Conditioned Media from Human Pulp Stem Cell Cultures Improve Bone Regeneration in Rat Calvarial Critical-Size Defects.

The aim of this study was to test whether lyophilized conditioned media from human dental pulp mesenchymal stem cell cultures promote the healing of critical-size defects created in the calvaria of rats. Prior to the surgical procedure, the medium in which dental pulp stem cells were cultured was frozen and lyophilized. After general anesthesia, an 8 mm diameter bone defect was created in the calvaria of twenty-four rats. The defects were filled with the following materials: xenograft alone (G1) or xenograft associated with lyophilized conditioned medium (G2). After 14 or 42 days, the animals were euthanized, and the specimens processed for histologic and immunohistochemical analysis. Bone formation at the center of the defect was observed only in the G2 at 42 days. At both timepoints, increased staining for VEGF, a marker for angiogenesis, was observed in G2. Consistent with this, at 14 days, G2 also had a higher number of blood vessels detected by immunostaining with an anti-CD34 antibody. In conclusion, conditioned media from human dental pulp mesenchymal stem cell cultures had a positive effect on the regenerative process in rat critical-size bone defects. Both the formation of bone and enhancement of vascularization were stimulated by the conditioned media.

Pulp-Dentin Complex Regeneration with Cell Transplantation Technique Using Stem Cells Derived from Human Deciduous Teeth: Histological and Immunohistochemical Study in Immunosuppressed Rats.

The aim of this study was to histologically verify the performance of pulp-derived stem cells used in the pulp-dentin complex regeneration. Maxillary molars of 12 immunosuppressed rats were divided into two groups: the SC (stem cells) group, and the PBS (just standard phosphate-buffered saline) group. After pulpectomy and canal preparation, the teeth received the designated materials, and the cavities were sealed. After 12 weeks, the animals were euthanized, and the specimens underwent histological processing and qualitative evaluation of intracanal connective tissue, odontoblast-like cells, intracanal mineralized tissue, and periapical inflammatory infiltrate. Immunohistochemical evaluation was performed to detect dentin matrix protein 1 (DMP1). In the PBS group, an amorphous substance and remnants of mineralized tissue were observed throughout the canal, and abundant inflammatory cells were observed in the periapical region. In the SC group, an amorphous substance and remnants of mineralized tissue were observed throughout the canal; odontoblasts-like cells immunopositive for DMP1 and mineral plug were observed in the apical region of the canal; and a mild inflammatory infiltrate, intense vascularization, and neoformation of organized connective tissue were observed in the periapical region. In conclusion, the transplantation of human pulp stem cells promoted partial pulp tissue neoformation in adult rat molars.

Horizontal Bone Augmentation With Autogenous and Collagenated Xenogeneic Bone Blocks: A Split-Mouth Prospective Clinical, Tomographic, and Histological Pilot Study.

The aim of this study was to compare the clinical, tomographic, and histological performance of collagenated xenogeneic bone blocks (CXBB) in horizontal bone augmentations for implant placement. Five patients with an absence of the 4 upper incisors and an HAC 3 horizontal bone defect, with a remaining of 3 to 5 mm, underwent a bone-grafting procedure with CXBB (test group [TG], n = 5) and autogenous graft (control group [CG], n = 5), with one type of graft used on the right side and other type on the left side. Changes in bone thickness and density (tomographic evaluation), levels of complications (clinically), and distribution pattern between mineralized and nonmineralized tissue (histomorphometrically) were analyzed. Tomographic analysis showed a horizontal bone increase of 4.25 ± 0.78 mm in the TG and 3.08 ± 0.8 mm in the CG between baseline and 8 months postoperatively (P < .05). The horizontal loss between the day of installation of the blocks and 8 months postoperatively was 1.02 ± 0.39 mm for the TG and 1.10 ± 0.71 mm for the CG (P > .05). With regard to bone density, the TG blocks right after installation had 440.2 ± 89.15 HU, and after 8 months, the region reached 730.7 ± 130.98 HU, representing an increase of 29.05%. For the CG blocks, bone density increased from 1052.2 ± 398.35 HU to 1222.5 ± 453.28 HU, representing an increase of 17.03%. The increase in bone density was significantly higher in the TG (P < .05). Clinically, no cases of exposure of the bone blocks and no failure of incorporation were observed. Histomorphometrically, the percentage of mineralized tissue was lower in the TG than in the CG (48.10% ± 2.88% and 53.53% ± 1.05%, respectively), and the opposite was verified for the levels of nonmineralized tissue (52.79% ± 2.88% and 46.47% ± 1.05%, respectively; P < .05). The use of CXBB achieved higher levels of horizontal gain, with lower bone density and lower levels of mineralized tissue when compared with the use of autogenous blocks.

