Maxillary Reconstruction with Xenogeneic Bone Graft, Platelet-Rich Fibrin, and Titanium Mesh for Rehabilitation with Implants: A 5-year Follow-Up Study.

Aim: Alveolar deficiency is considered one of the main limitations for placement of osseointegrated implants, as well as for their long-term success, especially in the anterior region of the maxilla. Objective: To report a clinical case of reconstruction of atrophic maxilla with deproteinized bovine bone associated with platelet-rich fibrin (PRF) and titanium mesh and to assess the linear and volumetric bone gains and rehabilitation with implants in a 5-year follow-up. Case: Patient with bone deficiency in the anterior maxilla region underwent bone reconstruction with deproteinized bovine bone associated with PRF and titanium mesh. After six months, the necessary bone height and volume were obtained for placement of implants, and the bone contour was restored in the anterior region, providing functional and aesthetic improvement. The amount of linear and volumetric bone gains was compared to baseline computed tomography scans. Three implants were placed in the grafted region, and a bone tissue sample was obtained at the time of their placement. Histological analysis showed neo-formed bone tissue in contact with the remaining particles of the biomaterial. After six months, the implants were activated, and the prosthesis was placed on the implants, which were monitored for five years. Conclusion: Implants can be placed predictably in regions with vertical and horizontal bone augmentations by using xenogeneic bone grafts associated with titanium mesh and PRF.

Performance of Polydioxanone-Based Membrane in Association with 3D-Printed Bioceramic Scaffolds in Bone Regeneration.

This study evaluated the bioactivity of 3D-printed ß-tricalcium phosphate (ß-TCP) scaffolds or hydroxyapatite (HA) scaffolds associated with polydioxanone (PDO) membrane (Plenum® Guide) for guided bone regeneration in rats. Fifty-four rats were divided into three groups (n = 18 animals): autogenous bone + PDO membrane (Auto/PG); 3D-printed ß-TCP + PDO membrane (TCP/PG); and 3D-printed HA + PDO membrane (HA/PG). A surgical defect in the parietal bone was made and filled with the respective scaffolds and PDO membrane. The animals were euthanized 7, 30, and 60 days after the surgical procedure for micro-CT, histomorphometric, and immunolabeling analyses. Micro-CT showed an increase in trabecular thickness and a decrease in trabecular separation, even with similar bone volume percentages between TCP/PG and HA/PG vs. Auto/PG. Histometric analysis showed increased bone formation at 30 days in the groups compared to 7 days postoperatively. Immunolabeling analysis showed an increase in proteins related to bone formation at 30 days, and both groups showed a similar immunolabeling pattern. This study concludes that 3D-printed scaffolds associated with PDO membrane (Plenum® Guide) present similar results to autogenous bone for bone regeneration.

Polydioxanone-Based Membranes for Bone Regeneration.

Resorbable synthetic and natural polymer-based membranes have been extensively studied for guided tissue regeneration. Alloplastic biomaterials are often used for tissue regeneration due to their lower immunoreactivity when compared with allogeneic and xenogeneic materials. Plenum® Guide is a synthetic membrane material based on polydioxanone (PDO), whose surface morphology closely mimics the extracellular matrix. In this study, Plenum® Guide was compared with collagen membranes as a barrier material for bone-tissue regeneration in terms of acute and subchronic systemic toxicity. Moreover, characterizations such as morphology, thermal analysis (Tm = 107.35 °C and crystallinity degree = 52.86 ± 2.97 %, final product), swelling (thickness: 0.25 mm ≅ 436% and 0.5 mm ≅ 425% within 24 h), and mechanical tests (E = 30.1 ± 6.25 MPa; σ = 3.92 ± 0.28 MPa; ε = 287.96 ± 34.68%, final product) were performed. The in vivo results revealed that the PDO membranes induced a slightly higher quantity of newly formed bone tissue than the control group (score: treated group = 15, control group = 13) without detectable systemic toxicity (clinical signs and evaluation of the membranes after necropsy did not result in differences between groups, i.e., non-reaction -> tissue-reaction index = 1.3), showing that these synthetic membranes have the essential characteristics for an effective tissue regeneration. Human adipose-derived stem cells (hASCs) were seeded on PDO membranes; results demonstrated efficient cell migration, adhesion, spread, and proliferation, such that there was a slightly better hASC osteogenic differentiation on PDO than on collagen membranes. Hence, Plenum® Guide membranes are a safe and efficient alternative for resorbable membranes for tissue regeneration.

