Today, several dental filling materials are available. Teeth can be filled with gold, porcelain, silver amalgam or tooth-colored, plastic and glass materials called composite resin fillings. The location and extent of the decay, cost of filling material, patients' insurance coverage, and dentist's recommendation assist in determining the type of filling that will best address patient’s particular needs.

Cast Gold Fillings: this type of filling material lasts at least 10 to 15 years and it doesn't corrode. It can withstand chewing forces without much problem. Unfortunately, gold cast fillings are more expensive than other materials. Restoration with help of this material requires at least two office visits. There is also a danger of galvanic shock which occurs when a gold filling is placed immediately next to a silver, amalgam filling and because of this a sharp pain (galvanic shock) may occur. The interaction between the metals and saliva causes an electric current to occur. Another disadvantage of this type of a filling is aesthetics - most patients don't like any "colored" fillings.

Silver Fillings (Amalgams): they are characterized by high durability – they will last at least 10 to 15 years and usually outlast composite fillings. Unfortunately, silver fillings don't match the color of natural teeth. In addition, in the process of restoration healthy parts of the tooth must often be removed to make a space large enough to hold the amalgam filling. This type of filling usually create a grayish hue to the surrounding tooth structure. Amalgam fillings are also more likely to crack and fracture due to a wider degree of expansion and contraction in the presence of hot and cold liquids. Lastly, some of patients may develop an allergic reaction to the mercury present in amalgam restorations.

Tooth-colored Composites: one of the biggest advantages connected with this type of a restoration is aesthetics – the shade/color of the composite fillings can be closely matched to the color of existing teeth. That is why composites are particularly well suited for use in front teeth or visible parts of teeth. Moreover, composite fillings actually chemically bond to tooth structure, providing further support to the tooth. In comparison with amalgam fillings less tooth structure needs to be removed when removing decay and preparing for the filling. The biggest disadvantage of this restorative material is its lack of durability. Composite fillings wear out sooner than other materials (lasting at least 5 years). What is more the restorative procedure lasts longer because of the process to apply the composite material. Restoration with this type of material will require also additional visits. Another downfall of this material is the expense – composite fillings can cost up to twice the cost of amalgams.

Ceramics: these fillings are made most often of porcelain, are more resistant to staining than composite resin material but are also more abrasive. This material generally lasts more than 15 years and can cost as much as gold.

Glass ionomer: this type of filling is made of acrylic and a specific type of glass material. This material is most commonly used for fillings below the gum line and for fillings in young children. Glass ionomers release fluoride, which can help protect the tooth from further decay. However, this material is weaker than composite resin and is more susceptible to wear and prone to fracture. Glass ionomer generally lasts 5 years or less with costs comparable to composite resin.

GLOSSARY
abrasive – ścierny, łatwo się ściera 
to address – adresować, ukierunkować się na 
amalgam – amalgamat 
be prone – być podatny 
be suited for – być przystosowany 
be susceptible – być podatny, wrażliwy na 
bond – spajać, wiązać 
composite resin fillings – materiał kompozytowy 
crack – pęknięcie 
determine – ustalić, decydować 
disadvantage – niedogodność, ujemna strona/cecha 
downfall – (tutaj) wada 
durability – wytrzymałość, trwałość 
electric current – prąd elektryczny 
expense – wydatek 
extent – rozmiar
fracture – złamanie, odłamanie
galvanic shock – szok galwaniczny
glass ionomer – glasjonomerowy cement
hue – odcień, barwa
insurance coverage – ubezpieczenie
match – dopasować 
mercury – rtęć
outlast – przetrwać, trwać dłużej niż
release – uwalniać
several – kilka, kilkanaście
staining – plamić, plamienie
support – wsparcie
surrounding – otaczający
wear out – zużyć się, zniszczyć się
withstand – wytrzymać, dobrze znosić
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Substitute underlined word with a synonym or a word with similar meaning from the GLOSSARY section

1. Two of the factors determining the cost of the restoration are the size of the decay and type of restorative material. 
2. Ceramic materials are not very long-lasting. They are also more prone to crack. 
3. Amalgam is not a very aesthetic type of filling because of the gray shade which is left on the restored and near-by teeth. 
4. Composites are very pleasantly looking, that’s why they are suitable for front teeth restorations. 
5. One of the negative aspects of cast gold filling is its cost. 
6. Ceramics are easily worn off.

Match patient’s questions with dentist’s answers

Patients’s questions: 
A. Is it true that dental amalgams have been banned in other countries?
B. How will you restore my tooth with composite filling? How does the process look like?
C. What are the typical symptoms of allergy to an amalgam filling? 
D. I had my tooth restored last week. My filling fell out this morning. Why?

Doctor’s answers: 
1. To do it, I will carefully remove the decayed area of your tooth, clean the area thoroughly, and apply the restoration material. I will shape the restoration, fitting it seamlessly with the surrounding teeth, and harden the material with a curing light. Then, I will complete the process by polishing and buffing the tooth to give it a shiny and smooth look and feel.

2. New fillings that fall out are probably the result of improper cavity preparation, contamination of the preparation prior to placement of the restoration or a fracture of the restoration from bite or chewing trauma.

3. No. Some news reporting has confused restrictions in a few countries with bans. Dentists around the world are using dental amalgams (silver fillings) to restore teeth that have dental decay.

4. Although it’s quite rare, symptoms of amalgam allergy are similar to those experienced in a typical skin allergy and include skin rashes and itching. Patients who suffer amalgam allergies typically have a medical or family history of allergies to metals.

Complete the text about amalgam use in pregnant women and children with words from the table

Dental amalgam, in 1)_____________ use for over 150 years, is one of the oldest materials used in oral health care. Its use extends beyond that of most drugs, and is 2)______________ in dentistry only by the use of gold. Dental amalgam is the 3)___________ result of mixing approximately 4)_____________ parts of elemental liquid mercury and an alloy powder composed of silver, tin, copper, and sometimes smaller amounts of zinc, palladium, or indium.

The dental amalgam 5)_________________ is a debate over the use of mercury amalgam as a dental filling. The concern centers around the 6)______________ health effects of toxicity or allergy which may be associated with constant mercury exposure, particularly as a potential cause of 7)________________ illnesses, autoimmune disorders, neurodegenerative diseases, birth defects, and mental

For years amalgam fillings were considered as safe. However, in the recent years we can hear more frequently that it may be harmful to pregnant and 8) ______________ women, children, people with compromised immune systems and unborn children.


Lesson 18 answers