In vitro studies on the effect of cleaning methods on different implant surfaces

The Effects of Ultrasonic Scaling and Air-Abrasive Powders on the Topography of Implant Surfaces: Scanning Electron Analysis and In Vitro Study

OBJECTIVES

 This in vitro study aimed to investigate the impact of bicarbonate air-abrasive powders and ultrasonic scaling with stainless steel tips on the micro- and nanotopography and roughness of three different implant-abutment junction titanium surfaces.

MATERIALS AND METHODS

 Three types of sterile and decontaminated titanium surfaces (RS, UTM, XA) were used for analysis. Nine disks per surface type were subjected to micro- and nanotopography analysis, scanning electron microscopy (SEM), roughness analysis, and fibroblast cultivation. Ultrasonic debridement and air polishing were performed on the surfaces. Human dermal fibroblasts were cultured on the surfaces for 5 days.

STATISTICAL ANALYSIS

 Data analysis adhered to ISO 25178 standards for surface texture assessment. SEM micrographs were used to reconstruct areas for extracting roughness parameters. Excel and Mex 6.0 software were utilized for quantitative and stereoscopic analysis.

RESULTS

 The study found varying effects on surface roughness posttreatment. RS Disco samples exhibited higher surface roughness compared with UTM and XA samples, both in average and nanoscale roughness. Decontamination led to increased surface roughness for all samples, particularly RS Disco. Fibroblast growth tests revealed enhanced cell network formation on decontaminated discs, possibly due to increased nanoscale roughness or the presence of bicarbonate salts.

CONCLUSION

 The study underscores the complex interplay between surface topography, microbial biofilm, and treatment efficacy in peri-implant disease management. While smoother surfaces may resist biofilm accumulation, increased nanoscale roughness postdecontamination can enhance fibroblast attachment and soft tissue integration. This dichotomy highlights the need for tailored treatment protocols that consider material-specific factors, emphasizing that successful implant therapy should balance microbial control with conducive surface characteristics for long-term osseointegration and soft tissue stability.

Efficacy of Biofilm Removal on the Dental Implant Surface by Sodium Bicarbonate and Erythritol Powder Airflow System

OBJECTIVE

 Peri-implantitis is a common complication in implant therapy and it is one of the main contributing factors to implant failure. This can be prevented by regular maintenance with mechanical debridement. One of the recent mechanical debridement methods is air abrasion therapy using different abrasive powders. This study aimed to evaluate the two common abrasive powders of different sizes (sodium bicarbonate and erythritol) for their biofilm cleaning efficacy on dental implant surfaces.

MATERIALS AND METHODS

 In an in vitro setting, a total of 33 implants were divided into three groups: Group 1 (n =11) = no treatment; group 2 (n = 11) = air abrasion therapy treated group using a sodium bicarbonate powder (AIRFLOW Powder Classic Comfort, EMS Electro Medical Systems, Nyon, Switzerland); and group 3 (n = 11) = air abrasion therapy treated group using an erythritol powder (AIRFLOW Powder Plus, EMS Electro Medical Systems, Nyon, Switzerland). The implants in each group were subjected to biofilm formation, and group 2 and group 3 were treated with air abrasion therapy of two different powders having different sizes with the same settings. The particle sizes were sodium bicarbonate (40 µm) and erythritol (14µm). The surface characteristics of the dental implants in three groups were studied from a digital camera and under the scanning electron microscope at different magnifications. The comparison of biofilm-removal efficacy between the three groups was performed by using a one-way analysis of variance with post-hoc Dunnett's T3 test. A p-value less than 0.05 was chosen to indicate statistical significance.

RESULTS

 There were no statistical differences (p > 0.05) between the two powder-treated groups for the biofilm cleaning efficacy. However, both groups showed significantly better biofilm-cleaning efficacy than the control group (p < 0.05).

CONCLUSION

 This suggests that both powders are effective in removing biofilm from the implant surface under ideal conditions. However, there was no clear distinction between the cleaning potential of the two powders, as both performed in a similar manner.

An In Vivo Investigation of Non-Metallic vs. Metallic Hand Scalers on Zirconia Implant-Supported Crowns: A Year-Long Analysis of Peri-Implant Maintenance

This study examined whether the degree of abutment surface modification that may occur with regular periodontal instrumentation has a clinical impact in terms of increased plaque accumulation and increased peri-implant tissue inflammation on zirconia implant abutments. Thirteen patients who had zirconia implant crowns were recruited in this randomized clinical trial. Each patient acted as their control and had either the buccal or lingual surface of their screw-retained implant restoration scaled with a metallic scaler and the other surface with a non-metallic scaler at 3, 6, 9, and 12 months. Cytokine testing of the peri-implant crevicular fluid was completed at 0, 3, and 12 months for IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α, or IFNγ. Implant crowns were removed at 12 months and evaluated under an atomic force microscope for the average roughness (Ra). The implant crowns were polished and re-inserted. The results were analyzed using the Kruskal-Wallis test, and post hoc tests were conducted with a significance level of α = 0.05. Significant differences in surface roughness (Ra) were observed between the metallic and non-metallic scalers. The median Ra values were 274.0 nm for metallic scalers and 147.1 nm for non-metallic scalers. However, there were no significant differences between the type of scaler used and the amount of clinical inflammation or cytokine production. Metallic scalers produced deeper, more aggressive surface alterations to the abutment/crown zirconia surface, but there was no statistically significant difference between the degree of surface alterations, amount of BOP, and the amplitude of cytokine inflammation produced.

Effect of Air Polishing on the Treatment of Peri-Implant Diseases: A Systematic Review and Meta-Analysis

Peri-implant diseases have become one of the notable biological complications of postrehabilitation with implant-supported restorations. Effective modalities for decontamination of biofilm deposits around implant surfaces are critical for resolution of the inflammation. Air polishing is one of the recommended clinical methods for treating peri-implant diseases. This systematic review assessed clinical evidence on efficacy of using air polishing technology for the management of peri-implant diseases, including peri-implant mucositis and peri-implantitis. Four electronic databases from January 1990 to December 2022 were searched to identify the relative human randomized clinical trials that applied air polishing for nonsurgical and surgical treatment of peri-implant mucositis and peri-implantitis. Twelve articles were selected. For treating peri-implant mucositis, air polishing showed a comparable effect to ultrasonic scaling in the reduction of bleeding on probing (BOP) and probing pocket depth (PPD). The nonsurgical approach of air polishing in treating peri-implantitis varied in the reduction of BOP, PPD, and clinical attachment level (CAL) in evaluated studies. Air polishing in the surgical treatment of peri-implantitis was comparable to mechanical cleaning, implantoplasty, and the use of Ti-brush, in regards to the significant reduction of BOP, PPD, and CAL, as well as the improvement of the bone level between baseline and follow-ups. The standardized mean difference with a 95% confidence interval of the studied parameters was estimated using the random effect model; however, statistical differences were not detected between air polishing and comparative modalities in the treatment of peri-implantitis. Within the limitations of this review, the application of air polishing did not result in more favorable outcomes in the treatment of peri-implant diseases compared to other modalities.