Bioresorbable Polymers: Advanced Materials and 4D Printing for Tissue Engineering.

Three-dimensional (3D) printing is a valuable tool in the production of complexes structures with specific shapes for tissue engineering. Differently from native tissues, the printed structures are static and do not transform their shape in response to different environment changes. Stimuli-responsive biocompatible materials have emerged in the biomedical field due to the ability of responding to other stimuli (physical, chemical, and/or biological), resulting in microstructures modifications. Four-dimensional (4D) printing arises as a new technology that implements dynamic improvements in printed structures using smart materials (stimuli-responsive materials) and/or cells. These dynamic scaffolds enable engineered tissues to undergo morphological changes in a pre-planned way. Stimuli-responsive polymeric hydrogels are the most promising material for 4D bio-fabrication because they produce a biocompatible and bioresorbable 3D shape environment similar to the extracellular matrix and allow deposition of cells on the scaffold surface as well as in the inside. Subsequently, this review presents different bioresorbable advanced polymers and discusses its use in 4D printing for tissue engineering applications.

Adipose Tissue-Derived Stem Cells: The Biologic Basis and Future Directions for Tissue Engineering.

Mesenchymal stem cells (MSCs) have been isolated from a variety of tissues using different methods. Active research have confirmed that the most accessible site to collect them is the adipose tissue; which has a significantly higher concentration of MSCs. Moreover; harvesting from adipose tissue is less invasive; there are no ethical limitations and a lower risk of severe complications. These adipose-derived stem cells (ASCs) are also able to increase at higher rates and showing telomerase activity, which acts by maintaining the DNA stability during cell divisions. Adipose-derived stem cells secret molecules that show important function in other cells vitality and mechanisms associated with the immune system, central nervous system, the heart and several muscles. They release cytokines involved in pro/anti-inflammatory, angiogenic and hematopoietic processes. Adipose-derived stem cells also have immunosuppressive properties and have been reported to be "immune privileged" since they show negative or low expression of human leukocyte antigens. Translational medicine and basic research projects can take advantage of bioprinting. This technology allows precise control for both scaffolds and cells. The properties of cell adhesion, migration, maturation, proliferation, mimicry of cell microenvironment, and differentiation should be promoted by the printed biomaterial used in tissue engineering. Self-renewal and potency are presented by MSCs, which implies in an open-source for 3D bioprinting and regenerative medicine. Considering these features and necessities, ASCs can be applied in the designing of tissue engineering products. Understanding the heterogeneity of ASCs and optimizing their properties can contribute to making the best therapeutic use of these cells and opening new paths to make tissue engineering even more useful.

Aesthetic outcome of immediately restored single implants placed in extraction sockets and healed sites of the anterior maxilla: a retrospective study on 103 patients with 3 years of follow-up.

OBJECTIVES: The aim of this study was to compare the aesthetic outcome of single implants in extraction sockets and healed ridges of the anterior maxilla by means of the pink aesthetic score/white aesthetic score (PES/WES) index. MATERIALS AND METHODS: This retrospective study was based on data from 103 patients (43 males, 60 females) aged 24-65 years (mean age 41.4 ± 13.8 years) who had been successfully treated with a single implant in the anterior maxilla, in four different clinical centres. Forty-two patients (mean age 46.5 ± 15.1 years) were treated with a single implant in a fresh post-extraction socket (immediate implant treatment, IIT), while 61 patients (mean age 38.0 ± 11.8 years) were treated with a single implant in a healed site (conventional implant treatment, CIT). Two independent calibrated examiners applied the PES/WES index to the 103 single-tooth restorations, respectively 3 months and 3 years after implant placement. RESULTS: A few biological (4.8%) and prosthetic (8.7%) complications were reported. Both IIT and CIT yielded satisfactory aesthetic outcomes. At the delivery of the final restoration, a PES/WES score of 16.6 ± 2.6 and 15.7 ± 3.0 was reported for IIT and CIT, respectively: this difference was not statistically significant. A higher decrease in the PES/WES score was observed with CIT over time. At 3 years, a PES/WES score of 16.4 ± 2.8 and 15.2 ± 3.3 was reported for IIT and CIT, respectively: this difference was statistically significant. IIT seemed to yield better aesthetic outcomes in young patients (≤30 years), with implants placed in central incisor/cuspid areas, in the presence of bone contouring. CONCLUSIONS: Both immediate and conventional single-implant treatment in the anterior maxilla can yield satisfactory aesthetic outcomes, when performed by experienced clinicians in well-selected cases. Further studies are needed to confirm these results.

