Comparison of decontamination efficacy of two electrolyte cleaning methods to diode laser, plasma, and air-abrasive devices.

OBJECTIVE: To compare the in vitro decontamination efficacy of two electrolytic cleaning methods to diode laser, plasma, and air-abrasive devices. MATERIAL AND METHODS: Sixty sandblasted large-grit acid-etched (SLA) implants were incubated with 2 ml of human saliva and Tryptic Soy Broth solution under continuous shaking for 14 days. Implants were then randomly assigned to one untreated control group (n = 10) and 5 different decontamination modalities: air-abrasive powder (n = 10), diode laser (n = 10), plasma cleaning (n = 10), and two electrolytic test protocols using either potassium iodide (KI) (n = 10) or sodium formate (CHNaO2) (n = 10) solution. Implants were stained for dead and alive bacteria in two standardized measurement areas, observed at fluorescent microscope, and analyzed for color intensity. RESULTS: All disinfecting treatment modalities significantly reduced the stained area compared to the untreated control group for both measurement areas (p < 0.001). Among test interventions, electrolytic KI and CHNaO2 treatments were equally effective, and each one significantly reduced the stained area compared to any other treatment modality (p < 0.001). Efficacy of electrolytic protocols was not affected by the angulation of examined surfaces [surface angulation 0° vs. 60° (staining %): electrolytic cleaning-KI 0.03 ± 0.04 vs. 0.09 ± 0.10; electrolytic cleaning-CHNaO2 0.01 ± 0.01 vs. 0.06 ± 0.08; (p > 0.05)], while air abrasion [surface angulation 0° vs. 60° (staining %): 2.66 ± 0.83 vs. 42.12 ± 3.46 (p < 0.001)] and plasma cleaning [surface angulation 0° vs. 60° (staining %): 33.25 ± 3.01 vs. 39.16 ± 3.15 (p < 0.001)] were. CONCLUSIONS: Within the limitations of the present in vitro study, electrolytic decontamination with KI and CHNaO2 was significantly more effective in reducing bacterial stained surface of rough titanium implants than air-abrasive powder, diode laser, and plasma cleaning, regardless of the accessibility of the contaminated implant location. CLINICAL RELEVANCE: Complete bacterial elimination (residual bacteria < 1%) was achieved only for the electrolytic cleaning approaches, irrespectively of the favorable or unfavorable access to implant surface.

In vitro surgical and non-surgical air-polishing efficacy for implant surface decontamination in three different defect configurations.

OBJECTIVES: Evaluation of surgical and non-surgical air-polishing in vitro efficacy for implant surface decontamination. MATERIAL AND METHODS: One hundred eighty implants were distributed to three differently angulated bone defect models (30°, 60°, 90°). Biofilm was imitated using indelible red color. Sixty implants were used for each defect, 20 of which were air-polished with three different types of glycine air powder abrasion (GAPA1-3) combinations. Within 20 equally air-polished implants, a surgical and non-surgical (with/without mucosa mask) procedure were simulated. All implants were photographed to determine the uncleaned surface. Changes in surface morphology were assessed using scanning electron micrographs (SEM). RESULTS: Cleaning efficacy did not show any significant differences between GAPA1-3 for surgical and non-surgical application. Within a cleaning method significant (p < 0.001) differences for GAPA2 between 30° (11.77 ± 2.73%) and 90° (7.25 ± 1.42%) in the non-surgical and 30° (8.26 ± 1.02%) and 60° (5.02 ± 0.84%) in the surgical simulation occurred. The surgical use of air-polishing (6.68 ± 1.66%) was significantly superior (p < 0.001) to the non-surgical (10.13 ± 2.75%). SEM micrographs showed no surface damages after use of GAPA. CONCLUSIONS: Air-polishing is an efficient, surface protective method for surgical and non-surgical implant surface decontamination in this in vitro model. No method resulted in a complete cleaning of the implant surface. CLINICAL RELEVANCE: Air-polishing appears to be promising for implant surface decontamination regardless of the device.

Influence of different agents on the preload force of implant abutment screws.