The Impact of Mechanical Debridement Techniques on Titanium Implant Surfaces: A Comparison of Sandblasted, Acid-Etched, and Femtosecond Laser-Treated Surfaces

This study evaluated the effects of various mechanical debridement methods on the surface roughness (Ra) of dental implants, comparing femtosecond laser-treated surfaces with conventionally machined and sandblasted with large-grit sand and acid-etched (SLA) implant surfaces. The fabrication of grade 4 titanium (Ti) disks (10 mm in diameter and 1 mm thick) and the SLA process were carried out by a dental implant manufacturer (DENTIS; Daegu, Republic of Korea). Subsequently, disk surfaces were treated with various methods: machined, SLA, and femtosecond laser. Disks of each surface-treated group were post-treated with mechanical debridement methods: Ti curettes, ultrasonic scaler, and Ti brushes. Scanning electron microscopy, Ra, and wettability were evaluated. Statistical analysis was performed using the Kruskal-Wallis H test, with post-hoc analyses conducted using the Bonferroni correction (α = 0.05). In the control group, no significant difference in Ra was observed between the machined and SLA groups. However, femtosecond laser-treated surfaces exhibited higher Ra than SLA surfaces (p < 0.05). The application of Ti curette or brushing further accentuated the roughness of the femtosecond laser-treated surfaces, whereas scaling reduced the Ra in SLA surfaces. Femtosecond laser-treated implant surfaces, with their unique roughness and compositional attributes, are promising alternatives in dental implant surface treatments.

Influence of eight debridement techniques on three different titanium surfaces: A laboratory study

OBJECTIVES

Debridement methods may damage implant surfaces. This in vitro study investigated eight debridement protocols across three implant surfaces to assess both biofilm removal and surface alterations.

MATERIAL AND METHODS

One hundred sixty commercially pure titanium discs were treated to simulate commercially available titanium implant surfaces-smooth, abraded and abraded and etched. Following inoculation with whole human saliva to create a mixed species biofilm, the surfaces were treated with eight debridement methods currently used for clinical peri-implantitis (n = 10). This included air abrasion using powders of glycine, sodium bicarbonate and calcium carbonate; conventional mechanical methods-piezoelectric scaler, carbon and stainless steel scalers; and a chemical protocol using 40% citric acid. Following treatment, remaining biofilm was analysed using scanning electron microscopy and crystal violet assays. For statistical analysis, ANOVA was applied (p < 0.05).

RESULTS

All debridement techniques resulted in greater than 80% reduction in biofilm compared with baseline, irrespective of the surface type. Glycine powder delivered through an air polishing system eliminated the most biofilm. Mechanical instruments were the least effective at eliminating biofilm across all surfaces and caused the greatest surface alterations. Citric acid was comparable with mechanical debridement instruments in terms of biofilm removal efficacy. Titanium surfaces were least affected by air abrasion protocols and most affected by mechanical methods.

CONCLUSIONS

Mechanical protocols for non-surgical debridement should be approached with caution. Glycine powder in an air polisher and 40% citric acid application both gave minimal alterations across all implant surfaces, with glycine the superior method in terms of biofilm removal.

Effects on the Titanium Implant Surface by Different Hygiene Instrumentations: A Narrative Review

Peri-implant disease is usually caused by the accumulation of dental biofilm around the implant, and this biofilm can irradiate the gingiva tissue, which leads to inflammation and, more severely, to a deterioration of the bone structure. There is a concern regarding the removal of biofilm from the implant surface by using different hygiene instruments. Some hygiene instruments may have some effect on the dental implant surface, resulting in roughening or damage to the implant surfaces. This study reviewed the effects of titanium implant surfaces on different hygiene instruments. A literature search was conducted from PubMed, ScienceDirect, and Scopus databases for articles published from 1992 to 2021. A total of 19 full-text papers with keywords of interest that met all the eligibility criteria were selected. Surface roughness was evaluated with a scanning electron microscope and also using a profilometer, laser scanning, scanning probe, and atomic force microscopes. A metal curette produced a roughened surface on the titanium implant, but a plastic curette did not alter the surface. Instrumentation with rubber cups left the surface unchanged and appeared to smoothen the surface, whereas the air-powder abrasive instrumentation altered the surface with the presence of micro pits and pores. A conventional metal ultrasonic scaler showed significant surface topographical changes and scratches on both titanium surfaces, as a diode laser, light-emitting diode (LED), and laser treatment did not show any alteration on the rough and smooth titanium surfaces. Thus, a non-metallic instrument such as a plastic curette, rubber cups, and novel technology including diode laser, LED, and laser treatment is appropriate and can be used for debridement on smooth and machined titanium implant surfaces as well as sandblasted and acid-etched (SLA), titanium plasma-sprayed (TPS), and resorbable blasted media (RBM) surfaces. The use of metallic instruments should be avoided, and it is not recommended.

Comparison of Different Chemical and Mechanical Modalities for Implant Surface Decontamination: Activity against Biofilm and Influence on Cellular Regrowth—An In Vitro Study

Objectives

The aim of this in vitro study was to compare the efficacy of chemical and mechanical methods for decontamination of titanium dental implant surfaces previously infected with polymicrobial biofilms in a model simulating a peri-implant defect. Furthermore, the effect of each decontamination protocol on MG-63 osteoblast-like cells morphology and adhesion to the treated implants was assessed.

Background

Peri-implantitis is a growing issue in dentistry, and evidence about implant surface decontamination procedures is lacking and inconclusive.

Methods

A total of 40 previously biofilm-contaminated implants were placed into a custom-made model simulating a peri-implant defect and randomly assigned to five treatment groups: (C) control (no treatment); (AW) air abrasion without any powder; (ESC) air abrasion with powder of erythritol, amorphous silica, and 0.3% chlorhexidine; (HBX) decontamination with a sulfonic/sulfuric acid solution in gel; and (HBX + ESC) a combination of HBX and ESC. Microbiological analysis was performed on five implants per treatment group, and the residual viable bacterial load measured in log 10 CFU/mL was counted for each bacterial strain and for the total number of colonies. The remaining three implants per group and three noncontaminated (NC) implants were used to assess surface biocompatibility using a scanning electron microscope and a backscattered electron microscope after seeding with MG-63 cells.

Results

A significant decontaminant effect was achieved using HBX or HBX + ESC, while no differences were observed among other groups. The percentage of implant surface covered by adherent MG-63 cells was influenced by the treatment method. Progressive increases in covered surfaces were observed in groups C, AW, ESC, HBX, HBX + ESC, and NC.

Conclusions

A combination of mechanical and chemical decontamination may provide more predictable results than mechanical cleaning alone.

Efficacy of titanium brush, 915 nm diode laser, citric acid for eradication of Staphylococcus aureus from implant surfaces

BACKGROUND

This study aimed to assess the efficacy of titanium brush, 915 nm diode laser, citric acid and the combination of latter two with titanium brush for decontamination of SLA surface mini-implants.

METHODS

Seventy-five mini-implants contaminated with Staphylococcus aureus (S. aureus) were randomly divided into five experimental groups (n = 12) of titanium brush (TiB), laser, citric acid (CA), brush-laser, and brush-acid, positive [n = 12; chlorhexidine mouthwash (CHX)] and negative [n = 2; phosphate buffered saline (PBS)] control groups and one no-treatment group (n = 1). After counting the colony forming units (CFUs), data were analyzed using the Kruskal-Wallis and Dunn post-hoc tests.

RESULTS

Regardless of the no-treatment and negative control groups, maximum and minimum CFUs were noted in the titanium brush and positive control groups. After CHX, minimum CFUs were noted in brush-acid group followed by brush-laser, laser, and acid groups. Generally, the Kruskal-Wallis test revealed a significant difference between the groups regarding the colony count (P < 0.001). Dunn post-hoc test showed that the difference between the titanium brush and acid-brush group was significant (P < 0.001) while the differences between the brush and laser groups with the brush-laser group were not significant (P > 0.077).

