A guide to common dental materials

Umair Afzal shares a guide to understanding tooth wear, including the different types, preventative measures and what causes it.

Umair Afzal shares a simple and concise overview of dental materials for dental students – a game-changer for revision.

While at dental school, I always found getting my head around the different clinic materials tricky.

Understanding their properties was a game-changer in my revision and helped me appreciate the role each material played in the care of our patients.

Below, I’ll briefly introduce the essential materials you’ll come across at dental school. I’ll break each material into its strengths, weaknesses and indications of use.

Part one: evaluating filling materials

Composite

Strengths:
- Robust, hard-wearing and easy to placeEasy to polish with pleasing aesthetics
- Less destructive prep than amalgam, crowns or veneers
Weaknesses:
- Hydrophobic and undergoes polymerisation shrinkage
- It can be time-consuming to layer. Requires a separate bonding agent.

Amalgam

Strengths
- Good compressive strength and wear resistance
- It is an easy-to-use chemical set and cheap
Weaknesses
- Non-adhesive and weak in thin sectionsThermal conductor and inaesthetic
- Reports of occasional lichenoid reaction
Indications
- Larger cavities affecting posterior teethAreas with heavy occlusal forces and unimportant aesthetics
- Patients with a high caries rate. Posterior restorations that extend subgingivally where moisture control cannot be achieved.

Glass-ionomer composites [GIC]

Strengths
- Easy to use and chemically bonds to enamel and dentine. No need for etch/bond
- Releases fluoride with a more significant preventative effect than composite
Weaknesses
- Weaker than other materials and poorer aesthetics than composite
- Poorer survival time compared to other materials. Varying working time
Indications
- Cavities below the cementoenamel junction
- Temporisation – simple to use and just needs to dry
- Stepwise excavation and can be used as a fissure sealant.

Part two: evaluating dental cements

Resin-modified glass ionomer cements

Strengths:
- Easy to apply and use. Releases fluoride. High bond to dentineGood compressive and tensile strength (greater than zinc phosphate)Better bond strength and mechanical properties than a resin composite cements
- Low solubility and contains metal and ceramic primers (ie silane coupling agents)
Weaknesses:
- Technique is sensitive and it is hard to remove excess after use
- Cement expands and can result in polymerisation shrinkage
Indications
- Metal-supported restorations with mechanically retentive preparations
- Crowns with strengthened cores. Inlays, onlays, veneers, posts, and resin-retained bridges.

Resin composite cements

Strengths
- High compressive strength, resistant to tensile fatigue, and insolubleGood marginal wear resistance and strong adhesion
- Good bond strength to sandblasted base metal alloys (micromechanical retention)
Weaknesses
- It is hard to place in a thin layer due to the high filler content and technique sensitive – contraindicated for eugenol-containing temporary cements
- Weak bond to dentine compared to a resin-modified glass ionomer cements.

Glass ionomer cements

Strengths:
- Fluoride release – absorbs fluoride from the environmentThere is some resistance to acid dissolution. Smooth consistency, low film thickness
- Marginal integrity with high physical strength
Weaknesses:
- Sensitive to early moisture contamination
Indications:
- Metal-supported restorations with mechanically retentive preparationsCrowns with strengthened cores (where mechanically retentive)
- Where moisture control is adequate. Self-cured.

Part three: evaluating endodontic materials

Sodium hypochlorite

Strengths:
- Dissolves organic tissue
- Antibacterial
- Cheap
- Good flow properties
Weaknesses:
- Toxic
- Damages clothing
- Painful and leads to severe tissue necrosis if extruded under pressure
- Long-term exposure can damage root dentine (removes the collagen).

Eugenol-based sealers

Strengths:
- Ease of manipulation and good flow properties
- Adhesion to dentinal walls and dimensional stability
- Insoluble and radiopaque
Weaknesses
- Poor usage can mean it is extruded into the periradicular tissues
- Slow setting time and reportedly stains tooth structure.

Final thoughts

As I delved into dental materials when revising for finals, I learnt about the invaluable role that they have in the field of dentistry.

A concise overview of these materials proved to be a game-changer during my revision process, solidifying my understanding of the procedures I was learning.

It is easy to get into lots of detail about materials. However, I found that keeping it simple and relevant to clinical practice will help you appreciate its use when providing clinical care for the patients under your care.