Answer: Is this a safe treatment for caries?

One of my goals in writing this blog... 

... is to develop some skills that are useful in general.  You know, real skills for real problems.  

In medicine, new treatments and therapies come to market every so often, and many people wonder--is this good for me?  Does this actually work?  What are the risks and benefits? 

In general, how do you evaluate these things?  

This week we consider the dental treatment SDF (Silver Diamine Fluoride).  It's a simple, low-cost way to treat teeth with a coating that not only prevents future cavities (caries), but also seems able to reverse the damage in some existing cavities. 

Suppose that you're considering getting this treatment for someone in your family.  How would you go about doing some checking to see if it's effective, and if it's safe.  (As you know, not all medical treatments turn out to be safe in the end; think radioactive water as a spa treatment... a really bad idea.) 

Ideally, we--the SearchResearchers of the world--would be able to do some kind of sanity check before taking on a new treatment regime. 

This leads to today's Challenge: 

1.  How would you go about determining if SDF is right for you, your family, or your child?  What would you do to research this?  Would you get SDF? 

We SRS folks have a fairly high bar for this kind of research.  We'd like to find multiple lines of support from sources we trust.  So I began with a simple query to learn more about SDF treatment: 

     [ how does SDF treatment work ] 

And found a quick answer at the California Dental Association: 

"Silver diamine fluoride (SDF) is a topical medication used to slow down or stop dental decay in both primary and permanent teeth. ... When applied to a tooth with a cavity, SDF hardens the softened tooth structure, turning the damaged portion of the tooth black in color."  

That's from the California Dental Association (the CDA, which I happen to know is a reputable information provider).  But true to my skeptical nature, I double checked:  the CDA has been around since 1870 and has a great record of being both a philanthropic organization and a provider of information about dentistry in general. 

Now I have an idea what it is and how it works.  It's interesting that they go on to say that: 

"SDF is a conservative approach to managing dental decay and can be used on teeth where there is no pain or discomfort. It is particularly useful for providing dental care to individuals who present challenges to receiving traditional treatment because of their age, behavioral issues, or medical conditions." 

At this point, I wanted  a broad range of perspectives on SDF treatment, so I did a simpler query: 

     [ SDF treatment ] 

and started opening up multiple tabs side-by-side.  Here are some of the pages I opened up (and a few things I learned from each):  

1. Silver Diamine Fluoride: A New, Old Approach to Dental Caries Management.  This is a presentation by Scott L. Tomar (DMD, DrPH) from the 2016 American Association of Community Dental Programs conference.  It's a pretty nice summary (with lots of photos) about how SDF is used, when it should be used, and when it shouldn't.  It gives a bunch of references to other articles about SDF, including what the toxicity is (extraordinarily low) and generally seems very practical.  This is someone who uses SDF in his practice and comments on how it's accepted.  (And gives some very practical advice about its use:  "SDF stains the crap out of everything.")  The author also points out that silver fluoride has been used in Japan for 80 years without any issues.  (Interestingly, they used it to turn teeth black as a cosmetic treatment for teeth!)  

2.  Found several fact sheets about SDF by various community dental programs.  (Little Pearls dentistry for kids; America Academy for Pediatric Dentistry and others.  They all agree--SDF is great for kids because there's no pain, just a gentle painting of the teeth with a microbrush.  Some parts of the teeth do turn black, but only the parts that already have cavities.  As they point out, "that's how you know it's working!"  They correctly point out that inner cavities and difficult to reach cavities are probably not a concern, and visible caries need some other kind of treatment.  

With the query: 

     [ SDF for adults ] 

I found another trove of papers from reputable sources.  For instance, 

3.  A paper from the American Dental Association on Guidelines for SDF treatment of pediatric and special needs patients.  They're more cautious, but point out that SDF works exceptionally well for pediatric and special needs patients (who might have difficulty brushing their own teeth), but that the results are so intriguing that they're going to do additional research. 

