MF+SF

__Title:__ The Effects of Liquid Type and Temperature on Tooth Enamel

__Problem:__ What liquid and what temperature cause tooth enamel to develop discoloration the quickest?

__Hypothesis:__ If the liquid is most acidic and the highest temperature then it will stain the tooth enamel the quickest(most).

__Procedure:__
 * 1) Wash and dry 12 raw eggs.
 * 2) Insert a long needle into the large end of each egg to make a small hole.
 * 3) Use the needle to make a slightly larger hole on the other side of the egg.
 * 4) Push the needle into the center of the egg and move it around to break the yolk.
 * 5) Hold the egg over the trash bowl with larger hole facing down.
 * 6) Place balloon inflater over the small hole and blow firmly until all of the egg comes out.
 * 7) Rinse out the egg by running a thin stream of water into the large hole.
 * 8) Blow out the extra water using the balloon inflater.
 * 9) Prop up the eggshell in a dish drainer for it to dry (Larger hole facing down).
 * 10) Measure 175 mL of each liquid, using a beaker.
 * 11) Do this 3 times.
 * 12) Place each measured liquid into a glass cup.
 * 13) Place a hollowed-out egg into each cup.
 * 14) Place one glass cup of each liquid into the refrigerator (39 degrees F), the oven (170 degrees F), and the kitchen counter (65 degrees F).
 * 15) Observe changes in color every 12 hours by removing the egg from its liquid with tongs.
 * 16) Record the amount of days (half days) it takes for significant discoloration, using discoloration scale. There is a 5 day limit.
 * 17) Repeat procedure 6 more times to complete 7 trials.

__Materials List:__
 * 1) Gatorade
 * 2) Coca-Cola
 * 3) Coffee
 * 4) Eggs
 * 5) Thermometer
 * 6) Refrigerator
 * 7) Oven
 * 8) Glass Cups
 * 9) Needle
 * 10) Camera
 * 11) Water
 * 12) Trash Bowl
 * 13) Sink
 * 14) Dish Drainer
 * 15) Beaker
 * 16) Tongs
 * 17) Balloon Inflater
 * 18) pH Indicator Strips
 * 19) Discoloration Ratings Chart (self-made, one for brown, one for red)

__Logbook:__ 11/5/11 - Collected all the materials needed for experimentation. Hollowed out twelve eggs, as described in the procedure. Measured 175 mL of each Gatorade, Coca-Cola, coffee, and water, and placed the liquids into cups. Performed this 3 times in order to set up trial 1. Tested the pH of each liquid and found that Coca-Cola is 3.5, Gatorade is 3, coffee is 2.5, and water is 7, so Coffee is the most acidic. Dropped a hollowed-out egg into each cup. Placed cups of each liquid into the appropiate temperature area, one of each in the oven, one of each in the refrigerator, and one of each on the kitchen counter. This was completed at 7 pm. Pictures were taken.

11/6/11 - Checked the eggs at 7 am. All of the eggs in water have received no discoloration. The egg in the hot Coca-Cola has reached a 5 on the discoloration scale which means it has already reached significant discoloration, the egg in room temperature Coca-Cola was a 3, and the egg in the cold Coca-Cola was also a 3. The egg in hot coffee was a 4 on my discoloration scale, the egg in room temperature coffee was also a 4 on the scale, and the egg in cold coffee was a 2. The egg in hot Gatorade reached a 3 and has started to erode, the egg in the room temperature Gatorade was a 3, and the egg in cold Gatorade was a 5 which means it also has reached significant discoloration. In the oven, the liquids have started to evaporate. Added 100 mL to each liquid in the oven. 11/6/11 (cont.) - Checked the eggs at 7 pm. Still all the eggs in water had received no discoloration. The egg in the room temperature Coca-Cola changed to a 4 and the egg in the cold Coca-Cola remained at a 3. The egg in the hot coffee reached significant discoloration, being a 5, the egg in the room temperature coffee remained at a 4, and the egg in the cold coffee changed to a 3. The egg in the hot Gatorade changed to a 4 and is still eroded and the egg in the room temperature Gatorade gained discoloration, now being a 4. Added 100 mL to the Gatorade in the oven, for it evaporated.

