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Purpose: After some initial setbacks in the 1970s, ceramic implants seem to be a promising alternative to titanium implants. Since the surface of an implant system represents the interface to surrounding biologic structures, the study focuses on cleanliness and surface topography. Clinical documentation of the corresponding systems completes the picture and allows a better evaluation of zirconia implant systems. Materials and Methods: Five different ceramic implant systems were selected randomly and purchased via blind-shopping: Z5s (Z-Systems), ZiBone (COHO), W implant (TAVDental), ceramic. implant (vitaclinical), and BioWin!/Standard Zirkon Implantat (Champions-Implants/ZV3 system). Three samples of each implant system underwent scanning electron microscopy (SEM) imaging and elemental analysis (EDS). Where appropriate, subsequent Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) was performed to identify the chemical nature of impurities. Surface topography was evaluated, and a search for clinical trials in the PubMed database, on the websites and by written request to each dental implant manufacturer, was performed. Results: Surfaces of Champions implants (ZV3) and Z-Systems implants were relatively clean, whereas the other investigated surfaces of vitaclinical, TAV Dental, and ZiBone implants all displayed organic contaminations on their surfaces. Four of the investigated ceramic implants showed a moderately rough implant surface. Only the vitaclinical ceramic. implant had minimal surface roughness. Three ceramic designs--vitaclinical, ZV3, and Z-Systems--had clinical trials documented with up to 3 years of follow-up and results varying between 82.5% and 100% survival. TAV Dental W and ZiBone implant systems lacked properly conducted clinical recording of results. Conclusion: The results of this study showed that it is technically possible to produce zirconia implants that are largely residue-free. On the other hand, the variety of significant residues found in this analysis raises concerns, as contamination may lead to undesirable biologic effects. The lack of clinical studies in peer-reviewed journals does not seem to be relevant for the approval of marketing, nor does the lack of surface cleanliness. In the authors' opinion, a critical analysis of these aspects should be included in a more stringent future analysis prior to the marketing of oral implant systems. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this split-mouth randomized clinical trial was to evaluate the primary and secondary stability of implants with hydrophilic surfaces in comparison to implants with conventional surfaces in the posterior region of the maxilla. Materials and Methods: Twenty patients with a bilateral edentulous ridge in the posterior area of the maxilla randomly received implants with two types of surfaces: (1) implants with the surface modified by double acid-etching and sandblasting (DAS, n = 20); and (2) implants with the surface modified by double acid-etching and sandblasting, stored in 0.9% saline solution to confer highly hydrophilic properties (DAS-H, n = 20) on the surface. The implants presented the same macrostructure with a hybrid design. The resonance frequency analysis was performed in order to obtain the implant stability quotient (ISQ) using Osstell. The ISQ analyses were performed just after placement of the implant (primary stability) and at 28, 40, and 90 days after the surgical procedure (secondary stability). Results: There were no differences between the DAS and DAS-H surfaces in the primary stability or during the conversion of the primary to the secondary stability; however, there was a reduction in the stability of the implants at 28 days, which increased significantly at 40 and 90 days in both surfaces. Conclusion: It can be concluded that the surface wettability of implants with a hybrid macrostructure did not increase the primary and secondary implant stability in the posterior region of the maxilla. [ABSTRACT FROM AUTHOR]

Purpose: To compare the onset of peri-implantitis, incidence of failure, and peri-implant marginal bone level changes between implants with a roughened surface and those with a machined/turned surface. Materials and Methods: All patients needing two dental implants of the same size on the left and right sides of the same arch, and not scheduled for immediate loading, were enrolled between October 2012 and February 2016. The patients were randomly allocated either to Nobel Biocare MkIII or Sweden & Martina Outlink2. Rough-surface implants and machined-surface implants were used from each company. After the preparation of two identical implant sites, each implant (rough or machined of the same group) was randomly allocated to the right and left sides of the same patient, following a split-mouth design. Outcome measures were peri-implantitis onset, incidence of failure, and peri-implant marginal bone level changes. Patients were followed up for 3 years after loading. Results: One hundred fourteen patients were enrolled and treated; nine patients dropped out. Following an intent-to-treat analysis to avoid overestimation, proportions are given related to the initial number of 114 patients. Peri-implantitis incidence was 4.39% for machined implants (5/114), 0.88% for rough implants (1/114), 1.75% in the Nobel Biocare group (2 cases), and 3.51% in the Sweden & Martina group (4 cases). The failure rate was 1.75% in machined implants (2/114), 0.88% in rough implants (1/114), 0.98% in the Nobel Biocare group (1/114), and 1.85% in the Sweden & Martina group (1/114). No statistically significant differences in marginal bone loss were found comparing different surfaces, while marginal bone loss was significantly lower in Nobel Biocare than in Sweden & Martina implants. Conclusion: Based on the results of this study, no significant differences can be demonstrated in either peri-implantitis or failure rate or in marginal bone loss between rough and machined implants. Marginal bone loss was significantly worse in machined-surface Sweden & Martina than in rough-surface Nobel Biocare implants. [ABSTRACT FROM AUTHOR]

