CONSERVATIVE DENTISTRY

IMI Clinic

Conservative dentistry is a branch of restorative dentistry that specialises in the treatment of decayed teeth. The procedures for removing the decay and closing the cavities resulting from deterioration of the enamel and decayed dentin, via use of special materials, instruments and technologies.

What are caries (tooth decay)?

conservative dentistry

Tooth decay (caries) is a degenerative disease of the hard tissues of the tooth – the enamel and dentin, due to infection. The infection starts on the surfaces of the teeth and progresses inwards until reaching the dental pulp, causing pain and inflammation.

There are numerous factors that cause tooth decay. Some of these are:

  • Bacteria
  • Sugar
  • Predisposing genetic factors
  • Age

Tooth decay is caused by common microorganisms normally found in the oral cavity, usually in the form of bacterial plaque. That is  why the very first form of prevention against tooth decay consists of thorough oral hygiene.

However, it should be noted that tooth decay can also develop in the event of a low immune system. . In this case, the potential pathogen of the bacteria comes into play and starts to dissolve the mineral and organic matrix making up the tooth, causing lesions in the form of cavities.

These bacteria feed on food residues, especially sugar, producing metabolites with an acid pH that gives rise to splits and openings in the tooth enamel. The latter, takes on a porous appearance in the case of “superficial tooth decay” and has the characteristic of always being asymptomatic.

Conversely, once the bacteria has passed right through the enamel of the teeth, they are able to reach the dentin which has a greater organic content and is crossed by tiny canals – called “tubules”. At this point , the decaying process picks up speed and creates cavities in the teeth, because the dentine matrix had been completely destroyed.
The closer the decay comes to the pulp tissue, the more the bacteria and toxic products of the decaying process are able to trigger inflammatory processes through the tubules. It is precisely this process that gives rise to the painful symptoms typical of deep decay, and is a condition called – pulpitis.

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Streptococcus mutans

Among the various bacteria found in the oral cavity one species is more cariogenic (i.e. it produces more decay) than the others: the streptococcus mutans. These anaerobic streptococci synthesise lactic or formic acid (depending on the amount of sugar), which dissolves the hard tissues of the tooth, triggered by glucose, a key component of food residues remaining in the mouth after a meal. Consequently, tooth decay is an authentic infectious disease that transforms bacteria that are normally harmless, into extremely harmful bacteria.

The symptoms and treatment of tooth decay

There are numerous symptoms of tooth decay. The best known include the following:

  • Sensitivity to sweet food
  • Pain (pulpitis), typical of deep decay.

The treatment of tooth decay involves the removal of the infected tissue, which is replaced with an appropriate material. In the event of the tooth pulp involvement being at an advanced state, it will be necessary to remove and replace this damaged tissue as well (endodontics).

In short, the term “conservative dentistry” indicates that the purpose of the treatment is to conserve or preserve the teeth  (if not treated) would be destroyed by the tooth decay.

What causes tooth decay in teeth?

There are certainly many different contributing factors, or more generally, conditions that increase the risk of contracting tooth decay as listed below.
The general conditions that increase the risk of tooth decay include:

  • Alterations to the saliva flow. The saliva fights tooth decay by buffering the acidity in the mouth. It is  both a microbicidal and immune function.
  • Disharmonious dental arch (crooked teeth), that facilitates the formation of cariogenic plaque making removal of the same very difficult.
  • Poor eating habits, including frequent snacking or an excessive consumption of sweet foods that increase the risk of tooth decay.

Why does sugar cause tooth decay?

Sugars which are stickier generate the most tooth decay. The high frequency of sugar intake maintains an acid pH in the mouth, and the demineralization effect is continuous. To prevent this it is necessary to brush teeth preferably within half an hour after each meal, as it is during the first minutes after eating food that the high level of acidity in the mouth creates the right environment for superficial demineralization. The latter, when combined with brushing, can cause chemical erosion over time.

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Treatment of tooth decay

The first-choice treatment of symptomatic and/or cavitated decay consists of the removal of the decayed tissue with mechanical or manual instruments. Afterwards, the remaining cavity is filled with a variety of different materials (from anti-aesthetic silver amalgam to more aesthetic materials such as composite, glass ionomer dental cements, gold or ceramic inlays), depending on the aesthetic and functional requirements.

How to prevent tooth decay

For the prevention of tooth decay it is essential to carry out professional oral hygiene at least twice a year. It is essential that you  make an appointment with your dentist who may avail of the collaboration of a dental hygienist.
It is equally important to pay great attention to oral hygiene  at home with the aid of instruments such as: a toothbrush, toothpaste and dental floss.
To add to this, you should consider fluoride which is able to re-mineralise tooth enamel, block the metabolic pathways of the bacteria responsible for tooth decay, and reduce the capacity of the bacteria to adhere to the tooth surfaces.

Sealing the molars

A useful practice of primary decay prevention involves the sealing of the furrows in the first molars of children aged 7-8 years.

In fact, it has been demonstrated that 90% of the decay lesions develop on 10% of the total tooth surfaces, represented precisely by the furrows on the occlusal surfaces of the molars. By sealing these furrows, with a fluid resin, it is possible to protect the tooth from the acidic bacterial attack.

This practice has been regularly carried out over a number of years, in various countries, including Italy. The procedure involves  thefurrows being roughened, by the dentist, with a chemical product (phosphoric acid). They are then sealed  with a resinous material that hardens under a lamp.

Finally, after an occlusal check of the teeth, fluoride paint is applied over the resin that intensifies the release of the substance.

It is also possible to permanently seal the furrows and dimples in the molars via the use of very fluid resins that are fixed to the teeth by means of etching and polymerisation.

How does modern conservative dentistry work?

Modern conservative dentistry is based on the concept of minimal invasiveness, and foresees the removal of the decayed tissue only. The decayed area is then replaced with a  restorative material, attached directly to the healthy tissue.

In recent years silver amalgams have been abandoned (that required retentive and therefore extensive preparation) in favour of the composites. A composite consists of the following:

  • Resinous matrix
  • Inorganic filler
  • Bonding agent (silane)
  • Activator

The resinous matrix is the chemically active component of the composite. It is initially in the form of a monomer fluid, where it is then converted into a rigid polymer (polymerisation). The matrix is the continuous phase to which all the other components are added.

Lamps for polymerisation

After the application, the photo-polymerisable composites are illuminated with a specific wavelength lamp,  in order to combine the monomers with the polymers. This process is accomplished by a molecule that acts as a photo-activator.

The composites are generally materials that have to be kept away from the saliva and humidity. In fact, in conservative dentistry, a rubber dam is normally used to ensure isolation of the operating field.

This dam is a thin layer of rubber in which holes are made so that teeth to  be treated are inserted. The layer is then stabilised with one or two hooks (and if necessary with ligatures made of dental floss)on the outside of the oral cavity the dam is supported by a metal or plastic arch that keeps it taut.

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