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Background: The aim of the current study was the evaluation of initial biofilm adhesion and development on laser-microtextured implant collar surfaces and the examination of effectivity of different biofilm management methods., Methods: Initial biofilm formation was investigated on hydrophobic machined and laser-microtextured (Laser-Lok) titanium surfaces and hydrophobic machined and laser-microtextured (Laser-Lok) titanium aluminium vanadium surfaces and compared to hydrophobic smooth pickled titanium surfaces, hydrophilic smooth and acid etched titanium surfaces, hydrophobic sandblasted large grid and acid etched titanium surfaces (titanium Promote) via erythrosine staining and subsequent histomorphometrical analysis and scanning electron microscopic investigations. After decontamination procedures, performed via tooth brushing and glycine powder blasting, clean implant surface was detected via histomorphometrical analysis., Results: After 24 h mean initial plaque area was detected in the following descending order: smooth pickled titanium > titanium Promote > hydrophilic smooth and acid etched titanium > Laser-Lok titanium > Laser-Lok titanium aluminium vanadium. The same order was determined after 48 h of biofilm formation. After glycine powder blasting all samples depicted almost 100% clean implant surface. After tooth brushing, Laser-Lok titanium (67.19%) and Laser-Lok titanium aluminium vanadium (69.80%) showed significantly more clean implant surface than the other structured surfaces, hydrophilic smooth and acid etched titanium (50.34%) and titanium Promote (33.89%). Smooth pickled titanium showed almost complete clean implant surface (98.84%) after tooth brushing., Conclusions: Both Laser-Lok surfaces showed less initial biofilm formation after 24 and 48 h than the other implant surfaces. In combination with the significant higher clean implant surfaces after domestic decontamination procedure via tooth brushing, both Laser-Lok surfaces could be a candidate for modified implant and abutment designs, especially in transmucosal areas.

Objectives: The objective of the study was to assess the influence of implantoplasty (IP) on the diameter, chemical surface composition, and biocompatibility of titanium implants in vitro., Material and Methods: Twenty soft tissue-level (TL; machined transmucosal-M and rough endosseous part-SLA) and 20 bone-level (BL; SLA) implants were allocated to IP covering 3 or 6 mm of the structured surface (SLA) area. The samples were subjected to diameter, energy-dispersive X-ray spectroscopy (EDX), and cell viability (ginigval fibroblasts, 6 days) assessments., Results: Median diameter reductions varied between 0.1 (TL 3 mm) and 0.2 mm (TL 6 mm). EDX analysis revealed that IP and M surfaces were characterized by a comparable quantity (Wt%) of elements C, O, Na, Cl, K, and Si, but a significantly different quantity of elements Ti and Al. When compared to SLA surfaces, significant differences were noted for elements C, O, Na, Ti, and Al. At BL implants, the extension of IP (i.e., 3 to 6 mm) was associated with a significant increase in cell viability., Conclusions: IP applied to SLA implants was associated with (i) a minimal diameter reduction, (ii) an undisturbed cell viability, and (iii) a chemical elemental composition comparable to M surfaces., Clinical Relevance: This specific IP procedure appears to be suitable for the management of exposed SLA implant surfaces.

Objectives: The aim of the current study was the evaluation of biofilm development on different implant surfaces., Material and Methods: Initial biofilm formation was investigated on five different implant surfaces, machined titanium (MTi), modified machined acid-etched titanium (modMATi), machined titanium zirconium (MTiZr), modified machined and acid-etched titanium zirconium (modMATiZr) and sandblasted large grid and acid-etched titanium zirconium surface (SLATiZr) for 24 and 48 h. Biocompatibility was tested after tooth brushing of the samples via cell viability testing with human gingival fibroblasts., Results: After 24 h of biofilm collection, mean plaque surface was detected in the following descending order: After 24 h: MTiZr > MTi > SLATiZr > modMATiZr > modMATi. Both M surfaces showed significant higher biofilm formation than the other groups. After 48 h: MTiZr > MTi > SLATiZr > modMATiZr > modMATi. After tooth brushing: SLATiZr > modMATi > modMATiZr > MTi > MTiZr. All native samples depicted significant higher cell viability than their corresponding surfaces after biofilm removal procedure., Conclusions: The TiZr groups especially the modMATiZr group showed slower and less biofilm formation. In combination with the good biocompatibility, both modMA surfaces seem to be interesting candidates for surfaces in transgingival implant design., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: The purpose of the present study was the evaluation of effectiveness and efficiency of a powder consisting of glycine and tricalcium phosphate in comparison to two established powders based on glycine or sodium bicarbonate in biofilm removal on titanium and zirconium implant surfaces., Materials and Methods: Biofilm was collected for 48 h by five volunteers. A total of 69 titanium and 69 zirconium samples were randomly assigned to test and control groups. Residual plaque areas (RPA) and treatment time were taken as parameters., Results: Within the titanium groups, mean RPA was determined in the following descending order: sodium bicarbonate > glycine > glycine + tricalcium phosphate. Differences between the groups were significant, p < 0.05. Mean treatment time in the titanium groups was determined in the following descending order without significant differences, p > 0.05: glycine + tricalcium phosphate > sodium bicarbonate > glycine. Regarding the zirconium groups, mean RPA was detected in the following descending order, without significant differences, p > 0.05: glycine > sodium bicarbonate > glycine + tricalcium phosphate. Mean treatment time of the glycine + tricalcium phosphate group was significantly lower than in the control groups, p < 0.05., Conclusions: It can be concluded that glycine + tricalcium phosphate seemed to be more effective than the control groups for biofilm removal on titanium and zirconium implant surfaces. Especially on zirconium surfaces, decontamination with glycine + tricalcium phosphate seemed to be more efficient than treatment with glycine or sodium bicarbonate., Clinical Relevance: The combination of glycine and tricalcium phosphate could improve the clinical outcomes of air-abrasive device in nonsurgical peri-implantitis therapy.

