Implant Surface Decontamination Research Articles

Successful Surgical Protocols in the Treatment of Peri-Implantitis: A Narrative Review of the Literature.

The aim was to identify and evaluate those surgical protocols reporting on positive clinical outcomes for treating peri-implantitis with 12 or more months of follow-up. Method of surface decontamination (SDC) was evaluated for any correlation with outcomes. A literature search was performed of all articles published in English between January 1, 2001 and April 30, 2015. Of the 639 identified, 26 satisfied the inclusion criteria. Outcomes reported on included reductions in bleeding on probing (BoP) and probing depth (PD), mean radiographic bone fill (RBF), and mean change in marginal soft tissue levels (MR±). Methods of SDC included mechanical debridement (MD) with and without saline use, MD plus laser or photodynamic therapy, MD with air powder abrasion, MD with chemotherapeutic implant surface decontamination, and combination approaches. The results suggested that various methods of SDC were effective. Heterogeneity of the studies made it impossible to determine correlations between clinical outcome and SDC method. Most studies over 12 months reporting better treatment outcomes employed a bone replacement. Additionally, studies where patients with periodontitis were treated before their peri-implantitis care also had better outcomes. The current review failed to reveal any correlation between any particular method for SDC or defect treatment protocol and positive clinical outcomes. Further comparative studies are warranted to determine the most appropriate approach for both of these topics.

Laser therapy in peri-implantitis treatment: literature review

Peri-implantitis is the most common reason for a late failure and can occur even after years of successful osseointegration. The role of microbial plaque accumulation in the development of peri-implantitis has been well documented. On the other hand, the ideal method of implant surface decontamination to re-establish the health of peri-implant tissue remains to be determined. Removal of bacterial deposits is essential in the treatment of peri-implant infections, and various therapeutic approaches have been described in the literature, including mechanical debridement, disinfection with chemotherapeutic agents, and laser therapy. Recently, there has been a plenitude of scientific data regarding the use of laser irradiation to achieve titanium surface decontamination. Thus, research is focusing on lasers' potential use in the treatment of peri-implantitis. The aim of this literature review is to analyze and evaluate the efficacy of laser therapy for the treatment of peri-implantitis.

Adjunctive Systemic and Local Antimicrobial Therapy in the Surgical Treatment of Peri-implantitis

The aim of the present randomized controlled clinical trial was to investigate the adjunctive effect of systemic antibiotics and the local use of chlorhexidine for implant surface decontamination in the surgical treatment of peri-implantitis. One hundred patients with severe peri-implantitis were recruited. Surgical therapy was performed with or without adjunctive systemic antibiotics or the local use of chlorhexidine for implant surface decontamination. Treatment outcomes were evaluated at 1 y. A binary logistic regression analysis was used to identify factors influencing the probability of treatment success, that is, probing pocket depth ≤5 mm, absence of bleeding/suppuration on probing, and no additional bone loss. Treatment success was obtained in 45% of all implants but was higher in implants with a nonmodified surface (79%) than those with a modified surface (34%). The local use of chlorhexidine had no overall effect on treatment outcomes. While adjunctive systemic antibiotics had no impact on treatment success at implants with a nonmodified surface, a positive effect on treatment success was observed at implants with a modified surface. The likelihood for treatment success using adjunctive systemic antibiotics in patients with implants with a modified surface, however, was low. As the effect of adjunctive systemic antibiotics depended on implant surface characteristics, recommendations for their use in the surgical treatment of peri-implantitis should be based on careful assessments of the targeted implant (ClinicalTrials.gov NCT01857804).

Identification of Enterococcus Faecalis and Pseudomonas Aeruginosa on and in Implants in Individuals with Peri-implant Disease: A Cross-Sectional Study.