CONCLUSIONS

Combined use of titanium brush and citric acid yielded superior results compared to other groups in reduction of S. aureus on implant surface.

Professional Mechanical Tooth Cleaning Method for Dental Implant Surface by Agar Particle Blasting

Oral dysfunction due to peri-implantitis and shortened life of implants has become a major concern. Self-care and removal of oral biofilms by professional mechanical tooth cleaning (PMTC) are indispensable for its prevention. However, if the surface roughness of the implant is increased, it may result in the adhesion of biofilm in the oral cavity. Therefore, the PMTC method can serve for long-term implant management. Calcium carbonate (CaCO₃) has been used as a cleaning method for implant surfaces; however, there is concern that the implant surface roughness could increase due to particle collision. Therefore, in this study, to establish a blasting cleaning method that does not adversely affect the implant surface, a new blasting cleaning method using agar particles was devised and its practical application examined. When the simulated stains were blasted with white alumina (WA) abrasive grains and CaCO₃ particles, the simulated stains were almost removed, the surface roughness changed to a satin-finished surface—which was thought to be due to fine scratches—and the surface roughness increased. Most of the simulated stains were removed on the surface of the sample blasted with glycine particles and agar particles. Conversely, the gloss of the sample surface was maintained after cleaning, and the increase in surface roughness was slight.

Thermal effect of a 445 nm diode laser on five dental implant systems: an in vitro study

The purpose of this in vitro study was to assess the thermal effect of the 445 nm diode laser on five dental implant systems. In an ailing implant protocol, five commercial dental implant systems were subjected to 445 nm diode laser energy at different wattages [W], exposure times, and modes (continuous wave [CW] vs. pulsed and contact vs. non-contact) of laser beam delivery. Scanning electron microscopy (SEM) allowed the evaluation of irradiated implant surfaces. A total of 2880 temperature response curves were recorded. The 445 nm wavelength caused temperature increases of more than 10 °C at or above the 0.8 W power level working in CW mode for 5 s and in pulsed mode at 3 W for 20 s with 10% duty cycle. Highest rises in temperature were seen in the Straumann Pure ceramic implant, lowest in the Ankylos system. SEM analysis revealed no surface alteration in all systems in non-contact mode. The applied laser is not inherently safe for the decontamination of ailing implants. From the results of this study it was concluded that different dental implant materials and geometries show different temperature response curves when subjected to 445 nm diode laser energy. Clinicians ought to be aware of this. Therefore, manufacturers of laser devices should provide implant-specific laser parameters for the decontamination process. However, both laser irradiation systems can prevent harmful rises in temperature and surface alteration when used at moderate laser parameters.

The In Vitro Evaluation of Preosteoblast Migration From 3-D-printed Scaffolds to Decontaminated Smooth and Minimally Rough Titanium Surfaces: A Pilot Study

In vitro evaluations are essential to gaining a better understanding of re-osseointegration, while reducing animal use and the overall costs of peri-implantitis studies. This pilot study evaluated preosteoblast migration from 3-D-printed scaffolds to decontaminated titanium microimplants, creating a system that tries to mimic the bone-implant interface. Smooth (S) and minimally rough (R) titanium microimplants were incubated in Escherichia coli cultures and divided into six groups according to the decontamination protocol applied: EDTA gel (EDTA); chlorhexidine (CHL); chlorhexidine-soaked gauze (GCHL); scaling (SC); titanium brush (TiB); and implantoplasty (IP). Pristine S and R microimplants were used as the controls (C). After the decontamination procedures, the microimplants were inserted in 3-D-printed polyurethane-based scaffolds previously inoculated with preosteoblast cell cultures. Cellular migration was assessed after 24, 72 and 120 hours by ATP quantification. At the 120-hour time point, there was no statistically significant difference between S-C, S-EDTA, S-CHL, S-GCHL and S-SC (p > 0.05), and between R-C, R-EDTA and R-GCHL (p > 0.05). The in vitro model developed in this pilot study successfully demonstrated cell migration on the different decontaminated surfaces. This methodology suggests that on smooth microimplants, EDTA, GCHL, SC and TiB decontamination may have a reduced impact on preosteoblast migration, while on minimally rough microimplants, EDTA and GCHL decontamination affected cell migration the least. However, when selecting a decontamination protocol, the effectiveness of the decontamination per se must also be considered.

The unfavorable role of titanium particles released from dental implants

Titanium is considered to be a metal material with the best biological safety. Studies have proved that the titanium implanted in the bone continuously releases titanium particles (Ti particles), significantly increasing the total titanium content in human body. Generally, Ti particles are released slowly without causing a systemic immune response. However, the continuous increased local concentration may result in damage to the intraepithelial homeostasis, aggravation of inflammatory reaction in the surrounding tissues, bone resorption and implant detachment. They also migrate with blood flow and aggregate in the distal organ. The release of Ti particles is affected by the score of the implant surface structure, microenvironment wear and corrosion, medical operation wear, and so on, but the specific mechanism is not clear. Thus, it difficult to prevent the release completely. This paper reviews the causes of the Ti particles formation, the damage to the surrounding tissue, and its mechanism, in particular, methods for reducing the release and toxicity of the Ti particles.

Titanium Wear of Dental Implants from Placement, under Loading and Maintenance Protocols

The objective of this review was to analyze the process of wear of implants leading to the shedding of titanium particles into the peri-implant hard and soft tissues. Titanium is considered highly biocompatible with low corrosion and toxicity, but recent studies indicate that this understanding may be misleading as the properties of the material change drastically when titanium nanoparticles (NPs) are shed from implant surfaces. These NPs are immunogenic and are associated with a macrophage-mediated inflammatory response by the host. The literature discussed in this review indicates that titanium NPs may be shed from implant surfaces at the time of implant placement, under loading conditions, and during implant maintenance procedures. We also discuss the significance of the micro-gap at the implant-abutment interface and the effect of size of the titanium particles on their toxicology. These findings are significant as the titanium particles can have adverse effects on local soft and hard tissues surrounding implants, implant health and prognosis, and even the health of systemic tissues and organs.

Improved biofilm removal using cavitation from a dental ultrasonic scaler vibrating in carbonated water

The use of cavitation for improving biofilm cleaning is of great interest. There is no system at present that removes the biofilm from medical implants effectively and specifically from dental implants. Cavitation generated by a vibrating dental ultrasonic scaler tip can clean biomaterials such as dental implants. However, the cleaning process must be significantly accelerated for clinical applications. In this study we investigated whether the cavitation could be increased, by operating the scaler in carbonated water with different CO₂ concentrations. The cavitation around an ultrasonic scaler tip was recorded with high speed imaging. Image analysis was used to calculate the area of cavitation. Bacterial biofilm was grown on surfaces and its removal was imaged with a high speed camera using the ultrasonic scaler in still and carbonated water. Cavitation increases significantly with increasing carbonation. Cavitation also started earlier around the tips when they were in carbonated water compared to non-carbonated water. Significantly more biofilm was removed when the scaler was operated in carbonated water. Our results suggest that using carbonated water could significantly increase and accelerate cavitation around ultrasonic scalers in a clinical situation and thus improve biofilm removal from dental implants and other biomaterials.

Effect of a Er, Cr:YSGG laser and a Er:YAG laser treatment on oral biofilm-contaminated titanium

OBJECTIVE

Implant surface decontamination is a challenging procedure for therapy of peri-implant disease. This study aimed to compare the effectiveness of decontamination on oral biofilm-contaminated titanium surfaces in Er:YAG laser, Er, Cr:YSGG laser, and plastic curette.

