vertical crown-root fracture. She underwent flapless immediate implant placement into the fresh molar socket with PRF. At the follow-up visit 15 d post procedure, the vascularization of soft tissue was visible. There was no swelling or pain after the surgery. Six months postoperatively, the regeneration of bone and soft tissues was visible. Subsequently, the definitive restoration was placed. The patient was satisfied with the aesthetic outcomes. CONCLUSION: The flapless immediate implant placement into the fresh molar socket with PRF is a feasible procedure. This case report demonstrates that PRF promotes bone and soft tissue regeneration apart from having an enhanced anti-inflammatory ability. Furthermore, the procedure involves a minimally invasive technique, thus reducing the surgical complexity.

Minimally invasive endoscopic maxillary sinus lifting and immediate implant placement: A case report.

BACKGROUND: This case report discusses a modified approach for maxillary sinus augmentation, in which platelet-rich fibrin, endoscope, simultaneous implant placement, and sinus floor elevation (PESS) were applied for a maxillary sinus floor lift in a 40-year-old patient. CASE SUMMARY: A 40-year-old woman suffered missing upper right first molar. Implant stability quotient and cone-beam computed tomography (CBCT) were used to evaluate the diagnosis. CBCT showed insufficient posterior maxillary bone with a mean residual alveolar bone height of only 3.5 mm. The patient underwent a minimally invasive sinus floor elevation endoscopically. The sinus membrane was elevated in two stages, and a 12-mm implant was placed immediately. At 3 mo postoperatively, the final impressions were accomplished, and a full-ceramic crown was fit-placed. A 6-mo follow-up demonstrated satisfactory aesthetic and functional results. CONCLUSION: This is the first report to use an endoscope for maxillary sinus floor lifting in cases with severe and insufficient bone height. This case report demonstrates the advantages of the PESS technique, which include minimal invasiveness with high precision, being applicable in cases with a residual alveolar bone height < 4 mm with a promising result, and a shortened treatment period from 12 to 3 mo.

[Research progress on chitosan composite scaffolds in bone tissue engineering].

Bone tissue engineering is a scientific field devoted to the development of materials that can repair or replace human bone tissue with biological and engineering methods. The stent, which provides structural support and adhesion sites for cell and tissue growth, is one of the key elements in tissue engineering. The scaffold may comprise metal, polymer, and ceramic biomaterial. The polymer scaffold is widely used due to its biocompatibility, biodegradability, and mechanical stability. Chitosan, as a natural polymer, is derived from chitin and has played a particularly important role in bone tissue engineering over the past two decades. In recent years, chitosan composites and their application in bone tissue engineering have received considerable attention due to their small foreign body reaction, excellent antibacterial properties, plasticity, suitability for inward cell growth, and bone conduction. This review will discuss the biocompatibility and osteogenesis research in vivo and in vitro of several common chitosan composites in bone tissue engineering.

Synergistic bactericidal activity of chlorhexidine-loaded, silver-decorated mesoporous silica nanoparticles.

Combination of chlorhexidine (CHX) and silver ions could engender synergistic bactericidal effect and improve the bactericidal efficacy. It is highly desired to develop an efficient carrier for the antiseptics codelivery targeting infection foci with acidic microenvironment. In this work, monodisperse mesoporous silica nanoparticle (MSN) nanospheres were successfully developed as an ideal carrier for CHX and nanosilver codelivery through a facile and environmentally friendly method. The CHX-loaded, silver-decorated mesoporous silica nanoparticles (Ag-MSNs@CHX) exhibited a pH-responsive release manner of CHX and silver ions simultaneously, leading to synergistically antibacterial effect against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. Moreover, the effective antibacterial concentration of Ag-MSNs@CHX showed less cytotoxicity on normal cells. Given their synergistically bactericidal ability and good biocompatibility, these nanoantiseptics might have effective and broad clinical applications for bacterial infections.

[Effect of zirconia abutment angulation on stress distribution in the abutment and the bone around implant: a finite element study].