To verify whether the parts of dental implants can be contaminated by opportunistic pathogens. In this cross-sectional study, 38 individuals (52 implants) were investigated. Samples for microbiologic analysis (for a total of 180 sites) were obtained from each individual, from three types of sites in the following order: (1) the peri-implant sulcus of each implant, (2) the gingival sulcus of adjacent teeth, and (3) inside the implant-abutment connection and the abutment of each implant. Swabs from the oral mucosa (cheeks, tongue, and pharynx) were also collected. Quantitative real-time polymerase chain reaction was carried out for total bacterial counts of Enterococcus faecalis and Pseudomonas aeruginosa. Two-way analysis of variance (sites, species) and Holm-Sidak tests were used for statistical analyses. No opportunistic bacteria were found in the gingival sulcus specimens (38 sites). E faecalis was detected in the peri-implant sulcus (3 of 52 sites) and the inner connection/abutment portion (3 of 52 sites). P aeruginosa was identified only in the oral mucosa swabs (1 of 38 sites) and represented the highest bacterial number (3.5 × 10⁶). Statistically significant differences were only found between species and in the peri-implant sulcus. Within the limitations of this study, significant differences in the presence and levels of nosocomial bacteria were detected in the peri-implant environment of diseased implants. From a clinical point of view, data from this study might suggest that, in patients affected by peri-implantitis, prostheses should be removed and the implant-abutment connection disinfected routinely, along with implant surface decontamination.

Effects of decontamination solutions on the surface of titanium: investigation of surface morphology, composition, and roughness.

To investigate the impact of treatments used to detoxify dental implants on the oxide layer morphology and to infer how changes in morphology created by these treatments may impact re-osseointegration of an implant. Pure titanium (cpTi) and the alloy Ti6Al4V were subjected to a series of chemical treatments and mechanical abrasion simulating surface decontamination of dental implants. The morphology and roughness of the surface layer before and after treatment with these solutions were investigated with optical and atomic force microscopy (OM, AFM). The solutions employed are typically used for detoxification of dental implants. These included citric acid, 15% hydrogen peroxide, chlorhexidine gluconate, tetracycline, doxycycline, sodium fluoride, peroxyacetic acid, and treatment with carbon dioxide laser. The treatments consisted of both immersions of samples in solution and rubbing with cotton swabs soaked in solution for 1, 2, and 5 min. Cotton swabs used were analyzed with energy dispersive spectroscopy (EDS). The microscopy investigation showed that corrosion and pitting of the samples were present in both metal grades with immersion and rubbing methods when employing more acidic solutions, which had pH <3. Mildly acidic solutions caused surface discoloration when coupled with rubbing but did not cause corrosion with immersion. Neutral or basic treatments resulted in no signs of corrosion with both methods. EDS results revealed the presence of titanium particles on all rubbing samples. It was demonstrated in this study that acidic environments coupled with rubbing are able to introduce noticeable morphological changes and corrosion on the surface of both titanium grades.

Clinical Outcomes of Using Lasers for Peri‐Implantitis Surface Detoxification: A Systematic Review and Meta‐Analysis

The aim of this systematic review is to compare the clinical outcomes of lasers with other commonly applied detoxification methods for treating peri-implantitis. An electronic search of four databases and a hand search of peer-reviewed journals for relevant articles were conducted. Comparative human clinical trials and case series with ≥ 6 months of follow-up in ≥ 10 patients with peri-implantitis treated with lasers were included. Additionally, animal studies applying lasers for treating peri-implantitis were also included. The included studies had to report probing depth (PD) reduction after the therapy. Seven human prospective clinical trials and two animal studies were included. In four and three human studies, lasers were accompanied with surgical and non-surgical treatments, respectively. The meta-analyses showed an overall weighted mean difference of 0.00 mm (95% confidence interval = -0.18 to 0.19 mm) PD reduction between the laser and conventional treatment groups (P = 0.98) for non-surgical intervention. In animal studies, laser-treated rough-surface implants had a higher percentage of bone-to-implant contact than smooth-surface implants. In a short-term follow-up, lasers resulted in similar PD reduction when compared with conventional implant surface decontamination methods.

Management of peri-implant mucositis and peri-implantitis.

