Implant stability in patients treated with platelet-rich fibrin and bovine bone substitute for alveolar ridge preservation is associated with peripheral blood cells and coagulation factors.

AIMS: The aim of the present study was to assess the association between dental implant stability and peripheral blood cell composition and levels of coagulation factors in patients treated with alveolar ridge preservation with platelet-rich fibrin (PRF) and bovine bone substitute. MATERIALS AND METHODS: Fifty patients were included between 2015 and 2017. PRF was prepared from autologous blood, in which blood cells and coagulation factor levels were measured. PRF and bovine bone were placed in the socket, followed by closure with PRF membrane. Implants were placed 14 (±2.5) weeks postextraction. The implant stability quotient was measured at t = 0, t = 10 days, t = 7 weeks, and t = 17 weeks by resonance frequency analysis. RESULTS: Erythrocyte count was inversely associated with PRF membrane length, but not with implant stability. Conversely, platelet count did not correlate with membrane size but inversely correlated with implant stability at 7 and 17 weeks. In addition, implant stability was directly correlated with levels FXIII (t = 0, p < .01), active von Willebrand factor (VWF; t = 0 and 7 weeks, p < .05), and total VWF (t = 7 weeks, p = .012). CONCLUSION: Implant stability following alveolar ridge preservation with PRF and bovine bone substitute is associated with circulating blood cells and coagulation factors. In particular, fibrin structure, VWF, and FXIII may be important modulators of implant stability.

Reparación atípica de alveolo en rehabilitación estética implantológica / Atypical socket repair in aesthetic implant rehabilitation

ABSTRACT Introduction: In implant therapy, adequate alveolar bone volume and favorable alveolar ridge architecture are important considerations to obtain positive functional and esthetic rehabilitation. Objective: Describe prosthodontic treatment in an extraction socket with advanced palatal bone resorption secondary to a root fracture through the use of an implant-supported single fixed prosthesis. Principal case data: 39-year-old male patient, without systemic disease, and completely dentate with no occlusal parafunction. Radiographic examination showed the presence of advanced palatal bone resorption, almost total loss of the palatal plate in all its extension secondary to a root fracture of the maxillary left lateral incisor and a large osteolytic area on the palatal aspect of the root. The procedure consisted in extraction of the maxillary left lateral incisor and eventual regeneration of the palatal plate using a resorbable collagen membrane, which was adapted to the bone defect. Then, particulate cortical bone allograft was compacted into the site. Four months after grafting the extraction site, an implant was placed. Six months after implant placement osseointegration was confirmed, and after several stages restoration with a zirconium dioxide abutment and a full ceramic crown was obtained and followed up for 2 years. Conclusions: Regeneration of the palatal plate was possible through the use of particulate cortical bone allograft and a resorbable collagen membrane adapted to the bone defect and placed in position to recreate the palatal plate. This allowed installation of an implant 4 months after the procedure. This technique allowed esthetic and functional results using a single fixed prosthesis(AU)

RESUMEN Introducción: Para la terapia con implantes, un volumen adecuado de hueso alveolar y una arquitectura favorable de la cresta alveolar son consideraciones importantes para obtener una rehabilitación funcional y estética positiva. Objetivo: Describir el tratamiento protésico en una cavidad de extracción con reabsorción ósea palatina avanzada secundaria a una fractura de la raíz, mediante el uso de una prótesis fija única con soporte de implante. Datos principales del caso: Paciente masculino de 39 años, sin enfermedad sistémica, completamente dentado sin parafunción oclusal. El examen radiográfico mostró la presencia de una reabsorción ósea palatina avanzada, una pérdida casi total de la placa palatina en toda su extensión secundaria a una fractura de la raíz del incisivo lateral superior izquierdo y una gran área osteolítica en el aspecto palatino de la raíz. El procedimiento consistió en la extracción del incisivo lateral superior izquierdo y la regeneración posterior de la placa palatina mediante una membrana de colágeno reabsorbible, que se adaptó al defecto óseo. Luego, el aloinjerto de hueso cortical particulado se compactó en el sitio. Cuatro meses después de injertar el sitio de extracción, se colocó un implante. Seis meses después de la colocación del implante, se confirmó la osteointegración y, después de varias etapas, se obtuvo una restauración con un pilar de dióxido de circonio y una corona de cerámica completa, la que fue seguida durante dos años. Conclusiones: La regeneración de la placa palatina fue posible mediante el uso de aloinjerto de hueso cortical particulado y una membrana de colágeno reabsorbible adaptada al defecto óseo y colocada en una posición para recrear la placa palatina. Esto permitió la instalación de un implante 4 meses después del procedimiento. Con esta técnica se obtuvieron resultados funcionales y estéticos utilizando una única prótesis fija(AU)

Tomographic late evaluation of xenogeneic bone grafts in sockets of impacted third molars.