11/7/11 - Checked eggs at 7 am. All eggs in the water had no discoloration. The egg in room temperature Coca-Cola remained a 4 on the ratings chart and the egg in cold Coca-Cola was now a 4. The egg in room temperature coffee stayed at a 4 and the egg in the cold coffee remained a 3. The egg in hot Gatorade was still a 4 with more erosion. Added about 75 mL to the gatorade in the oven. Checked eggs again at 7 pm. The eggs in water still had no discoloration. The egg in the room temperature Coca-Cola was again a 4 and the egg in the cold Coca-Cola reached a 5 meaning significant discoloration. The egg in room temperature coffee also made it to a 5, or significant discoloration and the egg in the cold coffee changed to a 4. The egg in the room temperature Gatorade reached a 5, so did the egg in hot Gatorade, so both reached significant discoloration. The egg in the hot Gatorade also was starting to fall apart due to erosion.

11/8/11 - Checked eggs at 7 am. All eggs in water had no discoloration. The egg in the room temperature Coca-Cola reached significant discoloration, it was a 5 on the scale. The egg in cold coffee stayed a 4. Checked the eggs again at 7 pm. The eggs in water still received no discoloration. The egg in the cold coffee remained at a 4 again.

11/9/11 - Checked the eggs at 7 am and 7 pm. For both checks the eggs in water received no discoloration. The egg in cold coffee remained at a 4 for both checks.

11/10/11 - Checked the eggs at 7 am and 7 pm. For both checks the eggs in water still received no discoloration. The egg in cold coffee was still a 4 for each check. So all of these eggs end the trial with taking 5 or more days to discolor.

11/12/11 - Hollowed out twelve more eggs. Measured 175 mL of each Gatorade, Coca-Cola, coffee, and water, and placed the liquids into cups. Performed this 3 times in order to set up trial 2. Dropped a hollowed-out egg into each cup. Placed cups of each liquid into the appropiate temperature area, one of each in the oven, one of each in the refrigerator, and one of each on the kitchen counter. This was done at 7 pm.

11/13/11 - Checked the eggs at 7 am. None of the eggs in the water started to discolor. The egg in hot Coca-Cola reached a 5 on the chart, obtaining signficant discoloration, the egg in room temperature Coca-Cola was a 3, and the egg in the cold Coca-Cola was also a 3. The egg in hot coffee received significant discoloration by reaching a 5, the egg in room temperature coffee was a 3, and the egg in cold coffee was a 2. The egg in hot Gatorade was a 4 and it was eroding, the egg in the room temperature Gatorade was a 4, and the egg in cold Gatorade already reached discoloration, it was a 5. Checked the eggs again at 7 pm. The eggs in water still had no discoloration. The egg in room temperature Coca-Cola was still a 3 and the egg in cold Coca-Cola was also remaining at a 3 on the chart. The egg in room temperature coffee was, again, a 3 and the egg in cold coffee changed to a 3. The egg in hot Gatorade was still a 4 and was still eroding and the egg in room temperature Gatorade reached significant discoloration, it was a 5. Added 100 mL to the Gatorade in the oven, since it started to evaporate.

11/14/11 - Checked the eggs at 7 in the morning. All the eggs in water had no discoloration. The eggs in both room temperature and cold Coca-Cola moved up to a 4. The egg in room temperature coffee was now a 4 and the egg in cold coffee was surprisingly a 4. The egg in hot Gatorade stayed at a 4 and was continuing to erode. Checked the eggs again at 7 pm. The eggs in water still have received no discoloration. The eggs in room temperature and cold Coca-Cola were both 4's. The eggs in room temperature and cold coffee were also both 4's again. The egg in hot gatorade was very eroded and reached a 5 on the chart.

11/15/11 - Checked the eggs at 7 am and at 7 pm. During both checks the eggs in water had no discoloration. The egg in room temperature Coca-Cola was 5 at 7 am, reaching significant discoloration and the egg in cold Coca-Cola was a 4 in the morning and in the evening. The egg in Room temperature coffee was, like the Coke, a 5 in the morning and the egg in cold coffee was a 4 in the morning and the night.

11/16/11 - Checked the eggs at 7 am and 7 pm. Both checks consisted of water having no discoloration. The egg in cold Coca-Cola turned to a 5 at 7 pm. The egg in cold coffee remained a 4 for both checks.

11/17/11 - Checked the four remaining eggs at 7 am and 7 pm. The eggs in the water had no discoloration. The egg in cold coffee remained at the 4 during both checks. This brought Trial 2 to a close.