Purpose: To compare the influence of ultraviolet (UV) irradiation and cold atmospheric pressure plasma (CAP) treatment on surface structure, surface chemistry, cytocompatibility, and cell behavior on zirconia in vitro. Materials and Methods: Zirconia samples (TZ-3YSB-E) were treated by UV irradiation, oxygen plasma, or argon plasma for 12 minutes each and compared with the nontreated samples. Surface analysis was conducted using scanning electron microscopy, roughness analysis, and x-ray photoelectron spectroscopy. Cell proliferation, viability, and cell attachment as well as cytotoxicity were evaluated using MC3T3-E1 murine osteoblasts cultivated directly on the zirconia samples. Results: Surface structure and roughness were not affected by the surface treatments. CAP and UV irradiation significantly reduced organic material and increased the surface oxidation on the zirconia samples. Furthermore, CAP and UV treatment significantly decreased the contact angle on the zirconia samples, indicating superhydrophilicity. Cell attachment was significantly increased on oxygen plasma--treated zirconia samples compared with the nontreated samples at all times (P < .001). After 24 and 48 hours, cell proliferation and viability (P < .001) were significantly increased on oxygen plasma--treated samples in comparison with the nontreated, UV-treated, and argon plasma--treated samples. Neither UV nor CAP treatment led to cytotoxicity. Conclusion: In vitro, surface treatment by UV irradiation or CAP causes a significant reduction of organic material, increases the hydrophilicity of zirconia, and improves the conditions for osteoblasts. The results stipulate that treatment of zirconia surfaces with oxygen plasma may favor cell proliferation. [ABSTRACT FROM AUTHOR]

Purpose: Decontamination of the rough surfaces of dental implants is a challenge in the treatment of peri-implantitis. An acceptable cleaning technique must be able to debride and detoxify the surface without traumatizing it. This study assessed the possible implant surface alterations following decontamination with laser, photodynamic therapy (PDT), and application of chlorhexidine (CHX). Materials and Methods: Of 16 dental implants with sandblasted, large-grit, acid-etched surfaces, Aggregatibacter actinomycetemcomitans was cultured on the surfaces of 15 implants for 48 hours. These 15 implants were divided into five groups of three and were subjected to erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation, 630 nm light-emitting diode and toluidine blue O photosensitizer, 810 nm diode laser, and indocyanine green-based photosensitizer, 2% CHX, and control group (no treatment). One implant remained intact. The morphology and element/phase identification of the implants were studied using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS), respectively. Results: The SEM images and EDS maps revealed that the decontamination methods did not alter the surface quality of the implants. However, in photodynamic therapy, sodium chloride that remained from rinsing liquid can make an adhesive layer on the surface of the treated implants. Conclusion: Er:YAG laser irradiation and PDT did not alter the surfaces of sandblasted, large-grit, acid-etched implants. [ABSTRACT FROM AUTHOR]

Purpose: The prevalence of peri-implantitis has increased significantly, forcing clinicians to search for ways to prevent it. Laser-microtextured surfaces promote soft tissue attachment and provide a tight seal around implants. Hence, the aim of this study was to examine the clinical, radiographic, and histologic features of ligature-induced peri-implantitis, as well as the effect of surgical treatment of these induced peri-implantitis lesions on laser-microtextured implants in a controlled animal model. Materials and Methods: Six mini-pigs (three males/three females) received 6 implants each (3 resorbable blast textured [RBT] implants and 3 laser-microtextured [LM] implants) in mandibular premolar sites, for a total of 36 implants. Two groups were identified based on the time point of sample analysis. After osseointegration was achieved, metal wire ligatures were placed and left for 12 weeks. Group 1 samples were then obtained, and group 2 samples received rescue therapy following a guided bone regeneration (GBR) protocol. Sample collection in group 2 was completed 12 weeks after the samples were submerged and treated. All samples were analyzed histologically and measurements were taken. Results: Four implants (three RBT, one LM) were lost at early time points because of implant instability. Interimplant distances and soft tissue thicknesses varied subtly between groups. More notable was the mean (± standard error of the mean) crestal bone loss (group 1: 1.860 ± 1.618 mm [LM] and 2.440 ± 2.691 mm [RBT]; group 2: 2.04 ± 1.613 mm [LM] and 3.00 ± 2.196 mm [RBT]) (P < .05), as demonstrated by a paired t test. Histologic pocket depth was also greater at RBT sites than at LM sites (4.448 ± 2.839 mm and 4.121 ± 2.251 mm, respectively, in group 1; and 3.537 ± 2.719 mm and 2.339 ± 1.852 mm, respectively [P < .005] in group 2). Conclusion: LM implants had less crestal bone loss and shallower histologic pocket depth compared with their RBT counterparts. Also, LM implants had higher bone fill when a rescue therapy (GBR) was performed. [ABSTRACT FROM AUTHOR]