METHODOLOGY

For oral biofilms formation, six participants wore an acrylic splint with eight titanium discs in the maxillary arch for 72 hours. A total of 48 contaminated discs were distributed among four groups: untreated control; decontamination with plastic curettes; Er, Cr:YSGG laser; and Er:YAG laser irradiation. Complete plaque removal was estimated using naked-eye and the time taken was recorded; the residual plaque area was measured and the morphological alteration of the specimen surface was observed by scanning electron microscopy. The total bacterial load and the viability of adherent bacteria were quantified by live or dead cell labeling with fluorescence microscopy.

RESULTS

The mean treatment time significantly decreased based on the treatment used in the following order: Er:YAG, Er, Cr:YSGG laser, and plastic curettes (234.9±25.4 sec, 156.1±12.7 sec, and 126.4±18.6 sec, P=0.000). The mean RPA in the Er, Cr:YSGG laser group (7.0±2.5%) was lower than Er:YAG and plastic curettes groups (10.3±2.4%, 12.3±3.6%, p=0.023). The viable bacteria on the titanium surface after Er, Cr:YSGG laser irradiation was significantly lower compared to the decontamination with plastic curette (P=0.05) but it was not significantly different from the Er:YAG laser irradiation.

CONCLUSION

We found that Er:YAG laser and Er, Cr:YSGG laser irradiation were effective methods for decontaminations without surface alterations.

Effectiveness and surface changes of different decontamination protocols at smooth and minimally rough titanium surfaces

BACKGROUND

The objective of this study is to evaluate titanium decontamination after different protocols while assessing changes in surface roughness, chemical composition, and wettability.

METHODS

Ninety-six smooth (S) and 96 minimally rough (R) titanium microimplants were used. Pristine microimplants were reserved for negative control (S-nC/R-nC, n = 9), while the remaining microimplants were incubated in Escherichia coli culture. Non-decontaminated microimplants were used as positive control (S-pC/R-pC, n = 3). The other microimplants were divided into seven different decontamination protocols (12 S/R per group): 24% EDTA, 2% chlorhexidine (CHL), gauze soaked in 2% chlorhexidine (GCHL), gauze soaked in ultrapure water (GMQ), scaling (SC), titanium brush (TiB), and implantoplasty (IP). Contaminated areas were assessed by scanning electron microscope images, chemical composition by energy dispersive X-ray spectroscopy, wettability by meniscus technique, and roughness by an optical profiler.

RESULTS

Higher residual bacteria were observed in R-pC compared with S-pC (P <0.0001). When comparing S and R with their respective pC groups, the best results were obtained with GCHL, SC, TiB, and IP, with no difference between these protocols (P >0.05). Changes in surface roughness were observed after all treatments, with S/R-IP presenting the smoother and a less hydrophilic surface (P <0.05). Apart from IP protocol, all the other groups presented a more hydrophilic surface in R than in S microimplants (P <0.003). All decontamination protocols resulted in a lower percentage of superficial Ti when compared with S/R-nC (P <0.002).

CONCLUSIONS

All decontamination protocols resulted in changes in roughness, wettability, and chemical composition, but GCHL, SC, TiB, an IP presented the best decontamination outcomes.

The impact of surface alteration on epithelial tissue attachment after the mechanical cleaning of titanium or zirconia surface

OBJECTIVE

Mechanical plaque removal may alter the surface morphology of the gingival penetration part of the implant. We applied an air-powered abrasive system (AP), titanium curette (TC), stainless curette (SC), ultrasound scaler (US), and titanium brush (TB) which are commonly used to remove plaque, to titanium or zirconia and the changes in surface morphology and the epithelial attach against substrata.

MATERIALS AND METHODS

(a) The morphological changes of titanium and zirconia after mechanical cleaning were assessed by scanning electron microscopy and a roughness analyser. (b) Oral epithelial cells of rats were inoculated on the surface of the materials after mechanical cleaning, and the adherence of epithelial cells was observed. (c) The maxillary first molars were extracted from the rats and replaced by experimental titanium or zirconia implants. The length of the immunoreactive laminin-332 band was observed at the implant-peri-implant epithelium interface.

RESULTS

(a) The surface roughness increased in experimental groups except the AP group. (b) Among the experimental groups, the AP group showed the highest number of attached cells. (c) The length of the immunoreactive laminin-332 band was longer in the control group than those in all five experimental groups. Among the experimental groups, the AP group showed the longest band.

CONCLUSION

All mechanical cleaning methods increased the surface roughness of the materials except AP. AP did not cause distinct implant surface alterations. Surface alteration caused by mechanical cleaning may evoke inferior for epithelial attachment and reduce resistance against foreign infiltration.

Effect of titanium or zirconia implant abutments on epithelial attachments after ultrasonic cleaning

Zirconia is widely employed as a material during dental implant work because of its superior esthetics. This study sought to evaluate the impact of titanium or zirconia implant abutments on epithelial attachments after ultrasonic cleaning. These implants were inserted into the extraction socket of rat maxillary first molars. Then, the length of the horseradish peroxidase (HRP) reaction was measured. In addition, titanium and zirconia disks were cleaned using an ultrasonic scaler, surface morphology changes were observed, and the number of epithelial cell attachments to the surface was measured. Ultimately, the surfaces of the titanium disks were easier to damage than those of the zirconia ones. There was no difference in the number of epithelial cell attachments between the two materials with the ultrasonic cleaning. The length of the HRP reaction was shorter on the zirconia implant abutment surface than on the titanium one after mechanical cleaning. In conclusion, zirconia is harder than titanium and a better choice for use in the epithelial tissue attachment. Zirconia is more suitable as a material for implant abutments than titanium.

Ultrastructural changes of smooth and rough titanium implant surfaces induced by metal and plastic periodontal probes

Objectives

To determine the ultrastructural changes of titanium surfaces of dental implants induced by the tip of periodontal probes.

Materials and methods

A total of 40 samples of smooth and rough surfaces of titanium implants were randomly assigned for the treatment with metal or plastic periodontal probes under application angles of 20° and 60°. Titanium surfaces have been evaluated with CLSM prior and following to experimental probing determining various standardized 2D and 3D roughness parameters.

Results

The average profile and surface roughness (Ra and Sa) showed no significant difference between treated and untreated samples on smooth and rough surface areas irrespective of the probe material. On smooth surfaces several amplitude roughness parameters were increased with metal probes but reached significance only for Rp (p = 0.007). Rough surface parts showed a slight but not significant reduction of roughness following to the contact with metal probes. The surface roughness remained almost unchanged on smooth and rough implant surfaces using plastic probes. The surface roughness on implant surfaces was not dependent on the application angle irrespective of the probe material.

Conclusion

Probing of titanium implants with metal probes and even less with plastic probes causes only minor changes of the surface roughness. The clinical significance of these changes remains to be elucidated.

Clinical relevance

Using plastic probes for the clinical evaluation of the peri-implant sulcus might avoid ultrastructural changes to titanium implant surfaces.

Evaluation of decontamination methods of oral biofilms formed on screw-shaped, rough and machined surface implants: an ex vivo study

Background

To evaluate the effect of several representative decontamination methods of oral biofilms on different implant surfaces.

