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The fine art of reading research

Dec. 1, 2002
Reading research is an art, a talent. It seems that most people do not take the time to develop that talent. Some learn to look at the tables and understand the complex mathematical machinations of standard deviations and ANOVA (ANalysis Of Variance) in college.

Reading research is an art, a talent. It seems that most people do not take the time to develop that talent. Some learn to look at the tables and understand the complex mathematical machinations of standard deviations and ANOVA (ANalysis Of Variance) in college. Some, like me, need further study. Some don't want to understand and never will learn the fine art of reading a paper and coming to an entirely different conclusion than the authors, then putting it aside for future rumination.

Reading research can be like looking at a master's painting. Why do some paintings live on in perpetuity? What is it about color, line and medium choices that appeal to so many for so long? Some people can fly through a fine art museum in nothing flat. Some people need help to see a fine brush stroke, quality in the medium, or what the painting may have meant to the painter. Just like admiring a painting by one of the masters, admiring research gets better and easier with exposure.

In our field, the basic foundational elements change so rapidly. It's difficult to keep up with the changes, and how each change impacts the rest of the dental hygiene practice and paradigm (are you tired of that word?). Papers published since this millennium began contain the following jaw-dropping info:

•Children of mothers who chew xylitol gum had 70 percent fewer areas of decay than the control group.

•The elderly people in a study of chewing gum had an increased ability to chew and taste.

•Treating gum disease in pregnant women decreases the chance of pre-term, low birthweight in babies.

•Teeth can heal.

Jaw-dropping to be sure. The references are available at the end of this article. Hygienists in private practice and especially those in academia should have access to and already have read these articles. They are foundation-jarring. Or, you can just take my word for it.

Rush Limbaugh unashamedly chides his radio audience not to bother with newspapers, TV news, or radio news. He says he will digest all the news that his audience needs to know and he will tell them what they need to know and what to think about it. He will not lead his flock astray, he says; he just saves them time. His message is delivered smoothly and confidently. Limbaugh's educated audience takes his helpful offer with a grain of salt. They are generally news junkies, CNN heads, and newspaper freaks. It's scary to think that some people do look to him for digested news.

Dental hygienists can be sheep or info-maniacs too.

In August, the Journal of Periodontology contained a research article on an intervention study conducted in Chile. The researchers intervened on behalf of unborn infants by treating the mother's periodontal disease before 28 weeks gestation. The study results showed that the babies had a higher birth weight as well as a longer gestation period than those delivered by untreated mothers. That is, they lowered the percent of pre-term birth as compared to the group without periodontal treatment.

The article had some very interesting side information. For instance, the researchers had a 95 percent confidence. Sounds as if they were pretty confident. Who establishes confidence? Is a 95 percent confidence high? Where do confidence standards start? If they start at 90 percent, maybe 95 percent isn't very good. Are studies published with 32 percent confidence?

Confidence level is one way to decide the strength of the information. A 95 percent confidence is a good one. It's a mathematical calculation done to determine the likelihood of the same result showing up again. So, in this case the researchers were able to be 95 percent sure that, given the same circumstances, the results would be the same 95 times out of 100.

Another number presented in the study was a p-value. This number is the end product of a mathematical calculation to show statistical relevance. The p-value shows the reader if the outcome was worthwhile — in other words, statistically significant. There is a general rule for the p-value; if the p-value is less than 0.05 then the intervention is statistically significant.

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The intervention study on pregnancy was probably difficult to design and calculate. There are a number of modifiable risk factors, such as uncontrolled diabetes, drug use, or smoking that can contribute to pre-term birth or low birthweight.

Of course, to make the study worthwhile at all the confounding pieces have to be accounted for and usually they are. It will say that in the body of the paper. All of these issues were addressed in this groundbreaking research report.

Here is a little table (preceding page) to keep in your reading room. If the actual calculations are of interest, they can be easily sought out. The little table just shows the term, what it should be to make the research worthy of consideration, and what it tells you.

Dental health care providers don't need to read research at all. They can graduate from college and have an attitude of "I'm finished! I never want to do that again." Then they turn into sheep like some of Rush Limbaugh's followers. Consider what the political thinker Alexander Herzen wrote: "It is possible to lead astray an entire generation, to strike it blind, to drive it insane, to direct it towards a false goal. Napoleon proved this."

Licensed oral health care providers can never challenge the status quo when allowing all thoughts to revolve around leisure time activities. This is how they can live a perfectly happy and safe life while simply going wherever the employer points. However, most people would agree that, given the choice, they would rather their medical care provider keep up on new and exciting developments in medicine.

Investing in a professional future takes time. Sometimes it takes suffering through a statistics class or a research course. Not only are there a number of journals dedicated to periodontal disease, there are a few journals dedicated to caries research microbiology and oral microbiology journals as well. Keeping current is a big job. It's easier in a study club setting where either a topic of the day is discussed weekly or monthly.

I used three different research textbooks to make this little table, as well as an Internet site and the counsel of a good Internet friend. You can learn how to use a new brain cell to read research and make conclusions, just as you can by studying art appreciation. You can share brain cells in a study club to learn in a small group, or ewe can just see a movie and trust me.


•Journal of Dental Research Vol 79 No. 3 2000. Söderling E, Isokangas P, Pienihäkkinen K, Tenovuo J: "Influence of Maternal Xylitol Consumption on Acquisition of Mutans Streptococci by Infants."

•Journal of Dentistry for Children January/April 2002. Autio J; "Effects of Xylitol Chewing Gum on Salivary Mutans Streptococcus in Preschool Children."

•Journal of Dental Research: July 2001. Alanen P, "Does Chewing Explain the Caries Preventive Results with Xylitol?"

•Journal of Periodontology August 2002. López N, Smith P, Guierrez J. "Periodontal Therapy May Reduce the Risk of Pre-term Low Birth Weight in Women With Periodontal Disease: A Randomized Controlled Trial."

•Journal of the American Geriatric Society, August 50 (8) 2002. Simons D, Brailsford SR, Kidd EA, Beighton D. "The Effect of Medicated Chewing Gums on Oral Health in Frail Older People: A 1-year Clinical Trial."

Shirley Gutkowski, RDH, BSDH, has been a full time practicing dental hygienist in Madison, Wis., since 1986. Ms. Gutkowski is published in print and on Internet sites, and speaks to groups through Cross Links Presentations. She can be contacted at [email protected].