se lines has been reported in three monkeys,” the promise of this result was limited because “it is admitted that the organisms used in the above experiment would be unsuitable for human use and it is not yet possible to incriminate any individual species [of bacteria] as the sole cause of human caries” . Jenkins saw fluoridation as “the only thoroughly well-established method of reducing caries which does not require the active (and usually reluctant) participation of the patient” .
Industry receives a preview of the NIDR’s research priorities.
ISRF got a preview of the NIDR’s research priorities for the NCP at the second ISRF symposium in September 1969 in Bethesda . Richard Greulich, the NIDR’s intramural scientific director , spoke on “The Future of Caries Control” one month before the NIDR Caries Task Force Steering Committee would first discuss NCP research priorities (Table 1) . Greulich said that while water fluoridation (which had been accepted in the US in 1965 as a “proved highly beneficial public health measure ready for widespread implementation” ) had achieved some success, The NIDR knew it was not the sole answer to eradicating dental caries:
From a public health point of view, we do not feel confident that fluoride is the only answer; and biologically speaking, it obviously is not because we have not talked to the other enterprises here. We have mentioned a host factor as represented or reflected by fluoridation. We have not talked to the microbes; we have not talked to the substrate or to nutrition. 
Greulich’s symposium presentation downplayed the value of limiting sucrose consumption as a means to control dental caries:
One could say, on logical grounds and good evidence, that if we could eliminate the consumption of sucrose, we could eliminate the problem—because we would be denying these pathogens their primary source of nutrient. We are realists, however, and we recognize the value of sucrose to nutrition. So while it is theoretically possible to take this approach to demonstrate it, and it has been demonstrated certainly in animal models, it is not practical as a public health measure. It is like saying the maximum speed of a jet plane is the speed of light. It just is not practical to try and evolve on to that point. And so in smooth surface caries, we have a more practical goal in working on the microorganism.  (emphasis added)
Similar to the approaches the sugar industry was promoting, Greulich identified interventions targeting bacteria as promising to the NIDR (Table 3, column B), including dextranases, for which the NIDR had been working with the pharmaceutical company Merck Sharpe & Dohme to think through the steps necessary for practical application . The NIDR was also hopeful about a laboratory finding on “low molecular weight dextrans,” another substance that might be delivered to keep bacteria from producing harmful acid when exposed to sugar .
Beyond its focus on decay-causing bacteria, Greulich told ISRF that the NIDR was investigating ways to modify sugar to reduce its harmful effects . These dietary modification interventions included adding phosphates to sugar, and the possibility of replacing table sugar, in the form of sucrose, with a liquid sugar, that split the sucrose molecules into glucose and fructose, which were thought to be less harmful to teeth . Just before concluding, Greulich again assured ISRF that the NIDR research was not a threat to sugar consumption: “I reiterate that the role of sucrose [in dental caries] is undeniable, yet there is very little that anyone would want to do about this other than to explore some of these possible [dietary] modifications” .
Industry convenes a panel that includes many members of the NIDR Caries Task Force.
In October 1969, the NIDR Caries Task Force Steering Committee met to identify research priorities . As Greulich predicted, the main approaches reviewed focused on interfering with bacteria and dietary modification of sugar (Table 3, column C) . However, a summary of the Caries Task Force Steering Committee meeting indicates that 