4. But in another paper, A systematic review of silver diamine fluoride: Effectiveness and application in older adults.  This is another study of another kind of cavity, this time in older adults.  The results are amazingly good--the effectiveness is incredibly high, and no adverse side-effects were noted. 

To be ultra-cautious, I did searches for: 

     [ SDF adverse reactions ] 

     [ SDF side-effects ] 

and found nothing of consequence.  Everyone noted the staining (and in particular, that if you get it on the patients tongue, they'll have a black mark that will last for a week or so... but it's painless and goes away quickly).  

Overall I read about 5 papers from very different sources (some very technical, from highly regarded journals) and another 10 or so summaries for patients by different dentists who use SDF.  

I admit I was slightly skeptical about this universal acclaim, but then I looked up the cost of the standard SDF medicine that the dentists use.  It's $100/bottle.  Each bottle has around 250 drops, or around 40¢/drop.  Each drop treats around 5 teeth.  You can do the math... that's 8 cents / tooth: Nobody is making any money on this. It just looks like a very effective, very cheap therapy for dental cavities.  

Oddly enough, I actually had to visit my dentist this week and when I asked her about SDF she too was concerned about potential blackening, but "otherwise it sounds great for kids!"  (She also asked if I was studying dentistry... Apparently few people ask about SDF.    

 

A funny aside:  Since it was Halloween, we considered vampire teeth.. like these...

If I were a vampire, I'd worry about the number of cavities caused by an all-blood diet.  I know that the Maasai of the African veldt have a large amount of cow blood and milk in their diet, and surprisingly, they have very low rates of dental cavities. But if very modern vampires (who might consume larger amounts of sugar in their diets) are concerned about caries on their fangs, then SDF might be just the ticket.  And if they happen to turn black, then so much the better, eh? 

Search Lessons 

In this case, the research is pretty overwhelmingly positive.  As one of the research papers I read (UCSF Protocol for Caries Arrest Using Silver Diamine Fluoride: Rationale, Indications, and Consent, J Calif Dent Assoc. 2016 Jan; 44(1): 16–28) pointed out: 

 "Silver diamine fluoride is an inexpensive topical medicament used extensively in other countries to treat dental caries across the age spectrum. No other intervention approaches the ease of application and efficacy. Multiple randomized clinical trials – with hundreds of patients each – support use for caries treatment, thus substantiating an intervention that addresses an unmet need in American dentistry. In August 2014 the Food and Drug Administration (FDA) cleared the first silver diamine fluoride product for market, and as of April 2015 that product is available."

Although I spent a fair bit of time looking for side-effects and adverse side effects (my searches also included the fancy medical term "contraindications," I just didn't find anything.  

So.. would I use this for me and my family?  Yes, although probably not on the front teeth!  

This was a surprisingly simple SRS Challenge.  It was probably a 30 minute task to become comfortable with the current state of research on SDF.  That's a remarkable thing to say.  (I remember when this same kind of background research would have taken days!)  

Search on!  

SearchResearch Challenge (10/31/18): Is this a safe treatment for caries?

Let's consider a real question... 

As you know, new therapies come onto the market every so often. Those therapies have risks and benefits.  How do you evaluate these things?  What do you do to actually do the research you need to evaluate these things? 

Consider this one:  SDF (Silver Diamine Fluoride) treatment is a way to treat teeth with a simple coating that not only prevents future cavities (caries), but also seems able to reverse the damage in some existing cavities.  

Suppose that you're considering getting this treatment for someone in your family.  How would you go about doing some checking to see if it's effective, and if it's safe.  (As you know, not all medical treatments turn out to be safe in the end; think radioactive water as a spa treatment... a really bad idea.)  

Ideally, we--the SearchResearchers of the world--would be able to do some kind of sanity check before taking on a new treatment regime.  

This leads to today's Challenge:  

1.  How would you go about determining if SDF is right for you, your family, or your child?  What would you do to research this?  Would you get SDF? 