Purpose: To test the antimicrobial properties, surface topography, reaction of surrounding tissue (biocompatibility) and osseointegration of ultrathin implant surfaces containing polysiloxane and nanoscaled silver particles. Materials and Methods: Implants with polysiloxane coating and nanoscaled silver particles (Ag/SiOxCy; HyProtect, Bio-Gate) were compared with implants with polysiloxane coating alone and with noncoated (grit-blasted and acid-etched) implants. A total of 72 implants were inserted into the calvaria of eight domestic pigs (nine implants each, three of each type). After 3 months, histologic sections were evaluated for inflammatory cell infiltration and bone implant contact. Results: Roughness parameters did not differ between all three implant types. The Ag/SiOxCy coating exhibited a good antimicrobial effect in vitro and no sign of inflammatory cell infiltration in vivo. The noncoated implants demonstrated 10.85% and 14.48% more bone contact than the polysiloxane-coated implants (P = .003) and the Ag/SiOxCy-coated implants (P ⩽ .001), respectively. Osseointegration was not significantly different between the Ag/SiOxCy-coated and polysiloxane-coated implants (P = .72). Conclusion: The osseointegration capability of the Ag/SiOxCy-coated implants was equal to that of the polysiloxane-coated implants but less than that of the grit-blasted and acid-etched implants. Because of the biocompatibility of the polysiloxane coating, further studies should be conducted in load-bearing models and in the oral cavity to investigate the antimicrobial effect of the embedded silver clusters. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the in vitro cleaning effects of different decontamination methods and their impacts on surface characteristics using clinically failed TiUnite implants (Nobel Biocare, Kloten, Switzerland). Materials and methods: Thirty clinically failed TiUnite implants were treated using different decontamination methods. Group 1 (control group) received physiological saline irrigation; Group 2 underwent erythritol powder air polishing (AIRFLOW Master Piezon, EMS Dental, Nyon, Switzerland); Group 3 was treated with erythritol powder air polishing with ethylenediaminetetraacetic acid brushing (FileRite PRC, Pulpdent, Watertown, MA, USA); Group 4 received ultrasonic scaling with polyetheretherketone tips (EMS Dental); Group 5 underwent ultrasonic scaling with polyetheretherketone tips with ethylenediaminetetraacetic acid; and Group 6 was treated with a combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic acid. Surface cleaning effects, quantified by relative contaminated area reduction and visual analogue scale score, as well as surface roughness and chemistry, were assessed after decontamination. The cleaning effects of each decontamination method were also compared between TiUnite and SLA (sandblasted, large-grit acid-etched; Straumann, Basel, Switzerland) implants. Results: Group 6 showed the highest relative contaminated area reduction (stereoscopic microscopy 83.92%, scanning electron microscopy 96.40%), visual analogue scale score (2.83) and reduction in surface roughness (thread bottom −0.78 μm, tip −1.35 μm), as well as an almost maximal decrease in the proportion of carbon (thread bottom −12.33%, tip −8.77%) and increase in that of titanium (thread bottom 13.71%, tip 10.73%). Polyetheretherketone remnants were observed in Groups 4 and 5 but appeared to be reduced in Group 6. When comparing the outcomes with those for SLA implants, no significant differences were found. Conclusion: Within the limitations of the present study, the combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic brushing achieved reasonable cleaning effects. The original surface modification did not seem to have any impact on the decontamination results for any of the methods examined. [ABSTRACT FROM AUTHOR]

Purpose: A moderately rough anodized titanium implant surface (TiUnite) was introduced in 2000. This review and meta-analysis aimed to assess implant survival and marginal bone level (MBL) changes documented in the literature. Materials and Methods: Repeated literature searches on dental implants were conducted, with the final search on October 7, 2016. The inclusion criteria were: prospective study, minimum of 20 patients, at least 12 months follow-up postloading, and TiUnite implant survival reported. Regression analysis was performed on implant survival and MBL change from implant surgery. Peri-implantitis as defined by the primary authors was reported at the patient level. Results: One hundred six out of 32,519 publications on dental implants met the inclusion criteria. Implant survival rates at 1 year were 99.50% at the implant level and 99.12% at the patient level, and survival rates at 10 years were 95.14% at the implant level and 91.50% at the patient level. Mean MBL change at 1 year was -0.409 mm at the implant level and -0.413 mm at the patient level, and at 5 years, it was -0.886 mm at the implant level and -1.029 mm at the patient level. Nineteen studies (18%) specifically reported peri-implantitis in 64 out of 1,229 patients with a mean followup of 47.89 months, indicating a prevalence of 5.20% at the patient level. Conclusion: Based on a metaanalysis of prospective studies, implants with the TiUnite surface provide a predictable treatment modality in a variety of indications. [ABSTRACT FROM AUTHOR]

Purpose: Commercially pure titanium (CpTi) and its alloys possess favorable mechanical and biologic properties for use as implants in orthopedics and dentistry. However, failures in osseointegration still exist and are common in select individuals with risk factors such as smoking. Therefore, in this study, a proposal was made to enhance the potential for osseointegration of CpTi discs by coating their surfaces with nanoplexes comprising polyethylenimine (PEI) and plasmid DNA (pDNA) encoding bone morphogenetic protein-2 (pBMP- 2). Materials and Methods: The nanoplexes were characterized for size and surface charge with a range of N/P ratios (the molar ratio of amine groups of PEI to phosphate groups in pDNA backbone). CpTi discs were surface characterized for morphology and composition before and after nanoplex coating using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). The cytotoxicity and transfection ability of CpTi discs coated with nanoplexes of varying N/P ratios in human bone marrow-derived mesenchymal stem cells (BMSCs) was measured via MTS assays and flow cytometry, respectively. Results: The CpTi discs coated with nanoplexes prepared at an N/P ratio of 10 (N/P-10) were considered optimal, resulting in 75% cell viability and 14% transfection efficiency. Enzyme-linked immunosorbent assay results demonstrated a significant enhancement in BMP-2 protein secretion by BMSCs 7 days posttreatment with PEI/pBMP-2 nanoplexes (N/P-10) compared to the controls, and real-time PCR data demonstrated that the BMSCs treated with PEI/pBMP-2 nanoplex-coated CpTi discs resulted in an enhancement of Runx-2, alkaline phosphatase, and osteocalcin gene expressions on day 7 posttreatment. In addition, these BMSCs demonstrated enhanced calcium deposition on day 30 posttreatment as determined by qualitative (alizarin red staining) and quantitative (atomic absorption spectroscopy) assays. Conclusion: It can be concluded that PEI/pBMP-2 nanoplex (N/P-10)-coated CpTi discs have the potential to induce osteogenesis and enhance osseointegration. [ABSTRACT FROM AUTHOR]

