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The Oral Health Services Research Centre has conducted clinical trials of oral health care products for industry since 1994, with over 20 studies conducted to date. Subjects are recruited from the local population, with up to 400 subjects being randomised per study.

Prior to commencement, all clinical trials have the approval of a properly constituted local Ethics Committee and of the regulatory authority (Irish Medicines Board).

A full service is available, including trial design, protocol writing, clearance with Ethics Committee and Irish Medicines Board, recruitment and screening of volunteers, stratification procedures, product dispensing and reconciliation, impartial interviewing techniques, validation procedures, microbiological measurements, biochemical tests, quality control, statistical analysis and report writing. All studies are performed in accordance with Good Clinical Practice guidelines. An in-house clinical trials examiner is available on site.

She has been trained (and calibrated where appropriate) in the following standardised indices / examination techniques:

• Caries: Backer-Dirks, Bennie, FOTI, Quantitative Laser Fluorescence, x-ray
• Plaque: Turesky Modification of the Quigley Hein Index, Rustogi Modification of Navy Index
• Gingivitis: Löe and Silness, MGI, Ainamo and Bay Gingival Bleeding Index
• Enamel opacities: Thylstrup-and Fejerskov Index, Developmental Defects of Enamel Index, Quantitative Laser Fluorescence
• Stain: Lobene Index, McPherson Modification of Lobene Index
• Sensitivity: Pressure (Yeaple probe), thermal (water at 5oC) and evaporative (air blast) stimuli.

Our most recent studies include:

Whitening
A randomised, double blind parallel design, controlled clinical trial on tooth stain removal involving 200 randomised subjects has been completed in November 2004.

A randomised, controlled, observer-blind, parallel group clinical trial on tooth stain inhibition involving 120 randomised subjects has been completed in April 2004.
2 study groups
6 week test period.
Index used: MacPherson modification of the Lobene stain index.

A randomised, double blind parallel design clinical trial on tooth stain prevention involving 100 randomised subjects was completed in March 2003.

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		Sensitivity A research project involving clinical examinations and focus group discussions on cervical dentinal sensitivity involving 47 subjects has been completed in August 2003. Stimuli used: tactile (Yeaple probe), thermal (water 5°C), and evaporative (air blast 20°C for 1 second).

A randomised, double-blind, parallel design clinical trial on cervical dentinal sensitivity reduction involving 149 randomised subjects has been completed in 1999. 2 study groups. 6-week test period (also 3-week pre-test phase and 2-week post-test phase). Stimuli used: tactile (Yeaple probe) and thermal (water 5°C).

Plaque
An observer blind, randomised crossover-design clinical trial on plaque acid production involving 24 randomised subjects has been completed in February 2004. 3 study groups. 3-way crossover: 2 test products and 1 placebo. 16-day test periods separated by 14-day washouts periods. Measurement: plaque pH, concentration of individual plaque acids.

A randomized, double-blind, parallel design clinical trial on dental plaque inhibition involving 67 randomised subjects was completed in May 2000. 2 study groups. 3-week test period. Index used: Turesky Modification of the Quigley-Hein Plaque Index

Gingivitis and plaque A randomised, double blind, parallel design clinical trial on gingivitis and plaque reduction involving 224 randomised subjects was completed in 2002. 2 study groups. 12 week test period. Indices used: Modified Gingival Index (Lobene), Bleeding Index of Saxton and Van Oudera, Gingival Index, Turesky Modification of the Quigley Hein Index, and Proximal Marginal Index. A randomised, double blind, parallel design clinical trial on gingivitis reduction, plaque inhibition, and stain accumulation involving 371 randomised subjects was completed in 2001. 3 study groups. 24-week test period. Indices used: Löe-Silness Index, Turesky Modification of the Quigley-Hein Index, and Lobene tooth stain scoring procedure.
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A randomised, double-blind, parallel design clinical trial on gingivitis and plaque inhibition involving 354 randomised subjects was completed in 2000.
3 study groups.
6 month test period.
Indices used: Loe-Silness Gingival Scoring Index as modified by Talbot, Mandel and Chilton, and the Turesky Modified Quigley-Hein Plaque Scoring Index.

Calculus
A randomised, observer-blind, parallel design clinical trial on supragingival dental calculus inhibition involving 246 randomised subjects was completed in 1999.
3 study groups.
12-week test period.
Index used: the Volpe-Manhold method, using a round Williams periodontal probe.

Caries One-year prospective design to determine the caries increment in children aged between 11 and 13 years was completed in 2001. 495 subjects were entered. Indices and examination techniques used: Bennie, Backer-Dirks, Fibreoptic Transillumination. Radike (subsample only). Radiographic examination (where indicated). Habits and Practices Questionnaire. Saliva samples cultured for Lactobacillus and S. mutans counts.