Of course I'm interested in what YOU think about SDF, but just as importantly, HOW did you come to this determination?  What steps did you take?  What sources you think are credible, and why?  

Please leave notes about your process in the comments below. I'm looking for some great thoughts here.  Let us all learn how you would do this! 

Search on! 


(And of course, since it's Halloween today, be sure to consider the effects of SDF on vampire teeth!) 

Answer: How can I find lists of things?

A list of items is a useful thing to have. 

When you're learning something new, having a list of examples of that thing gives you something to learn from.  It's a natural way to try and get your mind around a given topic.  We do this all the time.  

This week's Challenge is intended to show you how to quickly get a list of a category.    

As I mentioned, I wanted a list of Pre-Raphaelite artists, and was able to get Google to give me this list.    

But the Challenge was to find a general way to get such lists of things.  Here's the Challenge:  

1.  Can you find a way to find a set of each of the following:  

      a.  Pre-Raphaelite artists 

      b.  fictional works written in the Regency era

      c.  clans in Scotland

      d.  trees that are evergreen throughout the year 

      e.  Canadian Prime Ministers   

In the comments people found out how to do this fairly quickly.  (Note to Regular Readers--not all of the SRS Challenges are hard!!)  

For the Pre-Raphaelite, all I did was: 

     [ list of Pre-Raphaelite artists ] 

and that gave me the set you see above (that I re-arranged slightly to fit into the blog format).  Here's what the SERP looks like: 

Notice the link I highlighted with the red arrow?  That's a link to the Category page on this topic for "Pre-Raphaelite painters."  That's the Wiki version of the "list of all X" for that category.  

This is a useful thing to know about.  You can ALSO search for Category pages like this: 

(Notice that I changed the query slightly to "Scottish clans" -- I tried "clans of Scotland," but found that this worked better.)  

I also modified the evergreens query from the original Challenge question  "trees that are evergreen throughout the year" to [ list of evergreens ] 

As with the other SERPs, notice that there are a few "People Also Ask" questions that can be useful for your research.  

Probably the biggest surprise for me was that the query: 

     [ list of Regency novels ] 

worked SO well:  

HOWEVER.. You might have been thinking of works published in the Regency era (that is, between 1811 and 1822, like Pride and Prejudice) and not a more recent novel like Arabella (published in 1949).  

What happened?  Well, "Regency," when used to describe fiction, now also means:  

1.  Classic Regency fiction written between 1811 and 1822. The works of Jane Austen, Sir Walter Scott, Susan Ferrier, and Maria Edgeworth were all written during this time period.  

2.  Modern Regency fiction, that is, fiction set within the Regency era. These are primarily romance novels (called "Regency romances"), historical fiction set in that period, detective fiction, and military fiction.

A slightly different query, 

     [ list of Regency era novels ] 

gives a more satisfying result.  

And of course, this works with Canadian Prime Ministers as well:  

In this case, I'd like to see a full list of the PMs along with their terms in office, just to check for completeness.  


My favorite list?  Probably this list of early musical instruments.  (That's what you get when you go for Baroque!)   

Although in second place would have to be the Wikipedia List of Lists of Lists!  

Search Lessons

There are really three things to point out this week: 

1.  Check your results!  I know I say this all the time, but the Regency Challenge points it out again.  If you didn't look at some of the results, you might well think that Lord of Scoundrels was written in the early 19th century.  Not so.  Be sure to at least spot check items in any list that you find.  (You might find a scoundrel or two lying in wait.)  

2.  Remember the Category: pages of Wikipedia.  They're often not fought over very much, so they're a bit less likely to have vandalism... and there are Category: pages of things you might never have thought about.  They're worth a look. 

3.  The query [ list of ... ] is a handy construct to use when you're just beginning to learn about something.  

Enjoy your listing. 

Search on!  

The Baader-Meinhof effect and flying over the southwest United States

The frequency illusion... 