3D Printing/Additive Manufacturing Single Titanium Dental Implants: A Prospective Multicenter Study with 3 Years of Follow-Up.

This prospective 3-year follow-up clinical study evaluated the survival and success rates of 3DP/AM titanium dental implants to support single implant-supported restorations. After 3 years of loading, clinical, radiographic, and prosthetic parameters were assessed; the implant survival and the implant-crown success were evaluated. Eighty-two patients (44 males, 38 females; age range 26-67 years) were enrolled in the present study. A total of 110 3DP/AM titanium dental implants (65 maxilla, 45 mandible) were installed: 75 in healed alveolar ridges and 35 in postextraction sockets. The prosthetic restorations included 110 single crowns (SCs). After 3 years of loading, six implants failed, for an overall implant survival rate of 94.5%; among the 104 surviving implant-supported restorations, 6 showed complications and were therefore considered unsuccessful, for an implant-crown success of 94.3%. The mean distance between the implant shoulder and the first visible bone-implant contact was 0.75 mm (±0.32) and 0.89 (±0.45) after 1 and 3 years of loading, respectively. 3DP/AM titanium dental implants seem to represent a successful clinical option for the rehabilitation of single-tooth gaps in both jaws, at least until 3-year period. Further, long-term clinical studies are needed to confirm the present results.

In Vitro Behavior of Osteoblasts on Zirconia After Different Intensities of Erbium, Chromium-Doped: Yttrium, Scandium, Gallium, and Garnet-Laser Irradiation.

OBJECTIVE: This study investigated the osteoblastic behavior to yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) surface after different intensities of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation treatment. MATERIALS AND METHODS: Y-TZP blocks were randomized divided into 4 groups to Er,Cr:YSGG laser irradiation: group G1 = control (no laser irradiation); group G2 = 1.5 W; group G3 = 3.0 W; group G4 = 5.0 W, with air-water irrigation. The irradiated surface roughness (Sa and Ra) topography was evaluated. MC3T3-E1 osteoblast cells were cultured and seeded onto the treated surfaces at a plate density of 1 × 10 cells/mL. At the third and seventh days cell proliferation was measured by the colorimetric assay methods. The specimens were prepared to scanning electron microscope to observe adhesion and morphology of cells. RESULTS: MTT assay showed adhesion and proliferation of MC3T3-E1 cells in all groups. Compared with group G1 (control), the group G2 had a proliferation 1.4% higher (P > 0.05), the group G3 had a proliferation 3.1% higher (P < 0.05) and group G4 had a proliferation 4.5% higher (P < 0.01). After 7 days there was no difference among the groups (ANOVA, Newman-Keuls). CONCLUSIONS: Er,Cr:YSGG laser irradiation may have contributed to the greater and earlier cell spreading that was observed with the Y-TZP without alterations on surface topography.

Effects of a Low-Intensity Laser on Dental Implant Osseointegration: Removal Torque and Resonance Frequency Analysis in Rabbits.

The objective of this study was to investigate how a low-intensity laser affects the stability and reverse torque resistance of dental implants installed in the tibia of rabbits. Thirty rabbits received 60 dental implants with the same design and surface treatment, one in each proximal metaphysis of the tibia. Three groups were prepared (n = 10 animals each): conventional osseointegration without treatment (control group), surgical sites irradiated with a laser beam emitted in the visible range of 680 nm (Lg1 group), surgical sites irradiated with a laser beam with a wavelength in the infrared range of 830 nm (Lg2 group). Ten irradiation sessions were performed 48 hours apart; the first session was during the immediate postoperative period. Irradiation energy density was 4 J/cm(2) per point in 2 points on each side of the tibias. The resonance frequency and removal torque values were measured at 2 time points after the implantations (3 and 6 weeks). Both laser groups (Lg1 and Lg2) presented a significant difference between resonance frequency analysis values at the baseline and the values obtained after 3 and 6 weeks (P > .05). Although the removal torque values of all groups increased after 6 weeks (P < .05), both laser groups presented greater mean values than those of the control group (P < .01). Photobiomodulation using laser irradiation with wavelengths of 680 and 830 nm had a better degree of bone integration than the control group after 6 weeks of observation time.

Surface alterations of zirconia and titanium substrates after Er,Cr:YSGG irradiation.