Peri-implant diseases are defined as inflammatory lesions of the surrounding peri-implant tissues and include peri-implant mucositis (an inflammatory lesion limited to the surrounding mucosa of an implant) and peri-implantitis (an inflammatory lesion of the mucosa that affects the supporting bone with resulting loss of osseointegration). This review aims to describe the different approaches to manage both entities and to provide a critical evaluation of the evidence available on their efficacy. Therapy of peri-implant mucositis and nonsurgical therapy of peri-implantitis usually involve mechanical debridement of the implant surface using curettes, ultrasonic devices, air-abrasive devices or lasers, with or without the adjunctive use of local antibiotics or antiseptics. The efficacy of these therapies has been demonstrated for mucositis: controlled clinical trials show an improvement in clinical parameters, especially in bleeding on probing. For peri-implantitis, the results are limited, especially in terms of probing pocket-depth reduction. Surgical therapy of peri-implantitis is indicated when nonsurgical therapy fails to control the inflammatory changes. Selection of the surgical technique should be based on the characteristics of the peri-implant lesion. In the presence of deep circumferential and intrabony defects, surgical interventions should aim to provide thorough debridement, implant-surface decontamination and defect reconstruction. In the presence of defects without clear bony walls or with a predominant suprabony component, the aim of the surgical intervention should be the thorough debridement and the repositioning of the marginal mucosa to enable the patient to perform effective oral-hygiene practices, although this aim may compromise the esthetic result of the implant-supported restoration.

Implant decontamination with 2% chlorhexidine during surgical peri-implantitis treatment: a randomized, double-blind, controlled trial.

The objective of this randomized, double-blind, controlled trial was to evaluate the clinical, radiographic, and microbiological effects of implant surface decontamination with a 2% chlorhexidine (CHX) solution in comparison with a 0.12% chlorhexidine+0.05% cetylpyridinium chloride (CPC) solution during resective surgical peri-implantitis treatment. Forty-four patients (108 implants) with peri-implantitis were treated with resective surgical treatment consisting of bone re-contouring, surface debridement and chemical decontamination, and apically repositioned flap. Patients were randomly allocated to decontamination with a 2% CHX solution (test group) or 0.12% CHX+0.05% CPC (control group). Clinical and radiographic parameters were recorded before treatment (baseline), and at 3, 6, and 12months after treatment. Microbiological parameters were recorded during surgery. Multilevel analysis showed no significant differences in bleeding, suppuration, probing pocket depth, and radiographic bone loss between control and test group over three follow-up measurements (3, 6, and 12months) from baseline. Both decontamination procedures resulted in significant reductions in anaerobic bacterial counts on the implant surface, but no significant difference was noted between control and test group (mean log 3.37±2.34 vs. 3.65±2.87, P=0.99). The use of a 2% CHX solution for implant surface decontamination during resective peri-implantitis therapy does not lead to improved clinical, radiographic, or microbiological results compared with a 0.12% CHX+0.05% CPC solution. Overall, the additional use of CHX reduces anaerobic bacterial load on the implant surface better than mechanical debridement alone, but does not seem to enhance clinical treatment outcomes (ClinicalTrials.gov number NCT01852253).

