Monday, June 19, 2023

the ideal post drill for most posterior teeth is.. peeso drill size 2-3

the ideal post drill for most posterior teeth is:

  • a- gates glidden size  3
  • b- peeso drill size 3-6
  • c- profile size 60-70
  • peeso drill size 2-3.

Posterior tooth restorations:

The increase in prevention and hygiene have produced a significant decrease in the incidence of caries but restorations in posterior teeth are still necessary.

Materials for posterior tooth restorations:

The increase in prevention and hygiene have produced a significant decrease in the incidence of caries and the need for prosthetic treatment due to reasons of exodontics in the posterior sector. Although the affectation by this type of infections is minor, it continues to affect the patients, but the contact that they have with our dental clinic in Barcelona makes it possible that the caries is not in an advanced state and can proceed to its healing already a subsequent aesthetic restoration in premolars and molars.

Before the ceramic restorations provided the advantages they offer today, the most commonly used materials for restorations in the posterior sector were gold and silver amalgam. Gold had some important advantages such as less corrosion (with respect to amalgams), elasticity, marginal adaptation, low wear and durability but on the other hand it required overly invasive preparations, it was unsightly, did not adhere and had a high cost.

On the other hand, silver amalgam is a direct restoration, very simple to use with greater longevity and more economical, but it has a poor aesthetic appearance, does not adhere to dental structures, tends to expand and causes corrosion, staining and toxicity.

For all these reasons these two materials have been replaced in recent years by another type of restorative materials. In the search for the ideal restorative material, an attempt was made to find a tool that met the following conditions:
  • Allow a cavitary preparation as conservative as possible
  • Return the morphology and the original resistance to the tooth
  • Ensure external and internal adaptation and good sealing to prevent secondary caries, pulp involvement and tooth sensitivity
  • Be biocompatible with vital dental tissue
  • Provide longevity.

We have found two types of material that met most of these conditions and that are what our dentists in Barcelona currently use. We review the advantages and disadvantages of composite resins (composite) and ceramics (understood almost uniquely as porcelain) when restoring posterior teeth:

Composite resins for direct restorations:

Composite resins have some important strengths when we talk about applying direct restorations on the posterior teeth. It has a color so similar to the patient's teeth that provides a very natural aesthetic, does not contain mercury (so it is not toxic), adheres perfectly to the dental structure and demands a more conservative type of preparation than other materials.

On the other side of the coin we find that it has contraction to the polymerization of composite dental restorations, greater wear or abrasion due to contact with the other teeth, a difficult contact point and manipulation, requires more working time and has more incidence of secondary caries.

Composite resins for semi-direct restorations:

Composite resins are also used in semi-direct restorations, in which they have slightly different performance. In this case, they offer more hardness and resistance, better modeling of the interproximal zone and less marginal filtration (cement compensates for shrinkage). On the other hand, this option implies a higher cost and usually lasts less time.

Porcelain crowns or dental inlays:

Ceramic materials, specifically crowns and porcelain inlays, have become a very good alternative depending on the needs of the patient and the size of the lesion. Its strengths are the aesthetics they offer (almost identical to natural teeth), the fact that it does not wear out (so it lasts longer) and its ability to reinforce the dental structure. Its weak points are the possible wear of the antagonist and the fact that it is not elastic with what can be easily broken.

When do we choose composite resin and when ceramic?

The strategy followed by Propdental dentists is usually the following: when the cavity is less than 2mm, the tooth is restored with direct composite and when the cavity is greater than these 2mm, a ceramic restoration is used. It should be noted that porcelain restorations or dental inlays can be of three types, depending on the part of the crown they occupy, let's see them:

- Inlay:

this restoration does not cover any cusps. It is placed inlaid and placed inside without touching the cusps.

- Onlay:

in this case it does cover any of the cusps, so for its placement we carve one of the cusps (the functional one).

- Overlay:

This is the most invasive and is an alternative to the crown. To place it we carve all the cusps and then apply the restoration.