Material and methods

Eleven participants wore a hard resin splint carrying 6 rough (GC Aadva® implant; 3.3-mm diameter, 8-mm length) or machined (not commercially available) surface implants for 4 days to accumulate dental plaque naturally on the titanium surfaces of the implants. Apart from surface roughness, the morphology of all implants was identical. After detaching the implants from the splints, the ability of the following decontamination methods—gauze soaked in saline (G), ultrasonic scaler (US), air abrasive (Air), rotary stainless steel instrument (Rot), and Er:YAG laser (Las)—to cleanse the contaminated implant surface for 1 min extra-orally was tested. The control (Cont) group did not receive any decontamination. Scanning electron microscopic (SEM) investigation of one participant’s samples was employed to examine the post-instrumented implant surface for qualitative analysis, and bacterial culture of the remaining 10 participants’ samples was performed to count the number of colony-forming units (CFU) for quantitative analysis. The experimental sequence was initially performed for the rough surface implants and then similarly repeated for the machined surface implants. Bacterial CFU counts among the six groups were analyzed using the Steel-Dwass test, and differences between rough and machined surface implants were determined using the Mann-Whitney U test.

Results

G and Rot eliminated most biofilms on machined surface implants according to SEM analysis. G, Air, and Rot removed significantly more of the biofilms on rough and machined surface implants compared with US according to CFU counts. Moreover, G significantly reduced more biofilms than Las on machined surface implants. The analysis between rough and machined surface implants showed that Cont, G, and US were better able to cleanse biofilms on machined surface implants compared with rough surface implants.

Conclusions

Gauze soaked in saline and rotary stainless steel instruments may be advantageous for cleansing contaminated implant surfaces based on the qualitative and quantitative analyses. In contrast, air abrasives were not shown to be preferable in the qualitative analyses. Additionally, apart from the Er:YAG laser, the reduction of biofilms assessed in both qualitative and quantitative analyses demonstrated that all decontamination methods were better at cleansing machined surface implants compared with rough surface implants.

Temperature Changes and SEM Effects of Three Different Implants-Abutment Connection during Debridement with Er:YAG Laser: An Ex Vivo Study

The study aimed to evaluate a temperature increase in, and damage to, titanium implants during flapless laser debridement. The study analyzed 15 implants with various implant–abutment connections: a two-piece implant (n = 4) with a screw abutment (IA—Implant–Abutment) and a one-piece implant with a ball type fixture (BTF, n = 4) or fix type fixture (FTF, n = 4). The implants were placed in porcine mandibles 2 mm over a bone crest to imitate a peri-implantitis. The implants were debrided in contact mode for 60 s with a Er:YAG laser at fluence of 9.95 J/cm² (G1 group: 50 mJ/30 Hz); 19.89 J/cm² (G2 group: 100 mJ/30 Hz); 39.79 J/cm² (G3 group: 200 mJ/30 Hz), or a scaler with a ceramic tip (G4 control group: 4 W/20 Hz). The temperature was measured with thermocouples at implant and abutment levels. The damage in the titanium surface (n = 3, non-irradiated implants from each type) was assessed using SEM (Scanning Electron Microscopy). The temperature increase at the implant level for the laser was higher at IA in contrast with FTF and BTF. (p < 0.05) The temperature change at the abutment level was lower for the scaler in contrast to Er:YAG laser at FTF. (p < 0.0002) Er:YAG laser didn’t increase the temperature by 10 °C at 100 mJ/30 Hz and 50 mJ/30 Hz. Based on SEM analysis, cracks occurred on the surface of two-piece implants and were more pronounced. Cracks and the melting of the titanium surface of two-piece implants cleaned with Er:YAG laser at 100 or 200 mJ were observed. The specimens treated with the ultrasonic scaler with a plastic curette showed the remaining dark debris on the titanium surface. We recommend using Er:YAG laser at 50 mJ/30 Hz during flapless implants debridement.

Effect of Different Laser Wavelengths on Periodontopathogens in Peri-Implantitis: A Review of In Vivo Studies

Nowadays, many studies are examining the effectiveness of dental lasers in the treatment of peri-implantitis; however, most of them only report periodontal parameter changes. The authors of this review tried to address the question: “What is the effect of different laser wavelengths on oral bacteria that cause peri-implantitis?” An electronic search of PubMed and Cochrane Central Register of Controlled Trials was performed. The following search terms were used: (peri-implantitis OR periimplantitis) OR/AND (microbial OR microbiologic) AND (laser OR Er:YAG OR erbium OR diode OR Nd:YAG OR neodymium-doped OR Er,Cr:YSGG OR chromium-doped). Initially, 212 studies were identified. After screening the titles and abstracts and excluding studies according to predefined inclusion criteria, seven publications were included in the review. Three studies about the effect of aPDT (antimicrobial photodynamic therapy) reported a decrease in the different bacterial strains associated with peri-implantitis, e.g., A. actinomycetemcomitans, P. gingivalis, P. intermedia, T. denticola, T. forsythia, F. nucleatum, and C. rectus. Two studies showed that the high-power diode laser may have some effect on peri-implant pathogens. Two articles about the Er:YAG laser reported a lowering in the count of oral pathogens; however, it was hard to determine if this was due to the use of the laser. aPDT has the ability to decrease the count of peri-implant pathogens, whereas Er:YAG laser application shows no significant effect on oral bacteria in the long term.

Decontamination methods to restore the biocompatibility of contaminated titanium surfaces

Purpose

The reaction of cells to a titanium implant depends on the surface characteristics of the implant which are affected by decontamination. The aim of this study was to evaluate the cytocompatibility of titanium disks treated with various decontamination methods, using salivary bacterial contamination with dental pellicle formation as an in vitro model.

Methods

Sand-blasted and acid-etched (SA) titanium disks were used. Three control groups (pristine SA disks [SA group]; salivary pellicle-coated SA disks [pellicle group]; and biofilm-coated, untreated SA disks [NT group]) were not subjected to any decontamination treatments. Decontamination of the biofilm-coated disks was performed by 14 methods, including ultrasonic instruments, rotating instruments, an air-powder abrasive system, a laser, and chemical agents. MG63 cells were cultured in the presence of the treated disks. Cell proliferation assays were performed on days 2 and 5 of cell culture, and cell morphology was analyzed by immunofluorescence and scanning electron microscopy (SEM). A vascular endothelial growth factor (VEGF) assay was performed on day 5 of culture.

Results

The cell proliferation assay revealed that all decontaminated disks, except for the 2 groups treated using a plastic tip, showed significantly less cell proliferation than the SA group. The immunofluorescence and SEM analyses revealed that most groups showed comparable cell density, with the exception of the NT group, in which the cell density was lower and bacterial residue was observed. Furthermore, the cells grown with tetracycline-treated titanium disks showed significantly lower VEGF production than those in the SA group.

Conclusions

None of the decontamination methods resulted in cytocompatibility similar to that of pristine SA titanium. However, many methods caused improvement in the biocompatibility of the titanium disks in comparison with the biofilm-coated, untreated titanium disks. This suggests that decontamination is indispensable for the treatment of peri-implantitis, even if the original biocompatibility cannot be restored.

Effects of air abrasive decontamination on titanium surfaces: A systematic review of in vitro studies

BACKGROUND

Air abrasion (AA) is one of the decontamination methods that have demonstrated promising results in treating peri-implant diseases.

PURPOSE

This systematic review aimed at evaluating the in vitro effect of AA on surface change, cleaning efficacy, and biocompatibility of titanium surfaces and at comparing it with other decontamination methods.

MATERIALS AND METHODS

A comprehensive search was conducted up to April 2018 using PubMed, Scopus, and Google Scholar databases to identify studies on the decontamination effect of AA. All types of titanium surfaces, abrasive powders, contaminated surfaces, and measuring methods were included.