Objectives: To evaluate the impact of plaque accumulation on osseointegration at surface enhanced modified hydrophilic titanium-zirconium (TiZr) alloy and titanium (Ti) implants., Materials and Methods: TiZr and Ti implants with a sand-blasted, acid etched, and chemically modified endosseous and a machined (M) transmucosal portion were bilaterally (i.e., one implant type on each side) inserted in the maxilla of six foxhounds. In a split-mouth design, experimental mucositis was induced at one randomly assigned side (NPC), while the contralateral side received mechanical plaque removal three times per week (PC). After 16 weeks, tissue biopsies were processed for histological (primary outcome: bone-to-implant contact [BIC]) and immunohistochemical (CD68) analysis., Results: Mean BIC values varied between 81.96% (TiZrM) and 88.72% (TiM) in the NPC group, and between 87.88% (TiM) and 92.69% (TiZrM) in the PC group. Even though BIC values tended to be lower within the endosseous coronal compartment at NPC sites, within group (NPC vs. PC) comparisons failed to reach statistical significance at both types of implants. These non-BIC areas were not associated with any CD68 positive cells., Conclusions: Osseointegration of both TiZrM and TiM implants was not influenced by plaque accumulation in this experimental model., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: This study aimed to immunohistochemically evaluate staged guided bone regeneration and osseointegration of titanium implants using two bone graft substitutes in combination with a polyethylene glycol (PEG) membrane in a dog model., Materials and Methods: Saddle-type alveolar ridge defects were prepared in the lower jaws of 12 foxhounds and randomly filled with a natural bone mineral (NBM) or a biphasic calcium phosphate (SBC) and covered with an in situ gelling PEG membrane. After a healing period of 8 and 12 weeks (six animals each), modSLA titanium implants were inserted to heal in a submerged position. At 8 + 2 and 12 + 2 weeks, respectively, dissected blocks were processed for immunohistochemical analysis [osteocalcin (OC)]., Results: After 8 + 2 weeks, mean OC values (%) tended to be higher in the NBM group (NBM, 32.7 ± 8.9%), but failed to reach statistical significance over the SBC group (SBC, 24.4 ± 6.6%). After 12 + 2 weeks, mean OC values decreased in both groups and was almost identical in both groups (NBM 1.6 ± 1.2%/SBC 2.1 ± 1.4%)., Conclusion: It was concluded that all augmentation procedures investigated were characterised by a comparable OC activity during the process of bone regeneration and osseointegration of modSLA titanium implants.

Purpose: This case illustrates a pulp tissue-induced dentointegration of a titanium implant., Materials and Methods: One commercially available titanium implant with a sand-blasted and acid-etched surface was placed in the maxilla of a foxhound where the palatinal root of the previously (i.e., 8 weeks) removed first molar was unintentionally retained. After 8 weeks of nonsubmerged healing, the dissected block was prepared for immunohistochemical (osteocalcin) and histomorphometrical analysis., Results: A reparative hard tissue had formed within the artificially opened pulp canal. Also, the external layer of the exposed dentin due to the root fracture during tooth removal further developed into an atubular reparative dentin thus establishing a close contact with the adjacent titanium implant surface. The entire contact zone was demarcated by an intense osteocalcin antigen reactivity. A thin layer of osteocementum originated from the root surface and superimposed implant integration in the peripheral areas. Mean contact of osteodentin/osteocementum to the implant surface was 67.4 %, whereas bone-to-implant contact at the vestibular aspect was 63.5 %., Conclusion: The present case report provides the first histological evidence for a pulp tissue-induced dentointegration of a titanium implant.

Objectives: To assess the influence of two barrier membranes and two bone graft substitutes on staged guided bone regeneration and osseointegration of titanium implants in dogs., Materials and Methods: Saddle-type defects were prepared in the lower jaws of 6 fox hounds and randomly filled with a natural bone mineral (NBM) and a biphasic calcium phosphate (SBC) and allocated to either an in situ gelling polyethylene glycol (PEG) or a collagen membrane (CM). At 8 weeks, modSLA titanium implants were inserted and left to heal in a submerged position. At 8+2 weeks, respectively, dissected blocks were processed for histomorphometrical analysis (e.g., mineralized tissue [MT], bone-to-implant contact [BIC])., Results: The mean MT values (mm2) and BIC values (%) tended to be higher in the PEG groups (MT: NBM [3.4±1.7]; SBC [4.2±2]/BIC: NBM [67.7±16.9]; SBC [66.9±17.8]) when compared with the corresponding CM groups (MT: NBM [2.5±0.8]; SBC [2.3±1.6]/BIC: NBM [54.1±22.6]; SBC [61±8.7]). These differences, however, did not reach statistical significance., Conclusion: It was concluded that all augmentation procedures investigated supported bone regeneration and staged osseointegration of modSLA titanium implants., (© 2011 John Wiley & Sons A/S.)

Objectives: To investigate (i) the impact of different titanium implant surfaces on soft tissue integration over 6 months, and (ii) the influence of frequent clinical probing during the healing phase on the established mucosal seal., Material and Methods: Standardized clinical probing was randomly performed (12 dogs, probing versus control) at different transmucosal surfaces [machined (M), sand-blasted/acid-etched (SLA), and chemically modified acid-etched (modA), modSLA] at 2, 4, 8, and 12 weeks (i.e. 1 x , 2 x , 3 x , and 4 x). Histomorphometrical analysis (e.g. mucosal margin (PM) - apical extension of the junctional epithelium (aJE), PM - coronal level of bone-to-implant contact (CBI) was performed at 4, 8, 12, and 24 weeks., Results: While M and SLA groups revealed a split formation, epithelial cells and connective tissue were in close contact to modA and modSLA surfaces. Frequent clinical probing (i.e. 3 x and 4 x) increased mean pocket depths, PM-aJE, and aJE-CBI values in all groups and markedly disrupted the epithelial and connective tissue attachment., Conclusions: It was concluded that irrespective of the surface characteristics, a frequent clinical probing at short intervals during the healing phase was associated with dimensional and structural changes of the mucosal seal.