In vitro cleaning potential of three different implant debridement methods

To assess the cleaning potential of three different instrumentation methods commonly used for implant surface decontamination in vitro, using a bone defect-simulating model. Dental implants were stained with indelible ink and mounted in resin models, which represented standardized peri-implantitis defects with different bone defect angulations (30, 60 and 90°). Cleaning procedures were performed by either an experienced dental hygienist or a 2nd-year postgraduate student. The treatment was repeated 20 times for each instrumentation, that is, with a Gracey curette, an ultrasonic device and an air powder abrasive device (PAD) with glycine powder. After each run, implants were removed and images were taken to detect color remnants in order to measure planimetrically the cumulative uncleaned surface area. SEM images were taken to assess micromorphologic surface changes (magnification 10,000 ×). Results were tested for statistical differences using two-way ANOVA and Bonferroni correction. The areas of uncleaned surfaces (%, mean ± standard deviations) for curettes, ultrasonic tips, and airflow accounted for 24.1 ± 4.8%, 18.5 ± 3.8%, and 11.3 ± 5.4%, respectively. These results were statistically significantly different (P < 0.0001). The cleaning potential of the airflow device increased with wider defects. SEM evaluation displayed distinct surface alterations after instrumentation with steel tips, whereas glycine powder instrumentation had only a minute effect on the surface topography. Within the limitations of the present in vitro model, airflow devices using glycine powders seem to constitute an efficient therapeutic option for the debridement of implants in peri-implantitis defects. Still, some uncleaned areas remained. In wide defects, differences between instruments are more accentuated.

The use of laser therapy for dental implant surface decontamination: a narrative review of in vitro studies

The aim of this narrative review was to critically evaluate in vitro studies assessing the efficacy of lasers in the bacterial decontamination of titanium implant surfaces. The MEDLINE, Web of Knowledge and Embase electronic databases were used to search for articles relating to the use of lasers in the bacterial decontamination of titanium specimen surfaces using predetermined search statements. Clinical studies, case reports, case series, review articles and animal models were excluded. Study selection was carried out independently and then cross-checked by two authors through abstract viewing. Eighteen articles were selected for full-text analysis. Erbium-doped yttrium-aluminium-garnet lasers had a wide range of powers capable of inducing bacterial decontamination. While carbon dioxide and gallium-aluminium-arsenide diode lasers demonstrated the ability to produce bacterial decontamination, the bacterial sensitivity to each varied depending on the species involved. There is no concensus on the laser type or settings that are optimal for bacterial decontamination of titanium implant surfaces as studies employ various test specimens, contamination methodologies, irradiation settings and protocols, and outcome measures resulting in limited study comparability. More investigations are required to provide guidelines for the use of laser therapy in the decontamination of implant surfaces.

Laser Therapy as an Effective Method for Implant Surface Decontamination: A Histomorphometric Study in Rats

To the best of the authors' knowledge, a standard protocol for treating peri-implantitis is not yet established. A total of 150 titanium disks with smooth or rough surfaces contaminated with microbial biofilm were implanted subcutaneously in rats after undergoing one of three treatments: 1) low-intensity laser (LIL); 2) antimicrobial photodynamic therapy (aPDT); or 3) toluidine blue O (TBO). Sterile and contaminated disks served as negative (NC) and positive (C) control groups, respectively. After days 7, 28, and 84, tissue inflammation was evaluated microscopically by measuring the density of collagen fibers (degree of fibrosis) and concentration of polymorphonuclear neutrophils. Surface texture did not affect the degree of inflammation, but the area of reactive tissue was significantly greater for rough implants (2.6 ± 3.7 × 10(6) µm(2)) than for smooth ones (1.9 ± 2.6 × 10(6) µm(2); P = 0.0377). Group C presented the lowest and group NC presented the highest degree of fibrosis with significance only after day 7; these groups had the highest and lowest scores, respectively, for degree of inflammation. Group C showed the largest area of reactive tissue (9.11 ± 2.10 × 10(6) µm(2)), but it was not significantly larger than group LIL (P = 0.3031) and group TBO (P = 0.1333). Group aPDT showed the smallest area (4.34 ± 1.49 × 10(6) µm(2)) of reactive tissue among the treatment groups. After day 28, groups LIL, aPDT, TBO, and C resembled group NC in all the studied parameters. Group aPDT showed more favorable results in parameter area of reactive tissue than the other methods after day 7, but over longer time periods all methods produced outcomes equivalent to sterile implants.

