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Chemical modification to produce a hydrophilic microrough titanium (Ti) implant surface has been shown to increase osseointegration compared with microrough topography alone. This study aimed to investigate the roles of PI3K/Akt signaling pathway in regulating proliferation and differentiation of osteoblasts in response to surface microroughness and hydrophilicity. Ti disks were manufactured to present different surface morphologies: a smooth pretreatment surface (PT), a rough hydrophobic surface that was sand-blasted, large-grit, acid-etched (SLA), and an SLA surface with the same roughness that was chemically modified to possess high wettability/hydrophilicity (SLActive/modSLA). MC3T3-E1 cells were cultured on these substrates with or without LY294002, a PI3K inhibitor, and their behaviors, including cell viability (MTT colorimetric assay), alkaline phosphatase (ALP) activity, and osteogenic genes expression of osteopontin (OPN) and osteocalcin (OCN) were measured. Western blot was applied to detect the expression of PI3K/Akt signal pathway proteins. The results showed that a decrease in osteoblast proliferation associated with the Ti surfaces (SLActive > SLA > PT) correlated with an increase in activity of the osteogenic differentiation markers ALP. The peak of ALP activity appeared earlier at 7 days for the SLActive surfaces compared with the SLA and PT surfaces. Osteoblast proliferation, as well as the level of p-Akt, was significantly inhibited by LY294002 in all three Ti surfaces. The top value of ALP activity was increased with the inhibition of PI3K/Akt signaling pathway while the time of the peak appeared was not advanced. The expression levels of OPN and OCN were upregulated by the effect of surface roughness and hydrophilicity, which were further enhanced by LY294002. In conclusion, osteogenic responses to SLActive surface were moderately better than the SLA surface and protein expression studies indicated that PI3K/Akt signaling activation may be responsible for this increased osteogenic differentiation. Surface microroughness and hydrophilicity may affect osteoblast functions by targeting osteoblast proliferation and the early stage of osteoblast differentiation through PI3K/Akt signaling pathway. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 748-754, 2013. [ABSTRACT FROM AUTHOR]

PURPOSE: To observe the alteration of the interproximal papilla height after single implant restoration in the anterior maxilla and to assess the influence of gingival biotypes on papilla regeneration. METHODS: Thirty patients with single--tooth implant-supported restorations in the anterior maxilla were assigned to two groups according to labial mucosa thickness. Group A: labial mucosal thickness ≥1.5 mm and group B: labial mucosal thickness<1.5 mm. The presence of interproximal papilla as well as the distance between papilla apex and contact point were assessed at crown attachment (baseline) and after 6 months (follow-up).Statistical analysis was performed using SPSS19.0 software package. RESULTS: The 6-month survival rate of implants was 100%. The mean height of interproximal papilla at baseline and follow-up was (1.64 ±0.97) mm and (3.10 ±1.39) mm, respectively. A significant improvement in papilla height was found between baseline and follow-up (P<0.05). In group A, the mean distance from papilla apex to the contact point at mesial and distal aspects was (0.15±0.24) mm and (0.23±0.33) mm, respectively, and the presence of interproximal papilla were (97±5)% and (94 ±8)%, respectively. In group B, the mean distance from papilla apex to the contact point at mesial and distal aspects was (1.94±0.40) mm and (2.10±0.34) mm, respectively, and the presence of interproximal papilla was (53±9)% and (43±14)% respectively. Statistically significant difference was found between the two groups (P<0.05). CONCLUSIONS: The interproximal papilla height around single implant restorations could improve significantly after 6-month follow-up. The interproximal papilla height around single-tooth implants in the anterior maxilla was influenced by gingival biotype. The regenerative potential of thick-gingival biotype was better than that of thin-gingival biotype. Supported by National Natural Science Foundation of China (31070842) and Research Fund of Science and Technology Commission of Shanghai Municipality (09411955000,1052nm04500). [ABSTRACT FROM AUTHOR]

PURPOSE: To monitor the stability changes of Straumann implants using resonance frequency analysis(RFA) during healing period, and determine the factors that affect implant stability. METHODS: Fifty two Straumann implants were placed in 25 partially or totally edentulous patients. ISQ was tested by RFA on the day of surgery and consecutively at 1-, 4-, 6-, 8- and 12-week. All data were analyzed using general linear model by Minitab 14.13 software package. RESULTS: All the 52 implants achieved good primary stability at surgery. The mean implant stability quotient (ISQ) value was 64.39 ±0.66 on the day of surgery and dropped to the lowest point 4 weeks after surgery, then got notable increase between 4 and 6 weeks after surgery in the stability curve. Statistically significant differences was found between different bone types and implant insertion sites (P<0.05). There was no significant difference between different implant lengths and collar types. The survival rate during the 12 weeks of follow -up was 100% . CONCLUSIONS: Implant stability seems to be affected by bone types and implant insertion sites. More evidence is needed to support the influence of implant length and collar type on implant stability. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (09411955000). [ABSTRACT FROM AUTHOR]