Objectives: The aim of the present randomized-controlled double-blinded clinical multicenter study was to assess the use of either a new cross-linked (VN) or a native collagen membrane (BG) for the treatment of dehiscence-type defects at titanium implants., Material and Methods: A total of n=54 patients were recruited in four German university clinics. According to a parallel-groups design, dehiscence-type defects at titanium implants were filled with a natural bone mineral and randomly assigned to either VN or BG. Submerged sites were allowed to heal for 4 months. Primary (e.g., changes in defect length - DeltaDL, quality of newly formed tissue [0-4] - TQ) and secondary parameters (e.g., membrane exposure, tissue conditions at dehisced sites) were consecutively recorded., Results: Four patients were excluded due to an early wound infection (VN:3; BG:1), and one patient was lost during follow-up (VN). The mean DeltaDL was 3.0 +/- 2.5 mm in the VN, and 1.94 +/- 2.13 mm in the BG group. The assessment of TQ revealed comparable mean values in both groups (VN: 3.05 +/- 1.66, BG: 3.46 +/- 1.48). A significant correlation between membrane exposure and inflammation of the adjacent soft tissue was observed in the VN group. In both groups, the mean DL and TQ values were not significantly different at either non-exposed or exposed implant sites., Conclusion: The results of the present study have indicated that VN supported bone regeneration on a level non-inferior to BG. However, in case of a premature membrane exposure, cross-linking might impair soft-tissue healing or may even cause wound infections.

Objectives: To investigate the influence of platform switching on crestal bone level changes at non-submerged titanium implants over a period of 6 months., Material and Methods: Titanium implants (n=72) were placed at 0.4 mm above the alveolar crest in the lower jaws of 12 dogs and randomly assigned to either matching or non-matching (circumferential horizontal mismatch of 0.3 mm) healing abutments. At 4, 8, 12, and 24 weeks, dissected blocks were processed for histomorphometrical analysis. Measurements were made between the implant shoulder (IS) and the apical extension of the long junctional epithelium (aJE), the most coronal level of bone in contact with the implant (CLB), and the level of the alveolar bone crest (BC)., Results: At 24 weeks, differences in the mean IS-aJE, IS-CLB, and IS-BC values were 0.2 +/- 1.2, 0.3 +/- 0.7, and 0.3 +/- 0.8 mm at the buccal aspect, and 0.2 +/- 0.9, 0.3 +/- 0.5, and 0.3 +/- 0.8 mm at the lingual aspect, respectively. Comparisons between groups revealed no significant differences at either the buccal or the lingual aspects., Conclusions: It was concluded that (i) bone remodelling was minimal in both groups and (ii) platform switching may not be of crucial importance for maintenance of the crestal bone level.

In the past, several modifications of specific surface properties such as topography, structure, chemistry, surface charge, and wettability have been investigated to predictably improve the osseointegration of titanium implants. The aim of the present review was to evaluate, based on the currently available evidence, the impact of hydrophilic surface modifications of titanium for dental implants. A surface treatment was performed to produce hydroxylated/hydrated titanium surfaces with identical microstructure to either acid-etched, or sand-blasted, large grit and acid-etched substrates, but with hydrophilic character. Preliminary in vitro studies have indicated that the specific properties noted for hydrophilic titanium surfaces have a significant influence on cell differentiation and growth factor production. Animal experiments have pointed out that hydrophilic surfaces improve early stages of soft tissue and hard tissue integration of either nonsubmerged or submerged titanium implants. This data was also corroborated by the results from preliminary clinical studies. In conclusion, the present review has pointed to a potential of hydrophilic surface modifications to support tissue integration of titanium dental implants., (Copyright 2008 Wiley Periodicals, Inc.)

Studies have indicated that oral biofilm formation at structured titanium surfaces interferes with cell adhesion and proliferation, and its removal by means of conventional treatment procedures may not be sufficient to render these surfaces biologically acceptable. Therefore, the aim of the study was to evaluate the influence of different air-abrasive powders on cell viability at biologically contaminated titanium dental implant surfaces. Intraoral splints were used to collect an in vivo biofilm on sandblasted and acid-etched titanium discs for 48 h. A single (1x) and repeated (2x) use of four different powders (amino acid glycine or sodium bicarbonate particles; range of mean particle size (d(v50)):20-75 microm) was applied at two distances (1 and 2 mm) and angles (30 degrees and 90 degrees) to the surfaces. Specimens (2x) were incubated with SaOs-2 cells for 7 days. Residual biofilm (RB) areas (%), and surface alterations (SEM) (1x and 2x), as well as SaOs-2 cell viability, expressed as mitochondrial cell activity (MA) (counts/second) (2x specimens), were assessed. Comparable mean RB areas were observed within and between groups after both 1x (RB: 0.0% +/- 0.0% to 5.7% +/- 5.7%) and 2x (RB: 0.0% +/- 0.0%) treatments. All surface treatments did not lead to MA (2x) values comparable to the sterile control group. However, sodium bicarbonate particles resulted in significantly higher MA (2x) values than amino acid glycine powders of different sizes. This was associated with pronounced alterations of the surface morphology (2x). Within the limits of the present study, it was concluded that SaOs-2 cell viability at biologically contaminated titanium surfaces was mainly influenced by the particle type of the powder., ((c) 2008 Wiley Periodicals, Inc.)

Background: The aim of the present study was to investigate the effects of surface hydrophilicity and microtopography on soft and hard tissue integration at non-submerged titanium implants., Methods: Implantation of conventional sand-blasted large grit and acid-etched (SLA) and chemically modified SLA (modSLA) titanium implants with differently structured transmucosal surfaces (SLA implants: machined [M-SLA] or SLA [SLA-SLA]; modSLA implants: mod acid-etched [modA] [modA-modSLA] or modSLA [modSLA-modSLA]) was performed bilaterally in the upper and lower jaws of 15 beagle dogs. The animals were sacrificed after 1, 4, 7, 14, or 28 days. Tissue reactions were assessed histomorphometrically and immunohistochemically using monoclonal antibodies to transglutaminase II (angiogenesis) and osteocalcin., Results: Although the junctional epithelium commonly was separated from M-SLA and SLA-SLA implants by a gap, the epithelial cells appeared to be in close contact with modA-modSLA surfaces after 14 days of healing. Moreover, modA-modSLA and modSLA-modSLA groups showed a well-vascularized subepithelial connective tissue exhibiting collagen fibers that started to extend and attach partially perpendicular to the implant surface. The highest and statistically significant mean bone-to-implant contact areas were observed in the modA-modSLA and modSLA-modSLA groups at days 7, 14, and 28., Conclusion: Within the limits of this study, it may be concluded that soft and hard tissue integration was influenced mainly by surface hydrophilicity rather than by microtopography.