RESULTS

Overall, 1502 articles were identified. After screening the titles and abstracts, and carefully reading the full-texts, 48 articles published between 1989 and 2018 were selected. AA was considered almost safe, particularly for the nonmodified surfaces. Nevertheless, harder powders such as sodium bicarbonate tended to damage the surface more than glycine. AA resulted in surface change similar to plastic curettes and Er: YAG lasers. Regarding the cleaning efficacy, there was no significant difference between glycine and sodium bicarbonate, but different mixtures of calcium phosphate, hydroxyapatite, and erythritol were superior to glycine. AA was superior or equal to all other decontamination methods in cleaning. Regarding biocompatibility, AA was more successful in preserving biocompatibility for noncontaminated surfaces compared with contaminated surfaces and when used with erythritol and osteoinductive powders.

CONCLUSIONS

AA can efficiently remove contamination without serious damage to the surface. The main drawback of the AA method seems to be its limitation in restoring the biocompatibility of the surface.

In Vitro Comparison of the Efficacy of Peri-Implantitis Treatments on the Removal and Recolonization of Streptococcus gordonii Biofilm on Titanium Disks

Objective: To compare the efficacy of four commonly used clinical procedures in removing Streptococcus gordonii biofilms from titanium disks, and the recolonization of the treated surfaces. Background: Successful peri-implantitis treatment depends on the removal of the dental biofilm. Biofilm that forms after implant debridement may threaten the success of the treatment and the long-term stability of the implants. Methods:S. gordonii biofilms were grown on titanium disks for 48 h and removed using a plastic curette, air-abrasive device (Perio-Flow®), titanium brush (TiBrush®), or implantoplasty. The remaining biofilm and the recolonization of the treated disks were observed using scanning electron microscopy and quantified after staining with crystal violet. Surface roughness (Ra and Rz) was measured using a profilometer. Results:S. gordonii biofilm biomass was reduced after treatment with Perio-Flow®, TiBrush®, and implantoplasty (all p < 0.05), but not plastic curette (p > 0.05), compared to the control group. Recolonization of S. gordonii after treatment was lowest after Perio-Flow®, TiBrush®, and implantoplasty (all p < 0.05 vs. control), but there was no difference between the plastic curette and the control group (p > 0.05). Ra and Rz values ranged from 1–6 µm to 1–2 µm and did not differ statistically between the control, plastic curette, Perio-Flow, and TiBrush groups. However, the implantoplasty group showed a Ra value below 1 µm (p < 0.01, ANOVA, Tukey). Conclusions: Perio-Flow^®, TiBrush^®, and implantoplasty were more effective than the plastic curette at removing the S. gordonii biofilm and preventing recolonization. These results should influence the surgical management of peri-implantitis.

Comparison of a Novel Ultrasonic Scaler Tip vs. Conventional Design on a Titanium Surface

The aim of this in vitro study was to evaluate the alterations of a titanium surface after treatment with two different types of ultrasonic tips: conventional steel versus an innovative copper alloy silver-plated one. Twenty smooth-surface, grade IV unalloyed titanium discs were divided into two groups. The discs were ultrasonically instrumented and the scaler was connected with a loading machine. The surface morphology was examined using scanning electron microscopy (SEM) and fractal analysis of lacunarity was calculated to highlight the alteration of the surface using the two different tips. The SEM analysis showed different degrees of surface roughness between the two types of scaler tips. Moreover, these observations demonstrated that the new tip showed fewer irregularities on the disc’s surface than the conventional steel tip. The statistical and fractal analysis showed a statistically significant difference between the two groups. Surface alterations of titanium induced by the conventional ultrasonic tips were much greater than those made by copper alloy silver plated tips. The presented results suggest that the use of this new ultrasonic tip may reduce the alterations on the implant surface during its use in dental practice.

Potential Causes of Titanium Particle and Ion Release in Implant Dentistry: A Systematic Review

Implant surface characteristics, as well as physical and mechanical properties, are responsible for the positive interaction between the dental implant, the bone and the surrounding soft tissues. Unfortunately, the dental implant surface does not remain unaltered and changes over time during the life of the implant. If changes occur at the implant surface, mucositis and peri-implantitis processes could be initiated; implant osseointegration might be disrupted and bone resorption phenomena (osteolysis) may lead to implant loss. This systematic review compiled the information related to the potential sources of titanium particle and ions in implant dentistry. Research questions were structured in the Population, Intervention, Comparison, Outcome (PICO) framework. PICO questionnaires were developed and an exhaustive search was performed for all the relevant studies published between 1980 and 2018 involving titanium particles and ions related to implant dentistry procedures. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed for the selection and inclusion of the manuscripts in this review. Titanium particle and ions are released during the implant bed preparation, during the implant insertion and during the implant decontamination. In addition, the implant surfaces and restorations are exposed to the saliva, bacteria and chemicals that can potentially dissolve the titanium oxide layer and, therefore, corrosion cycles can be initiated. Mechanical factors, the micro-gap and fluorides can also influence the proportion of metal particles and ions released from implants and restorations.

Cleaning effect of osteoconductive powder abrasive treatment on explanted human implants and biofilm-coated titanium discs

The aim of this study is to test the cleaning effect and surface modification of a new implant surface treatment on explanted dental implants and titanium discs. It is a modified air powder abrasive (APA) treatment applied using osteoconductive powders. Twenty-eight in vitro Ca-precipitated organic film-coated titanium discs and 13 explanted dental implants were treated. In a 2-step approach, 3 powders were used: hydroxylapatite (HA) and biomimetic calcium phosphate (BioCaP), which are osteoconductive, and erythritol, which is not. APA treatment was applied. (Air pressure: 2.4 bar; water flow for cleaning: 41.5 ml/min, for Coating 1: 2.1 ml/min, and for Coating 2: 15.2 ml/min.) The test groups were as follows: Group 1: HA cleaning + BioCaP Coating 1; Group 2: HA cleaning + BioCaP Coating 2; Group 3: erythritol cleaning + BioCaP Coating 1; Group 4: erythritol cleaning + BioCaP Coating 2; Group 5: HA cleaning; Group 6: erythritol cleaning; and control: no powder. Cleaned areas were calculated by point counting method. Surface changes and chemical content were evaluated using light microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Cleaning effect between groups was compared by a pairwise Student's t test. The significance level was fixed at p < .05. Cleaning effect on the discs was 100% in all test groups and 5% in the control. Powder particles in varying size and shape were embedded on the surface. All HA- or CaP-treated surfaces showed Ca and P content but no surface damage. Calcified biofilm remnants were removed from the implant surface by the test groups, whereas in control groups, they remained. APA treatment with CaP and HA powders under clinically applicable pressure settings gives positive results in vitro; therefore, they could be promising when used in vivo.

