Sand-blasted Acid-etched Implants Research Articles

Enhanced osteogenic differentiation of mesenchymal stem cells by surface lithium modification in a sandblasted/acid-etched titanium implant.

This study investigated the osteogenesis-related cell functions of osteoprogenitor cells modulated by surface chemistry modification using lithium (Li) ions in a current clinical oral implant surface in order to gain insights into the future development of titanium (Ti) implants with enhanced osteogenic capacity. Wet chemical treatment was performed to modify a sandblasted/acid-etched (SLA) Ti implant surface using Li ions. The osteogenesis-related cell response to the surface Li ion-modified SLA sample was evaluated using two kinds of murine bone marrow stem cells, bipotent ST2 cells and primary multipotent mesenchymal stem cells (MSCs). The modified surface exhibited the formation of an Li-containing Ti oxide layer with plate-like nanostructures. The Li-incorporated surface enhanced early cellular events, including spreading, focal adhesion formation and integrin mRNA expression (α2, α5, αv and β3), and accelerated osteogenic differentiation of bipotent ST2 cells compared with unmodified SLA surface. Surface Li modification significantly increased GSK-3β phosphorylation and suppressed β-catenin phosphorylation, and promoted the subsequent osteogenic differentiation of primary MSCs. These results indicate that surface chemistry modification of SLA implants by wet chemical treatment with Li ions induces a more favorable osseointegration outcome through the promotion of the osteogenic differentiation of bone marrow MSCs via the positive regulation of GSK-3β and β-catenin activity.

In vivo studies of titanium implant surface treatment by sandblasted, acid-etched and further anchored with ceramic of tetracalcium phosphate on osseointegration

The objective was to investigate and compare the osseointegrative responses of sandblasted/acid-etched (SLA) and calcium phosphate (CaP) implants in vivo. The CaP implant was prepared by control group of SLA surface modification and anchoring with sintering ceramic of tetracalcium phosphate (TTCP) to form a mechanical interlocking film. Customized screw Ti implants (size O 2.0 mm × 6 mm length) were utilized to histologically examine the bone-to-implant contact (BIC) after implantation. The implant stability quotient scales in the postoperative implants within femurs were recorded. Subsequently, the postoperative implants were scanned using microcomputed tomography (micro-CT), and the topography was examined microscopically to analyze the BIC conditions. The SLA and CaP implant groups showed increased bone mineral density (g/cm3) and BIC (%). Compared with the SLA implant, the CaP implant with TTCP improved the early osteointegration of the BIC at 1-month post-operation and demonstrated quantitative effects on the BIC at 1-month post-operation. SLA and CaP implants all showed good osseointegration through micro-CT analysis (1–6 months). The current findings suggest the CaP anchoring Ti surface demonstrated improvement in early stages of osseointegration and thus shows the potential clinical benefits of TTCP anchoring on Ti surfaces in bone-level solutions.

Evaluation of oral microbial corrosion on the surface degradation of dental implant materials.

Titanium (Ti) dominates as the material of choice for dental implant systems. Recently, titanium-zirconium alloy (TiZr) and zirconia (ZrO₂ ) have emerged as alternative materials due to higher mechanical strength and lower corrosion susceptibility. Oral pathogenic bacteria can colonize Ti surfaces, leading to surface degradation, which has yet to be investigated on TiZr and ZrO2 . The aim of this study was to compare in vitro oral bacterial adhesion and subsequent surface degradation on commercial Ti, TiZr, and ZrO2 implants. Ti, TiZr, and ZrO2 implants with sandblasted, acid-etched (SLA) surfaces in addition to modified SLA-treated (modSLA) Ti implants (n=3) were immersed for 30 consecutive days in Streptococcus polyculture. Post-immersion, adherent bacterial count was quantified. Optical microscopy was used to assess qualitative degradation and score Ti-based implants based on degree of surface damage while electrochemical testing quantified corrosion behavior. Analysis of variance followed by post-hoc Tukey test was used to statistically compare quantitative results (α=0.05). Ti-SLA, Ti-modSLA, and TiZr-SLA implants exhibited localized features characteristic of corrosion attack while ZrO2 -SLA implants experienced minimal changes in surface morphology as compared to non-immersed control. Corrosion features were more numerous on Ti-modSLA implants but smaller in size as compared with those on Ti-SLA and TiZr-SLA implants. No significant differences in corrosion resistance (polarization resistance and corrosion rate) were observed between Ti-SLA, Ti-modSLA, and TiZr-SLA implants. TiZr and ZrO2 dental implant surfaces were not more susceptible to colonization and surface degradation by oral Streptococcus species than commercially pure Ti implants.