The aim of the present pilot study was to histologically/immunohistochemically investigate initial and early subepithelial connective tissue attachment at transmucosal parts of modified (mod) and conventional sandblasted, large grit and acid-etched (SLA) titanium implants. Implantation of modSLA and SLA implants was performed bilaterally in both the mandible and maxilla of four beagle dogs. The implants were submerged to prevent bacterial contamination. The animals were killed after 1, 4, 7 and 14 days. Peri-implant tissue reactions were assessed histologically (Masson Goldner Trichrome stain-MG) and immunohistochemically (IH) using monoclonal antibodies to fibronectin (FN) and proliferating cell nuclear antigen (PCNA). The surgical procedure of implant submerging resulted in the formation of an artificial gap in the transmucosal area of both types of implants. After 14 days of healing, MG stain revealed the formation of well-organized collagen fibres and numerous blood vessels in a newly formed loose connective tissue zone adjacent to modSLA. While some fibres were oriented in a parallel direction, others have started to extend and attach partially perpendicular to the implant surface. In contrast, SLA implants appeared to be clearly separated by a dense connective tissue zone with parallel-running collagen fibres and rare blood vessel formation. First signs of a positive FN and PCNA staining adjacent to both implant surfaces were observed at day 4. Within the limits of a pilot study, it might be concluded that modSLA titanium surfaces might possess the potential to promote subepithelial connective tissue attachment at the transmucosal part of the implant.

Objectives: 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., Material and Methods: 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)., Results: 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))., Conclusion: 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.

Recently, a chemically modified ultra-hydrophilic sand-blasted, large grit and acid-etched (modSLA) titanium surface has been introduced in order to enhance bone apposition. Indeed, preliminary preclinical and clinical data have indicated that modSLA implants may enhance bone apposition during early stages of wound healing. These positive effects on bone regeneration might be probably mainly due to the hydrophilic surface properties noted for modSLA which ensured a stabilization of the blood clot. The aim of the present review article is to evaluate, based on the currently available evidence, the potential impact of modSLA surfaces for implant dentistry.

Background: The aim of the present study was to evaluate the influence of an erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG laser [ERCL]) on 1) the surface structure and biocompatibility of titanium implants and 2) the removal of plaque biofilms and reestablishment of the biocompatibility of contaminated titanium surfaces., Methods: Intraoral splints were used to collect an in vivo supragingival biofilm on sand-blasted and acid-etched titanium disks for 24 hours. ERCL was used at an energy output of 0.5, 1.0, 1.5, 2.0, and 2.5 W for the irradiation of 1) non-contaminated (20 and 25 Hz) and 2) plaque-contaminated (25 Hz) titanium disks. Unworn and untreated non-irradiated, sterile titanium disks served as untreated controls (UC). Specimens were incubated with SaOs-2 osteoblasts for 6 days. Treatment time, residual plaque biofilm (RPB) areas (%), mitochondrial cell activity (MA) (counts per second), and cell morphology/surface changes (scanning electron microscopy [SEM]) were assessed., Results: 1) ERCL using either 0.5, 1.0, 1.5, 2.0, or 2.5 W at both 20 and 25 Hz resulted in comparable mean MA values as measured in the UC group. A monolayer of flattened SaOs-2 cells showing complete cytoplasmatic extensions and lamellopodia was observed in both ERCL and UC groups. 2) Mean RPB areas decreased significantly with increasing energy settings (53.8 +/- 2.2 at 0.5 W to 9.8 +/- 6.2 at 2.5 W). However, mean MA values were significantly higher in the UC group., Conclusion: Within the limits of the present study, it was concluded that even though ERCL exhibited a high efficiency to remove plaque biofilms in an energy-dependent manner, it failed to reestablish the biocompatibility of contaminated titanium surfaces.

The aim of the present study was to investigate bone formation to recombinant human bone morphogenetic protein-2 (rhBMP-2)-biocoated and rhBMP-2-nonbiocoated titanium implants after implantation in dogs. Implantation of sand-blasted and acid-etched (C), chromosulfuric acid surface-enhanced (CSA), and rhBMP-2-biocoated CSA [BMP-A: noncovalently immobilized rhBMP-2 (596 ng/cm(2)), BMP-B: covalently immobilized rhBMP-2 (819 ng/cm(2))] implants was performed in both the mandible and tibia of dogs. After 4 weeks of healing, the percentage of direct bone to implant contact (BIC) and the induced bone density (BD) at a distance of less than and greater than 1 mm adjacent to each implant was assessed. Histomorphometric analysis of implants inserted in the mandible and tibia revealed that BIC values appeared to be highest in the BMP-B group, followed by BMP-A, CSA, and C. BD as measured at a distance of <1 mm revealed obvious differences between groups: BMP-B>BMP-A>CSA>C. However, no differences between groups were observed at a distance of >1 mm. Within the limits of the present study, it may be concluded that rhBMP-2 immobilized by covalent and noncovalent methods on CSA-treated implant surfaces seemed to be stable and promoted direct bone apposition in a concentration-dependent manner.

The aim of the present study was to evaluate the influence of plaque biofilm removal on the mitochondrial activity of human SaOs-2 osteoblasts grown on titanium surfaces. Volunteers wore acrylic splints with structured titanium discs for 72 h to build up plaque biofilms (n = 30). Specimens were randomly instrumented using either (1) an ultrasonic system at two power settings (EMS1, EMS2) + chlorhexidine (CHX), or (2) plastic curettes + CHX. Untreated (NC, n = 10) and sterile (C, n = 10) titanium discs served as controls. Specimens were incubated with SaOs-2 cells for 6 days. Treatment time (T), residual plaque biofilm (RPB)/clean implant surface areas (%), mitochondrial cell activity (MA) (counts/second), and cell morphology (SEM) were assessed. Statistical analysis revealed the following mean scores (+/-SD): RPB areas: P (58.5 +/- 4.9) > EMS1 (38.4 +/- 4.1) > EMS2 (28.3 +/- 2.0); T: PC (292 +/- 30) = EMS1 (244 +/- 24) > EMS2 (199 +/- 25); MA: C (1.544.661 +/- 203.442) > PC (597.559 +/- 566.984) = EMS2 (389.875 +/- 409.300) = EMS1 (356.653 +/- 293.863; n.s.) > NC (138.676 +/- 86.666). In NC and PC groups, cells were predominantly rounded in shape. However, in the EMS groups, some cells had started to spread, showing complete cytoplasmatic extensions of the cell body on the titanium surface. A monolayer of flattened cells was generally observed in the C group. Within the limits of the present study, it was concluded that MA seemed to be impaired by the presence of RPB areas. However, its removal alone might not be the crucial step in the reestablishment of the biocompatibility of titanium surfaces.