PURPOSE: To investigate the effect of three different zirconia angular abutments on the stress distribution in bone and abutment using three-dimensional finite element analysis, and provide instruction for clinical application. METHODS: Finite element analysis (FEA) was applied to analyze the stress distribution of three different zirconia/titanium angular abutments and bone around implant. RESULTS: The maximum Von Minses stress that existed in abutment, bolt and bone of the angular abutment model was significantly higher than that existed in the straight abutment model. The maximum Von Minses stress that existed in abutment, bolt and bone of the 20 ° angular abutment model was significantly higher than that existed in 15 ° angular abutment model. There was no significant difference between zirconia abutment model and titanium abutment model. CONCLUSIONS: The abutment angulation has a significant influence on the stress distribution in the abutment, bolt and bone, and exacerbates as the angulation increases, which suggest that we should take more attention to the implant orientation and use straight abutment or little angular abutment. The zirconia abutment can be used safely, and there is no noticeable difference between zirconia abutment and titanium abutment on stress distribution.

[The effect of platelet-rich fibrin on biologic characteristics of osteoblasts].

PURPOSE: To investigate the effect of platelet-rich fibrin on biologic characteristics of osteoblasts. METHODS: Osteoblasts were cultured with or without a PRF membrane. The cell proliferation was detected by MTT. The alkaline phosphatase (ALP) stain and the positive expression of collagen type I, osteoprotegerin and RANKL were measured. The data was statistically analyzed with SPSS17.0 software package. RESULTS: PRF promoted cell proliferation and increased expression of ALP, collagen typeI and OPG significantly, but there was no significant impact on expression of RANKL. CONCLUSIONS: PRF promotes osteoblasts proliferation, differentiation and OPG expression. PRF is involved in bone remodeling via regulating expression of OPG and RANKL.

The effects of natural and modified clinoptilolite on intestinal barrier function and immune response to LPS in broiler chickens.

The protection of intestinal barrier function and the anti-inflammatory effects of natural clinoptilolite (NCLI) and modified clinoptilolite (MCLI) were investigated in broilers that were repeatedly challenged with lipopolysaccharide (LPS). A total of 288 1-d-old broiler chicks were divided equally into three treatment groups: control, NCLI-treated (2%) and MCLI-treated (2%). Half of the birds from each treatment group were challenged with 0.9% NaCl solution or LPS (250µg/kg body weight, administered orally) at 16, 18 and 21d of age. The results indicated that, prior to LPS challenge, the diet had no effect on bird growth performance (P>0.05). The oral administration of LPS was also not associated with any significant changes in poultry performance (P>0.05). In LPS-challenged birds that were pretreated with NCLI (2%) or MCLI (2%), the LPS-induced increases in the plasma and intestinal mucosa concentrations of TNF-α, IL-1ß, IL-2, IL-6, IL-4 and IL-10 were dramatically attenuated. Additionally, significant decreases in the plasma d-lactic acid and diamine oxidase (DAO) levels were found in birds that were pretreated with NCLI or MCLI. Furthermore, both NCLI and MCLI reduced the sICAM-1 concentration in the intestinal mucosa. In conclusion, NCLI and MCLI are able to prevent the LPS-induced intestinal mucosa damage and inflammatory response in vivo. These beneficial effects suggest that NCLI and MCLI act as anti-inflammatory agents in part by inhibiting neutrophil infiltration and hyperactivation and by suppressing the secretion of various plasma and intestinal mucosa inflammatory mediators.

[Effect of alendronate sodium on torque-out testing on implant-bone interfaces in estrogen-deficient rabbits with alendronate systemic administration].

OBJECTIVE: To investigate the influence of systemic application of Alendronate sodium, a bone resorption inhibitor, on the osseointegration of implant-bone interface in estrogen-deficient rabbits through mechanical assessment. METHODS: 27 five-month-old Japanese white female rabbits were randomly divided into three groups (9 rabbits each group). An ovariectomy group (OVX), an ovariectomy and Alendronate sodium group (ALN) and a shamed-operated group (S). 12 weeks after operation, implants were installed into bilateral distal femurs and proximal tibias in each group. Alendronate sodium was administrated by intraperitoneal injection in ALN group; meanwhile equivalent of normal saline was administrated by intraperitoneal injection in OVX group and S group. Bone mineral density was measured right after the implant operation and also in 4, 8, 12 weeks. Torque-out values were measured in 4, 8, 12 weeks after animal sacrifice. RESULTS: Bone mineral density of tibias in ALN group was closed to S group and was significantly different from OVX group (P < 0.05) after 8 weeks. While after 12 weeks, the bone mineral density of tibias and femurs in ALN group was both closed to S group and was significantly different from OVX group (P < 0.05). The torque-out values of tibias in ALN group were closed to S group and were significantly different from OVX group (P < 0.05) after 8 weeks. After 12 weeks, the torque-out values of tibias and femurs in ALN group were both closed to S group and were significantly different from OVX group (P < 0.05). CONCLUSION: Systemic application of Alendronate sodium in osteoporosis rabbits can improve the bone-implant osseointegration significantly.