... aka the Baader-Meinhof effect, happens when you learn something new, and then suddenly start to see it everywhere.  This happens when you finally decide to buy a new car and after weeks of agonizing, you finally pick that very special one, the very distinctive car that speaks to only you.  You're so happy.  

And then you start to see that car everywhere. It's not distinctive at all, but actually pretty common.  

That's the Baader-Meinhof effect.  It happens because you don't notice all of the cars that are just like it before you made the choice--it's an illusion of the frequency of the item.  

It also happens with words.  If I use the term whale shark and you learn that as a new concept, suddenly you'll see it everywhere.  Trust me, you'll start to see whale shark everywhere now.  

So when Regular Reader Ramón wrote it with a Washington Post article, it was a nice example of this effect.  He found a real, live example of our Challenge from last week:  How can I make a movie of my flight?  In that post, I show you how to make a video by using Google Earth to capture a flight path.  

Ramón noticed that the Post article "Flying over Trump's wall" used the exact same technique (although they did some great post-production video editing).   In an early part of the fly-over, it looks like this: 

Thanks for the find, Ramón!  Now we all know how this brilliant piece of visualization was created.  

Search (and visualize) on! 

SearchResearch Challenge (10/18/18): How can you find lists of things?

I often find myself in the position of looking... 

... for a list of things.  It's a natural way to try and get your mind around a given topic--if I can give you a list of items in that category, you'll get a sense of how that category of thing is defined (or at least how it looks).  People often do this when it's hard to define something precisely.  The difference between a vegetable and a fruit is tricky, but if I tell you that apples, strawberries, bananas, and grapes are all fruits while potatoes, carrots, corn, and peas are all vegetables, you'll start to get the idea. This doesn't give you a technical definition (difficult question: is a cucumber a fruit or a vegetable?), but it gives you a working intuition.  

This came up for me a few weeks ago when I went to see an art exhibition of the Pre-Raphaelites.  I love their artwork, and while I knew a few of the artists (Dante Gabriel Rossetti, John Everett Millais, and John William Waterhouse, I couldn't name any others, although I know I'd recognize their names).  Who are these folks??   Here's the kind of thing I wanted to get from a search:  

This week's Challenge is to figure out the best way to search on Google for a set of things that share a common property.  That is, to find a way to create this image above.  The Challenge: 

1.  Can you find a way to find a set of each of the following:  

      a.  Pre-Raphaelite artists 

      b.  fictional works written in the Regency era

      c.  clans in Scotland

      d.  trees that are evergreen throughout the year 

      e.  Canadian Prime Ministers   

Once you figure out how to do this, you'll be able to this, and much more!

As always, be sure to tell us how you do it. 

AND... if you find a particularly interesting set of things, be sure to leave a comment telling us about the great set you found (and what it is!).  

Search on! 

Answer: How can I make a movie of my flight?

My goal was simple...  

... I just wanted a movie that's a scan of the flight path.    

Why?  Because as I was looking out the window, I saw beautiful things, extraordinary things, and I wanted to be able to stop the plane and look around a bit.  How could I do that?  

So this became a search for a tool that would let me do exactly this.  I set up the Challenge like this:    

1.  Can you make a movie that recreates the experience of flying from San Francisco to Austin?  Obviously, you don't want it to take all 4 hours.  How about a 2 minute version of the flight that just shows off the really interesting parts between Arizona and West Texas? 

This isn't an ordinary SearchResearch Challenge--this is really a Challenge about (A) How to find such a tool?  and (B) How to use the tool to create a video that follows the flight path.   (You'll get to choose your own tool, along with your altitude and camera angles.)  

How can I find a tool that could do this?   I started with a bit of a question to Google: 

     [ make a movie flight over the earth ] 

The results were pretty interesting--here's the SERP:  

Just looking at this suggests that I can make a video like this with Google Earth Pro.  Great!  

