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

Abstract

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.

Keywords: dental biofilm; dental hygiene; instrumentation; oral implants.

FIGURE 1

SEM images of biofilm growth on the titanium surfaces of the control group at various time points of inoculation at 1000× and 5000× magnification

FIGURE 2

SEM images of experimental surfaces of titanium discs and commercial titanium implants at 1000× magnification

FIGURE 3

Effect of different powders used in air polishing systems applied to the three titanium implant surface types. SEM magnification 5000×

FIGURE 4

Effect of an ultrasonic scaler with a titanium tip, a carbon fibre scaler and a titanium hand scaler on the three titanium implant surface types. SEM magnification 5000×

FIGURE 5

Effect of a nickel–titanium brush and citric acid on the three titanium implant surface types. SEM magnification 5000×. Note the dramatic effect of the brush on the disc surface, compared with the lack of damage from the citric acid

FIGURE 6

Polished group treatments ranked in order from most effective to least effective. Sample groups are shown, ordered from best to worst. Those shown within the same rank are not significantly different from one another. **Indicates p < 0.01. NS indicates not statistically significant. Data are shown for crystal violet calculated as the percentage reduction compared with baseline. Bru, nickel–titanium brush; Ca, calcium carbonate powder; Citr, citric acid; Gl, glycine powder; H P, Hand scaling using a Premier graphite/carbon fibre scaler; H T, Hand scaling using a titanium scaler; Na, sodium bicarbonate powder; US t, ultrasonic with titanium tip

FIGURE 7

Abraded group treatments ranked in order from most effective to least effective **Indicates p < 0.01. NS indicates not statistically significant. Data is shown for crystal violet calculated as the percentage reduction compared to baseline. Bru, nickel–titanium brush; Ca, calcium carbonate powder; Citr, citric acid; Gl, glycine powder; H P, Hand scaling using a Premier graphite/carbon fibre scaler; H T, Hand scaling using a titanium scaler; Na, sodium bicarbonate powder; US t, ultrasonic with titanium tip

FIGURE 8

SLA group treatments ranked in order from most effective to least effective. ***Indicates p < 0.001. N.S indicates not statistically significant. Data are shown for crystal violet calculated as the percentage reduction compared to baseline. Bru, nickel–titanium brush; Ca, calcium carbonate powder; Citr, citric acid; Gl, glycine powder; H P, Hand scaling using a Premier graphite/carbon fibre scaler; H T, Hand scaling using a titanium scaler; Na, sodium bicarbonate powder; US t, ultrasonic with titanium tip