OBJECTIVE: It is necessary to preserve height and thickness of the alveolar bone to facilitate rehabilitation with osteointegratable implants or simply to maintain bone integrity after extraction. Biomaterials associated with resorbable or non-resorbable membranes, when placed in the region of the socket, may contribute to avoid this unwanted reabsorption. OBJECTIVE: The objective of this study was to evaluate the distance of the crest of alveolar ridge to the cementoenamel junction (CEJ) of the lower second molars and the bone density of the third molar socket filled with Gen-Tech®, 5 years after an exodontia using cone beam computed tomography (CBCT) to visualize the central region of the sockets, without overlapping of the buccal and lingual cortical bones. MATERIAL AND METHODS: A total of 12 individuals from an initial group of 39 patients submitted to extraction of the unruptured lower third molars and grafting of an association of inorganic bovine bone matrix, organic bovine bone matrix, collagen and bone morphogenetic proteins (BMP) (Gen-Tech®) on one side and the contralateral sockets filled only by clot, returned to control after 5 years, and were submitted to CBCT. The distance from the crest of alveolar bone to the CEJ and the bone density (BD) were measured using the i-CAT Vision Software. RESULTS: The results showed that the distance from the crest of alveolar bone to the CEJ in the control group was similar to that observed before the exodontia; in the experimental group, this distance was smaller. Considering the BD measurement, a significantly higher density was observed in the experimental group (p<0.05). CONCLUSION: Part of the biomaterial was not absorbed and allowed the stability of the evaluated parameters after 5 years, being able to be used as a bone substitute in the socket.

Biocompatibility and osteoconductivity of PLCL coated and noncoated xenografts: An in vitro and preclinical trial.

BACKGROUND: Cells, scaffolds, and growth factors are the key components in bone tissue engineering. Scaffold composition, topography, and architecture influence the amount of regenerated bone in the implantation site. The aims of the study were to compare viability and proliferation of mesenchymal stem cells (MSCs) seeded onto two commercial xenografts: Bio-Oss (BO) and bioactive bone bovine (BB). Next, these materials were compared for histomorphometric bone formation in a socket preservation model in rats. MATERIALS AND METHODS: MSCs were seeded onto monolayers of BO or BB granules. Cell viability and proliferation were evaluated after incubation of 0, 2, 20, and 48 h. A total of 24 Sprague Dawley rats underwent unilateral extraction of maxillary molars. Rats were randomly divided into three groups: natural healing (nongrafted socket) or socket preservation with either BO or BB. Rats were sacrificed after 8 weeks, and histomorphometric analysis was done to evaluate bone formation and residual scaffold at the extraction site. RESULTS: Differences in the metabolic activity of MSCs that were seeded onto BO or BB was observed at 2 h after seeding: the metabolic activity was elevated compared to baseline in the BB (P = .046) and not changed in the BO wells (P = .84). After 20 h, the metabolic activity of MSCs seeded onto BO was decreasing (P = .005), while cell viability was not changed in the BB group (P = .356). Intergroup comparison revealed higher metabolic activity of MSCs seeded on BB after 48 h compared with BO (P = .016). The in vivo results demonstrated differences in socket healing between the groups: percentage of new bone was higher in the BB compared to BO group (39.1 ± 14.3 vs. 23.7 ± 10.8%, respectively, P = .096). Connective tissue portion was higher in the BO group compared with BB (73.7 ± 11.1 vs. 49.6 ± 13.7%, respectively, P = .018). Residual grafting martial was higher in the BB (11.34 ± 4.18 vs. 2.62 ± 1.23%, P = .011). CONCLUSIONS: The results of this study demonstrating higher vitality and proliferation of MSCs seeded onto BB. Furthermore, following ridge preservation, higher percentage of new bone and lower residual scaffold were found in the BB compared with BO. This enhanced regenerative response might be the result of an enhancement of metabolic activity in cells attached to it. Further research will be needed to understand the precise mechanism.

Comparison of different grafting materials for treatment of bone defect distal to the molar in canine.