Purpose: Osseointegration has been defined in many ways, from both basic science and clinical perspectives, but generally represents the restoration of bony homeostasis following implant placement and is usually judged by some form of bone/implant disruption test. In this study, bone anchorage to two different implant surfaces, in tensile and shear modes, was compared to investigate the relation between implant surface topography and osseointegration over time. The purpose was to determine if mathematical parameters could be derived that would reflect the biologic relevance of the implant surface design. Materials and Methods: Rectangular titanium implants (n = 244) were placed in the distal femora of 122 male Wistar rats proximal to the knee joint. Implants were either microsurfaced (MS) or nanosurfaced (NS). Animals were euthanized at one of six time points ranging from 5 days to 6 months, and the force required to disrupt the bone implant interface, in either shear or tension, was measured using an Instron machine. Data were analyzed by fitting the function F = C (1–e-x/τ), where F is the measured disruption force, C is the predicted average maximum disruption force, x is the time postimplantation, and τ is a time constant defined as the time required for F to reach 63.2% of C. Results: Analysis showed that shear testing resulted in significantly larger values of C than seen in tension, but no significant difference was observed when comparing the values of C for NS and MS implants in shear (P = .7). Thus, in accord with clinical reports, both implants performed equivalently at longer implantation periods. The differences in C were significant in tension (P < .05). Importantly, NS implants had a significantly smaller τ than the MS implants (P < .01, in shear), but no significant differences were observed in τ due to mechanical testing vector. The disruption force values reached a plateau with time, representing bony homeostasis as a result of osseointegration. With time, both implant surfaces reached the same maximum (C) values, in shear. However, the value of τ was smaller in NS compared to MS implants, which represented a higher rate of osseointegration. Conclusion: Thus, τ emerges as a measureable and biologically relevant parameter that can be employed to compare the osseointegration potential of putative implant surfaces. [ABSTRACT FROM AUTHOR]

Purpose: To compare the outcome of immediately loaded single implants with a machined or a roughened surface. Materials and methods: Fifty patients had two implant sites randomly allocated to receive flaplessplaced single Syra implants (Sweden & Martina), one with a machined and one with a roughened surface (sand-blasted with zirconia powder and acid etched), according to a split-mouth design. To be loaded immediately, implants had to be inserted with a torque superior to 50 Ncm. Implants were restored with definitive crowns in direct occlusal contact within 48 h. Patients were followed for 6 months after loading. Outcome measures were prosthetic and implant failures and complications. Results: Two machined implants and four roughened implants were not loaded immediately. Six months after loading no dropout occurred. One implant loaded late, which had a rough implant surface, failed 20 days after loading (P (McNemar test) = 0.625; difference in proportions = -0.04; 95% CI: -0.15 to 0.07). Three crowns had to be remade on machined implants and four on roughened implants (P (McNemar test) = 1.000; difference in proportions = -0.02; 95% CI: -0.12 to 0.08). Three machined and five roughened implants experienced complications (P (McNemar test) = 0.625; difference in proportions = -0.04; 95% CI: -0.15 to 0.07). There were no statistically significant differences between groups for crown and implant losses as well as complications. Conclusions: Up to 6 months after loading both machined and roughened flapless-placed and immediately loaded single implants provided good and similar results, however, longer follow-ups are needed to evaluate the long-term prognosis of implants with different surfaces. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this randomized controlled clinical split-mouth trial was to compare anodized implant surfaces and implant surfaces modified by acid etching in terms of primary and secondary stability. Materials and Methods: Forty-six implants were placed bilaterally in the posterior mandibles of 23 patients. Each patient received one implant with a surface treated by acid (AC) and the other with an anodized implant surface (ANO). The selection of the side where the implant was placed was chosen randomly by lot. The implants were evaluated with respect to insertion torque within the surgical bed and primary and secondary stability by testing the implant stability quotient (ISQ) at five different times (immediate postoperative period and 21, 30, 60, and 180 days after surgery). The paired t test was used to compare the two groups, and ANOVA Repeated Measures complemented by the Tukey posttest were used for longitudinal analysis of the implants in each group. All tests were applied with a confidence level of 95% (P < .05). Results: No statistically significant difference was detected between the AC and ANO groups regarding insertion torque. ISQ analysis revealed that the AC group showed statistically higher values than the ANO group at the 21-day period (P < .05); however, no other statistically significant differences were detected at the other times. Conclusion: The different surfaces were similar in terms of primary and secondary stability of implants placed in the posterior mandible. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this case series study was to evaluate clinical and radiographic changes of soft and hard tissues around tapered, platform-switched, laser-microtextured implants 24 months after crown placement. Materials and Methods: Twenty tapered, platform-switched, laser-microtextured collar implants were placed in 20 patients. Full-mouth plaque score, full-mouth bleeding score, probing depth, and mucosal recession were recorded at the time of crown cementation and after 24 months follow-up. The marginal bone-level changes at the mesial and distal aspects of the implants were calculated by subtracting from baseline and 24-month implant marginal bone level. Results: In terms of the full-mouth plaque score and full-mouth bleeding score, tapered, platform-switched, laser-microtextured implants showed statistically significant improvements at 6 months when compared to baseline (P < .001). Statistically significantly deeper probing depths (P < .001) were found when comparing baseline and at 24 months at mesial, lingual, and distal sites. However, no statistically significant difference was found at the buccal aspects (P = .064). Radiographic marginal bone loss at 2-year follow-up for tapered, platform-switched, laser-microtextured implants was 0.72 ± 0.16 mm and 0.67 ± 0.15 mm at the mesial and distal sites, respectively. Conclusion: Within the limits of this study, tapered, platform-switched, laser-microtextured implants maintained marginal bone level (less than 1 mm radiographic bone loss) as well as limited mucosa recession over a 2-year period. [ABSTRACT FROM AUTHOR]