Re-establishment of Biocompatibility of the In Vitro Contaminated Titanium Surface Using Osteoconductive Powders With Air-Abrasive Treatment

To achieve re-osseointegration on implant surfaces exposed to peri-implant infections, treatment should re-establish biocompatibility. The aim of this study was to test whether air powder abrasive treatment (APA) using osteoconductive powders can, in addition to cleaning, increase the biocompatibility of the contaminated implant surface. Ninety-six in vitro Ca-precipitated, organic film layer-coated sandblasted and acid-etched titanium discs were treated by APA using erythritol, hydroxylapatite (HA), and biocalcium phosphate (BioCaP) powders (n = 16 per group). Six treatment modalities were created (HA or erythritol cleaning with/without BioCaP coating). MC3T3-E1cells were seeded on discs, and cell attachment, viability, proliferation, and differentiation were evaluated. Pristine discs were used as control (control 1). Contaminated and nontreated discs were used as control (control 2). The cells were stretched and attached in all test groups. The cell viability and proliferation (DNA amount) in all test groups were significantly higher than in the pristine and contaminated disc groups. There was no significant difference between the test groups. The differentiation (alkaline phosphatase activity) of the cells on treated discs was significantly higher than on the contaminated discs but lower than in the pristine group. The cell viability in control 2 was significantly lower than the control 1. The APA with osteoconductive powder on contaminated titanium surfaces promoted the cell viability, proliferation, and differentiation of the MC3T3-E1 cells. The biocompatibility of the surface was higher than that of the contaminated discs. The tested aspects of cell response, with the exception of differentiation, reached to the level of the pristine surface. The in vitro results showed that APA with osteoconductive powders could be a promising method for implant surface treatment.

Effectiveness of implant surface debridement using particle beams at differing air pressures

Because implant surface decontamination is challenging, air powder abrasive systems have been suggested as an alternative debridement method. This in vitro study investigated the effectiveness of different powder formulations and air pressures in cleaning implant surfaces and the extent of surface damage. A validated ink model of implant biofilm was used. Sterile 4.1 × 10 mm Grade 4 titanium implants were coated in a blue indelible ink to form a uniform, visually detectable biofilm-like layer over the implant threads and mounted into a bone replica material with bony defects to approximate peri-implantitis. Air powder abrasive treatments were undertaken using glycine, sodium bicarbonate, or calcium carbonate powder at air pressures of 25, 35, 45, and 55 psi. Digital macro photographs of the threads were stitched to give composite images of the threads, so the amount of ink remaining could be quantified as the residual area and expressed as a percentage. Implant surfaces were also examined with scanning electron microscopy to grade the surface changes. No treatment cleaned all the surface of the threads. The powders were ranked in order of decreasing effectiveness and decreasing surface change into the same sequence of calcium carbonate followed by sodium bicarbonate followed by glycine. Higher air pressure improved cleaning and increased surface change, with a plateau effect evident. All powders caused some level of surface alteration, with rounding of surface projections most evident. With air powder abrasive systems, there is a trade-off between cleaning efficacy and surface damage. Using this laboratory model, sodium bicarbonate and calcium carbonate powders were the most effective for surface cleaning when used at air pressures as low as 25 psi.

Evaluation of the Removal Bacteria on Failed Titanium Implants After Irradiation With Erbium-Doped Yttrium Aluminium Garnet Laser

Peri-implantitis may occur because of biologic or mechanical factors. It can be treated by a variety of methods. The aim of the present study is to evaluate implant surface of failed oral titanium implants after being irradiated with erbium laser.

Influence of low direct electric currents and chlorhexidine upon human dental biofilms

Dental biofilms have been widely associated with biological complications of oral implants. Currently, no consensus exists regarding the most reliable anti-infective approach to treat peri-implantitis. This study aimed to investigate whether low direct electric currents (DC) could influence chlorhexidine (CHX) 0.2% antimicrobial efficacy against human dental biofilms. To support biofilm accumulation, discs made with machined titanium (Ti) or hydroxyapatite (HA) were used. Five volunteers wore during 24 h an intraoral thermoformed splint on which ten specimens were bonded. Biofilms were then collected and treated ex vivo. During each antimicrobial experiment (N = 20 replicates), two modalities of treatment (CHX/PBS = control groups and CHX/PBS+5mA = test groups) were tested (n = 5 discs each) and the number of viable bacteria evaluated in LogCFU/mL at baseline, 0.5, 1, 2 and 5 min. The proportion of killed bacteria was also estimated and compared statistically at each time point between control and test groups. CHX+/-5mA induced a mean viability reduction around 90-95% after 5 min of treatment whatever the surface considered (Ti/HA). A significant difference regarding the bactericidal effect was noted on Ti surfaces after 0.5, 1 and 2 min in favor of the CHX+5mA modality when compared to CHX alone (p < 0.05). PBS+5mA also had a certain antimicrobial effect (58%) after 5 min on Ti surfaces. This effect was significantly higher than that observed with PBS (25%) (p < 0.05). This study showed that low DC (5mA) can have an antibiofilm effect and are also able to enhance chlorhexidine 0.2% efficacy against human dental biofilms grown on titanium surfaces.

Effects of Surface Conditions of Titanium Dental Implants on Bacterial Adhesion

OBJECTIVE

The study is to evaluate the effect of surface roughness of titanium implants on bacterial adhesion and then to investigate the efficacy of the three cleaning treatments for bacterial removal in titanium surfaces.

BACKGROUND DATA

Although surface debridement is the basic element for treatment of peri-implantitis to reduce bacterial adhesion, adjunctive therapies such as antiseptics and laser debridement have been proposed to improve the nonsurgical treatment options of the peri-implant infection.

METHODS

Titanium specimens were divided into five groups: No. 1200 grit sandpaper polishing (Grit), 50 μm (SB50), 100 μm (SB100), and 250 μm Al2O3 sandblasting (SB250), and sandblasting, large-grit, and acid-etching (SLA). Surface roughness (Ra), contact angle, and surface morphology were examined. The subsequent adhesion of Escherichia coli on the different substrates was assayed. After 8 h of bacterial culture, three different cleaning treatments, including plastic curettage, air-powder abrasive system, and Er:YAG laser debridement, were applied on the specimens.

RESULTS

The Ra value changed from the lower value of 0.2 μm for the Grit group to the significantly higher value of 2.7 μm for the SB250 group, indicating a significant difference from the SLA group (2.0 μm). The average contact angle of SLA (101°) was significantly higher than the other groups. No significant difference in E. coli bacterial adhesion was found among the all roughened groups, except the SB50 and SB250 groups at 12 h of culture. The use of three cleaning treatments did not induce significant surface alterations. However, the E. coli adhesion was significantly reduced in the air-powder abrasive system and laser debridement in comparison with that treated with the plastic curettage.

CONCLUSIONS

Laser debridement could be a useful cleaning method for peri-implantitis therapy.

Decontamination of titanium implants using physical methods

OBJECTIVES

Current decontamination methods of titanium (Ti) implant present limited success in achieving predictable re-osseointegration. We hypothesized that even though these techniques could be useful in elimination of bacteria, they might be unsuccessful in removing organic contaminants and restoring the original surface composition. The aim of this study was to assess the effect of four decontamination methods on the surface chemistry and bacterial load of biofilm-contaminated implant surfaces in order to improve implant surface decontamination.

MATERIAL AND METHODS

The ability of clinically available methods such as metal and plastic curettes, Ti brushes and Er: YAG laser to decontaminate Ti implant surfaces was assessed. Surface morphology, chemical composition and properties of machined Ti discs (Ø 5.0 and 1.0 mm thick) were analysed before and after oral biofilm contamination using scanning electron microscope and X-ray photoelectron spectroscopy. The presence and viability of bacteria were evaluated with live-dead assays.

RESULTS

Biofilm contamination created an organic layer rich in hydrocarbons and bacteria that covered entirely the Ti surfaces. This organic layer has tightly adhered to Ti surfaces and could not be completely removed with any of the methods assessed. Ti brushes achieved greater elimination of organic contaminants and bacteria than curettes and Er: YAG laser; however, none of them was able to restore the original surface chemistry. Alternatively, Er: YAG laser-treated surfaces showed the lowest live-to-dead bacterial ratio.