Osteocalcin and Runx2 Expression in Anterior Maxillary Reconstructions Using Bone Xenografts Associated to Bone Marrow Aspirate Concentrate.

Background: It is known that a large number of mediators involved in osteogenesis can influence bone development and repair; however, whether these mediators could be used as markers of bone maturity has yet to be determined. Aim: To evaluate the expression of osteocalcin (OC) and Runt-related transcription factor 2 (Runx2) in bone biopsies obtained during the reconstruction of atrophic anterior maxillae using particulate bone xenografts with or without association of autogenous bone marrow aspirate concentrate (BMAC). Materials and Methods: Ten patients were distributed into two groups (n = 5), according to the type of grafting material used: Control group (CG), particulate bone xenograft alone, and test group (TG), particulate bone xenograft combined with BMAC. A bone specimen was removed from the graft area 4 months after grafting, before implant placement. The specimens were processed and submitted to immunohistochemical analysis for detection of OC and Runx2. Histomorphometry was used to ascertain the percentage of stained areas in both groups. The Wilcoxon Mann-Whitney U-Test was used in the statistical analysis (P < 0.05). Results: The immunohistochemical analysis revealed a significantly higher OC expression in the TG than in the CG, namely 27.40 ± 1.34% and 11.40 ± 2.70%, respectively (P < 0.05), and a significantly higher Runx2 expression in the TG than in the CG, namely 2.80 ± 0.84% and 0.40 ± 0.55%, respectively (P < 0.05). Conclusion: The OC and Runx2 expression levels were higher when BMAC was associated with the bone xenograft than when it was not.

Comparative analysis of two biomaterials mixed with autogenous bone graft for vertical ridge augmentation: A histomorphometric study in humans.

BACKGROUND: The vertical increase of the alveolar ridge dimension using allograft or xenograft mixed with autogenous bone graft and covered by a nonabsorbable high-density polytetrafluoroethylene (d-PTFE) membrane is well documented in the literature. PURPOSE: The aim of this study was to assess vital mineralized tissue formation in vertical ridge augmentation (VRA) procedures using autogenous bone chips mixed either with an allograft or a xenograft. METHODS: This prospective clinical trial recruited 16 partially edentulous patients to undergo vertical ridge augmentation in one or more sites, making up a total of 24 samples for histological evaluation. Patients were sequentially stratified into Group A (treated with a freeze-dried bone allograft [FDBA] mixed with autogenous bone) or to Group B (treated with a bovine xenograft mixed with autogenous bone). Histological samples were analyzed according to the biomaterial used for VRA. Histological samples were obtained on the same day of membrane removal and implant placement. RESULTS: Thirty-three implants were placed in 16 sites of regenerated bone via VRA, 13 patients with ridge augmentation in the posterior mandible, and 3 patients with VRA in the anterior maxilla. Group A (FDBA + autogenous) and Group B (xenograft + autogenous) showed a percent vital mineralized tissue (VMT) area of 67.64 ± 16.84 and 60.93 ± 18.25, respectively. A significant difference between the two biomaterials was not observed. CONCLUSION: When mixed with autogenous bone, either allografts or xenografts may provide a successful augmentation. Either mixture could serve as reliable alternative in VRA for obtaining a high percentage of VMT.

Influence of Titanium Surface Treatments on Viability of Periodontal Fibroblasts Grown in an Osteogenic Culture Medium.

Background: The integrity of the protective seal provided by the gingiva in direct contact with the implant surface is one of the main factors involved in the prevention of peri-implantitis. Aim: The aim of this study was to assess the viability of periodontal fibroblasts grown in an osteogenic culture medium in contact with titanium surfaces treated either with acid etching alone or with acid etching + anodizing. Materials and Methods: Periodontal fibroblasts grown in an osteogenic culture medium were distributed in a control group, with cells grown in culture bottles, and two experimental groups, with cells grown in contact with titanium disks measuring 6 mm in diameter. The surface of the disks was subjected to acid etching alone (AEG, n = 25) or to acid etching + anodizing (ANG, n = 25), and then evaluated using scanning electron microscopy (SEM). Cell viability was assessed by the [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium] bromide test on days 1, 2, 3, 7, and 14 of the cell culture. The Mann-Whitney test was used for the statistical analysis (P < 0.05). Results: The SEM assessment revealed that the surface of AEG specimens had micrometric characteristics, whereas the surface of ANG specimens had nanometric characteristics. No significant difference was observed among the groups regarding cell viability at any of the evaluation time points. Conclusion: The titanium surface treatments tested did not affect the viability of periodontal fibroblasts in an osteogenic culture medium.