PURPOSE: The aim of this study was to evaluate the Trausim implants bone remodelling at early stage of implantation, to provide necessary experimental parameters for improving the characteristics of the surface treatment technique. METHODS: 14 Labrador dogs were prepared for teeth extraction of the mandible first premolar to first molar under general anesthesia. After bone healing for 3 months, each dog was implanted with 3 Trausim implant and 3 Straumann implant. 2,4,8 and 12 weeks later, the animals were sacrificed and bone-to-implant contact (BIC%) was assessed using histological and histomorphometrical methods. All statistical analysis was performed using SPSS 19.0 software package. RESULTS: All 84 implants achieved clinical stability at the time of insertion, the healing was uneventful. Bone-to-implant percentage was highest at 8-week for Trausim implant (71.64%±6.66%) and Straumann implant (72.98%±8.97%). At 12-week it was lower than at 8-week, but stability was as usual. Moreover, at different healing periods, no significant difference for BIC% between Trausim and Straumann implants was found. CONCLUSION:The present study showed that Trausim implants induce good bone-to-implant contact after implantation. The BIC% was similar to Straumann implants. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality(09411955000). [ABSTRACT FROM AUTHOR]

Surface roughness of titanium-based implants may enhance osteogenic differentiation of cells in vitro and bone-to-implant contact in vivo. Nevertheless, how surface roughness regulates the signaling pathway of osteoblasts is little understood. The study intended to investigate specifically the roles of extracellular signal-regulated kinase 1/2 (ERK1/2) pathway in regulating osteogenic differentiation of MC3T3-E1 murine preosteoblast cells on Ti surfaces. Substrates applied were two groups of titanium disks: (1) sand-blasted and acid-etched rough surfaces (SLA) and (2) smooth pretreated Ti surfaces (PT). Surface morphology of the two groups was examined by scanning electron microscope, and cell morphology cultured on Ti disks was observed by confocal microscope. The levels of alkaline phosphatase (ALP) activity and calcium deposition were measured and compared between the two groups. Real-time polymerase chain reaction was applied to detect the expression levels of osteogenic genes including runt related protein 2 (Runx2), osterix (OSX), osteocalcin (OCN) and osteoprotegerin (OPN) of the cells cultured on the two groups of substrates and on SLA surfaces treated with ERK1/2 inhibitor, PD98095. ERK1/2 activities in MC3T3-T1 cells were measured by Western-blotting on the two surfaces with or without PD98095. Cells cultured on rougher SLA surfaces displayed a more differentiated morphology. ALP activities at 7 days and 14 days and the calcium deposition at 28 days were significantly higher on SLA surfaces. The expression levels of Runx2, OSX, OPN and OCN were upregulated by the effect of surface roughness and PD98095 further upregulated the expression levels of these osteogenic genes on SLA surfaces. ERK1/2 phosphorylation was continuously inhibited by surface roughness at 2 days, 4 days and 6 days. In contrast, no marked alterations in ERK1/2 phosphorylation on PT surfaces were observed. PT surfaces treated with PD98095 (50 μ M) and SLA surfaces without PD98095 both demonstrated reduced ERK1/2 phosphorylation of the cells, and the inhibitive effect of SLA surfaces was milder than that of PD98095. In conclusion, ERK1/2 pathway may be a negative regulator of cell differentiation in a dosage-dependent manner, and the enhancing effect of surface roughness on osteoblastic differentiation may be mediated through inhibiting ERK1/2 pathway. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012. [ABSTRACT FROM AUTHOR]

Purpose: To observe the alteration of the interproximal papilla height after single implant restoration in the anterior maxilla and to assess the influence of gingival biotypes on papilla regeneration., Methods: Thirty patients with single-tooth implant-supported restorations in the anterior maxilla were assigned to two groups according to labial mucosa thickness. Group A: labial mucosal thickness≥1.5 mm and group B: labial mucosal thickness<1.5 mm. The presence of interproximal papilla as well as the distance between papilla apex and contact point were assessed at crown attachment (baseline) and after 6 months (follow-up).Statistical analysis was performed using SPSS19.0 software package., Results: The 6-month survival rate of implants was 100%. The mean height of interproximal papilla at baseline and follow-up was (1.64±0.97) mm and (3.10±1.39) mm, respectively. A significant improvement in papilla height was found between baseline and follow-up(P<0.05). In group A, the mean distance from papilla apex to the contact point at mesial and distal aspects was (0.15±0.24) mm and (0.23±0.33) mm, respectively, and the presence of interproximal papilla were (97±5)% and (94±8)%, respectively. In group B, the mean distance from papilla apex to the contact point at mesial and distal aspects was (1.94±0.40) mm and (2.10±0.34) mm, respectively, and the presence of interproximal papilla was (53±9)% and (43±14)% respectively. Statistically significant difference was found between the two groups(P<0.05)., Conclusions: The interproximal papilla height around single implant restorations could improve significantly after 6-month follow-up. The interproximal papilla height around single-tooth implants in the anterior maxilla was influenced by gingival biotype. The regenerative potential of thick-gingival biotype was better than that of thin-gingival biotype.