11/28/11 - Hollowed out twelve more eggs. Measured 175 mL of each Gatorade, Coca-Cola, coffee, and water, and placed the liquids into cups. Performed this 3 times in order to set up trial 3. Dropped a hollowed-out egg into each cup. Placed cups of each liquid into the appropiate temperature area, one of each in the oven, one of each in the refrigerator, and one of each on the kitchen counter. This was done at 7 pm. 11/29/11 - Checked the eggs at 7 am. All of the eggs in water have received no discoloration. The egg in the hot Coca-Cola has reached a 5 on the discoloration scale which means it has already reached significant discoloration, the egg in room temperature Coca-Cola was a 2, and the egg in the cold Coca-Cola was also a 2. The egg in hot coffee was a 4 on my discoloration scale, the egg in room temperature coffee was a 3 on the scale, and the egg in cold coffee was a 2. The egg in hot Gatorade reached a 3 and has started to erode, the egg in the room temperature Gatorade was a 4, and the egg in cold Gatorade was a 5 which means it also has reached significant discoloration. In the oven, the liquids have started to evaporate. Added 100 mL of each liquid to the glasses in the oven. Checked the eggs at 7 pm. Still all the eggs in water had received no discoloration. The egg in the room temperature Coca-Cola remained a 2 and the egg in the cold Coca-Cola moved to a 3 on the chart. The egg in the hot coffee reached significant discoloration, being a 5, the egg in the room temperature coffee remained a 3, and the egg in the cold coffee also remained a 2. The egg in the hot Gatorade changed to a 4 and is still eroded and the egg in the room temperature Gatorade showed no more discoloration from the morning and is still a 4. Added 100 mL to the Gatorade in the oven, for it evaporated.

11/30/11 - Checked the eggs at 7 in the morning. All the eggs in water had no discoloration. The egg in the room temperature Coca-Cola moved up to a 3. The egg in the cold Coca-Cola remained a 3. The egg in room temperature coffee was now a 4 and the egg in cold coffee remained a 2, which was quite different from the last trial at the same time. The egg in hot Gatorade stayed at a 4 and was continuing to erode and the egg in the room temperature Gatorade remained a 4. Checked the eggs again at 7 pm. The eggs in water still have received no discoloration. The egg in the room temperature coffee remained a 4 and the egg in the cold coffee remained a 2. The eggs in room temperature and cold Coca-Cola were both 3's. The egg in room temperature Gatorade remained a 4 and the egg in hot gatorade was very eroded and reached a 5 on the chart.

12/1/11 - Checked the eggs again at 7 am. The eggs in water still have received no discoloration. The egg in the room temperature coffee remained a 4 and the egg in the cold coffee moved to a 3. The egg in room temperature Coca-Cola moved to a 4 and cold Coca-Cola egg was still a 3. The egg in room temperature Gatorade remained a 4. There was very little difference in coloration when the eggs were checked at 7pm. All of the eggs had the same rating as the morning check except for the egg in the cold Coca-Cola which moved up to a 4 on the discoloration chart.

12/2/11 - Checked the eggs again at 7 am. The eggs in water still have received no discoloration. The eggs in room temperature and cold coffee remained the same at 4 and 3 respectively. The egg in the room temperature Gatorade also remained the same as the previous check at 4. There was a color change with the room temperature Coca-Cola, it was now a 5, but the cold Coca-Cola remained a 4. At the 7 pm check, the cold Coca-Cola moved to a 5 with significant discoloration as did the room temperature Gatorade. It was now a 5. The other eggs remained the same as the rating from the morning.

12/3/11 - Checked the remaining eggs at 7 am and 7 pm. The eggs in the water had no discoloration. All of the other eggs remained the same as the previous check, except for one egg. The egg in the cold coffee was now a rating of 4 at the morning check. Trial 3 has ended.

12/6/11 - Hollowed out twelve more eggs. Measured 175 mL of each Gatorade, Coca-Cola, coffee, and water, and placed the liquids into cups. Performed this 3 times in order to set up trial 4. Dropped a hollowed-out egg into each cup. Placed cups of each liquid into the appropiate temperature area, one of each in the oven, one of each in the refrigerator, and one of each on the kitchen counter. This was done at 7 pm.