This article describes the clinical and radiologic long-term results of a healthy, nonsmoker women aged 62 at the time of treatment, with severely resorbed edentulous jaws in which bar and clip supported complete dentures were delivered in both jaws and followed for 8 years after prosthesis delivery. The patient had been edentulous in both arches since she was 50 years old. Treatment included the placement of four mandibular implants with maximum spacing anterior to the mandibular nerve, and four maxillary implants anterior to sinus wall without tilting the posterior implants, because of the insufficient bone quantity necessary to angulate implants. Guided bone regeneration was required in the maxilla, due to a bone atrophy that limited the placement of conventional dental implants. After 4 months, a second-stage surgery was performed, and after 1 month of healing time the patient received definitive restorations. Implant survival rate, patient satisfaction, marginal bone maintenance, and soft tissue conditions at the modified titanium surface of the dental implants were evaluated after 8 years of function. A multifactorial approach, clinician-patient relationship, and vigilant maintenance of oral hygiene were needed in order to ensure an optimal treatment and a long-term successful result. Positive results regarding bone maintenance in the long-term perspective, also on regenerated bone, were observed using implants with implant-retained bar overdentures, when adequate levels of oral hygiene and prosthodontic adjustments are maintained. [ABSTRACT FROM AUTHOR]

Purpose: To compare the 2-year survival and peri-implant bone loss of implants with and without a fluoride modification under immediate loading conditions in completely edentulous mandibles. Materials and Methods: A total of 125 Osseospeed implants (test group) were placed in 25 patients requiring a fixed rehabilitation. Implants were loaded immediately (baseline) with a provisional screw-retained prosthesis. Implant survival and bone level changes were analyzed at 3, 12, and 24 months. Results were compared with the outcome of 25 previously treated patients with immediately loaded TiOblast implants using the same treatment protocol (control group). Results: Implant survival was 100% for both groups. After 3, 12, and 24 months, the mean bone loss for the control group was 0.60, 0.81, and 0.84 mm on the patient level and 0.60, 0.80, and 0.86 mm on the implant level. For the test group, a mean bone loss of 0.14, 0.11, and 0.11 mm was for the patient; and 0.14, 0.11, and 0.11 mm with the implant as statistical unit after 3, 12, and 24 months, respectively. No statistically significant differences were observed comparing peri-implant bone loss at 3 months with 12 and 24 months in both groups, but the control group showed more peri-implant bone loss compared with the test-group (P < .001). Moreover, the control group showed an increasing interquartile range over time, suggesting that not every implant is reaching steady-state bone levels. Conclusions: Immediate loading of implants placed in the completely edentulous mandible is a successful treatment option with high survival rates and limited bone loss after 2 years. However, initial crestal bone preservation significantly benefits from fluoride modification. [ABSTRACT FROM AUTHOR]

Purpose: To characterize the surface of implants from Brazilian companies by light interferometry and evaluate the level of control of the surface treatment process. Materials and Methods: Oral implants from the five largest Brazilian companies were evaluated topographically. The surfaces of the implants were analyzed on the tops, valleys, and flanks of the threads, totaling nine measurements for each unit. The implants and results were separated in groups by their types of surface treatment and compared with wellknown international implants used as references. Results: The implants examined presented a mean height deviation of less than 1 μm, which was considered minimally rough, except for the SIN-SW implant (1.01 μm) and the Vulcano Actives design (1.26 μm). The surface enlargement values varied considerably in relation to the reference implant, with lower values noted in the group of implants subjected to sandblasting and acid-etching and with higher values obtained in the group treated by acid-etching and anodizing. There were statistically significant differences between batches of implants from all companies assessed, indicative of a substantial variance in implant topography from one batch to another. Conclusions: The low values of roughness found in the measurements and the differences between the values of the batches suggest that these companies should consider improving their surface treatments to achieve more uniform roughness. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the air powder abrasive treatment as an implant surface cleaning method for peri-implantitis based on the existing literature. Materials and Methods: A PubMed search was conducted to find articles that reported on air powder abrasive treatment as an implant surface cleaning method for peri-implantitis. The studies evaluated cleaning efficiency and surface change as a result of the method. Furthermore, cell response toward the air powder abrasive-treated discs, reosseointegration, and clinical outcome after treatment is also reported. Results: The PubMed search resulted in 27 articles meeting the inclusion criteria. In vitro cleaning efficiency of the method is reported to be high. The method resulted in minor surface changes on titanium specimens. Although the air powder abrasive-treated specimens showed sufficient levels of cell attachment and cell viability, the cell response decreased compared with sterile discs. Considerable reosseointegration between 39% and 46% and improved clinical parameters were reported after treatment when applied in combination with surgical treatment. The results of the treatment are influenced by the powder type used, the application time, and whether powder was applied surgically or nonsurgically. Conclusion: The in vivo data on air powder abrasive treatment as an implant surface cleaning method is not sufficient to draw definitive conclusions. However, in vitro results allow the clinician to consider the method as a promising option for implant surface cleaning in periimplantitis treatment. [ABSTRACT FROM AUTHOR]