This study investigated changes in the roughness parameters (Sa in µm(2) and Ra in µm) of yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) and large-grit sandblasted acid-etched (SLA) titanium (TI) materials after decontamination by erbium chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation. Twenty disks were analyzed in this study: 10 disks of Y-TZP (5 mm in diameter and 3 mm in height), standardized with CAD-CAM procedures, and 10 disks of SLA TI (5 mm in diameter and 4 mm in thickness). Disks were randomized into four groups (n = 5), according to whether laser irradiation was performed: Y-TZP_G1 and TI_G1 were not treated by laser (control groups), whereas Y-TZP_G2 and TI_G2 were irradiated with Er,Cr:YSGG laser (1.5 W/20 Hz, air-water cooling proportion of 80%/25%). The surface topography of the disks was analyzed by confocal light microscopy. The mean Sa and Ra values were calculated from five profiles from each group. The results were statistically analyzed by t-test at the 95% confidence level (α = 0.05). For Y-TZP, the Sa results (in mean ± SD) for Y-TZP_G1 and Y-TZP_G2 were 2.60 ± 1.1 and 0.80 ± 0.17 µm(2), respectively, and the Ra results were 2.01 ± 0.71 and 0.18 ± 0.15 µm, respectively (both p < .05). For SLA TI, the Sa results for TI_G1 and TI_G2 were 1.99 ± 0.5 and 3.37 ± 0.75 µm(2), respectively, and the Ra results were 1.78 ± 0.53 and 3.84 ± 0.63 µm, respectively (both p < .05). Er,Cr:YSGG laser irradiation alters the surface roughness of zirconia and SLA TI.

Thermal effects on zirconia substrate after Er, Cr: YSGG irradiation / Alteração de temperatura em substrato de zircônia após irradiação com laser Er, Cr: YSGG

Objective: The objective of the present study was to investigate the thermal effects of Er,Cr:YSGG laser irradiation (1.5W/20Hz) on yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP). Material and Method: Fifteen disks of Y-TZP (AS Technology TitaniumFIX, São José dos Campos, Brazil) with 5 mm diameter and 3 mm high standardized with CAD-CAM were used. The Y-TZP disks were randomized in three groups (n=5): Y-TZP-G1 = control (no laser treatment); Y-TZP-G2 = Y-TZP + Er,Cr:YSGG laser (air-water cooling proportion 80%/25%); Y-TZP-G3 = Y-TZP + Er,Cr:YSGG laser (air-water cooling proportion 80%/0%). A thermopar (SmartMether, Novus, Porto Alegre, RS, Brazil) was attached to a digital thermometer (SmartMether, Novus, Porto Alegre, RS, Brazil) fixed to the opposite irradiated surface. The temperature gradients (∆T) were calculated (∆T = Final Temperature - Initial Temperature) for each group. Values were statistically analyzed by one-way ANOVA at the 95% confidence level and compared by Tukey post-hoc test (α=0.05) for each material. One sample of each group was analyzed by confocal white light microscopy. Result: The ANOVA test showed significant differences for the factor "laser" (p<.001). The temperature gradients (∆T value) showed the following results: Y-TZP-G1 = 0 ºC; Y-TZP-G2 = -1.4 ºC and Y-TZP-G3 = 21.4 ºC. The ∆T values (ºC) of the non-refrigerated group were higher than the refrigerated group. The roughness value (Ra) ranged from 4.50 to -33.65 µm. Conclusion: The water refrigeration for Er,Cr:YSGG irradiation is essential to avoid thermal increase in the Y-TZP.

Objetivo: O objetivo do presente estudo foi investigar os efeitos térmicos do laser de Er,Cr:YSGG (1,5W/20Hz) em zircônia tetragonal policristalina estabilizada com ítrio (Y-TZP). Material e Método: Quinze discos de Y-TZP (AS Technology Titanium FIX, São José dos Campos, Brasil) com 5 mm de diâmetro e 3 mm de altura padronizados com CAD-CAM (computer-aided design e computer-aided manufacturing) foram usados. Os discos de Y-TZP foram randomicamente distribuídos em três grupos (n=5): Y-TZP-G1 = controle (sem irradiação); Y-TZP-G2 = Y-TZP + Er,Cr:YSGG (proporção resfriamento ar-água 80%/25%); Y-TZP-G3 = Y-TZP + Er,Cr:YSGG (proporção resfriamento ar-água 80%/0%). Um termopar (SmartMether, Novus, Porto Alegre, RS, Brasil) acoplado a um termômetro digital (SmartMether, Novus, Porto Alegre, RS, Brasil) foi fixado na face oposta à superfície irradiada. Os gradientes de temperatura ∆T foram calculados (∆T = Temperatura final - Temperatura inicial) para cada grupo. Os valores foram analisados estatisticamente por one-way ANOVA com 95% de confiança e comparados pelo teste Tukey (α=0,05). Uma amostra de cada grupo foi analisada por microscopia confocal de luz branca. Resultado: O: O teste ANOVA mostrou diferenças significativas para o fator "laser" (p< 0,001). Os gradientes de temperatura (valores de ∆T) apresentaram os seguintes resultados: Y-TZP-G1 = 0 ºC; Y-TZP-G2 = -1,4 ºC e Y-TZP-G3= 21,4 ºC. O valor de ∆T (ºC) do grupo sem refrigeração foi maior do que o grupo refrigerado. Os valores de rugosidade (Ra) variaram de 4,50 até -33,65 µm. Conclusão: A refrigeração com água para a irradiação do laser de Er,Cr:YSGG é essencial para evitar o aumento de temperatura de Y-TZP.