The aim of the present study was to evaluate the influence of different treatment approaches on: (1) the removal of early plaque biofilms grown on titanium implants, and (2) the biocompatibility of the instrumented implant surfaces. Five volunteers wore acrylic splints with sand-blasted and acid-etched titanium discs for 24 h to build up supragingival plaque. A total of 80 specimens were randomly assigned to the following groups: (1) an Er:YAG laser (100 mJ/pulse, 10 Hz) (Y), (2) an ultrasonic system (U), (3) plastic curettes and rinsing with chlorhexidine digluconate (P), or (4) unworn titanium discs (C). Autoclaved specimens were incubated with SAOS2 cells for three days. The following parameters were measured: treatment time (T), residual plaque biofilm (RPB) and clean implant surface (CIS) areas (%), and mitochondrial cell activity (MA) (counts/s). Statistical analysis within and between groups revealed the following mean scores (+/-SD): RPB areas: P (61.1+/-11.4)>U (36.8+/-4.5)>Y (5.8+/-5.1); CIS areas: Y (94.2+/-5.1)>U (63.2+/-4.5)>P (38.9+/-11.2); T: Y (5.6+/-1.2)>U (2.4+/-0.5)>P (2.3+/-0.5); MA: C (1.528.636+/-188.371)>U (831.594+/-370.228)>Y (678.250+/-367.902)>P (144.105+/-120.961). Within the limits of the present study, it may be concluded that Y seems to be most suitable for the removal of supragingival early plaque biofilms grown on SLA titanium implants, and (2) all treatment procedures failed to restore the biocompatibility of previously-contaminated SLA titanium surfaces.

The aim of the present study was to investigate the effects of an Er:YAG laser (ERL) and the Vector ultrasonic system (VS) on the biocompatibility of titanium implants in cultures of human osteoblast-like cells (SAOS-2). One hundred and sixty-eight titanium discs with four different surfaces (sand-blasted and acid-etched, titanium plasma-sprayed, machine-polished, and hydroxyapatite-coated) were used to evaluate cell attachment. The samples were equally and randomly assigned to the following groups: (1) an ERL at an energy level of 100 mJ/pulse and 10 Hz using a special application tip, (2) the VS using carbon fibre tips, or (3) untreated control (C). The discs were placed in culture plates, covered with a solution of SAOS-2 cells, and incubated for 7 days. The specimens were then washed with phosphate buffer to remove cells not attached to the surface, and the adherent cells were stained with hematoxilin-eosin. Cells were counted using a reflected light microscope and the cell density per mm2 was calculated. Additionally, cell morphology and surface alterations of the titanium discs after treatment were investigated using scanning electron microscopy (SEM). All titanium discs treated with ERL demonstrated nearly the same cell density per mm2 as the untreated C surfaces. There was a significant decrease in the number of cells that attached to the implant surfaces treated with VS. The SEM examination showed no visible differences between lased and C titanium surfaces. All surfaces treated with VS showed conspicuous surface damage and debris of the used carbon fibres. The results of the present study indicate that (i) ERL does not damage titanium surfaces and subsequently does not influence the attachment rate of SAOS-2 cells, and (ii) VS, used with this type of carbon fibre tip, does not seem to be suitable for the instrumentation of titanium surfaces.

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Objectives: To assess the clinical performance of an equine‐derived collagen‐containing bone block (CXBB) for lateral alveolar ridge augmentation and staged implant placement. Material and Methods: A total of n = 16 patients (16 implants) had received a modified surgical protocol for lateral ridge augmentation using a size‐adapted rigidly fixed CXBB and contour augmentation. After 26 weeks of submerged healing, the primary endpoint was defined as the final ridge width (RW26) sufficient to place an adequately dimensioned titanium implant at the respective sites. Secondary outcomes included the gain in ridge width (RWg) and the need for secondary grafting. Clinical outcomes (bleeding on probing—BOP, probing depth—PD, and mucosal recession—MR) were assessed at implant loading and after a median observation period of 12.3 months. Results: In all patients (n = 16) investigated, RW26 allowed for a successful placement of an adequately dimensioned titanium implant at respective sites exhibiting mean RWg values of 5.09 ± 1.07 mm. A soft tissue dehiscence was noted in one patient (6.3%), and a secondary grafting was needed in two patients (12.5%) The changes in mean BOP, PD, and MR values at V9 amounted to 10.23 ± 30.11%, 0.14 ± 0.80 mm, and −0.01 ± 0.04 mm, respectively. Conclusions: CXBB may represent a feasible approach for lateral alveolar ridge augmentation and two‐stage implant placement. [ABSTRACT FROM AUTHOR]

