Periodontal therapy patients with 5-6 mm pockets could possibly be maintained if they are able to clean to the base of the periodontal pockets. The use of chemotherapeutic liquids should offer promise in managing these conditions; however, their use has been limited due to the lack of a home care armamentarium to predictably deliver these agents to the depths of the periodontal pockets.¹ Studies have shown sulcus penetration of fluids by mouth rinsing alone is less than 2mm.^1-3

Oral irrigators may have the potential to deliver liquids more efficiently than rinsing. Yet, studies conducted on oral irrigators concluded pockets greater than 4 mm in depth are difficult to irrigate,^1-5 and effective irrigation depends on ejection site pressure, irrigator tip design and presence of subgingival calculus.⁶  Several investigators have examined the relationship of the placement of the irrigation cannula and liquid penetration into the sulcus. One study showed when the tip of a supragingival irrigator was positioned at either a 45° or 90° degree to the long axis of the tooth, irrigation solutions penetrated to an average of one-half the depth of the pockets.⁷  Larner and Greenstein⁶ found irrigators positioned subgingivally were more efficient than those positioned supragingivally at delivering liquids to the depth of periodontal pockets.  An investigation by Hardy et al.⁸ determined irrigation to the base of both shallow and deep pockets only occurred when the irrigating cannula was placed 3.0 mm subgingivally. Given this data, the question still remains as to whether patients are capable of applying such irrigation techniques in a home care regimen.

In order to find an easier and more efficient home care method for dental patients, some studies have suggested a combination of cleaning modalities. These studies have suggested incorporating a water pressure device with toothbrushing, interdental stimulation, and professional prophylaxis may help reduce plaque and improve solution penetration into the periodontal pocket.^1,11  Wunderlich et al.¹ studied the relationship between the probed sulcus depth and the degree of subgingival penetration of a solution using an irrigation technique and a rinsing technique. They reported the mean percentage of penetration for 2-4 mm pockets was greater after a prophylaxis was performed. In addition, other researchers⁶ have found both supragingival and subgingival irrigators achieved superior irrigation into 7-10 mm pockets after calculus had been removed from the roots of teeth. Thus, it is possible there is a relationship between plaque and calculus removal and the successful irrigation of periodontal pockets. While powered toothbrushes have proven to be efficient in removing dental plaque^12-15, their use in conjunction with oral irrigation has not been tested as a method of improving sulcus penetration.

Various protocols have been established to evaluate the effectiveness of sulcular irrigation techniques. Published techniques include application of irrigation solutions containing disclosing dyes applied prior to tooth extraction, then measuring the stained tooth surfaces extra-orally.^{2, 3, 6-8}  Wunderlich¹ applied a fluorescent irrigating solution and then used photographs to measure the penetration of the solution into the pocket. While these techniques allow for accurate measure of sulcular penetration, none measure the volume and quality of the solution penetrating into the periodontal pocket.

The current study had three goals: 1) to compare a powered brush/irrigating device to rinsing with a solution following brushing with a powered toothbrush, 2) to evaluate the safety and adaptability of the patients to these devices and, 3) to introduce a new technique designed for efficient collection of samples from the base of the sulcus.

The first goal was to evaluate a powered brush/irrigating device (HydraBrush Oral Health System™ Oralbotics, Inc. Escondido, CA) for its ability to deliver a solution to the bottom of 5-6 mm pockets, compared to rinsing with a solution following brushing with a powered toothbrush (Sonicare Elite™ 7800 Philips Oral Healthcare, Inc. Snoqualmie, WA). The hypothesis in the present study was using an experimental device, the bristles of the unit may deflect the gingival tissue, allowing simultaneous improved irrigation of a solution into the periodontal pockets. The control protocol for this study was selected because the Sonicare Elite has been shown in laboratory studies to remove plaque up to 3 mm beyond its bristle tips^12,13  and up to 1 mm subgingivally in a clinical study.¹⁴ Therefore, the investigators are of the opinion the effectiveness of this toothbrush at removing subgingival plaque may allow a deeper penetration of a rinsing solution.

Secondly, the safety of the devices was evaluated by giving the subjects a diary in which to document any bleeding and discomfort, during the two weeks of this study. Finally, a new technique designed for efficient collection of samples from the base of the sulcus was introduced. The quantity and quality of penetration of the dye solution into periodontal pockets was evaluated by extracting the applied solution with the tip of a micropipette, and analyzing its color concentration.