Influence of Dental Pulp Harvesting Method on the Viability and Differentiation Capacity of Adult Dental Pulp-Derived Mesenchymal Stem Cells.

OBJECTIVE: To compare two pulp harvesting methods for stem cell expansion, namely, conservative pulpotomy and pulpectomy from exodontia. METHOD: Ten freshly extracted sound third molars from five patients were selected. Five were used in the control group, where pulp harvesting was performed by exodontia and the remaining teeth were used in the test group, where the pulp was harvested by conservative pulpotomy (preserving the tooth). This was a split-mouth design study, where a third molar from one side was randomly allocated into the test group and the contralateral tooth in the control group. After pulp harvesting, the following evaluations were performed: cell morphology, sterility test, immunophenotyping, differentiation assays, first pass live cell counts, time to cryopreservation, and total number of expanded cells at the end of the fourth pass. RESULTS: Regarding morphology, the cells from both groups presented a fibroblastic phenotype. All samples were sterile. Immunophenotyping demonstrated a positive expression for CD105, CD90, and CD73 and negative expression for CD45 in both groups. Differentiation assays were positive for osteogenic and chondrogenic differentiation in both groups. Regarding live cell counts in the first passage, the control group had 95.8% live cells in the total count and the test group 91.2% (p < 0.05). The time required for cryopreservation was equivalent in both groups 51.6 days and 52.6 days, respectively (p > 0.05). The total number of cells at the end of the fourth passage was 5,286,782 and 5,736,862, respectively (p > 0.05). CONCLUSION: These results suggest that adult stem cell harvesting from conservative pulpotomy is as effective as the traditional exodontia-based method.

Acellular dermal matrix in skin wound healing in rabbits - histological and histomorphometric analyses.

OBJECTIVES: To analyze the histology and histomorphometry of healing associated with acellular dermal matrix in skin wounds in rabbits. METHODS: Twelve male rabbits were divided into two groups: the control group (CG) and the matrix group (MG). Three skin wounds with a total area of 20 × 20 mm were created on the dorsal region of each animal. Photographic records of the lesions taken over a 21-day period and use of the ImageJ program allowed calculation of the wound contraction rate. The lesions were biopsied on days 3, 14 and 21 for histomorphometric analysis to define the thicknesses of the dermis and epidermis (hematoxylin-eosin) and calculate the densities of type I and type III collagen (picrosirius). RESULTS: No significant difference in the healing rate was found between the groups (p>0.05). The MG presented greater epidermal thickness on day 3 (p<0.05) and on days 14 and 21 (p<0.001). The MG presented greater dermal thickness throughout the study period (p<0.05). The type I collagen density was higher in the MG throughout the study period (p<0.05), and the type III collagen density was higher in the MG on days 3 and 14 (p<0.05) and on day 21 (p<0.001). CONCLUSION: The use of acellular dermal matrix increased the thickness of the dermal and epidermal layers and the amount of type I and III collagen during skin wound healing and did not alter the rate of wound contraction.

Bone marrow aspirate concentrate and platelet-rich fibrin in fresh extraction sockets: A histomorphometric and immunohistochemical study in humans.