STATEMENT OF PROBLEM: Screw loosening is a common problem in implant dentistry; however, information is sparse on the influence of different fluids on the screw threads. PURPOSE: The purpose of this in vitro study was to investigate the influence of 4 different fluids and agents (saliva, blood, chlorhexidine [CHX] gel, and special sealing silicone) on the preload force of abutment screws. MATERIALS AND METHODS: The test specimens (N=50) consisted of a thread sleeve resembling the implant, an abutment analog, and an abutment screw. The tightening of the screw with a torque wrench was performed in 5 steps (15 Ncm, 20 Ncm, 25 Ncm, 30 Ncm, and 35 Ncm). Each agent was applied in the lumen of the thread sleeve of 10 specimens. Ten dry thread sleeves served as the control. Comparisons between 2 independent groups were performed with the t test or Wilcoxon-Mann-Whitney test, as appropriate. The Bonferroni correction was used for multiple comparisons (α=.05). RESULTS: Preload forces increased linearly with the applied tightening torque for dry implant lumina, as well as for saliva, blood, silicone, and CHX gel in the implant lumina or thread sleeves. In general, none of the tested agents resulted in significantly higher preload forces compared with the dry control. CONCLUSIONS: The agents investigated did not have any lubricant action on implant abutment screws.

In vitro efficacy of three different implant surface decontamination methods in three different defect configurations.

OBJECTIVES: Evaluation of in vitro efficacy of three different implant surface decontamination methods in a peri-implant bone defect model. MATERIAL AND METHODS: A total of 180 implants were stained with indelible red color and distributed to standardized peri-implant bone defect resin models with a circumferential defect angulation of 30°, 60°, or 90° (supraosseous defect). Sixty implants were assigned to each type of defect. All implants were cleaned by the same examiner. For each type of defect, 20 implants were cleaned for 2 min with one of 3 devices: curette (CUR), sonicscaler (SOSC), or air abrasion with glycine powder (APA). Thereafter, photographs were taken from both sides of each implant and the cumulative uncleaned implant surface area was measured by color recognition technique. Scanning electron micrographs (SEM) were examined to assess morphologic surface damages. RESULTS: The cleaning efficacy as percent (%) of residual color was significantly different for each of the 3 defect angulations (p < 0.001) for each treatment device: 30° CUR: 53.44% > SOSC: 19.69% > APA: 8.03%; 60° CUR: 57.13% > SOSC: 11.4% > APA: 0.13%; and 90° CUR: 48.1% > SOSC: 13.07% > APA: 0.58%. The differences between the three different cleaning modalities within each defect type were also significant (p < 0.005). SEM micrographs showed no surface damages after the use of APA. CONCLUSION: Air powder abrasion is the most efficient (APA > SOSC > CUR) and less surface damaging treatment modality for each defect angulation in this in vitro model.

In vitro efficacy of non-surgical and surgical implant surface decontamination methods in three different defect configurations in the presence or absence of a suprastructure.

OBJECTIVES: Analysis of the in vitro efficacy of non-surgical and surgical dental implant surface decontamination with or without suprastructure. MATERIALS AND METHODS: Three hundred and sixty implants were dipped in indelible red and distributed to 30°, 60°, or 90° angulated bone defect models. One hundred and twenty implants were used for each bone defect, 40 of which were assigned to a decontamination method (CUR: curette; SOSC: soundscaler; APA: air powder abrasion). Of these, 20 were subjected to a simulated non-surgical (NST) or surgical treatment (ST), with/without mucosa mask, of which 10 were carried out with (S+) or without (S-) suprastructure. Uncleaned implant surface was assessed by both-sided implant surface photography. Surface morphology changes were analyzed using scanning electron microscopy (SEM). RESULTS: Cleaning efficacy was significantly better within NST if the suprastructure was removed (p < 0.001). No significant difference was found within ST (p = 0.304). Overall, cleaning efficacy in the order APA > SOSC>CUR decreased significantly (p < 0.0001) for both S+ and S- in NST as well as ST. Separated by NST/ST, S+/S-, defect angulation and decontamination method, only isolated significant differences in cleaning efficacy were present. Linear regression analysis revealed significant associations of remnants with the treatment approach, decontamination method, and defect angle (p < 0.0001). SEM micrographs showed serious surface damage after use of CUR and SOSC. CONCLUSIONS: Suprastructure removal is an additional option to improve cleaning efficacy of non-surgical implant surface decontamination in this in vitro model.

Influence of Anodizing Stages on the Preload Force of Implant-Abutment Screws and Their Benefits Regarding the Concept of Immediate Implant Placement-An In Vitro Study.