12/7/11 - Checked the eggs at 7 am. None of the eggs in the water started to discolor. The egg in hot Coca-Cola reached a 5 on the chart, obtaining signficant discoloration, the egg in room temperature Coca-Cola was a 3, and the egg in the cold Coca-Cola was also a 3. The egg in hot coffee received significant discoloration by reaching a 5, the egg in room temperature coffee was a 3, and the egg in cold coffee was a 2. The egg in hot Gatorade was a 4 and it was eroding, the egg in the room temperature Gatorade was a 4, and the egg in cold Gatorade already reached discoloration, it was a 5. Checked the eggs again at 7 pm. The eggs in water still had no discoloration. The egg in room temperature Coca-Cola was still a 3 and the egg in cold Coca-Cola was also remaining at a 3 on the chart. The egg in room temperature coffee was, again, a 3 and the egg in cold coffee changed to a 3. The egg in hot Gatorade was still a 4 and was still eroding and the egg in room temperature Gatorade reached significant discoloration, it was a 5. Added 100 mL to the Gatorade in the oven, since it started to evaporate. 12/8/11 - Checked the eggs at 7 in the morning. All the eggs in water had no discoloration. The eggs in both room temperature and cold Coca-Cola moved up to a 4. The egg in room temperature coffee was now a 4 and the egg in cold coffee was surprisingly a 4. The egg in hot Gatorade stayed at a 4 and was continuing to erode. Checked the eggs again at 7 pm. The eggs in water still have received no discoloration. The eggs in room temperature and cold Coca-Cola were both 4's. The eggs in room temperature and cold coffee were also both 4's again. The egg in hot gatorade was very eroded and reached a 5 on the chart.

12/9/11 - Checked the eggs at 7 am and at 7 pm. During both checks the eggs in water had no discoloration. The egg in room temperature Coca-Cola was 5 at 7 am, reaching significant discoloration and the egg in cold Coca-Cola was a 4 in the morning and in the evening. The egg in Room temperature coffee was, like the Coke, a 5 in the morning and the egg in cold coffee was a 4 in the morning and the night.

12/10/11 - Checked the eggs at 7 am and 7 pm. Both checks consisted of water having no discoloration. The egg in cold Coca-Cola turned to a 5 at 7 pm. The egg in cold coffee remained a 4 for both checks.

12/11/11 - Checked the four remaining eggs at 7 am and 7 pm. The eggs in the water had no discoloration. The egg in cold coffee remained at the 4 during both checks. This brought Trial 4 to an end.

12/15/11 - Hollowed out twelve more eggs. Measured 175 mL of each Gatorade, Coca-Cola, coffee, and water, and placed the liquids into cups. Performed this 3 times in order to set up trial 2. Dropped a hollowed-out egg into each cup. Placed cups of each liquid into the appropiate temperature area, one of each in the oven, one of each in the refrigerator, and one of each on the kitchen counter. This was done at 7 pm.

12/16/11 - Checked the eggs at 7 am. All of the eggs in water have received no discoloration. The egg in the hot Coca-Cola has reached a 5 on the discoloration scale which means it has already reached significant discoloration, the egg in room temperature Coca-Cola was a 3, and the egg in the cold Coca-Cola was a 2. The egg in hot coffee was a 4 on my discoloration scale, the egg in room temperature coffee was a 3 on the scale, and the egg in cold coffee was a 2. The egg in hot Gatorade reached a 3 and has started to erode, the egg in the room temperature Gatorade was a 4, and the egg in cold Gatorade was a 5 which means it also has reached significant discoloration. In the oven, the liquids have started to evaporate. Added 100 mL of each liquid to the glasses in the oven. Checked the eggs at 7 pm. Still all the eggs in water had received no discoloration. The egg in the room temperature Coca-Cola remained a 3 and the egg in the cold Coca-Cola also remained a 2 on the chart. The egg in the hot coffee reached significant discoloration, being a 5, the egg in the room temperature coffee remained a 3, and the egg in the cold coffee also remained a 2. The egg in the hot Gatorade changed to a 4 and is still eroded and the egg in the room temperature Gatorade showed no more discoloration from the morning and is still a 4. Added 100 mL to the Gatorade in the oven, for it evaporated.

12/17/11 - Checked eggs at 7 am. All eggs in the water had no discoloration. The egg in room temperature Coca-Cola remained a 3 on the ratings chart and the egg in cold Coca-Cola was now a 3. The egg in room temperature coffee stayed at a 3 and the egg in the cold coffee moved to a 3. The egg in the room temperature Gatorade moved to a 5 rating. The egg in hot Gatorade was still a 4 with more erosion. Added about 75 mL to the gatorade in the oven. Checked eggs again at 7 pm. The eggs in water still had no discoloration. The egg in the cold Coca-Cola remained a 3 and the egg in the cold Coca-Cola also remained a 3. The eggs in room temperature coffee and Coca-Cola both moved to a 4. The egg in hot Gatorade was a 5 and reached significant discoloration. The egg in the hot Gatorade also was starting to fall apart due to erosion.