After a few queries of the form:  [ how to make a video in Google Earth ], I was able to piece together a way to create the video.  Here's how I did it: 

1.  Open Google Earth Pro and draw a path.  Here I approximate it with 2 segments--one starting at SFO airport, bending slightly in New Mexico and then continuing on to Austin. Just use the "path tool" in the toolbar at the top.   Two clicks, and then I gave the path a name:  SFO/AUS path. Click on the path tool (shown below) to make it:  

In the image below, I created a path, and added to yellow push pins (just to make the start/stop locations more visible).  This is the flight path.  

2.  Save the path as a tour.  First select the path on the left; then click on the "Play Tour" button.  This will make the Play Tour toolbar appear like this: 

The Play Tour controller will popup to the right of that menu item in the lower left of the window.  This will let you save the SFO/AUS path as a Tour:  

Once you've got that, you can click on the floppy disk icon (far right in above diagram--no, I don't know why they show a floppy disk icon as the "Save" button).  

That will create a new item in the list in the upper left--here I named it "SFO/AUS Tour."  

3.  Now... Open the Movie Maker tool.  It's in the menu pulldown list Tools>Movie Maker.  Note: You need to close the Play Tour controller first!  This will make the tour playback automatically and will create a video as a side-effect. 

Here's an example of what that Tour video looks like (this isn't the entire flight from SFO to Austin, it's just a sample of the path... it gives you a good idea).  URL: https://www.youtube.com/watch?v=c0sRxmPoRWo

There are lots of options you can do to make it fly in the way you want.  In particular, you could move the view position manually to fly over the entire route quickly.  Here's what that video would look like.  It's kind of jerky because I'm actually pulling the viewpoint along moment to moment, and I wasn't super careful.  

My original goal, remember, was to be able to fly along the flight path and stop wherever I wanted.  As wonderful as YouTube is, the UI for YouTube isn't the best way to inspect the terrain as you fly overhead.  For that, you want a downloadable MP4 file that you can open with a video controller (like Quicktime Player).  Here's the link to that video.  Try right-clicking the link to download it, open in your favorite video controller,  and then try zipping back and forth like a boss--you can easily pause, go forward, go backward.  It's a very different experience than YouTube (or any online video system) can do.  Direct manipulation is really handy sometimes.  This is one of those times.  

Search Lessons 

Finding the right tool is often a prerequisite to satisfying your search goals.  In this case, we had to find the right tool, and a simple search found that Google Earth could do this.  After figuring that out (and downloading Google Earth Pro), it was a process of figuring out how to actually make a movie that would follow the flight path of the plane.  THAT involved a bit of futzing around, but once I figured out the sequence of button clicks, it was straight forward.  

And now I have my video... on my computer, ready to zip back and forth along the flight path. 

Search on!  

(A new Challenge tomorrow to get us back on track!) 




   

Delay of game... (Oct 10, 2018)

I hate to do this to you... 

... because the answer to last week's Challenge is fun..  but I'm doing a tour of upstate New York this week.  I'm teaching at Cornell today and the University of Rochester tomorrow.  

"Far above Cayuga's waters..."  
Cornell University

As a side-effect, I've had no time to write up my answer to the "Can you make a video?" Challenge. 

BUT... I'll have time this weekend, so I'll post my solution next Monday, October 15.  

Keep searching (and making those videos) until then! 

In the meantime, I'll be teaching (and occasionally looking for the color changes in the fall leaves... which I have to admit, seem rather muted this season).  

Search on! 

Fermi Estimation again (Part 2)

Estimation is an art... 

... that deserves practice.  And by practice, I mean that you very deliberately look at your mistakes and learn from them.  

In an earlier post about Fermi Estimation, I showed how I estimated Enrico Fermi's height by this method.  Here's an infographic showing what I did.  

That's great.  

HOWEVER... As good as estimation is, it's worth checking your work from time to time in order to learn where you can be better.  