The tightening torque applied to a screw in a provisional restoration immediately after implant placement in a fresh extraction socket is often too low to gain sufficient preload force. Therefore, abutment screw loosening is a common complication. The aim of this study was to investigate whether it is possible to increase the preload force of a given tightening torque by anodizing parts of the implant-abutment complex. In test group 1 (TG1), only the abutment screw was anodized, in four different stages, whereas in test group 2 (TG2), the abutment and the threaded sleeve were anodized in four anodizing stages (TG2a-TG2d). The control group (CG) consisted of non-anodized components. The results were tested for normal distribution, and the components were subsequently parametrically analyzed using a linear model. Both test groups showed higher preload forces compared to the non-anodized control group. The CG obtained an average preload force of 390 N at a tightening torque of 35 Ncm. Comparable values were already obtained at a tightening torque of 20 to 30 Ncm in TG1c/D and TG2b/d. It can be concluded that anodization of abutment screws and components is an effective measure to increase the preload force of the abutment screws by a given tightening torque.

Correction: Ratka et al. The Effect of In Vitro Electrolytic Cleaning on Biofilm-Contaminated Implant Surfaces. J. Clin. Med. 2019, 8, 1397.

There was an error in the original article [...].

In Vitro Efficacy of Three Different Nonsurgical Implant Surface Decontamination Methods in Three Different Defect Configurations.

PURPOSE: Assessment of in vitro efficacy of three different nonsurgical implant surface decontamination methods in three peri-implant bone defect simulation models. MATERIALS AND METHODS: A total of 180 implants were allocated to differently angulated (30, 60, and 90 degrees) peri-implant bone defect resin models, each covered by a mucosa mask. All implants were stained with indelible red color and assigned to one of the three defect models. In each simulated bone defect group, 20 implants were decontaminated for 2 minutes with a curette (CUR), sonic scaler (SOSC), or air-powder abrasion device (APA) with glycine powder. Photos were taken from both sides of each implant to measure the percentage of uncleaned implant surface area. Scanning electron microscopy (SEM) was used to assess the implant surface for morphologic damage. RESULTS: Among the three defect angulations, a significantly different cleaning efficacy (P < .001) for each treatment method was found (30 degrees: CUR [67.33%], SOSC [62.70%], APA [39.33%]; 60 degrees: CUR [61.59%], SOSC [54.31%], APA [23.91%]; 90 degrees: CUR [66.82%], SOSC [55.77%], APA [28.03%]). SEM did not show any considerable surface damage after APA treatment in comparison with after CUR or SOSC. CONCLUSION: Air-powder abrasion proved to be the most efficient nonsurgical treatment device for each type of defect in this in vitro model with the least noticeable surface change. No decontamination method resulted in complete cleaning of the color remnants on the implant surface.

Treatment of Peri-implantitis-Electrolytic Cleaning Versus Mechanical and Electrolytic Cleaning-A Randomized Controlled Clinical Trial-Six-Month Results.

OBJECTIVES: The present randomized clinical trial assesses the six-month outcomes following surgical regenerative therapy of periimplantitis lesions using either an electrolytic method (EC) to remove biofilms or a combination of powder spray and electrolytic method (PEC). MATERIALS AND METHODS: 24 patients with 24 implants suffering from peri-implantitis with any type of bone defect were randomly treated by EC or PEC. Bone defects were augmented with a mixture of natural bone mineral and autogenous bone and left for submerged healing. The distance from implant shoulder to bone was assessed at six defined points at baseline (T0) and after six months at uncovering surgery (T1) by periodontal probe and standardized x-rays. RESULTS: One implant had to be removed at T1 because of reinfection and other obstacles. None of the other implants showed signs of inflammation. Bone gain was 2.71 ± 1.70 mm for EC and 2.81 ± 2.15 mm for PEC. No statistically significant difference between EC and PEC was detected. Significant clinical bone fill was observed for all 24 implants. Complete regeneration of bone was achieved in 12 implants. Defect morphology impacted the amount of regeneration. CONCLUSION: EC needs no further mechanical cleaning by powder spray. Complete re-osseointegration in peri-implantitis cases is possible.

Heat Generation at the Implant-Bone Interface by Insertion of Ceramic and Titanium Implants.