Purpose: Because vertical ridge augmentation with autogenous bone blocks carries with it a risk of graft resorption and donor site morbidity, the aim of the present study was to compare histologically the healing following vertical ridge augmentation using screwable, xenogenous deproteinized blocks or autologous bone blocks in dogs. Materials and Methods: Standardized vertical mandibular defects were surgically created in edentulous ridges of six foxhounds. Two bone blocks (6 × 10 × 15 mm) were inserted on each mandibular side and fixed with both a titanium implant and an osteosynthetic screw. Three different therapies were tested: (1) xenogenous block alone; (2) xenogenous block, covered with a chemically cross-linked collagen membrane; and (3) autologous blocks, harvested during defect preparation. After 3 months of submerged healing, the miniscrews were removed and replaced by dental implants. Following an additional healing period of 3 months, the animals were sacrificed, and dissected blocks were prepared for histomorphometric analysis. Results: During the primary healing period, three of 12 hemimandibles (six blocks) had to be removed because of severe inflammatory reactions (two xenogenous block sites with collagen membrane, one autologous block site). In general, histologic analysis revealed that xenogenous blocks, used alone or combined with a collagen membrane, exhibited osteoconductive properties on a level equivalent to that of autologous blocks, resulting in means of 50% to 60% of ossification of the blocks. Some parts of the xenograft were encased in soft tissue, partly surrounded by multinuclear giant cells. However, all groups showed obvious signs of bone/graft resorption. Conclusions: Within the limits of the present study, it was concluded that the examined screwable xenogenous bone block might be a useful scaffold for ridge augmentation procedures. However, the combination of xenogenous blocks with a cross-linked collagen membrane did not appear to improve outcomes. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: To assess and compare the efficacy and safety of autogenous tooth roots (TR) and autogenous bone blocks (AB) for lateral alveolar ridge augmentation and two‐stage implant placement. Material and Methods: A total of 30 patients in need of implant therapy and lateral ridge augmentation were allocated to parallel groups receiving either (a) healthy autogenous tooth roots (e.g. retained wisdom or impacted teeth) (n = 15) or (b) cortical autogenous bone blocks harvested from the retromolar area. After 26 weeks of submerged healing, the primary endpoint was defined as the crestal ridge width (mm) (CW26) being sufficient to place an adequately dimensioned titanium implant at the respective sites. Results: Soft tissue healing was uneventful in both groups. CW26 at V isit 6 allowed for a successful implant placement in all patients of both TR (15/15) and AB groups (15/15). Mean CW26 values amounted to 10.06 ± 1.85 mm (median: 11.0) in the TR and 9.20 ± 2.09 mm (median: 8.50) in the AB group, respectively. The difference between both groups did not reach statistical significance (p = 0.241). Conclusions: TR may serve as an alternative graft to support lateral alveolar ridge augmentation and two‐stage implant placement. [ABSTRACT FROM AUTHOR]

Objectives To assess the efficacy of periodontally diseased tooth roots used as autografts for lateral ridge augmentation and two-stage early osseointegration of titanium implants. Material and Methods Ligature-induced periodontitis lesions were established at the maxillary premolars in n = 8 foxhounds. Extracted, scaled and root planed pre-molar roots ( PM-P) as well as retromolar cortical autogenous bone ( AB) blocks were used for horizontal ridge augmentation of mandibular chronic-type defects. At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Histological analyses included crestal ridge width ( CW), augmented area ( AA) and bone-to-implant contact ( BIC). Results Both PM-P and AB grafts were gradually organized and replaced by newly formed bone. Median CW ( PM-P: 3.83 versus AB: 3.67 mm), AA ( PM-P: 10.18 versus AB: 9.82 mm2) and BIC ( PM-P: 50.00% versus AB: 35.21%) values did not reach statistical significance between groups ( p > 0.05, respectively). Histologically, PM-P grafts were not associated with any inflammatory cell infiltrates. Conclusions PM-P autografts may reveal a structural and biological potential to serve as an alternative autograft to AB. [ABSTRACT FROM AUTHOR]

Background Peri-implant mucositis and peri-implantitis are a raising issue in dental implantology. Peri-implant infections are mainly caused by the formation of biofilm. Different surface textures exhibit various conditions for biofilm formation resulting in several speed of maturation and development. Materials and Methods On three different titanium implant surfaces, machined-surface ( M), sandblasted large grit, and acid-etched surface ( SLA) and machined-modified acid-etched surface (mod MA) initial biofilms were collected. Plaque formation was investigated by erythrosine staining and energy-dispersive X-ray spectroscopy ( EDX). For testing the biocompatibility of these plaque-settled surfaces, autoclaved specimens were settled with human gingival fibroblasts, and cell viability was tested. Results The mean initial plaque surface was detected in the following descending order: M > SLA > mod MA. The differences between these groups were significant. The highest cell viability was detected in the M groups, whereas mod MA and SLA showed comparable results. The results of initial biofilm formation were proved by EDX. Conclusions Within the limitations of this study, conclusion can be made that mod MA surface shows significant slower initial biofilm formation which could be an advantage in initial transgingival healing process and also an easement for oral hygiene of patients because maturation of plaque is retarded, and immature biofilms are easier to remove. [ABSTRACT FROM AUTHOR]

Objectives To assess the impact of microgrooved abutments and the insertion depth on crestal bone changes at titanium implants with platform switch. Materials and Methods A total of n = 3 titanium implants (conical abutment connection) were inserted in each hemimandible of n = 6 foxhounds with the implant shoulder ( IS) located at either epicrestal, supracrestal (+1 mm), or subcrestal (−1 mm) positions and randomly (split-mouth design) connected with machined or partially microgrooved healing abutments. At 20 weeks, tissue biopsies were processed for histological (primary outcome: net bone loss - NET) analyses. Results Subcrestal positioning of IS tended to be associated with higher mean NET values (mm) at both machined (subcrestal [−0.72 ± 0.32] > epicrestal [−0.34 ± 0.21] > supracrestal [+0.20 ± 0.64]) and microgrooved (subcrestal [−0.48 ± 0.25] > epicrestal [−0.13 ± 0.54] > supracrestal [+0.33 ± 0.58]) abutments. However, these differences failed to reach statistical significance. Conclusions The insertion depth may have a direct influence on crestal bone-level changes at both types of abutments investigated. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the impact of a cross-linked- (VN) collagen membrane on the long-term stability of peri-implant health over 6 years. Material and methods: Vestibular dehiscence-type defects at titanium implants (19 patients, 19 implants) were augmented using a natural bone mineral and randomly allocated to either VN or a native collagen membrane (CM) and left to heal in a submerged position for 4 months. Clinical parameters (i.e. Bleeding on Probing-BOP, probing pocket depth-PD, mucosal recession-MR) were recorded at 4 and 6 years after prosthesis installation. Results: At 4 and 6 years, both VN and CM revealed comparable mean BOP, PD and MR values at both vestibular and oral aspects. Changes in these parameters from 4 to 6 years were minimal (vestibular aspect-VN: -3.3 ± 48.2%, -0.1 ± 0.5 mm, -0.1 ± 0.3 mm; CM: -1.8 ± 33.7%, 0.0 ± 0.4 mm, -0.1 ± 0.7 mm) and not significantly different between groups. At 6 years, the incidence of mucositis and peri-implantitis was comparable in both groups (VN: 60.0% and 20.0%; CM: 33.3% and 33.3%). Conclusion: In conclusion, the present follow-up observation failed to identify any beneficial impact of VN over CM on peri-implant health at 4 and 6 years. [ABSTRACT FROM AUTHOR]