The use of porous titanium granules for treatment of peri-implantitis lesions: preliminary clinical and radiographic results in humans

The aim of the present study is to report on preliminary clinical and radiographic results of using porous titanium granules for treatment of peri-implantitis lesions. A retrospective cohort of 18 implants presenting with peri-implantitis in 16 consecutive patients from two private practices had been evaluated. Treatment included open flap debridement of the lesion, implant surface decontamination using tetracycline, filling of the defect with porous titanium granules and apically positioning of the flaps. Patients' demographics, site and implant characteristics, as well as clinical and radiographic evaluation as baseline and time of follow-up were recorded. Patients' age ranged from 44 to 79 years with a mean of 61.3 ± 9.5 years. Follow-up time after treating peri-impantitis lesions ranged from 6 to 15 months (mean 7.5 ± 3.9). Two out of the 18 implants still presented with bleeding and suppuration at follow-up and thus the treatment was considered as a failure. This resulted in an overall success rate of 88% for the treatment. Mean bone loss prior to treatment was 4.4 ± 2.1 mm and was reduced following treatment to 2.3 ± 2.1 mm. The use of porous titanium granules might be a viable treatment option in cases of peri-implantitis lesions. Further large-scale long-term studies are warranted in order to assess the additional benefit from this treatment option compared to other available alternatives. assiduous.

Decontamination of dental implant surface in peri-implantitis treatment: a literature review.

Etiological treatment of peri-implantitis aims to reduce the bacterial load within the peri-implant pocket and decontaminate the implant surface in order to promote osseointegration. The aim of this literature review was to evaluate the efficacy of different methods of implant surface decontamination. A search was conducted using the PubMed (Medline) database, which identified 36 articles including in vivo and in vitro studies, and reviews of different decontamination systems (chemical, mechanical, laser and photodynamic therapies). There is sufficient consensus that, for the treatment of peri-implant infections, the mechanical removal of biofilm from the implant surface should be supplemented by chemical decontamination with surgical access. However, more long-term research is needed to confirm this and to establish treatment protocols responding to different implant characterics. Key words:Peri-implantitis, treatment, decontamination, implant surface, laser.

Implant decontamination during surgical peri‐implantitis treatment: a randomized, double‐blind, placebo‐controlled trial

The objective of this randomized, double-blind, placebo-controlled trial was to study the effect of implant surface decontamination with chlorhexidine (CHX)/cetylpyridinium chloride (CPC) on microbiological and clinical parameters. Thirty patients (79 implants) with peri-implantitis were treated with resective surgical treatment consisting of apically re-positioned flap, bone re-contouring and surface debridement and decontamination. Patients were randomly allocated to decontamination with 0.12% CHX+0.05% CPC (test-group) or a placebo-solution (without CHX/CPC, placebo-group). Microbiological parameters were recorded during surgery; clinical and radiographical parameters were recorded before (pre-) treatment (baseline), and at 3, 6 and 12months after treatment. Nine implants in two patients in the placebo-group were lost due to severe persisting peri-implantitis. Both decontamination procedures resulted in significant reductions of bacterial load on the implant surface, but the test-group showed a significantly greater reduction than the placebo-group (log 4.21±1.89 versus log 2.77±2.12, p=0.006). Multilevel analysis showed no differences between both groups in the effect of the intervention on bleeding, suppuration, probing pocket depth and radiographical bone loss over time. Implant surface decontamination with 0.12% CHX+0.05% CPC in resective surgical treatment of peri-implantitis leads to a greater immediate suppression of anaerobic bacteria on the implant surface than a placebo-solution, but does not lead to superior clinical results. The long-term microbiological effect remains unknown.

Surgical therapy for the control of peri‐implantitis

Articles on surgical treatment of peri-implantitis in humans published up to December 2011 were included. Twenty-six studies were selected, thus limiting the available evidence. There is marked heterogeneity between study designs and case definitions for peri-implantitis in the studies cited, limiting the generalization of the reported results. Adjunctive systemic antibiotics were used in most studies, but no study evaluated the adjunctive benefit of systemic antibiotics. Access flap surgery, removal of granulation tissue and implant surface decontamination has been demonstrated to decrease plaque index, BOP, suppuration, probing depths and to arrest bone loss for 58% of implant sites over 5 years. Laser treatment of the exposed implant surface during surgery was not shown to be beneficial. Available data indicate that it is possible to obtain defect fill of peri-implantitis defects following surgical-treatment modalities with concomitant placement of bone or bone substitutes in such defects. However, there is lack of evidence that placement of membranes in addition to grafting procedures provides any additional defect fill. Surgical therapy for treating peri-implantitis is a predictable method for treating peri-implant disease and patients receiving this therapy have benefited from it in the short term.

