The Swedish health authorities have given a Nobel Biocare dental implant product a clean bill of health following fears that it could cause jawbone loss.
But they said the Swiss-Swedish company would have to change instructions for the implant's use before it can resume marketing.
Share prices recovered on Wednesday's news after an alarming dip earlier this year.
An investigation in Sweden was sparked by criticism from two Gothenburg University professors that the NobelDirect implant could lead to bone loss in the jaw.
They claimed that data taken from 300 patients showed that the implant leads to higher bone loss in a third of cases compared with older implants, but Nobel Biocare always denied the claims.
The probe also examined a second similar dental implant that had not been part of the tests.
Sweden's Medical Products Agency (MPA) has now declared both products safe, but demanded modifications to their instructions.
"We are not sure that the product has worked completely right if one has followed the previous instructions. We don't have data that are clear enough to withdraw the product today," said MPA director Lennart Philipson.
Nobel Biocare welcomed the decision and said they would cooperate with the Swedish authorities, but made no further statement. The firm must comply with the MPA order by January 8 next year.
Dental implants account for around 2.6 per cent of total Nobel Biocare annual sales. However, the health scare has not resulted in any significant loss of revenue, according to Bank Sarasin analyst Samuel Stursberg.
The firm will still be relieved by the decision that leaves them with little more than a "black eye", he told swissinfo.
"This was more about possible damage to the company's image and the threat of litigation in the United States [where the product is also sold]," Stursberg said.
"If it [NobelDirect] had been withdrawn in Sweden it would probably have been withdrawn throughout the rest of Europe too. That ban could possibly have spread to the US."
Stursberg added that medical and pharmaceutical firms are particularly vulnerable to negative reports on their products.
"That is just the industry and all investors have to live with that. I think in this case the reaction was overdone because, although it is a medical device, it is only dental as opposed to orthopaedics where this can be more problematic," he said.
"I never saw this as that dramatic. Very few people thought there would be no restrictions imposed by the MPA, the only question was if they applied to the market or not."
swissinfo, Matthew Allen with agencies
Nobel Biocare is the world number one in the dental implant market ahead of Straumann (also based in Switzerland).
The company is domiciled in Zurich, with headquarters in Zurich and Gothenburg, Sweden.
Production takes place at four sites located in Sweden and the US and Nobel has around 1,650 employees.
The company recently reported a 43% rise in third quarter net profits to €33.1 million (SFr52.57 million). Net profits for the first nine months of 2006 increased to €107.8 million compared with €80.5 million in the corresponding period of 2005.