12/18/11 - Checked the eggs at 7 in the morning. All the eggs in water had no discoloration. There was no change in discoloration from the last time the eggs were checked. The eggs in the cold coffee and Coca-Cola remained at 3 and the eggs in room temperature coffee and Coca-Cola remained at 4. At 7pm, the only difference from the morning check was that the egg in the room temperature Coca-Cola reached significant discoloration and was now a 5.

12/19/11 - At 7am, the eggs were checked. All eggs in water had no discoloration. The egg in the cold Coca-Cola moved to a 4 rating, but the egg in the cold coffee remained at a rating of 3. The egg in the room temperature reached significant discoloration with a rating of 5. At 7pm, there was no change from the morning check. The egg in the cold Coca-Cola remained a 4 and the egg in the cold coffee remained a 3.The eggs in the water showed no discoloration.

12/20/11 - Checked the eggs at 7am and there were no changes from the previous check. The eggs in the cold Coca-Cola and the cold coffee had ratings of 4 and 3 respectively and the eggs in the water had no discoloration. At the 7pm check, all eggs remained at their same morning ratings. This ends Trial 5.

12/21/11 - The next two trials will be performed at the same time in order to complete the experiment. Hollowed out 24 eggs. Measured 175 mL of each Gatorade, Coca-Cola, coffee, and water, and placed the liquids into cups. Performed this 6 times in order to set up trials 6 and 7. Dropped a hollowed-out egg into each cup. Placed cups of each liquid into the appropriate temperature area, two of each in the oven, two of each in the refrigerator, and two of each on the kitchen counter. This was done at 7pm.

12/22/11 - Trial 6: Checked the eggs at 7am. All of the eggs in the water had no discoloration at all. The egg in the hot Gatorade had a discoloration rating of 3 and was eroding as in previous trials. The egg in the room temperature Gatorade had a rating of 4. The egg in the cold Gatorade reached significant discoloration and had a rating of 5. The egg in the hot Coca-Cola also reached significant discoloration with a rating of 5. The egg in the room temperature Coca-Cola only reached a rating of 2, as did the egg in the cold Coca-Cola. The egg in the hot coffee had a rating of 4 and the egg in the room temperature coffee had a discoloration rating of 3. The egg in the cold coffee only reached a rating of 2.

Trial 7: Checked the eggs at 7am. All of the eggs in the water showed no discoloration. The egg in the hot Gatorade had a rating of 3 and was eroding, The egg in the room temperature Gatorade had a rating of 4 and the egg in the cold Gatorade had significant discoloration with a rating of 5. The egg in the hot Coca-Cola reached a rating of 5 showing significant discoloration. The egg in the room temperature Coca-Cola had a rating of 3 and the egg in the cold Coca-Cola had a rating of 2. The egg in the hot coffee had a discoloration rating of 4. The egg in the room temperature coffee had a rating of 3 and the egg in the cold coffee had a rating of 2.

Trial 6: Checked the eggs at 7pm. All of the eggs in the water remained the same with no discoloration. The eggs in the hot Gatorade had a rating of 4 and showed more erosion. The egg in the room temperature Gatorade had a rating of 4. The egg in the room temperature Coca-Cola remained at the rating of 2, but the egg in the cold Coca-Cola moved to a 3. The egg in the room temperature coffee remained at a rating of 3 and the egg in the cold coffee remained at a 2.

Trial 7: Checked the eggs at 7pm. All of the eggs in the water had no discoloration. The egg in the hot Gatorade was eroding and moved to a rating of 4 and the egg in the room temperature Gatorade remained at a 4. The egg in the room temperature Coca-Cola was a 3 and the egg in the cold Coca-Cola had a rating of 2 on the discoloration chart. The egg in the hot coffee moved to a rating of 5 with significant discoloration. The egg in the room temperature coffee remained at a 3. The egg in the cold coffee was a rating of 2.

12/23/11 - Trial 6: Checked the eggs of 7am. All of the eggs in the water showed no discoloration. The eroding egg in the hot Gatorade remained at a 4. The egg in th room temperature Gatorade also remained at a 4. The ratings for the eggs in the room temperature and cold Coca-Cola were both 3s. The egg in the room temperature coffee was a 4 and the egg in the cold coffee remained at the rating of 2.