Osseointegration of Titanium Implants With Different Rough Surfaces: A Histologic and Histomorphometric Study in an Adult Minipig Model.

Many chemical and physical modifications of titanium surfaces were introduced, aiming at improving surface bioactivity, but few comparative evidence exists. To evaluate histologically in minipigs the osseointegration of implants made of commercially pure (CP) titanium or titanium alloy, treated by different roughening procedures. Three sandblasted acid-etched (SA) surfaces, 2 anodized (AN), and 1 double acid-etched (DAE) were compared. Surface microtopography was characterized with scanning electron microscope; surface element composition was also assessed. One implant per group was inserted in each proximal tibia of 2 minipigs. Three months after healing, block biopsies were taken for histomorphometric analysis. Implant stability quotient (ISQ) was measured at insertion and before harvesting. The highest amount of cortical bone-implant contact was observed around SA implants and showed positive correlation with surface roughness. The greatest increase in ISQ was observed in CP-AN implants. In the medullary region, SA implants showed the best osteogenic response, whereas inflammatory cells were found around DAE and alloy-AN implants. SA surfaces were more osteogenic than anodized or dual acid-etched ones, although not significantly. Surface roughness affected osseointegration.

In vivo effect of immobilisation of bone morphogenic protein 2 on titanium implants through nano-anchored oligonucleotides.

The aim of the present study was to test the hypothesis that immobilisation of bone morphogenic proteins on the surface of titanium implants through nano-anchored oligonucleotides can enhance peri-implant bone formation. Non-coding 60-mer DNA oligonucleotides (ODN) were anchored to the surface of custom made sandblasted acid etched (SAE) titanium screw implants through anodic polarisation, gamma-sterilised with a standard dose of 25 kGy, and were hybridised with complementary 30-mer strands of DNA oligonucleotides conjugated to rhBMP2. Blank SAE implants, SAE implants with nano-anchored ODN and SAE implants with nano-anchored ODN and non-conjugated rhBMP2 served as controls. The implants were inserted into the tibiae of 36 Sprague Dawley rats. Perforations at the head and the tip of the implants allowed for bone ingrowth. Bone ingrowth into perforations and bone implant contact (BIC) as well as bone density (BD) at a distance of 200 µm from the implant surface were assessed after 1 , 4 and 13 weeks. Implants with nano-anchored ODN strands hybridised with conjugated rhBMP2 exhibited enhanced bone ingrowth into the perforations and increased BIC after 1 week as well as increased BIC after 4 weeks compared to controls. No difference was seen after 13 weeks. Bone density around the outer implant surface did not differ significantly at any of the intervals. It is concluded that rhBMP2 immobilised on the surface of titanium implants through nano-anchored oligonucleotide strands can enhance bone implant contact. The conditions of sterilisation tested allowed for handling under clinically relevant conditions.

Assessment of the effect of chemical agents used in dentistry on the removal of Porphyromonas gingivalis and Escherichia coli from sandblasted acid-etched titanium dental implants: an in vitro study.