[Research on the influence of different implant site on the implant-bone-interface stress distribution in zygomatic implant denture].

OBJECTIVE: To probe the implant-bone-interface stress distribution of zygomatic implant denture concerning different implant sites. METHODS: Three-dimensional finite element model for severe atrophy maxillary posterior-tooth area was established biomechanically in this study by computer technique and zygomatic implant was simulated into the model in the first-maxillary-premolar region, the second-maxillary-premolar region, the first-maxillary-molar region and the second-maxillary-molar region respectively. Vertical loading, buccal (30 degrees) loading and lingual (30 degrees) loading were preformed, 100 N. Then these load cases were calculated and analyzed. RESULTS: 1) When the implant site was placed in the first-maxillary-premolar region, the buccal side of zygomatic implant exposed out of the bone and didn't meet the clinical request. 2) As far as the tensile stress peak value in the maxillary posterior-tooth area was concerned, the highest value was recorded when the implant was placed in the second-maxillary-molar region, and then the medium value was recorded when the implant was placed in the second-maxillary-premolar region, and the smallest was recorded when the implant in the first-maxillary-molar region. As far as the compressive stress peak value in the maxillary posterior-tooth area was concerned, the highest value was recorded when the implant was placed in the second-maxillary-molar region, and then the medium was recorded when the implant was in the first-maxillary-molar region, and the smallest value was presented when the implant was in the second-maxillary-premolar region. As far as the tensile and compressive stress peak values in the zygomatic area were concerned, the highest value was recorded when the implant was in the second-maxillary-premolar region, and then the medium value when the implant was in the first-maxillary-molar region, and the smallest when the implant was in the second-maxillary-molar region. CONCLUSION: The first-maxillary-molar region is the best implant site of zygomatic implant denture.

[A retrospective study of infection after onlay graft].

OBJECTIVE: To investigate the treatment and prevention of infection after alveolar crest onlay bone graft. METHODS: From January 2006 to May 2010, 11 infection cases after onlay graft on alveolar crest were reviewed to evaluate the infection time, clinical situation, treatment measure, and therapeutic effect. RESULTS: The infection of all 11 cases occurred about 15 days after bone graft, which showed either soft tissue fistulae or bone graft exposure in the oral cavity. Three cases failed because of persistent infection. The infection of the other 8 cases was controlled after a series of comprehensive therapy, and most of the bone graft was reserved and implant restoration finally completed. CONCLUSIONS: After the effective and comprehensive therapy, infected bone graft can be reserved. But to ensure the survival rate of bone graft, the most important thing is to prevent infection in perioperative period.

[Finite element analysis of the effects of implant thread locations on stress distribution].

OBJECTIVE: To investigate the effects of different implant thread locations on stress distribution in implant and bone under concentrated load, and discuss the best design of location of implant thread. METHODS: The stress in implant-bone interface of implants with different thread locations (model A, B, C, D), which were loaded in axial and oblique 450 to axle, were analyzed by Solidworks 2005 plus and Cosmos/works 7.0 software. RESULTS: The stresses in cervical cortical bone of implant with model C were lower than others. But under oblique load, the stresses of implant and cancellous bone in model C were higher than model A. The stresses distribution of model B was obviously concentrated, and under axial load, all kinds of stresses in this model were higher than others. The stress distribution in model A and D were more even, the stress concentrated more on implant neck, upper part of cortical bone and the lowest thread on implant. The stresses in interface under oblique load were much higher than those under axial load. CONCLUSION: The location of thread has effect on stress distribution in implant-bone interface. More attention should be paid to it when we design implants, and we should try to avoid oblique load in implant prosthodontics.

[Stress analysis of the staggered and straight placement of implants in the mandibular posterior region under the localized load].