Enxerto de osso da calvária para reconstruções dos maxilares. A técnica através de um caso clínico / Calvarium bone as a donor site for major maxillary reconstructions. The technique trough a clinical case

O objetivo deste trabalho é o de apresentar, através de um caso clínico, a utilização do osso da Cavária como material de enxertia em grandes reconstruções dos maxilares. Esta área doadora tem se mostrada apropriada por fornecer osso em volume e qualidade, sendo compatível com a instalação de implantes ósseo integrados. Os resultados apresentados a técnica fornecem subsídios científicos suficientes para a aplicação da técnica com índices de sucesso como do osso menor reabsorção e melhor pós-operatório para os pacientes.

Viability of autogenous bone grafts obtained by using bone collectors: histological and microbiological study

The use of autogenous bone grafts is considered to be the best choice for reconstructive surgery. In the periodontal literature, the utilization of osseous coagulum was suggested by the end of the sixties. The purpose of this study is to consider the use of bone collectors (bone traps) as an alternative method for obtaining material to fill small bone imperfections, such as fenestrations and dehiscences. Thirty samples were obtained from bone drilling during fixture installation in patients (13 men and 17 women, with an average age of 54 years) requiring treatment at the Department of Periodontology and Implant Dentistry, University of Santo Amaro. These samples were fixed in 10 percent neutral formaldehyde for 24 hours and subjected to histological preparation, in order to evaluate the presence of viable osteoblasts. In addition, the material was placed in a fluid thioglycolate medium and incubated for 24 hours at 36 ± 1°C in aerobiosis and anaerobiosis. Bacterial growth evaluation was made by using six different culture media (MacConkey agar, blood agar base, mannitol salt agar, Anaerokit LTD medium, Anaerokit LTD - bile medium, Anaerinsol). The results show that, if proper care is taken to prevent saliva contamination during the surgical procedure, this method of collecting autogenous bone may be useful in situations where small amounts of bone are required

Viability of autogenous bone grafts obtained by using bone collectors: histological and microbiological study.

The use of autogenous bone grafts is considered to be the best choice for reconstructive surgery. In the periodontal literature, the utilization of osseous coagulum was suggested by the end of the sixties. The purpose of this study is to consider the use of bone collectors (bone traps) as an alternative method for obtaining material to fill small bone imperfections, such as fenestrations and dehiscences. Thirty samples were obtained from bone drilling during fixture installation in patients (13 men and 17 women, with an average age of 54 years) requiring treatment at the Department of Periodontology and Implant Dentistry, University of Santo Amaro. These samples were fixed in 10% neutral formaldehyde for 24 hours and subjected to histological preparation, in order to evaluate the presence of viable osteoblasts. In addition, the material was placed in a fluid thioglycolate medium and incubated for 24 hours at 36 1 C in aerobiosis and anaerobiosis. Bacterial growth evaluation was made by using six different culture media (MacConkey agar, blood agar base, mannitol salt agar, Anaerokit LTD medium, Anaerokit LTD - bile medium, Anaerinsol). The results show that, if proper care is taken to prevent saliva contamination during the surgical procedure, this method of collecting autogenous bone may be useful in situations where small amounts of bone are required.

Regeneraçäo tecidual guiada em defeito periodontal: relato de caso / Guided tissue regeneration in periodontal defects: case report

Os autores visam através da utilizaçäo de enxerto ósseo homógeno, membrana reabsorvível e splintagem rígida dos dentes, obter uma regeneraçäo dos tecidos de suporte do elemento dental. O caso clínico teve acompamhamento durante 18 meses por meio de exame clínico, sondagem e radiografias