BACKGROUND: The extraction of impacted mandibular 3rd molar is highly related to bone defect distal to the adjacent 2nd molar. PURPOSE: The aim of this study was to evaluate the effect of different grafting materials for the treatment of bone defect distal to the mandibular molar in canine model. MATERIALS AND METHODS: In 12 beagle dogs, bilateral mandibular 2nd and 3rd molars were extracted and entire mesial bone of the 2nd molar extracted socket was surgically removed. Twenty-four bone defects (4 mm width and 8 mm depth) were randomly assigned to 4 groups, and grafted using 1 of the following protocols: (1) group C: no graft; (2) group Ta: autogenous bone (AB); (3) group Tb: deproteinized bovine bone mineral (DBBM) with a collagen membrane (CM); and (4) group Tab: an equal mixture of AB/DBBM + CM. Quantitative imageology analyses using micro-CT and fluorescence microscopy, as well as qualitative analyses using histological and histomorphometric evaluations, were characterized at postoperative 12 weeks. Significant differences of all variables were tested by multivariate analysis (P < .05). RESULTS: The defect depth was significantly lower in groups Ta, Tb, and Tab (1.70, 1.97, and 1.61 mm, respectively; mean) than in the group C (3.66 mm, P < .01, all). Compared to the sites received DBBM/CM, sites grafted with AB or AB/DBBM exhibited significant greater and faster new bone formation (P < .01). The percentage of DBBM remnants area (%) was significantly higher in group Tb than in group Tab (10.43% and 1.13%, P < .01; mean). CONCLUSIONS: Our data suggested grafting AB alone, DBBM/CM, or AB/DBBM/CM resulted in similar periodontal parameters in canine. Furthermore, the AB could accelerate new bone regeneration and mineralization, and promote the biodegradation of DBBM.

Tomographic late evaluation of xenogeneic bone grafts in sockets of impacted third molars

Abstract It is necessary to preserve height and thickness of the alveolar bone to facilitate rehabilitation with osteointegratable implants or simply to maintain bone integrity after extraction. Biomaterials associated with resorbable or non-resorbable membranes, when placed in the region of the socket, may contribute to avoid this unwanted reabsorption. Objective The objective of this study was to evaluate the distance of the crest of alveolar ridge to the cementoenamel junction (CEJ) of the lower second molars and the bone density of the third molar socket filled with Gen-Tech®, 5 years after an exodontia using cone beam computed tomography (CBCT) to visualize the central region of the sockets, without overlapping of the buccal and lingual cortical bones. Material and Methods A total of 12 individuals from an initial group of 39 patients submitted to extraction of the unruptured lower third molars and grafting of an association of inorganic bovine bone matrix, organic bovine bone matrix, collagen and bone morphogenetic proteins (BMP) (Gen-Tech®) on one side and the contralateral sockets filled only by clot, returned to control after 5 years, and were submitted to CBCT. The distance from the crest of alveolar bone to the CEJ and the bone density (BD) were measured using the i-CAT Vision Software. Results The results showed that the distance from the crest of alveolar bone to the CEJ in the control group was similar to that observed before the exodontia; in the experimental group, this distance was smaller. Considering the BD measurement, a significantly higher density was observed in the experimental group (p<0.05). Conclusion Part of the biomaterial was not absorbed and allowed the stability of the evaluated parameters after 5 years, being able to be used as a bone substitute in the socket.

[High level Le Fort I osteotomy and bone grafting for correction of secondary mid-face deformities in cleft patients].

OBJECTIVE: To explore the feasibility of combining high level Le Fort I osteotomy with bone grafting in the same operation for correction of secondary mid-face deformities in cleft patients. METHODS: From January 2002 to January 2005, 10 patients suffering from secondary mid-face deformities were treated. There were 4 males and 6 females, aged from 16 to 32 years. The unilateral cleft was involved in 8 patients and the bilateral cleft in 2 patients. All patients received combining high level Le Fort I osteotomy with bone grafting in the same operation. The horizontal corticotomy of high level Le Fort I osteotomy on anterior wall of maxillary bone is higher than that of traditional Le Fort I osteotomy, it is only 5 mm close to infraorbital foramen. RESULTS: All 10 patients were satisfied with their appearances after operation. Dental articulation was improved greatly in 9 patients. With an X-ray re-examination, maxillary was returned to normal position in all patients. After a follow up from 6 months to 2 years, dental arch had good appearance. The X-ray films showed no obvious bone absorption. The density of grafting bone was approximation to the normal bone. CONCLUSION: High level Le Fort I osteotomy can make not only maxillary advance, but also regions of lateral and floor of nose and partial infraorbital region advance. Combining with bone grafting in the same operation can decrease the frequency of operation, save the treatment expense and obtain an ideal effect. So it is an effective method for correction of the secondary mid-face deformities in cleft patients.

Uso do enxerto desmineralizado homógeno em alvéolo pós-extração: relato de casos / Demineralized homogeneous bone graft in sockets after extraction: a report of two cases

Este artigo revisa as bases científicas para a utilização do enxerto ósseo desmineralizado humano membranas biológicas e relata a sua aplicação em dois casos clínicos. Os enxertos homógenos foram utilizados em alvéolos pós-extração com presença de secreção purulenta. Após um período de 90 dias, implantes foram colocados nos alvéolos, e o mesmo protocolo de tratamento foi utilizado nos dois casos.