The aim of this study was to evaluate the capability of chemicals to decontaminate Escherichia coli (E coli) or Porphyromonas gingivalis (P gingivalis) from sandblasted acid-etched (SAE) titanium dental implants. SAE titanium dental implants were contaminated with E coli or P gingivalis and incubated in a sterile bacterial culture media under aerobic and anaerobic conditions, respectively. The implants were treated with 10 different conditions: calcium hydroxide [Ca(OH)₂] paste for 1 minute and saline irrigation for 1 minute; Ca(OH)2 paste for 1 minute and 0.2% chlorhexidine digluconate (CHXD) irrigation for 1 minute; 0.2% CHXD for 1 minute; Dakin's solution for 1 minute; tetracycline hydrochloride (T-HCl) as a 1 g per 20 mL solution for 1, 2, and 3 minutes; and T-HCl paste for 1, 2, and 3 minutes. All implants were irrigated with 1 mL of saline solution and incubated under aerobic and anaerobic conditions for 24 hours or 48 hours for E coli- and P gingivalis-contaminated implants, respectively. The control group was submitted to all procedures except for the chemical treatments. Aliquots were removed, and turbidity was measured by spectrophotometry. The level of bacterial growth in control cultures was considered to have a decontamination percentage (DC%) of 0. Spectrophotometric analysis showed that all chemical treatments resulted in significantly higher DC% compared to controls for SAE implants contaminated with E coli (P < .05) or P gingivalis (P < .05). For the P gingivalis experiments, SAE implants treated with Ca(OH)₂ paste and saline solution had a lower DC% (39.3%) than those in the other treatment groups. In the E coli experiments, DC% was significantly lower for SAE implants treated with Ca(OH)₂ paste and saline solution (48.7%), Dakin's solution (92.7%), or T-HCl paste for 1 minute (96.6%) than those in the other groups. The DC% of SAE implants contaminated with E coli or P gingivalis by means of chemicals commonly used in dentistry is high, with the exception of Ca(OH)₂ paste burnished for 1 minute and then irrigated with saline solution for 1 minute.

Vertical Osteoconductive Characteristics of Titanium Implants with Calcium‐Phosphate‐Coated Surfaces – A Pilot Study in Rabbits

Osteoconductive characteristics of different implant surface coatings are in the focus of current interest. The aim of the present study was to compare the vertical osteoconductivity at the implant shoulder of supracrestal inserted calcium-phosphate coated implants (SLA-CaP) with conventional sand-blasted/acid-etched (SLA) implants in a rabbit model. SLA-CaP and SLA implants were inserted bilaterally in the mandible of four rabbits in a split-mouth design. The implants were placed 2 mm supracrestal. After 3 weeks, at the left and right implant shoulder, the percentage of linear bone fill (PLF) as well as bone-implant contact (BIC-D) were determined. After 3 weeks, newly formed woven bone could be found at the shoulder of the most of both surface-treated implants (75%). PLF was significantly higher in SLA-CaP implants (11.2% vs. 46.5%; n = 8, p = .008). BIC-D was significantly increased in the SLA-CaP implants (13.0% vs. 71.4%; n = 8, p < .001) as well. The results of this study show for the first time that calcium-phosphate coated surfaces on supracrestal inserted implants have vertical osteoconductive characteristics and increase the bone-implant contact at the implant shoulder significantly in a rabbit model. In clinical long-term settings, these implants may contribute to a better vertical bone height.

Sandblasted/Acid-Etched vs Smooth-Surface Implants: Implant Mobility and Clinical Reaction to Experimentally Induced Peri-Implantitis in Beagle Dogs