Purpose: To compare the metabolic activity at the bone-implant interface of implants with machined and rough surfaces using bone scintigraphy during the in vivo process of osseointegration in a rabbit model, as well to establish a correlation between activity index (AI) and the bone-implant contact percentage (%BIC). Materials and Methods: Twenty-four implants were placed (12 with a machined surface and 12 with a rough titanium oxide surface) in 12 New Zealand White rabbits. Preoperatively and during the postoperative period (at 15 days and at monthly intervals), animals underwent bone scintigraphy with technetium 99m-methylene diphosphate (Tc-99m-MDP), and the AI for each implant was calculated by planar and pinhole collimator scintigraphy. A total of 240 AIs were obtained; after animal sacrifice at 105 days postsurgery, the %BIC was measured by scanning electron microscopy in 10 samples of each implant surface type. Results: The activity-time curve showed a similar morphology for both implant types and both scintigraphy techniques. The maximum mean AI appeared after 15 days of implantation and was higher in machined implants. Significant differences were not found in the %BIC according to implant type. A significant correlation between the mean activity registered in the first postoperative scintigraph and the mean %BIC at the end of the study was observed for machined implants only. Conclusions: Tc-99m-MDP is useful for the assessment of osseous metabolic activity associated with different microsurfaces. The association between mean AI and %BIC was only demonstrated for machined implants in the first postoperative scintigraphy image. [ABSTRACT FROM AUTHOR]

Purpose: This paper reports on an in vitro comparison of osteoblast and mesenchymal stem cell (MSC) adhesion, proliferation, and differentiation related to two different surface treatments applied to the same implant design to determine whether the interaction between cells and implants is influenced by surface structure and chemical composition of the implants. Materials and Methods: Thirty-nine implants with a sandblasted (SB) surface and 39 implants with a grit-blasted and high-temperature acid-etched (GBAE) surface were used. The implant macrostructures and microstructures were analyzed by high- and low-voltage scanning electron microscopy (SEM) and by stereo-SEM. The surface chemical composition was investigated by energy dispersive analysis and x-ray photoemission spectroscopy. SaOS-2 osteoblasts and human MSCs were used for the evaluation of cell proliferation and alkaline phosphatase enzymatic activity in contact with the two surfaces. Results: The GBAE surface showed fewer contaminants and a very high percentage of titanium (19.7%) compared to the SB surface (14.2%). The two surfaces showed similar mean roughness (Ra), but the depth (Rz) and density (RSm) of the porosity were significantly increased in the GBAE surface. The GBAE surface presented more osteoblast and MSC proliferation than the SB surface. No statistically significant differences in alkaline phosphatase activity were found between surfaces for either cellular line. Conclusions: The GBAE surface showed less surface contaminants and a higher percentage of titanium (19.7%) than the SB surface. The macro/micropore structured design and chemical composition of the GBAE surface allowed greater cell adhesion and proliferation and an earlier cell spreading but did not play an obvious role in in vitro cellular differentiation. [ABSTRACT FROM AUTHOR]

Purpose: Immediate loading is among the most innovative techniques in implant therapy today. This pilot study investigates the biomechanical outcome of various designs and surfaces that claim to shorten implant treatment. Materials and Methods: In each quadrant of two mongrel dogs, four different implants were used for immediate loading. The following implants were placed 3 months after tooth extraction: screw with low thread profile and anodic oxidized surface (LPAOS), solid screw with wide thread profile and titanium plasma spray coating (WPTPS), screw with low profile and hybrid design of double-etched and machined surface (LPHES), and screw with two thread profiles and a sandblasted and acid-etched surface (DTSAE). The insertion torque of each implant was above 35 Ncm. Resonance frequency analysis was performed after implant placement and again after sacrifice. Additionally, the removal torque and the amount of embedded titanium particles in the peri-implant bone were measured. Results: All 16 prostheses were functional after a 5-month loading period. The highest mean removal torque values were recorded with WPTPS implants (24.4 Ncm/mm), followed by DTSAE implants (22.3 Ncm/mm) and LPAOS implants (18.7 Ncm/mm); the lowest score was obtained by LPHES (12.0 Ncm/mm). The ISQ values increased between the time of surgery and recall for all systems on average, but a significant positive correlation was found for DTSAE only. Significantly higher amounts of titanium were found in the surrounding bone with WPTPS (0.76%) and LPAOS (0.41%) in comparison with DTSAE (0.10%) and LPHES (0.03%). Conclusion: Immediate loading is possible with various designs and surfaces if high primary stability can be achieved during implant placement. [ABSTRACT FROM AUTHOR]