PURPOSE: The aim of this study is to record material- and surface-dependent heat dissipation during the process of inserting implants into native animal bone. MATERIALS AND METHODS: Implants made of titanium and zirconium that were identical in macrodesign were inserted under controlled conditions into a bovine rib tempered to 37 °C. The resulting surface temperature was measured on two bone windows by an infrared camera. The results of the six experimental groups, ceramic machined (1), sandblasted (2), and sandblasted and acid-etched surfaces (3) versus titanium implants with the corresponding surfaces (4, 5, and 6) were statistically tested. RESULTS: The average temperature increase, 3 mm subcrestally at ceramic implants, differed with high statistical significance (p = 7.163 × 10-9, resulting from group-adjusted linear mixed-effects model) from titanium. The surface texture of ceramic implants shows a statistical difference between group 3 (15.44 ± 3.63 °C) and group 1 (19.94 ± 3.28 °C) or group 2 (19.39 ± 5.73 °C) surfaces. Within the titanium implants, the temperature changes were similar for all surfaces. CONCLUSION: Within the limits of an in vitro study, the high temperature rises at ceramic versus titanium implants should be limited by a very slow insertion velocity.

The Effect of In Vitro Electrolytic Cleaning on Biofilm-Contaminated Implant Surfaces.

PURPOSE: Bacterial biofilms are a major problem in the treatment of infected dental and orthopedic implants. The purpose of this study is to investigate the cleaning effect of an electrolytic approach (EC) compared to a powder-spray system (PSS) on titanium surfaces. MATERIALS AND METHODS: The tested implants (different surfaces and alloys) were collated into six groups and treated ether with EC or PSS. After a mature biofilm was established, the implants were treated, immersed in a nutritional solution, and streaked on Columbia agar. Colony-forming units (CFUs) were counted after breeding and testing (EC), and control (PSS) groups were compared using a paired sample t-test. RESULTS: No bacterial growth was observed in the EC groups. After thinning to 1:1,000,000, 258.1 ± 19.9 (group 2), 264.4 ± 36.5 (group 4), and 245.3 ± 40.7 (group 6) CFUs could be counted in the PSS groups. The difference between the electrolytic approach (test groups 1, 3, and 5) and PSS (control groups 2, 4, and 6) was statistically extremely significant (p-value < 2.2 × 10-16). CONCLUSION: Only EC inactivated the bacterial biofilm, and PSS left reproducible bacteria behind. Within the limits of this in vitro test, clinical relevance could be demonstrated.

Effects of Screw Configuration on the Preload Force of Implant-Abutment Screws.

PURPOSE: The aim of this study was to investigate the effects of tightening torque, screw head angle, and thread number on the preload force of abutment screws. MATERIALS AND METHODS: The test specimens consisted of three self-manufactured components (ie, a thread sleeve serving as an implant analog, an abutment analog, and an abutment screw). The abutment screws were fabricated with metric M1.6 external threads. The thread number varied between one and seven threads. The screw head angles were produced in eight varying angles (30 to 180 degrees). A sensor unit simultaneously measured the preload force of the screw and the torsion moment inside the screw shank. The tightening of the screw with the torque wrench was performed in five steps (15 to 35 Ncm). The torque wrench was calibrated before each step. RESULTS: Only the tightening torque and screw head angle affected the resulting preload force of the implant-abutment connection. The thread number had no effect. There was an approximately linear correlation between tightening torque and preload force. CONCLUSION: The tightening torque and screw head angle were the only study parameters that affected the resulting preload force of the abutment screw. The results obtained from this experiment are valid only for a single torque condition. Further investigations are needed that analyze other parameters that affect preload force. Once these parameters are known, it will add value for a strong, but detachable connection between the implant and abutment. Short implants and flat-to-flat connections especially will benefit significantly from this knowledge.

The micromechanical behavior of implant-abutment connections under a dynamic load protocol.

BACKGROUND: The implant-abutment connection (IAC) is known to be a key factor for the long-term stability of peri-implant tissue. PURPOSE: The aim of the present in vitro study was to detect and measure the mechanical behavior of different IACs by X-ray imaging. MATERIALS AND METHODS: A total of 20 different implant systems with various implant dimensions and IACs (13 conical-, 6 flat-, and 1 gable-like IAC) have been tested using a chewing device simulating dynamic and static loading up to 200 N. Micromovements have been recorded with a high-resolution, high-speed X-ray camera, and gap length and gap width between implant and abutment have been calculated. Furthermore, X-ray video sequences have been recorded to investigate the sealing capacity of different IACs. RESULTS: Out of the 20 implant systems, eight implant systems with a conical IAC showed no measurable gaps under static and dynamic loading (200 N). By contrast, all investigated implant systems with a flat IAC showed measurable gaps under dynamic and static loading. X-ray video sequences revealed that a representative conical IAC had sufficient sealing capacity. CONCLUSION: Within the limits of the present in vitro study, X-ray imaging showed reduced formation of microgaps and consecutive micromovements in implants with conical IAC compared to flat IACs.