The aim of this study was to evaluate the level of mineralized tissue and expression of bone markers in sockets grafted with platelet-rich fibrin and bone marrow aspirate concentrate (BMAC). Patients requiring extraction of one maxillary anterior tooth were randomized into three groups. After tooth extraction, the sockets in the control group (CG) were permitted to fill with blood clot. In the platelet-rich fibrin group (PRFG), after blood processing, the sockets were grafted with PRF plug. In the bone marrow aspirate concentrate combined with platelet-rich fibrin group (BM/PG), after blood and bone marrow processing, the sockets were grafted with a mixture of PRF plug and BMAC. After 6 months, the sites were reopened and bone cores were harvested and prepared for histomorphometric and immunohistochemical evaluation. The following levels were measured: mineralized tissue, expression of RUNX-2, and osteocalcin. Fifteen patients were included in this study. The histomorphometric analysis showed a more pronounced level of mineralized tissue in PRFG and BM/PG (54.20 ± 4.31% and 64.70 ± 6.74%, respectively) when compared with CG (40.60 ± 5.98%) (p = 0.0283 and p = 0.0090, respectively). The expression of RUNX-2 was very low in BM/PG (0.80 ± 0.84%) and absent in CG and PRFG (p = 0.0528). Osteocalcin expression was higher for BM/PG (23.40 ± 1.52%) when compared with CG and PRFG (18.40 ± 2.07% and 16.20 ± 1.92%, respectively) (p = 0.0117 and p = 0.0088, respectively). This preliminary study indicates that clinical use of bone marrow aspirate concentrate, when combined with platelet-rich fibrin as a carrier, might have some potential to increase mineralization in fresh extraction sockets.

Acellular dermal matrix in skin wound healing in rabbits - histological and histomorphometric analyses

OBJECTIVES: To analyze the histology and histomorphometry of healing associated with acellular dermal matrix in skin wounds in rabbits. METHODS: Twelve male rabbits were divided into two groups: the control group (CG) and the matrix group (MG). Three skin wounds with a total area of 20 × 20 mm were created on the dorsal region of each animal. Photographic records of the lesions taken over a 21-day period and use of the ImageJ program allowed calculation of the wound contraction rate. The lesions were biopsied on days 3, 14 and 21 for histomorphometric analysis to define the thicknesses of the dermis and epidermis (hematoxylin-eosin) and calculate the densities of type I and type III collagen (picrosirius). RESULTS: No significant difference in the healing rate was found between the groups (p>0.05). The MG presented greater epidermal thickness on day 3 (p<0.05) and on days 14 and 21 (p<0.001). The MG presented greater dermal thickness throughout the study period (p<0.05). The type I collagen density was higher in the MG throughout the study period (p<0.05), and the type III collagen density was higher in the MG on days 3 and 14 (p<0.05) and on day 21 (p<0.001). CONCLUSION: The use of acellular dermal matrix increased the thickness of the dermal and epidermal layers and the amount of type I and III collagen during skin wound healing and did not alter the rate of wound contraction.

Barbell Technique: A Novel Approach for Bidirectional Bone Augmentation: Technical Note.

Horizontal bone reconstruction is a common augmentation procedure used in implant dentistry to achieve adequate 3-dimensional ridge reconstruction to permit proper dental implant positioning. However, most available techniques are focused on unidirectional bone reconstruction (grafting only on the buccal side). This study was carried out to validate an innovative device that is indicated for bidirectional bone augmentation. The study consisted of 4 patients who required bidirectional horizontal bone augmentation of the upper jaw. Two computerized tomographies were performed (T0 at baseline and T1 at 6 months postoperative examinations). Mean bone thickness in the studied sites at T0 was 2.30 ± 0.65 and mean bone thickness achieved was 9.11 ± 1.08 mm at T1, with an overall bone gain of 6.81 ± 1.33 mm. Concerning the specific gains in direction, buccal and palatal bone augmentations were 4.89 ± 0.94 and 1.92 ± 0.42 mm, respectively. Based on these results, it can be concluded that the use of this novel device allows for the achievement of bidirectional horizontal bone augmentation.

Prevalence of horizontal alveolar changes in edentulous patients: a retrospective tomographic study.

Horizontal bone loss after tooth extraction is a common finding that demands bone reconstruction in various cases. The aim of this study was to assess the horizontal alveolar status in partially and completely edentulous patients using cone-beam computed tomography (CBCT). In total, 1516 CBCT scans of 1404 adult patients were analyzed. Assessment of the images was performed in accordance with the previously published horizontal alveolar change (HAC) classification, which categorizes horizontal bone defects into four classes: HAC 1, HAC 2, HAC 3 and HAC 4 (from the least severe to the most severe condition). Analysis of 1048 scans from partially edentulous patients presented a distribution of 63.55%, 22.14%, 13.36% and 0.95% in HAC 1, HAC 2, HAC 3 and HAC 4, respectively. Analysis of 468 scans from completely edentulous patient images presented a distribution of 19.87%, 28.63%, 41.67% and 9.83% in HAC 1, HAC 2, HAC 3 and HAC 4, respectively. Based on these results, as in HAC 4, no cancellous bone was found between the cortical buccal and lingual/palatal bone plates, it seems reasonable to state that the absence of cancellous bone is higher in completely edentulous patients than in partially edentulous patients. Therefore, the absence of cancellous bone seems to be higher in completely edentulous than in partially edentulous patients.