Trial 7: Checked the eggs at 7am. All of the eggs in the water showed no change in coloration. The egg in the hot Gatorade remained at a rating of 4 and was continuing to erode. The egg in the room temperature Gatorade moved to a 5 showing significant discoloration. The eggs in the room temperature Coca-Cola and in the cold Coca-Cola were both a 3. The eggs in the room temperature coffee and in the cold coffee also had ratings of 3.

Trial 6: Checked the eggs at 7pm. All of the eggs in the water had no discoloration. The egg in the hot Gatorade reached significant discoloration with a rating of 5. The egg in the room temperature Gatorade remained at a rating of 4. The egg in the room temperature Coca-Cola had a rating of 3 and the egg in the cold Coca-Cola also had a rating of 3. The egg in the room temperature coffee had a discoloration rating of 4 and the egg in the cold coffee had a rating of 2.

Trial 7: Checked the eggs at 7pm. All of the eggs in the water had no discoloration. The egg in the hot Gatorade reached a rating of 5. The egg in the room temperature Coca-Cola had a rating of 4 and the egg in the cold Coca-Cola was a 3. The egg in the room temperature coffee moved to a rating of 4 and the egg in the cold coffee remained at the rating of 3.

12/24/11 - Trial 6: Checked the eggs at 7am. Again, the eggs in the water had no discoloration. The egg in the room temperature Gatorade had a discoloration rating of 4 as did the eggs in the room temperature Coca-Cola and in the room temperature coffee. The eggs in the cold Coca-Cola and in the cold coffee had ratings of 3.

Trial 7: Checked the eggs at 7am. All of the eggs in the water had no discoloration. The egg in the room temperature Coca-Cola had a rating of 4 and the egg in the cold Coca-Cola had a rating of 3. The egg in the room temperature coffee had a discoloration rating of 4 and the egg in cold coffee was a 3.

Trial 6: Checked the eggs at 7pm. The eggs in the water showed no discoloration. The egg in room temperature Gatorade had a rating of 4. The eggs in the room temperature and the cold Coca-Cola had ratings of 4. The egg in room temperature coffee had a discoloration rating of 4 and the egg in the cold coffee had a rating of 3.

Trial 7: Checked the eggs at 7pm. The eggs in the water had no change in coloration. The egg in room temperature Coca-Cola had moved to a 5 with significant discoloration. The egg in the cold Coca-Cola had a discoloration rating of 3. The egg in the room temperature coffee had a rating of 4 and the egg in the cold coffee had a rating of 3.

12/25/11 - Trial 6: Checked the eggs at 7am. The eggs in the water showed no discoloration. The egg in the room temperature Gatorade remained at a rating of 4. The egg in the room temperature Coca-Cola showed significant discoloration with a rating of 5. The egg in the cold Coca-Cola had a rating of 4. The egg in the room temperature coffee had a rating of 4 and the egg in the cold coffee was a 3.

Trial 7: Checked the eggs at 7am. All of the eggs in water showed no discoloration. The egg in cold Coca-Cola had a rating of 4. The egg in the room temperature coffee moved to a 5 and showed significant discoloration. The egg in the cold coffee had a rating of 3.

Trial 6: Checked the eggs at 7pm. All of the eggs in the water still had no discoloration. The egg in the room temperature Gatorade showed significant discoloration with a rating of 5. The egg in the cold Coca-Cola also had a rating of 5. The egg in the room temperature coffee had a rating of 4 and the egg in the cold coffee had a rating of 3.

Trial 7: Checked the eggs at 7pm. All of the eggs in the water had no discoloration. The egg in the cold Coca-Cola had a rating of 4 and the egg in the cold coffee was a 3. 12/26/11 - Trial 6: Checked the eggs at 7am. The eggs in the water remained the same with no discoloration. The eggs in the room temperature coffee and in the cold coffee had discoloration rating of 4.

Trial 7: Trial 7: Checked the eggs at 7am. All of the eggs in the water had no discoloration. The egg in the cold Coca-Cola had a rating of 4 and the egg in the cold coffee had a rating of 3.

Trial 6: Checked the eggs at 7pm. All of the eggs in the water had no discoloration. There was no change from the 7am observation. The eggs in the room temperature coffee and in the cold coffee remained at the ratings of 4. This ends Trial 6.