Objectives To histologically assess the effectiveness of a porcine-derived collagen matrix ( CM) and a subepithelial connective tissue graft ( CTG) for the coverage of single mucosal recessions at osseointegrated dental implants. Materials and methods Chronic-type mucosal Miller Class I-like recessions (mean clinical defect height: 0.67 ± 0.33-1.16 ± 0.19 mm) were established at the buccal aspect of titanium implants with platform switch in six beagle dogs. The defects were randomly allocated to either (1) coronally advanced flap surgery ( CAF) + CM, (2) CAF + CTG or (3) CAF alone. At 12 weeks, histomorphometrical measurements were made (e.g.) between the implant shoulder ( IS) and the mucosal margin ( PM) and IS and the outer contour of the adjacent soft tissue (mucosal thickness [ MT]). Results All treatment procedures investigated were associated with an almost complete soft tissue coverage of the defect area (i.e. coronal positioning of PM relative to IS). Mean IS- PM and MT values tended to be increased in both CAF + CM (1.04 ± 0.74 mm/0.71 ± 0.55 mm) and CAF + CTG (0.88 ± 1.23 mm/0.62 ± 0.66 mm) groups when compared with CAF (0.16 ± 0.28 mm/0.34 ± 0.23 mm) alone. These differences, however, did not reach statistical significance. Conclusions Within the limits of this pilot study, it was concluded that all treatment procedures investigated were effective in covering soft tissue recessions at titanium implants. [ABSTRACT FROM AUTHOR]

Objectives To histologically evaluate and compare the performance of healing abutments with either hydrophobic or hydrophilic surface properties in humans. Materials and Methods According to a parallel-group design, titanium implants placed in the posterior mandible and maxilla of 30 patients were randomly assigned to either (1) hydrophobic machined (M), (2) chemically modified hydrophilic (mod) acid etched ( MA) titanium (Ti) (mod MA1) or (3) mod MA Ti- Zirconium alloy (mod MA2) healing abutments and left to heal in a transmucosal position. At 8 weeks, the abutments and a limited soft tissue biopsy were harvested according to a standardized procedure and processed for histological analysis (primary outcomes: percentage epithelial- ( EC) and subepithelial connective tissue contact ( CTC) to the abutment surface). Results The surgical procedure was associated with an incomplete mucosal coverage of the study abutments in nine patients, and an unintentional submerged healing procedure in three patients. Per protocol analysis (18 patients) has pointed to an improved quantitative EC [mod MA2 (53.45 ± 28.25) > mod MA1 (32.25 ± 24.3) > M (23.15 ± 16.09)] and CTC [mod MA2 (75.12 ± 43.22) > mod MA1 (69.41 ± 46.74) > M (47.63 ± 19.28)] (%) to mod MA surfaced abutments. Conclusions It was concluded that mod MA surfaces may have the potential to enhance soft tissue adhesion at the transmucosal aspect of titanium dental implants. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the impact of residual defect height (RDH) following guided bone regeneration (GBR) in dehiscence-type defects on the long-term stability of peri-implant health after a period of 4 years. Material and methods: The RDH values in dehiscence-type defects at titanium implants were clinically assessed after 4 months of submerged healing following augmentation using a natural bone mineral (NBM) and a randomized application of either a cross-linked- (VN) or a native collagen membrane (BG) ( n=12 patients each). The RDH values were classified as absent (0 mm, control; n=8), minimal (1 mm, test 1; n=8), or advanced (>1 mm, test 2; n=8). Clinical parameters (i.e. bleeding on probing [BOP], probing pocket depth [PD], mucosal recession [MR]) were recorded (mesio-, mid-, and disto-buccal aspects) at 4 years after prosthesis installation. Results: The mean PD (2.9±0.7, 2.8±0.7, 2.7±0.8 mm) values at 4 years were comparable in all the groups investigated. The mean MR values tended to be increased in both the test groups (0.5±0.7, 0.4±0.6 mm, respectively), when compared with the control group (0.2±0.3 mm) ( P>0.05, respectively). The mean BOP values were also increased in both the test groups (45.8±30.5%, 54.1±24.8%, respectively), even reaching statistical significance when comparing test 2 and control (29.1±21.3%) groups ( P=0.02). Conclusion: The present study indicated that (i) implants exhibiting RDH values >1 mm are at a higher risk of developing peri-implant disease and (ii) positive RDH values may be associated with an increase in MR and may therefore compromise the overall esthetic outcome of implant therapy. To cite this article: Schwarz F, Sahm N, Becker J. Impact of the outcome of guided bone regeneration in dehiscence-type defects on the long-term stability of peri-implant health: clinical observations at 4 years. Clin. Oral Impl. Res 23, 2012; 191-196. doi: 10.1111/j.1600-0501.2011.02214.x [ABSTRACT FROM AUTHOR]

Objectives: 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. Material and Methods: 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. Results: 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 mm2) 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 mm2)]. Within modSLA groups, significantly highest BF values were observed at submerged implants. Conclusion: 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. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present study was to investigate histomorphometrically the influence of platform switching on crestal bone changes at non-submerged wide-body titanium implants in a dog model. Material and Methods: One-stage insertion of sand-blasted and acid-etched screw-type implants with either matching (CAM) or smaller-diameter healing abutments (CPS) were randomly assigned to the lower jaws of nine beagle dogs. The animals were killed after 7, 14, and 28 days of non-submerged healing. Dissected blocks were processed for histomorphometrical analysis. Measurements were made between the implant shoulder (IS) and: – the apical extension of the long junctional epithelium (aJE), – the most coronal level of bone in contact with the implant (CLB), and – the level of the alveolar bone crest (BC). Results: At 7, 14, and 28 days, the mean IS–aJE values were significantly the lowest at CPS implants. However, after 28 days of healing, both groups revealed significantly increased mean IS–BC values at the buccal aspect of the alveolar bone. The difference in IS–CLB and IS–BC between groups was not significant. Conclusions: Within the limits of the present study, it was concluded that both CAM and CPS implants revealed crestal bone-level changes after 28 days of healing. [ABSTRACT FROM AUTHOR]

