Xylitol's long-term protection.
Some of the preventive effects created by xylitol use seem outright magical.
For example, studies have demonstrated that the act of having regularly consumed xylitol over the long-term imparts a continued cavity-prevention effect that can last for some months, and possibly even as long as 5 years, after the person has completely stopped using it.
Here's the proof.
As evidence of this phenomenon, consider the findings of Hujoel (1999).
This study selected a test population of 288 six-year old children that was divided up into different subgroups, one of which chewed xylitol gum on a daily basis over a two year time frame. At the end of this period the children's exposure to xylitol was terminated.
Over the course of the next five years (a time period that began at that point when the use of xylitol gum had been ceased), the children were periodically evaluated by dentists for tooth decay. Their findings were that the children who had had the xylitol exposure experience a 59% reduction in their tooth decay rate, as compared to the group of children who received no xylitol.
Just to recap.
We want to make this point clear. The children who received this anti-cavity effect had chewed xylitol gum regularly for a two-year period and then stopped this activity totally.
Then, over the course of the next five years, a time frame when these children received absolutely no additional exposure to xylitol at all, there was a residual effect from having had their original exposure that provided a 59% reduction in cavities. Pretty astounding wouldn't you say?
The story continues, various teeth benefited differently.
When these researchers evaluated their data more closely, they noticed that the level of long-term residual protection varied for different teeth. And, in regard to this fact, it was the timing of the xylitol use that turned out to be the critical factor in determining the amount of protection that was afforded.
This study's findings revealed the following.
- Residual long-term cavity protection effect provided for teeth that had already erupted prior to the use of xylitol. = None.
- Residual long-term cavity protection effect provided for teeth that didn't erupt until one full year of xylitol consumption had been completed. = A 93% reduction in cavities.
- Residual long-term cavity protection effect provided for teeth that erupted after two years of xylitol use. = An 88% reduction in tooth decay.
Let's recap this information too.
1) Amazingly, the simple act of regularly chewing xylitol-sweetened gum is capable of providing anti-cavity protection for children's teeth, even for several years after they have quit using it.
2) Mysteriously, this effect is only bestowed upon certain teeth, specifically those that don't erupt until at least one year after xylitol usage has been begun (including those teeth that erupt long after the use of xylitol has been ceased).
3) And, curiously, this same xylitol exposure does not provide this long-term tooth decay prevention for teeth that erupt before the first year of xylitol usage has been completed.
Seems confusing doesn't it?
Here's the explanation.
These mystical anti-cavity effects are easily explained in light of the following theory.
Research studies have determined that the initial bacterial colonization of a tooth's surface takes place at that time when it first erupts (first comes through the gums and is exposed to the oral environment). Once this initial colonization has taken place, these bacteria become the dominant inhabitants of the tooth's surface (such as in a tooth groove or pit) for the remainder of the person's life.
This means that the type of bacteria that initially colonize a tooth plays an important role in determining the life-long risk that tooth has for experiencing decay. Grooves and pits initially colonized by non-cariogenic bacteria (types of bacteria that can't cause cavities) typically will not be replaced by cariogenic bacteria later on.
Since the long-term use of xylitol is detrimental to the population of cariogenic bacterial living in a person's mouth, its use helps to insure that those bacteria that initially colonize a tooth's surface will be more likely to be non-harmful types.
Case closed, mystery solved.