Trial 7: Checked the eggs at 7pm. All of the eggs in the water showed no discoloration. The egg in the cold Coca-Cola had a rating of 4 and the egg in the cold coffee had a rating of 3. This ends Trial 7.

__Data Tabl____es__
 * Trial 1 || Water || Coke || Coffee || Gatorade ||
 * Hot || 5+ days || 0.5 day || 1 day || 2 days ||
 * Room || 5+ days || 2.5 days || 2 days || 2 days ||
 * Cold || 5+ days || 2 days || 5+ days || 0.5 day ||


 * Trial 2 || Water || Coke || Coffee || Gatorade ||
 * Hot || 5+ days || 0.5 day || 0.5 day || 2 days ||
 * Room || 5+ days || 2.5 days || 2.5 days || 1 day ||
 * Cold || 5+ days || 3.5 days || 5+ days || 0.5 day ||


 * Trial 3 || Water || Coke || Coffee || Gatorade ||
 * Hot || 5+ days || 0.5 day || 1 day || 2 days ||
 * Room || 5+ days || 3.5 days || 5+ days || 4 days ||
 * Cold || 5+ days || 4 days || 5+ days || 0.5 day ||


 * Trial 4 || Water || Coke || Coffee || Gatorade ||
 * Hot || 5+ days || 0.5 day || 0.5 day || 2 days ||
 * Room || 5+ days || 2.5 days || 2.5 days || 1 day ||
 * Cold || 5+ days || 3.5 days || 5+ days || 0.5 day ||


 * Trial 5 || Water || Coke || Coffee || Gatorade ||
 * Hot || 5+ days || 0.5 day || 1 day || 2 days ||
 * Room || 5+ days || 3 days || 3.5 days || 1.5 days ||
 * Cold || 5+ days || 5+ days || 5+days || 0.5 day ||


 * Trial 6 || Water || Coke || Coffee || Gatorade ||
 * Hot || 5+ days || 0.5 day || 1 day || 2 days ||
 * Room || 5+ days || 3.5 days || 5+ days || 4 days ||
 * Cold || 5+ days || 4 days || 5+ days || 0.5 day ||

= = =__**Tooth Enamel Discoloration**__= __**Abstract**__ The goal of this project is to compare the discoloration time of eggs (representing tooth enamel) placed in four different liquids at three different temperatures and to determine if the egg in the hot coffee discolored in the fastest time. An egg was placed in each of the liquids at each temperature. The ratings of discoloration was recorded every twelve hours for up to a five day period. The eggs in the cold Gatorade and the hot Coca-Cola had the shortest average discoloration time of 0.5 days. The eggs in the water (control group) at all temperatures had the longest average discoloration time of 5+ days showing no discoloration at all.
 * Trial 7 || Water || Coke || Coffee || Gatorade ||
 * Hot || 5+ days || 0.5 day || 1 day || 2 days ||
 * Room || 5+ days || 3 days || 3.5 days || 1.5 days ||
 * Cold || 5+ days || 5+ days || 5+ days || 0.5 day ||

The results of the experiment were not what was expected since the hot coffee with the greatest acidity and temperature did not have the shortest discoloration time. It had the second shortest time of 0.86 days. Surprisingly, one of the liquids that was the coldest and was not the most acidic (Gatorade) discolored the eggs in the shortest amount of time. It can be concluded that the hottest and most acidic liquids may not stain tooth enamel in the shortest amount of time.

This project has a research application to determine which liquids have the capability to stain teeth the fastest. Having an understanding of which liquids stain tooth enamel in the shortest time would allow one to limit liquids that may be harmful to maintaining a healthy, white smile.

__**Problem**__ How will liquid acidity and temperature affect the staining of tooth enamel?

__**Hypothesis**__ If the liquid is most acidic and the highest temperature, then it will stain the tooth enamel in the shortest time because the high acidity and temperature breaks down the enamel the fastest.