Horizontal Bone Reconstruction on sites with different amounts of native bone: a retrospective study.

The lack of guidelines for bone augmentation procedures might compromise decision making in implantology. The objective of this study was to perform a retrospective study to verify the outcomes of horizontal bone reconstruction in implant dentistry with different types of materials and amounts of native bone in the recipient bed to allow for a new guideline for horizontal bone reconstruction. One hundred preoperative CT scans were retrospectively evaluated and categorized in accordance to horizontal bone defects as presence (Group P) or absence (Group A) of cancellous bone in the recipient bed. Different approaches were used to treat the edentulous ridge and the outcomes were defined either as satisfactory or unsatisfactory regarding the possibility of implant placement. The percentage distribution of the patients according to the presence or absence of cancellous bone was 92% for Group P and 8% for Group A. In Group P, 98% of the patients had satisfactory outcomes, and the use of autografts had 100% of satisfactory outcomes in this group. In Group A, 37.5% of the patients had satisfactory outcomes, and the use of autografts also yielded 100% of satisfactory outcomes. The use of allografts and xenografts in Group A had 0% and 33.3% of satisfactory outcomes, respectively. Therefore, it seems reasonable to speculate that the presence of cancellous bone might be predictive and predictable when the decision includes bone substitutes. In cases of absence of cancellous bone in the recipient bed, the use of a vitalized graft seems to be mandatory.

Horizontal Bone Reconstruction on sites with different amounts of native bone: a retrospective study

Abstract: The lack of guidelines for bone augmentation procedures might compromise decision making in implantology. The objective of this study was to perform a retrospective study to verify the outcomes of horizontal bone reconstruction in implant dentistry with different types of materials and amounts of native bone in the recipient bed to allow for a new guideline for horizontal bone reconstruction. One hundred preoperative CT scans were retrospectively evaluated and categorized in accordance to horizontal bone defects as presence (Group P) or absence (Group A) of cancellous bone in the recipient bed. Different approaches were used to treat the edentulous ridge and the outcomes were defined either as satisfactory or unsatisfactory regarding the possibility of implant placement. The percentage distribution of the patients according to the presence or absence of cancellous bone was 92% for Group P and 8% for Group A. In Group P, 98% of the patients had satisfactory outcomes, and the use of autografts had 100% of satisfactory outcomes in this group. In Group A, 37.5% of the patients had satisfactory outcomes, and the use of autografts also yielded 100% of satisfactory outcomes. The use of allografts and xenografts in Group A had 0% and 33.3% of satisfactory outcomes, respectively. Therefore, it seems reasonable to speculate that the presence of cancellous bone might be predictive and predictable when the decision includes bone substitutes. In cases of absence of cancellous bone in the recipient bed, the use of a vitalized graft seems to be mandatory.

Use of Bone Allograft With or Without Bone Marrow Aspirate Concentrate in Appositional Reconstructions: A Tomographic and Histomorphometric Study.

OBJECTIVES: To evaluate bone allograft associated to bone marrow aspirate concentrate (BMAC), in maxillary reconstructions. MATERIALS AND METHODS: Ten patients with alveolar bone deficiency in the anterior maxilla were randomly divided into control group (CG) and test group (TG). A bone block allograft was placed in both groups, but the graft was impregnated with BMAC only in TG. Computed tomography was performed 7 days (T1) and 6 months (T2) after the grafting procedure, and volume and bone density measurements were carried out. Histomorphometric analysis was performed at T2. RESULTS: Bone volume loss from T1 to T2 was significant only in TG. The bone density in the buccal region of the graft was significantly higher in TG than in CG. There was no significant difference between the groups, in respect to mineralized tissue (MT) and nonmineralized tissue (NMT), in that MT values were 37.77% ± 15.19% and 43.85% ± 10.94%, and NMT values were 62.15% ± 14.90% and 56.30% ± 10.72%, respectively, for CG and TG. The intragroup difference for the MT/NMT ratio was statistically significant in CG but not significant in TG. CONCLUSIONS: The use of BMAC resulted in an improved pattern of bone formation, with higher bone density in the peripheral regions of the graft.

Long-term Retrospective Study of Implants Placed after Sinus Floor Augmentation with Fresh-frozen homologous block.