CONCLUSIONS

Ti brushes were more effective than curettes (metal or plastic) and Er: YAG laser in decontaminating Ti implant surfaces, although none of these techniques was able to completely eliminate surface contamination. Er: YAG laser was more effective than curettes and Ti brushes in killing the biofilm bacteria.

Influence of different instrumentation modalities on the surface characteristics and biofilm formation on dental implant neck, in vitro

OBJECTIVES

To evaluate surface characteristics of implants after using different instruments and biofilm formation following instrumentation.

MATERIAL AND METHODS

Thirty-five commercially available dental implants were embedded into seven plastic models, attached to a phantom head and randomly assigned to seven instrumentation groups: (1) stainless steel (SSC) or (2) titanium curettes (TC); air-polisher using glycine-based (3) perio (PP) or (4) soft (SP) powders or (5) erythritol powder (EP); and an ultrasonic device using (6) stainless steel (PS) or (7) plastic-coated instruments (PI). Half of each implant neck in each group (n = 5) was treated once (30 s), while the other half was left uninstrumented (control). An eighth (8) treatment group used a bur/polisher to smooth two implants (SM). Following instrumentation implants were rinsed (5 ml Ringer's solution), analysed under a scanning electron microscope (SEM) and subjected twice (separately) to bacterial colonization with Streptococcus gordonii (2 h) and a mixed culture (S. gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, Porphyromonas gingivalis and Tannerella forsythia; 24 h).

RESULTS

Visual assessment of SEM pictures revealed surface modifications (smoothening to roughening) following instrumentation. These alterations differed between the instrument groups and from the control. Quantitative scoring of the photographs revealed that SSC caused a significantly rougher surface compared to other instruments (P < 0.05), except for SP (P = 0.057) and PP (P = 0.108). After bacterial colonization no significant differences (P > 0.05) were evident between instrumented or control surfaces in either culture.

CONCLUSIONS

Overall, no significant differences were observed in the surface characteristics (except for SSC) or bacterial colonization based on one-time instrumentation.

An In Vitro Evaluation of Alumina, Zirconia, and Lithium Disilicate Surface Roughness Caused by Two Scaling Instruments

PURPOSE

Plaque control is crucial for the prevention of inflammatory periodontal disease. Hand scaling instruments have been shown to be efficient for the removal of plaque; however, routine periodontal prophylactic procedures may modify the surface profile of restorative materials. The purpose of this study was to assess in vitro the changes in roughness of alumina, zirconia, and lithium disilicate surfaces treated by two hand scaling instruments.

MATERIALS AND METHODS

Forty-eight alumina specimens, 48 zirconia specimens, and 48 lithium disilicate specimens, were selected. All specimens were divided into three groups of 16 each; one group for each material was considered the control group and no scaling procedures were performed; the second group of each material was exposed to scaling with steel curettes simulating standard clinical conditions; the third group of each material was exposed to scaling with titanium curettes. After scaling, the surface roughness of the specimens was evaluated with a profilometer. First, a statistical test was carried out to evaluate the difference in surface roughness before the scaling procedure of the three materials was effected (Kruskal-Wallis test). Subsequently, the effect of curette material (steel and titanium) on roughness difference and roughness ratio was analyzed throughout the entire sample and within each material group, and a nonparametric test for dependent values was conducted (Wilcoxon signed-rank test). Finally, the roughness ratios of the three material groups were compared by means of a Kruskal-Wallis test and a Wilcoxon signed-rank test. Upon completion of profilometric evaluation, representative specimens from each group were prepared for SEM evaluation to evaluate the effects of the two scaling systems on the different surfaces qualitatively.

RESULTS

After scaling procedure, the roughness profile value increased in all disks. Classifying the full sample according to curette used, the roughness of the disks treated with a steel curette reached a higher median value than that of the titanium group. Zirconia demonstrated the least significant increase in surface roughness. The result was 3.9 times of the initial value as compared to 4.3 times for alumina and 4.6 times for lithium disilicate.

CONCLUSIONS

Comparison of profilometer readings before and after instrumentation, carried out with different hand scaling instruments, highlighted both a statistically and clinically relevant increase in material roughness.

Tooth polishing: The current status

Healthy teeth and gums make a person feel confident and fit. As people go about their daily routines and with different eating and drinking habits, the tooth enamel turns yellowish or gets stained. Polishing traditionally has been associated with the prophylaxis procedure in most dental practices, which patients know and expect. However, with overzealous use of polishing procedure, there is wearing of the superficial tooth structure. This would lead to more accumulation of local deposits. Also, it takes a long time for the formation of the fluoride-rich layer of the tooth again. Hence, now-a-days, polishing is not advised as a part of routine oral prophylaxis procedure but is done selectively based on the patients’ need. The article here, gives an insight on the different aspects of the polishing process along with the different methods and agents used for the same.

Effectivity of air-abrasive powder based on glycine and tricalcium phosphate in removal of initial biofilm on titanium and zirconium oxide surfaces in an ex vivo model

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.

Health, Maintenance, and Recovery of Soft Tissues around Implants

BACKGROUND

The health of peri-implant soft tissues is one of the most important aspects of osseointegration necessary for the long-term survival of dental implants.

PURPOSE

To review the process of soft tissue healing around osseointegrated implants and discuss the maintenance requirements as well as the possible short-comings of peri-implant soft tissue integration.

MATERIALS AND METHODS

Literature search on the process involved in osseointegration, soft tissue healing and currently available treatment modalities was performed and a brief description of each process was provided.

RESULTS

The peri-implant interface has been shown to be less effective than natural teeth in resisting bacterial invasion because gingival fiber alignment and reduced vascular supply make it more vulnerable to subsequent peri-implant disease and future bone loss around implants. And we summarized common procedures which have been shown to be effective in preventing peri-implantitis disease progression as well as clinical techniques utilized to regenerate soft tissues with bone loss in advanced cases of peri-implantitis.

CONCLUSION

Due to the difference between peri-implant interface and natural teeth, clinicians and patients should pay more attention in the maintenance and recovery of soft tissues around implants.

Biofilm removal from implants supported restoration using different instruments: a 6-month comparative multicenter clinical study

OBJECTIVES

The aim of this study was to compare the efficacy of different instruments on biofilm removal from implant supported restorations.

MATERIALS AND METHODS

The study was designed as comparative multicenter clinical study including patients proceeding from the Milan, Naples, and Buenos Aires, with a peri-implant mucositis. Implants enrolled for the study were allocated in 4 groups and treated with ultrasonic scalers with plastic tips, with titanium curettes, with airflow with glycine powder, and with rubber cup and polishing paste, respectively. mPI was assessed at baseline, immediately after therapy, at 1, 3, and 6 months. mBI, PD, and REC were assessed at baseline, 1, 3, and 6 months. All parameters were recorded on six sites per implant. Kruskal-Wallis and Mann-Whitney tests were used to compare groups and centers. A generalized linear model for repeated measures was chosen for inter-group comparison. An intra-group comparison was performed with repeated measure ANOVA test to assess differences between baseline and recalls.

RESULTS

A total of 89 patients (39 males, 50 females) were enrolled in the study, and 141 implants were available for the analysis. 55 implants were enrolled in University of Buenos Aires, 32 in University of Milan, and 54 in University of Naples. There were no significant differences between the four groups in inflammatory status reduction of peri-implant mucosa.

CONCLUSIONS

Non-surgical therapy is effective in reducing peri-implant mucositis. Sonic scaler with plastic tip and rubber cup with polishing paste showed higher efficacy when compared with titanium curettes or airflow with glycine powder.