The aim of the present pilot study was to histologically/immunohistochemically investigate initial and early subepithelial connective tissue attachment at transmucosal parts of modified (mod) and conventional sandblasted, large grit and acid-etched (SLA) titanium implants. Implantation of modSLA and SLA implants was performed bilaterally in both the mandible and maxilla of four beagle dogs. The implants were submerged to prevent bacterial contamination. The animals were killed after 1, 4, 7 and 14 days. Peri-implant tissue reactions were assessed histologically (Masson Goldner Trichrome stain-MG) and immunohistochemically (IH) using monoclonal antibodies to fibronectin (FN) and proliferating cell nuclear antigen (PCNA). The surgical procedure of implant submerging resulted in the formation of an artificial gap in the transmucosal area of both types of implants. After 14 days of healing, MG stain revealed the formation of well-organized collagen fibres and numerous blood vessels in a newly formed loose connective tissue zone adjacent to modSLA. While some fibres were oriented in a parallel direction, others have started to extend and attach partially perpendicular to the implant surface. In contrast, SLA implants appeared to be clearly separated by a dense connective tissue zone with parallel-running collagen fibres and rare blood vessel formation. First signs of a positive FN and PCNA staining adjacent to both implant surfaces were observed at day 4. Within the limits of a pilot study, it might be concluded that modSLA titanium surfaces might possess the potential to promote subepithelial connective tissue attachment at the transmucosal part of the implant. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present pilot study was to investigate initial and early tissue reactions to modified (mod) and conventional sand-blasted, large grit and acid-etched (SLA) titanium implants. Material and methods: Implantation of modSLA and SLA implants was performed bilaterally in both the mandible and maxilla of dogs. The animals were sacrificed after a healing period of 1, 4, 7 and 14 days, respectively. Peri-implant tissue reactions were assessed in non-decalcified tissue sections using conventional histology (Toluidine blue-TB and Masson Goldner Trichrome stain-MG) and immunohistochemistry using monoclonal antibodies to transglutaminase II (TG) (angiogenesis) and osteocalcin (OC). Bone density (BD) and bone to implant contact (BIC) were assessed histomorphometrically. Results: Day 1 revealed an early TG antigen reactivity in the provisional fibrin matrix adjacent to both implant surfaces. Day 4 was characterized by the formation of a collagen-rich connective tissue (MG), which revealed the first signs of OC synthesis adjacent to modSLA surfaces. Immunohistochemical staining for TG revealed a direct correlation between angiogenesis and new bone formation, which was clearly identifiable after 7 days by means of increasing BD, BIC and OC values. After 14 days, modSLA surfaces seemed to be surrounded by a firmly attached mature, parallel-fibered woven bone. Conclusions: Within the limits of the present study, it might be concluded that the combination of immunohistochemical and conventional histological stainings in non-decalcified tissue sections is a valuable technique to evaluate the initial and early stages of wound healing around endosseous titanium implants. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to investigate the effects of an enamel matrix protein derivative (EMD) on attachment, proliferation, and viability of human SaOs2 osteoblasts on titanium implants. A total of 220 sand-blasted and acid-etched (SLA) titanium discs were placed into 24-well culture plates. Before cell inoculation, McCoy’s 5A medium (MCM) containing EMD at 25 µg/ml, 50 µg/ml, 100 µg/ml, and 200 µg/ml was added, and the culture plates were incubated for 30 min. As control, MCM alone was used. Human osteoblast-like cells (SaOs2) (2×104 cells, fourth passage) were suspended in MCM containing 1% penicillin/streptomycin and 10% fetal bovine serum and then inoculated into the well chambers. The medium was changed after 3 days without the addition of EMD. At days 1, 3, and 6, DNA content of the cells was assessed using the CyQuant cell proliferation assay kit, and mitochondrial activity of the cells was measured using a CellTiter-Glo luminescent cell viability assay. The presence of EMD on the titanium discs at days 1 and 6 was evaluated using immunofluorescence stain (IFS) by means of polyclonal antibodies against amelogenin. Additionally, cell morphology was investigated using scanning electron microscopy. Enamel matrix derivative at 25 µg/ml, 50 µg/ml, 100 µg/ml, and 200 µg/ml demonstrated similar increases in cell proliferation as the control medium at days 3 and 6 (P>0.05 between groups, respectively). Proliferation, however, appeared to be ameliorated with increasing EMD concentrations. At 25 µg/ml and 50 µg/ml, EMD also demonstrated an increase in cell viability similar to the control medium at days 3 and 6 (P>0.05 between groups, respectively), while EMD at 100 µg/ml and 200 µg/ml resulted in statistically significant higher increase in cell viability than in the control medium at day 6 (P<0.001 between groups, respectively). In all test groups, IFS at day 6 was markedly lower than at day 1. Scanning electron microscopy revealed comparable cell morphology in all groups. Within the limits of the present study, it was concluded that EMD enhanced cell proliferation and viability of human SaOs2 osteoblasts on SLA titanium implants in a concentration-dependent manner. [ABSTRACT FROM AUTHOR]

Copyright of Clinical Oral Implants Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: To assess the effects of differently sized titanium (Ti) and zirconia (Zr) particles on (1) the metabolic activity of osteosarcoma-derived osteoblasts (SaOs-2) and human gingival fibroblasts (HGF) and (2) the cytokine expression of monocytes (THP-1) Methods: Ti (60–80 nm and 100 nm) and Zr (2 μm and 75 μm) particles were incubated with SaOs-2, HGF, and THP-1 cells. At days 0, 2, 4, and 7 and 0, 1, 2, and 4 (THP-1), the mitochondrial activity was assessed and enzyme-linked immunosorbent assays were used to determine interleukin (IL)-1 beta and IL-6 concentrations of stimulated THP-1 at day 1. Results: Ti60–80, Ti100, Zr2, and Zr75 particles were associated with gradual and significant within-group decreases in the viability of SaOs-2 and HGF cells. These effects were less pronounced in the Zr group. Similar to control cells, THP-1 did not reveal any significant increases in IL-1 beta and IL-6 concentrations. Viability of THP-1 was merely impaired in the presence of Ti100. Conclusions: Ti and Zr particles had a detrimental effect on the viability of SaOs-2 and HGF, but no proinflammatory effect on THP-1. [ABSTRACT FROM AUTHOR]