AIM: The aim of this study was to analyze and follow-up implants placed in the posterior maxillary regions previously grafted with homologous bone. MATERIALS AND METHODS: Forty-one grafts with homologous bone blocks were performed in maxillary sinuses, and 121 implants were placed in premolar and molar regions approximately 6 months after the grafts. Patients were followed up for periods varying from 12 to 124 months after rehabilitation. RESULTS: The results showed two implant failures, for a 98.3% success rate during the follow-up period. DISCUSSION: The implants placed had an average torque of 40 N-cm, regardless of the, design, diameter, and length of the implants used. CONCLUSION: After following up on the implants placed in this study, we concluded that those placed in regions of the maxillary sinuses previously grafted with homologous bone blocks had high long-term success rates and met the functional masticatory requirements.

Comparative Study Between Mesenchymal Stem Cells Derived from Bone Marrow and from Adipose Tissue, Associated with Xenograft, in Appositional Reconstructions: Histomorphometric Study in Rabbit Calvaria.

PURPOSE: This study analyzed the use of bone marrow-derived mesenchymal stem cells and adipose tissue-derived stem cells, associated with xenograft, in appositional reconstructions in rabbit calvaria using histomorphometry. MATERIALS AND METHODS: Fifteen New Zealand rabbits, weighing 3.5 to 4.0 kg and aged between 10 and 12 months, were randomly divided into three groups. Appositional bone reconstruction situations were created in the calvaria of the animals using titanium cylinders, fitted with titanium occlusive caps. Bone decortication was performed to promote bleeding. Inside the cylinders, only xenograft was positioned in the control group (CG; n = 5); xenograft combined with mesenchymal bone marrow-derived stem cells was positioned in group 1 (G1; n = 5), and a xenograft combined with adult mesenchymal stem cells derived from adipose tissue was positioned in group 2 (G2; n = 5). After 56 days, all rabbits were euthanized and their parietal bones processed for histomorphometric analysis, and the following parameters were evaluated: newly formed bone; residual graft particles; soft tissue; vital bone titanium contact, also called the level of osseointegration; and the level of bone volume contained inside the cylinders, also called the internal bone volume. RESULTS: The histomorphometric study revealed the following for CG, G1, and G2: newly formed bone of 18.96% ± 9.00%, 27.88% ± 9.98%, and 22.32% ± 7.45%; residual graft particles of 28.43% ± 2.44%, 23.31% ± 3.11%, and 27.58% ± 3.98%; soft tissue of 52.61% ± 10.80%, 50.23% ± 8.72%, and 49.90% ± 8.76%; vital bone titanium contact of 4.98% ± 4.30%, 34.91% ± 7.82%, and 20.87% ± 5.43%; and internal bone volume of 88.36% ± 25.97%, 98.73% ± 19.05%, and 98.52% ± 19.87%, respectively. No statistical difference between groups for newly formed bone, residual graft particles, soft tissue, and internal bone volume (P > .05) were verified. CONCLUSION: Regarding vital bone titanium contact, it was observed that the use of bone marrow mesenchymal stem cells, when compared with the adipose mesenchymal stem cells, showed the highest level of osseointegration, and both of them obtained superior levels to the xenograft alone.

Implantes cerâmicos em casos estéticos: uma nova possibilidade clínica / Dental ceramic implants in aesthetic cases: a new clinical possibility

A substituição de um elemento dental por um implante em pacientes que apresentam tecido gengival delgado gera uma preocupação devido à translucidez gengival, onde a coloração acinzentada do titânio pode levar ao fracasso estético do tratamento. Desta maneira, os implantes de zircônia se diferenciam principalmente por sua coloração clara, a qual se aproxima das características de cor da raiz, e por sua biocompatibilidade, além de possibilitarem a escolha do paciente por um tratamento totalmente livre de metal. Portanto, este relato de caso clínico demonstrou uma inovação técnica por meio da utilização de um implante confeccionado em zircônia para solução de um caso clínico de alta complexibilidade estética em uma paciente jovem, com fenótipo gengival delgado e alto grau de exigência estética. O caso foi finalizado com prótese cimentada e facetas metal free confeccionadas por meio de cerâmica injetada. Após a finalização do caso, concluiu-se que, apesar da desvantagem relacionada à sensibilidade técnica, o implante confeccionado em zircônia possibilitou a solução estética deste caso clínico de fenótipo gengival delgado, sem a necessidade de utilização de enxertos gengivais.