This study uses a sandblasted/acid-etched implant vs a smooth-surface implant to compare implant mobility and clinical reactions of peri-implant tissues to experimentally induced peri-implantitis in Beagle dogs. The right and left mandibular premolars were extracted from 5 Beagle dogs, and 2 smooth-surface (SS) implants and 2 sandblasted/acid-etched (SLA) implants were placed in each animal. After 120 days, healing abutments were connected. Fifteen days later, the prosthetic abutments were connected, the hygiene regimen was suspended, and peri-implantitis was induced by the insertion of cotton ligatures into the soft tissue around the implants. At baseline and 30, 60, and 90 days later, clinical attachment level (CAL), probing depth (PD), and mobility (MO) were measured. Probing depth increased significantly in the SLA group alone when baseline PD was compared with 30-, 60-, and 90-day evaluations (P < .05). No significant differences were noted between the 2 implant groups (P > .05). The loss in CAL was significant in both groups when the baseline value was compared with 30-, 60-, and 90-day evaluations (P < .02). Comparison between the 2 implant groups revealed a greater loss in CAL in the SLA group at the 90-day evaluation period (P = .04). A significant increase in mobility was seen in both groups when baseline values and 90-day evaluations were compared (P < .04). However, no statistically significant differences were noted between the 2 implant groups (P > .05). Experimentally induced peri-implantitis results in a greater loss of CAL in SLA implants than in SS implants in dogs; however, no differences in mobility or in PD have been noted between the 2 implant groups.

Bone regeneration in dehiscence‐type defects at non‐submerged and submerged chemically modified (SLActive®) and conventional SLA titanium implants: an immunohistochemical study in dogs

The aim of the present study was to evaluate bone regeneration in dehiscence-type defects at non-submerged and submerged titanium implants with chemically modified (mod) and conventional sandblasted/acid-etched (SLA) surfaces. Standardized buccal dehiscence defects were surgically created following implant site preparation in both the upper and lower jaws of 12 beagle dogs. Both types of implants were randomly assigned to either a non-submerged or a submerged healing procedure. After 1, 2, 4, and 8 weeks, dissected blocks were processed for histomorphometrical [e.g. new bone height (NBH), per cent linear fill (PLF), percentage of bone to implant contact (BIC-D), area of new bone fill (BF)] and immunohistochemical analysis. At 8 weeks, non-submerged and submerged SLA implants revealed significantly lower mean NBH (1.1+/-0.8-1.9+/-1.2 mm), PLF (27.7+/-20.3-46.0+/-28.5%), BIC-D (26.8+/-10.4-46.2+/-16.2%), and BF (1.3+/-0.9-3.4+/-2.8 mm(2)) values than respective modSLA implants [NBH (2.6+/-0.8-4.3+/-0.1 mm), PLF (64.2+/-19.4-107.2+/-4.7%), BIC-D (67.5+/-18.8-82.1+/-14.8%), BF (2.9+/-1.0-6.7+/-1.1 mm(2))]. Within modSLA groups, significantly highest BF values were observed at submerged implants. It was concluded that (i) modSLA titanium surfaces promoted bone regeneration in acute-type buccal dehiscence defects and (ii) a submerged healing procedure improved the outcome of healing additionally.

Bone regeneration in dehiscence‐type defects at chemically modified (SLActive®) and conventional SLA titanium implants: a pilot study in dogs

The aim of the present study was to evaluate bone regeneration in dehiscence-type defects at titanium implants with chemically modified (mod) and conventional sand-blasted/acid-etched (SLA) surfaces. Standardized buccal dehiscence defects (height: 3 mm, width: 3 mm) were surgically created following implant site preparation in both the upper and lower jaws of four beagle dogs. modSLA and SLA implants were inserted bilaterally according to a split-mouth design. The animals were sacrificed after 2 and 12 weeks (n=2 animals each). Dissected blocks were processed for histomorphometrical analysis: defect length, new bone height (NBH), percent linear fill (PLF), percent of bone-to-implant contact (BIC-D) and area of new bone fill (BF). Wound healing at SLA implants was predominantly characterized by the formation of a dense connective tissue at 2 and 12 weeks, without significant increases in mean NBH, PLF, BIC-D or BF values. In contrast, modSLA implants exhibited a complete defect fill at 12 weeks following implant placement. In particular, histomorphometrical analysis revealed the following mean values at 12 weeks: NBH (3.2+/-0.3 mm), PLF (98%), BIC-D (82%) and BF (2.3+/-0.4 mm(2)). Within the limits of the present study, it was concluded that modSLA titanium surfaces may promote bone regeneration in acute-type buccal dehiscence defects at submerged implants.