In that earlier estimation post, Regular Reader Chris wrote in with a great comment.  Here's what he wrote: 

As Jon said in an earlier post, the average size Italian was 5 feet 6, but I would say he is below average height. My estimates would make him between 5 and 5"3"

Using this image and assuming an bench height of about 30 inches, this would make him only 60 inches tall (5 feet). Using this image with Robert Oppenheimer (on the left)  I estimate him [Fermi] at about 5'2". According to the NY Times Obituary, Oppenheimer was 6 ft...  Likewise in this photo he [Fermi] is a good foot shorter than Chancellor Hutchins (right) who was 6'3" according to Commentary Magazine. 

Aside from being a GREAT example of using photos to estimate height (rule of thumb: use more than one photo to verify; also get the heights of other items in the photos), this also bring up another valuable estimation heuristic:  Always double check your work.  

What went wrong in my original post?  That's easy to spot:  My original estimate of his head size was 9.4 inches (21.9 cm).  Where did THAT number come from ?  From two sources:  (1) my estimate of his head size by comparison with the control panel behind him.  I know the size of those control knobs, and I estimated from that.  (2) I measured my own head size.  Since the two numbers were close, I went with that number. 

Thing is, I'm taller than Oppenheimer and a bit shorter than Hutchins.  So it's not a surprise that my head measurement would produce a fairly tall estimate.  

Chris showed us a great estimation validation method--Look at the person side-by-side with known people (and known heights).  

Here's another picture showing three famous physicists:  E. O. Lawrence, Enrico Fermi, and Isidor Isaac Rabi standing side-by-side.  A quick search for Lawrence shows his height at 6 feet (182.8 cm).  A quick search for Rabi shows his height at 5' 4" (162.5 cm)  So this estimate by photograph is probably pretty accurate.   Fermi was a bit shorter than his friends, right around 5' 3" or so.  

Estimation Lesson 

1.  If you take an initial estimate and multiply it by 7.5, then any error you have in your initial guess is going to be magnified by 7.5!  Caution:  Make sure your initial data is pretty close before you go multiplying it by a fairly large facto.  

2.  It's always good to have two very different ways of estimating.  In this case, a quick photo check would have shown that my original estimate was off.  I'll do that next time for sure!  

Estimate on! 

SearchResearch Challenge (10/3/18): How can I make a movie of my flight?

Last week I flew from San Francisco to Austin, Texas... 

... as usual, I had a window seat to I could see the landscape slowly rolling past the window.  In my opinion, this is one of the most wonderful things you can do: look out the window at the glorious southwestern geology.  

At some point in my flight, I saw many extraordinary things... forests, craters, mountains, brilliant white salt flats, and center-pivot irrigation systems that defined small communities in the middle of a vast loneliness.  

What I really wanted to do was to make a film that would capture all of the beauty of the country we were passing over.  Alas, I didn't think to tape my video camera to the outside of the plane.. and have it run for the 4 hour flight.  

Here's the path we took from San Francisco, over Phoenix, over El Paso and over West Texas into Austin.  

After I landed, I thought that there MUST be a way to do this with a bit of online research.  After all, we know that there's a lot of aerial imagery out there.  So... this led to this week's Challenge:  

1.  Can you make a movie that recreates the experience of flying from San Francisco to Austin?  Obviously, you don't want it to take all 4 hours.  How about a 2 minute version of the flight that just shows off the really interesting parts between Arizona and West Texas? 

This isn't an ordinary SearchResearch Challenge--this is really a Challenge about (A) How to find such a tool?  and (B) How to use the tool to create a video that follows the flight path.   (You'll get to choose your own tool, along with your altitude and camera angles.)  

Be sure to tell us how you did it (and what searches you had to do).  AND, if you would, please post your video to YouTube so we can all see what you made.  

Of course, once you've made the video, be sure to tell us what interesting and wonderful things you found along the way.  

Here's one of the things I found--a huge patch of white sand (naturally enough, this is White Sands National Monument).  It's a big white sandy beach in the southern part of New Mexico.  It's really obvious--once you see it and learn where it is, you won't be able to NOT spot it on any aerial photo of New Mexico.  

After this, you'll literally see the world differently. 

Search on!