Purpose: To compare the time-dependent cumulative survival rates of smooth- and rough-surface dental implants. Materials and Methods: A retrospective chart review was conducted for two time periods: January 1, 1991, through December 31, 1996, during which smooth-surface implants were used, and January 1, 2001, through December 31, 2005, during which rough-surface implants were used. This study included all implants placed and restored in one institution during the two time frames. Data were collected relative to patient age, gender, implant diameter, implant length, and anatomic location of implants. To facilitate the comparison, implants from the first and second time periods were followed through mid-1998 and mid-2007, respectively. Associations of patient/implant characteristics with implant survival were evaluated using marginal Cox proportional hazards models (adjusted for age and gender) and summarized with hazard ratios and corresponding 95% confidence intervals. Results: A total of 593 patients (322 women and 271 men; mean age, 51.3 ± 18.5 years) received 2,182 smooth-surface implants between 1991 and 1996, while 905 patients (539 women and 366 men; mean age, 48.2 ± 17.8 years) received 2,425 rough-surface implants between 2001 and 2005. At 5 years after implant placement, survival rates were 94.0% and 94.5%, respectively, for smooth- and rough-surface implants (difference not significant). Among the smooth implants, implant length ≤ = 10 mm and anatomic location were identified as significantly associated with implant failure. In contrast, among the rough implants, implant length ≤ = 10 mm and anatomic location were not identified as risk factors for implant failure. Conclusions: Based on this retrospective study of two groups of patients with different implant surfaces and more than 2,000 implants in each group, there was no significant difference in the survival rates of smooth- and rough-surface dental implants. Anatomic location and implant length ≤ = 10 mm were associated with failures of the smooth-surface implants only. [ABSTRACT FROM AUTHOR]

Purpose: The use of nanotechnology to enhance endosseous implant surfaces may improve the clinical control of inter facial osteoblast biology. This study investigated the influence of a nanostructure-coated implant surface on osteoblast differentiation and its effects on bone-to-implant contact (BIC) and removal torque values. Materials and Methods: Titanium disks were machined (M) or machined and subsequently treated by acid etching (Ac) or by dipping in an aluminum oxide solution (Al2O3). Surfaces were characterized by scanning electron microscopy, atomic force microscopy, and x-ray microanalysis. For the in vitro experiment, rat mesenchymal stem cells (rMSCs) were grown in osteogenic supplements on the disk surfaces for 3 days. Real-time polymerase chain reaction (PCR) was used to measure mRNA levels of several gene products (bone sialoprotein, osteocalcin, osteopontin, and RUNX-2). For the in vivo experiment, titanium implants were placed in rat tibiae and harvested after 3 to 21 days for measurement of bone-specific mRNA levels by real-time PCR. Removal torque and BIC were measured 3 to 56 days after placement. Results: Average height deviation (Sa, in nm) values for M, Ac, and Al2O3 implants were 86.5, 388.4, and 61.2, respectively. Nanostructured Al2O3 topographic features applied to machined implants promoted MSC commitment to the osteoblast phenotype. Greater bone-specific gene expression was observed in tissues adjacent to Al2O3 implants, and associated increases in BIC and torque removal were noted. Conclusion: Nanostructured alumina may directly influence cell behavior to enhance osseointegration. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this in vitro study of titanium abutments was to investigate the extent of treatment traces, the roughness depth, and the quantity of titanium or, in the case of coated abutments, titanium nitride (TiN) removed from the surface after treatment with various instruments. Materials and Methods: Eleven uncoated, mechanically smoothed abutments and 11 TiN-coated abutments were used. The abutments were treated with titanium, steel, and plastic curettes; a rubber cup; an ultrasonic scaler with a steel tip; and an air scaler and cleaning powder. There were two 2 × 2-mm test fields on each abutment; each was subjected to standardized treatment with an instrument. The untreated surfaces of each abutment served as controls. The roughness depth (Rz) and profile height of treated and untreated surfaces were measured with a profilometer; profile height served as a basis for determining the amount of substance removed by treatment. The treatment traces were analyzed by scanning electron microscopy and light microscopy. Results: Both the ultrasonic scaler and the steel and titanium curettes left pronounced traces on the uncoated abutments and increased Rz. Substantial substance removal was recorded following the use of the ultrasonic scaler (17.57 ± 2.87 μm) and the steel curettes (8.48 ± 2.81 μm) on the uncoated abutments. In tests of the coated abutments, measurable substance removal (4.80 ± 0.99 μm) and increased roughness depth were noted only with use of the steel curettes. The treatment traces left by the other instruments were distinctly less pronounced than on the uncoated abutments. Light microscopy revealed detachment of the TiN coating after use of the ultrasonic scaler, titanium curettes, and steel curettes. Slight to moderate treatment traces were recorded after use of the rubber cup; no substance removal was observed. On the TiN-coated abutments, only slight treatment traces, if any, were recorded, and there was no substance removal. A planing effect (ie, an Rz decrease of 66.4%) was observed. The plastic curette and the air scaler caused no damage to the titanium or TiN surfaces. Discussion and Conclusion: The TiN-coated abutments displayed fewer treatment traces, less roughness depth, and less substance removal after being treated with various instruments. Two concerns, however, are the detachment of the coating after only few actions with steel and titanium curettes or with an ultrasonic scaler with steel tip, and the greater initial roughness depth of coated implants. [ABSTRACT FROM AUTHOR]