Machined titanium disc decontamination using photodynamic therapy: an in vitro study

ObjectiveThis study investigated less invasive protocols that do not injure peri-implant tissues during implant surface decontamination and evaluated, in vitro, the efficacyof microbiological decontamination of machined surface titanium discs with photodynamic therapy.MethodsForty eight titanium disc contaminated with 10μL of a Streptococcus sanguinis suspension were randomly divided into groups: 1) titanium disc contaminated with Ss (titanium disc suspension) without treatment; 2) titanium disc suspension rinsed with saline solution; 3) titanium disc suspension rinsed with 0.2% chlorhexidine digluconate; 4) titanium disc suspension treated with Photosensitizer Methilene Blue; 5) titanium disc suspension treated with Photosensitizer Methilene Blue associated with laser diode; 6) titanium disc suspension treated with diode laser. After the treatments, the titanium disc were submersed in 3mL of sterile brain-heart infusion broth under aerobic conditions at 37ºC for 48 hours. Three petri plates were seeded per sample and maintained under aerobic conditions at 37ºC for 48 hours, after which the number of colony forming units per milliliter was counted.ResultsThe Kruskal-Wallis test complemented by Dunn test showed that chlorhexidine digluconate eliminated titanium disc contamination (p&lt;0.05). All the other groups (2, 4, 5, 6) had fewer colony-forming units than group 1 (p&lt;0.05).ConclusionWithin the limitations of this study, Photodynamic Therapy reduced titanium disc contamination but was not better than 0.2 % chlorhexidine digluconate rinsing.Indexing terms: Chlorhexidine. Implant. Laser. Titanium.

Decontamination of dental implant surfaces by means of photodynamic therapy

Several implant surface debridement methods have been reported for the treatment of peri-implantitis, however, some of them can damage the implant surface or promote bacterial resistance. Photodynamic therapy (PDT) is a new treatment option for peri-implantitis. The aim of this in vitro study was to analyze implant surface decontamination by means of PDT. Sixty implants were equally distributed (n = 10) into four groups and two subgroups. In group G1 there was no decontamination, while in G2 decontamination was performed with chlorhexidine. G3 (PDT − laser + dye) and G4 (laser, without dye) were divided into two subgroups each; with PDT performed for 3 min in G3a and G4a, and for 5 min in G3b and G4b. After 5 min in contact with methylene blue dye (G3), the implants were irradiated (G3 and G4) with a low-level laser (GaAlAs, 660 nm, 30 mW) for 3 or 5 min (7.2 and 12 J). After the dilutions, culture media were kept in an anaerobic atmosphere for 1 week, and then colony forming units were counted. There was a significant difference (p < 0.001) between G1 and the other groups, and between G4 in comparison with G2 and G3. Better decontamination was obtained in G2 and G3, with no statistically significant difference between them. The results of this study suggest that photodynamic therapy can be considered an efficient method for reducing bacteria on implant surfaces, whereas laser irradiation without dye was less efficient than PDT.