OBJECTIVE: To compare the stress distribution of the staggered and straight placement of implants in the mandibular posterior region. METHODS: Using three-dimensional finite element approach to analyze the stress distribution and variance regularity under the localized load. RESULTS: Under vertical load, the stress peak value reduced when wide implant was placed straight (min: 3.70 MPa), but slightly increased when normal implant was placed staggered (max: 8.32 MPa); under the inclined load from buccal to lingual direction, the stress peak value reduced when the wide implant was placed in straight line (min: 12.29 MPa) or normal implant was placed staggered with buccal offset configuration (min: 15.48 MPa), but increased with lingual offset configuration (max: 23.60 MPa). CONCLUSIONS: Wide implant (> or = 4 mm) with straight placement should be adopted to reduce the stress peak value and improve stress distribution, when the buccolingual diameter of the alveolar ridge in the mandibular posterior region was wide.

[Effects of alveolar bone resorption on stress of tooth/implant-supported restoration connected by precision attachment].

OBJECTIVE: To investigate the effects of alveolar bone resorption on stress of tooth/implant-supported restoration connected by precision attachment using three-dimensional finite element(FEM) approach. METHODS: The FEM was applied to analyze the stress distribution of tooth/implant-supported restoration connected by precision attachment under various loading conditions when the alveolar bone was absorbed to different level. RESULTS: The stress values of the tooth, implant and their surrounding bone increased when their surrounding bone decreased by bone absorption. CONCLUSION: The stress values of the tooth, implant and their surrounding bone were closely related with the bone resorption.

Ectodysplasin receptor-mediated signaling is essential for embryonic submandibular salivary gland development.

Hypohidrotic (anhidrotic) ectodermal dysplasia (HED), the most common of the approximately 150 described ectodermal dysplasias, is a disorder characterized by abnormal hair, teeth, sweat glands, and salivary glands. Mutations in the EDA (ectodysplasin-A) and EDAR (ectodysplasin-A receptor) genes are responsible for X-linked and autosomal HED, respectively. Abnormal phenotypes similar to HED are seen in Tabby (Eda(Ta)) and downless (Edar(dl)) mutant mice. Although recent studies have focused on the role of Eda/Edar signaling during hair and tooth development, very little is known about its role during embryonic submandibular salivary gland (SMG) development. To this end, we analyzed the SMG phenotypes in Tabby (Ta) and downless (dl) mutant mice and determined that Ta SMGs are hypoplastic, whereas dl SMGs are severely dysplastic. The absence of SMG ducts and acini in dl SMGs suggests that Eda/Edar signaling is essential for lumina formation and glandular histodifferentiation. Our localization of Eda and Edar proteins at sites of lumen and acini formation supports this conclusion. Moreover, the presence of SMGs in both Ta and dl mutant mice, as well as the absence of immunodetectable Eda and Edar protein in Initial Bud and Early Pseudoglandular stage SMGs, indicate that Eda/Edar-mediated signaling is important for branching morphogenesis and histodifferentiation, but not for initial gland formation. To initially delineate the morphoregulatory role of Eda/Edar-mediated signaling during embryonic SMG development, we cultured embryonic day 14 SMGs with enhanced or abrogated Eda/Edar signaling. Eda supplementation induced a significant increase in SMG branching, and enhanced activation of NF-kappaB. Abrogating Eda/Edar signaling by adding the soluble form of Edar to bind endogenous ligand in embryonic SMGs results in a significant dose-dependent decrease in branching morphogenesis. Taken together, our results suggest that the Eda/Edar/NF-kappaB pathway exerts its effect on SMG epithelial cell proliferation, lumina formation, and histodifferentiation.

[Three dimensional finite element stress analysis on superstructure of the fixed bridge supported by tooth-implant].

OBJECTIVE: To reveal the stress distribution in the superstructure of fixed bridge supported by tooth-implant in the process of mastication for improvement of denture design. METHODS: The stress distribution and displacement of the superstructure were studied and analyzed by means of CT Scan, CAD and three-dimensional finite element when various loads were applied. RESULTS: (1) The stress distribution in abutments under oblique loads at forty-five degrees was uneven and the peak value was 4 - 6 times higher than that under vertical loads. Stress concentration occurred with significant compressive stress. (2) Compressive stress widely distributed in the middle area of occlusal surface of pontic, whose peak value under concentrated loads was significantly higher than that under disperse loads. The loading direction had no effect on the stress concentration. (3) The maximum displacement of implant abutment in medial-distal direction was greater than that of the neck of nature tooth. CONCLUSIONS: The mechanic complications of superstructure could be prevented by reducing oblique loads and concentrated ones. It is certain that the further improvements of curve-resistance of pontics and press-resistance of abutments are available.