Purpose: Implant surface decontamination is one of the main goals in the treatment of peri-implantitis. The purpose of the study was to demonstrate possible alterations of different implant surfaces after laser irradiation using the CO2- and Nd:YAG lasers. Materials and Methods: Three different types of titanium implants (sandblasted, plasma sprayed, HA-coated) were exposed to different laser types (CO2 and Nd:YAG) at different power settings (2.0, 4.0, and 6.0 W). The CO2 laser was applied in the pulsed or continuous mode; the Nd:YAG laser was used in the pulsed mode. SEM was used to examine the laser-treated surfaces. Results: The SEM examination showed that the pulsed or continuous mode of the noncontact CO2 laser with power settings between 2.0 and 6.0 W did not modify the implant surface, regardless of implant type. The contact pulsed Nd:YAG-laser produced extensive alterations and melting of the implant surface in all types of implants using low or high power settings (2. 0 to 6.0 W). Conclusion: The pulsed Nd:YAG laser should be avoided for clinical use in the peri-implant tissues because of the damage and modification of the retentive implant surface. In contrast, the CO2 laser could not modify the implant surface at the power settings used here and may be applied in cases of peri-implant pathology without limitations. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to conduct a comparative histometric analysis of bone-implant interface between a rough titanium surface and smooth implants in low-density human jawbone after 3, 6, and 12 months of submerged, undisturbed healing. Six adult volunteer patients undergoing standard implant placement were enrolled in this project. Each patient received 1 smooth and 1 rough implant. After 3, 6, and 12 months, the implants were harvested for histometric analysis. The values of boneimplant contact were the following: 3 months smooth 6.2%, 3 months rough 58.9%, 6 months smooth 3.55%, 6 months rough 72.9%, 12 months smooth 6.7%, and 12 months rough 76.75%. The results showed that in low-density bone the rough surface dramatically enhanced the amount of bone-toimplant contact. Because of the small number of implants examined, definite conclusions cannot be drawn, even though the statistical analysis showed significant differences between the smooth and rough groups (P = .0129; F = 76.065). Nevertheless, a trend was evident in these observations: while a rough implant surface may enhance the rate of osseointegration, it is not able to significantly change the bone density, and an implant placed in low-density bone is at a higher risk of failure when occlusal loading begins. [ABSTRACT FROM AUTHOR]

The aim of this in vitro study using implants and abutments was to examine traces left by various cleaning instruments and to determine the quantity of substance removal. The implants and relevant abutments were Screw-Vent implants (Dentsply), titanium plasma-coated full-screw implants (Straumann), and standard Brånemark implants (Nobel Biocare). The instruments used were titanium curettes, Gracey curettes, plastic curettes, rubber cups with Zircate prophy paste, the Cavitron Jet ultrasonic scaler with universal inserts and airpolishing nozzles with Prophy-Jet cleaning powder, and the Densonic sonic scaler with SofTip disposable prophy tips and universal tips. Two test fields (2 X 2 mm) on the respective implant head and abutment underwent standard treatment with each instrument. With the full-screw implants, an additional two test fields were examined from the transition of the titanium plasma coating to the implant head. Untreated implants and abutment surfaces served as controls. The treated and untreated surfaces were examined by scanning electron microscopy for work traces and by optical laser profilometry for substance removal. The results showed that the Cavitron Jet ultrasonic unit, the Densonic sonic scaler with universal tips, and the Gracey curette left pronounced traces and induced high substance removal. The titanium curette and the Densonic sonic scaler with SofTip disposable prophy tips left virtually no traces and removed very little substance. The rubber cup, the plastic curette, and the Cavitron Jet airpolishing system left the implant surfaces unchanged. All instruments apart from the rubber cup and Cavitron Jet airpolishing system left pronounced traces at the transition of the implant head to the titanium plasma coating of the full-screw implants. The Cavitron Jet airpolishing system, the rubber cup, the plastic curette, and, with some reservations, the Densonic sonic scaler with SofTip plastic fittings and the titanium curette, appear to be suitable for cleaning implant surfaces. [ABSTRACT FROM AUTHOR]

Between January 1992 and October 1992, 100 Minimatic screw implants made of titanium alloy with rough acid-etched surfaces were placed in 63 consecutive partially edentulous patients. At second-stage (uncovering) surgery performed after a 4- to 6-month healing period, none of the implants showed any signs of mobility, peri-implant infection, or bone loss. After an additional healing phase averaging 2 weeks, the patients were restored with fixed prostheses. Patients were reexamined every 3 months for 1 year, with all 63 patients available for evaluation during this period. Periapical radiographs were taken preoperatively, immediately after surgery, and at 6 and 12 months after implantation. There were no signs of peri-implant radiolucencies in any of the implants, and alveolar bone loss was less than 1 mm on average 1 year after implantation. Based on Plaque Index, sulcular bleeding index, pocket probing depth, attachment level, width of keratinized mucosa, and hand-tested mobility, 99 implants were considered successful and 1 (which developed peri-implant infection) was considered a failure. Study results substantiate other reports that implants with a rough surface can yield predictable good results. [ABSTRACT FROM AUTHOR]