The Advertising Standards Authority was outside its immediate area of expertise when it ruled an advertisement by the manufacturers of Ribena Toothkind was misleading, according to the chairman of the British Dental Health and Science Committee, Dr Geoff Craig.

Commenting on the ASA's decision asking Smithkline Beecham to delete claims on advertisements that "Ribena Toothkind does not encourage tooth decay", Dr Craig told " This is a scientific matter and the ASA is not a scientific body and we stand by the claim made by Smithkline Beecham that Ribena Toothkind does not encourage tooth decay."

Following a two year investigation by the ASA, prompted by complaints challenging the claim, the ASA has requested the advertisers to delete the statement claiming it is absolute and not comparative.

But, Smithkline Beecham is going to challenge the ASA and is hoping to have the ruling overturned after being granted permission to apply for a judicial review in the high court.

According to Neil McCrae, spokesman for Smithkline Beecham: "We are dismayed at the ASA's decision but now it is a matter of principle because the product was researched extensively for four years by leading bodies in this field and by the BDA, and we believe the BDA is the best authority."

Ribena Toothkind was researched by the Food and Drink Accreditation Panel, an independent panel consisting of four leading UK researchers and Dr Craig continued to say: "We have absolute confidence in the panel and its decision and with normal usage of Ribena Toothkind the risk of decay and erosion is considered negligible and the BDA also challenges the ASA ruling."

But, said the ASA's external affairs manager, Steve Ballinger an ASA independent review decided there was no case to answer and upheld the ruling and the judicial review is the last possible chance Smithkline Beecham can have the decision overturned.

Ballinger added: "Our decision is final and we expect Smithkline Beecham to delete the claim from advertisements."