The replacement of a dental element in patients with thin gingival tissue generates a concern due to gingival translucency, where the titanium gray coloration can lead to failure of the treatment. Thus, the zirconia implants are distinguished primarily by their coloration and their biocompatibility, in addition to enabling the selection of a totally metal-free treatment. Therefore, this clinical report, showed an innovative technique using a zirconia implant in a clinical situation with high complex esthetic needs for in a young patient with thin gingival phenotype and high level of aesthetic requirement. The clinical case was concluded with cemented prosthesis and metal-free veneers made by pressed ceramics. After the end of the case, it was concluded that, despite the disadvantage related to the technical sensitivity, the zirconia implant provided an aesthetic solution of this clinical case of thin gingival phenotype, without the need of gingival grafts.

Can bone marrow aspirate concentrate change the mineralization pattern of the anterior maxilla treated with xenografts? A preliminary study.

OBJECTIVE: To evaluate bony reconstruction of the atrophic anterior maxilla using particulate grafts with or without autologous bone marrow aspirate concentrate (BMAC). MATERIALS AND METHODS: Eight patients with atrophy of the anterior maxilla due to teeth loss were selected and split into groups according to the type of material used: Control Group (CG) (n = 4) - particulate xenograft only and Test Group (TG) (n = 4) - a combination of particulate xenograft and BMAC. Both groups received a collagen membrane to cover the xenograft. After 4 months, during implant placement, a sample of bone was removed from the graft area using a 2 mm diameter trephine bur. The specimens were fixed and preserved for histomorphometric evaluation, which included the following parameters: Mineralized tissue (MT) and non-MT (NMT). Cone beam computed tomography was performed at 3 time intervals to measure bone thickness: (1) Before grafting, (2) 4 months and (3) 8 months postgrafting, using localized bone gain (mm) as the outcome variable. RESULTS: Tomographic analysis revealed bone gain in CG of 3.78 ± 1.35 mm and 4.34 ± 1.58 mm at 4 and 8 months, respectively. TG showed an increase of 3.79 ± 0.52 mm and 4.09 ± 1.33 mm after 4 and 8 months, respectively. Histomorphometric analysis revealed that, for CG, MT- and NMT-related values were 52.3% ± 16.78% and 47.70% ± 5.55%, respectively, whereas for TG, they were 65.04% ± 20.98% and 34.96 ± 10.38, respectively. CONCLUSION: Although radiographic bone gain appeared similar between the groups, the use of BMAC obtained via the BMAC(®) method revealed an increased mineralization trend in the anterior maxilla. It must be highlighted, however, that this is a preliminary study with a relatively small sample population and further studies with larger sample sizes are needed to verify these results.

Ectopic Implantation of Hydroxyapatite Xenograft Scaffold Loaded with Bone Marrow Aspirate Concentrate or Osteodifferentiated Bone Marrow Mesenchymal Stem Cells: A Pilot Study in Mice.

PURPOSE: To evaluate the influence of bone marrow cells in the bone formation in an ectopic subcutaneous model in mice. MATERIALS AND METHODS: Six BALB/c mice were divided into three groups of two each. In all groups, xenograft was implanted subcutaneously. In the negative control group, the xenograft was hydrated with saline solution. In the positive control group, the xenograft was embedded with osteodifferentiated adult mesenchymal stem cells derived from the bone marrow. In the experimental group, the xenograft was embedded with bone marrow aspirate concentrate. After 4 weeks, the animals were sacrificed and prepared for histologic, histomorphometric, and immunohistochemical analysis. The following tissues were evaluated: preosteoid tissue, loose connective tissue, and remaining xenograft particles. RESULTS: There was a statistically significant difference (P = .008) in the preosteoid tissue area between the negative control group (0 ± 0%) and the other two groups, with 42 ± 11% for the experimental group and 56 ± 5% for the positive control group. Similarly, there was a statistically significant difference (P = .006) in the loose connective tissue area between the negative control group (49 ± 18%) and the other two groups, with 3 ± 9% for the experimental group and 0 ± 0% for the positive control group. Regarding the xenograft area, there was not a statistically significant difference between the three groups (P = .143). CONCLUSION: The use of a mineralized scaffold loaded with either concentrated bone marrow aspirate or with osteogenically induced bone marrow mesenchymal stem cells favored the formation of osteoid tissue as opposed to the scaffold alone.