In situ dental implant installation after decontamination in a previously peri-implant diseased site: a pilot study

PurposeThe aim of this study was to examine whether a previous peri-implantitis site can affect osseointegration, by comparing implant placement at a site where peri-implantitis was present and at a normal bone site. A second aim of this study was to identify the tissue and bone reaction after treating the contaminated implant surface to determine the optimal treatment for peri-implant diseases.MethodsA peri-implant mucositis model for dogs was prepared to determine the optimal treatment option for peri-implant mucositis or peri-implantitis. The implants were inserted partially to a length of 6 mm. The upper 4 mm part of the dental implants was exposed to the oral environment. Simple exposure for 2 weeks contaminated the implant surface. After 2 weeks, the implants were divided into three groups: untreated, swabbed with saline, and swabbed with H2O2. Three implants from each group were placed to the full length in the same spot. The other three implants were placed fully into newly prepared bone. After eight weeks of healing, the animals were sacrificed. Ground sections, representing the mid-buccal-lingual plane, were prepared for histological analysis. The analysis was evaluated clinically and histometrically.ResultsThe untreated implants and H2O2-swabbed implants showed gingival inflammation. Only the saline-swabbed implant group showed re-osseointegration and no gingival inflammation. There was no difference in regeneration height or bone-to-implant contact between in situ implant placement and implant placement in the new bone site.ConclusionsIt can be concluded that cleaning with saline may be effective in implant decontamination. After implant surface decontamination, implant installation in a previous peri-implant diseased site may not interfere with osseointegration.

Anti‐infective surgical therapy of peri‐implantitis. A 12‐month prospective clinical study

The aim of this prospective cohort study was to evaluate an anti-infective surgical protocol for the treatment of peri-implantitis. Thirty-six implants in 24 partially dentate patients with moderate to advanced peri-implantitis were treated using an anti-infective surgical protocol incorporating open flap debridement and implant surface decontamination, with adjunctive systemic amoxicillin and metronidazole. Treatment outcomes were assessed at 3, 6 and 12months. Patient-based statistical analyses using multiple regression analyses were performed. There was 100% survival of treated implants at 12months. At 3months, there were statistically significant (P<0.01) reductions in mean probing depths (PD), Bleeding on Probing (BoP) and suppuration. The greater the mean PD at baseline, the greater the PD reduction at 3months. At 3months, there was also a significant mean facial mucosal recession of 1mm (P<0.001). All these changes were maintained at 6 and 12months. At 12months, all treated implants had a mean PD<5mm, while 47% of the implants had complete resolution of inflammation (BoP negative). At 12months, 92% of implants had stable crestal bone levels or bone gain. There were no significant effects of smoking on any of the treatment outcomes. For the treatment of peri-implantitis, an anti-infective protocol incorporating surgical access, implant surface decontamination and systemic antimicrobials followed by a strict postoperative protocol was effective at 3months with the results maintained for up to 12months after treatment.

Adsorption and photocatalytic degradation of human serum albumin on TiO 2 and Ag–TiO 2 films

Titanium dioxide is a useful material in the biomedical field as it has excellent biocompatibility based on its non-toxicity and non-inflammatory properties. Furthermore, TiO 2 can be excited by UV light to create charge carriers giving rise to photocatalytic redox reactions at the surface and photo-induced super-hydrophilicity. These properties might be exploited for surface decontamination of medical devices and implants. With this in mind, titanium dioxide TiO 2 films were prepared on stainless steel substrates using magnetron sputtering. Silver loaded (Ag–TiO 2) films were prepared by the photocatalytic reduction of Ag + from solution. The adsorption of human serum albumin (HSA) was studied. Surface analysis methods used included X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and atomic force microscopy (AFM). The TiO 2 films were predominantly anatase crystal phase and the photoreduced Ag was present at greater than 90% of the silver content as Ag 0 on the surface. Ag loading of the TiO 2 markedly enhanced the Raman signal (ca. 15-fold), but caused significant changes to the spectrum indicating non-specific binding of protein side chain residues to the Ag. The amide I and III modes remained well-resolved and were used to estimate the conformational change induced by the Ag. Raman analysis showed an increase in the intensity of the band at ∼1665 cm −1 assigned to the disordered conformation, suggesting that the adsorption to the Ag sites induces conformational changes in the protein. UVB irradiation of the protein contaminated surfaces caused further changes in the protein conformation, consistent with denaturation and enhanced binding and oxidation, thought to be induced through a photocatalytic mechanism.