__**Experimentation**__ __Background Information__: This experiment compared discoloration times of eggs (representing tooth enamel) of four liquids at three different temperatures. The four liquids were water (the control), red Gatorade, Coca-Cola and coffee. The temperatures of each liquid were 3.3 degrees Celsius (cold), 20 degrees Celsius (room), and 76.7 degrees Celsius (hot).The number of days were recorded as to when each egg reached the significant discoloration rating of 5. The discoloration rating was based on the Discoloration Ratings Chart (shown in the Materials List section). Seven trials were performed and the averages of the times for each egg were calculated. The times will be compared to determine which liquid at what temperature will cause significant discoloration in the least amount of days. In this experiment, the independent variables were the liquid type and temperature and the dependent variable was the discoloration time. The results will also show which liquid type and temperature affect the staining of tooth enamel the most. It was hypothesized that the liquid with the greatest acidity and highest temperature would stain tooth enamel in the shortest amount of time. __Procedure__: Using pH strips, the pH of each liquid was recorded. The eggs were hollowed out according to the procedure using a needle and a balloon inflater. Using a beaker, 175mL of each liquid was measured and poured into glass cups. A hollowed-out egg was placed into each cup. One glass cup of each liquid was placed in the appropriate temperature environment: the refrigerator (3.3 degrees C), the oven (76.7 degrees C), and the kitchen counter (20 degrees C). The eggs were checked every twelve hours by removing the egg with tongs and observing the discoloration and comparing it to the Discoloration Chart. The discoloration rating was logged for each egg. The number of days it took for each egg to reach a rating of 5 (significant discoloration) was recorded in the trial table. There was a five day limit and seven trials were completed.

__**Experimental Results**__





__**Discussion**__ Analyzing the data in the table and on the graph, it shows that cold Gatorade and hot Coca-Cola have the shortest average significant discoloration times at 0.5 day for both liquids. These liquids, however, are not the most acidic (pH 3.0 and 3.5). Hot coffee has the second shortest time at 0.86 day and is the most acidic (2.5 pH). Considering that hot Coca-Cola is not a liquid that anyone would actually drink, the cold Gatorade is the liquid that discolors tooth enamel the most out of all the liquids that were tested. The hot coffee is second most likely to stain teeth out of the liquids tested. After that, the tested liquids that would discolor or stain tooth enamel from most likely to least likely are: hot Gatorade, room temperature Gatorade, room temperature Coca-Cola, room temperature coffee, cold Coca-Cola, cold coffee, and water at all temperatures. Cold coffee and water at all temperatures have the same discoloration time of 5 days since these liquids did not reach the significant discoloration rating of 5 by the end of the trial period of five days, but this data is somewhat deceiving. The eggs that were in the water did not even have a rating of 1 since there was no change in coloration at all. However, the egg in the cold coffee did reach a discoloration rating of 3 or 4 during the trials and would eventually reach a rating of 5 if given more days in the trials. Water, on the other hand, does not seem to have the capability of staining tooth enamel.

This experiment could be improved by testing even more liquids to show their staining capability. Other liquids that could be tested include grape juice, tea, cranberry juice and orange soda. A modification that could be incorporated into the experiment is rinsing the egg with water or brushing the egg with toothpaste before returning it to the liquid. This would simulate the rinsing or brushing of teeth twice a day.

The major source of error is observer error. It can be difficult to determine the discoloration rating when the color of the egg is in between two of the color ratings. Usually the lower rating was logged just as a precaution. Another source of error involves the eggs. The shells of some eggs seemed to be "thinner" than the shells of other eggs as they were being hollowed out. The needle would puncture the shell much easier than the eggs with "thicker" shells. This may explain the discrepancy of logged results in the data tables. For example, the significant discoloration time for the eggs in the room temperature gatorade had a range of 1 to 4 days. The "thinner" eggs may have had the shorter time of 1 day as compared to the "thicker" eggs.

__**Conclusion**__ Comparing the average significant discoloration times, it shows that hot Coca-Cola and cold Gatorade stain or discolor tooth enamel in the shortest amount of time. These liquids were not the most acidic though. Coffee was the most acidic liquid that was tested and hot coffee had the second shortest time so this liquid is also a major stainer of teeth. Even though the hot coffee came in second place, my hypothesis should be rejected since the cold Gatorade was not the most acidic nor the hottest. The discoloration of tooth enamel seems to be affected by more than just the temperature and acidity of certain liquids.

__**Applications**__ This experiment has applications in the real world. The results of this experiment could inform dentists and the public about the drinks that stain teeth the most. Avoidance of these liquids, like red Gatorade, would improve the whiteness of teeth. The study could be varied by concentrating on the types of acid in each of the liquids and how these acids affect the eggs. This experiment could also be taken further by testing the stained eggs by brushing them with whitening toothpaste and testing other products, like at-home whitening kits, that claim to whiten teeth. Results of this testing would show which toothpaste or kit whitens teeth the best.