Clinical case co-author dr Jordi Manauta
Class IV are the most challenging restorations. In this case we will review some essential steps to make this discipline more enjoyable. Let’s start with these 4 basic rules in mind:
1. We have to superimpose different materials that, instead of copying nature, blend between translucent and opaque to obtain an outcome similar to the tooth.
2. We have to prioritize management of the shape and anatomy instead of the small characterizations. Photographs, tools, matrices, and instruments are incredibly helpful in accomplishing this.
3. Finishing and polishing techniques must be easy, fast, and efficient, and it should be possible for the hygienist to replicate at check-up and maintenance appointments.
4. We have to know how to manage the restoration in the long run, i.e. how to modify and correct it in case it changes color or suffers some chipping or fracture. So this patient had suffered a class IV non complicated fracture on tooth 21. We decided to restore it immediately, thus no wax-up was available. Shade was selected before doing anything else. Shade selection will be discussed in another article.
Protocol contemplates all possible situations, from removing an old restoration, to restoring different types of margin. In this particular case, where no previous restoration was present, steps 1 and 2 are not necessary, while step 5 and 6 were not the chosen margins for this case. It is important to adapt the protocol to our best convenience.
Direct Anterior Styleitaliano Sequence for anterior teeth
STYD5 Margin finder
STYD2 Composite removal
STYD6 Medium-long bevel
STYD7 -or- chamfer
STYD8 Proximal margin
If bevels are correctly selected, they are respectful of tissue and offer a very good boost to the blending effect. 45-degree bevels are for the middle third and are used in most situations. as the protocol establishes the D6 bur was used (STYD6) from the Style Diretto Kit (Intensiv, Switzerland)
Selective etching of the enamel was performed for a minimum of 15 seconds and a maximum of 30 (difference between starting point and end point).
Thorough wash of the acid etching gel.
Universal bonding application scrubbing during 20 seconds.
Extended polymerization is one of the key factors in the quality of the bonding layer.
In order to work index-free, the goal is to obtain a manageable defect by adding up resources. We will focus on creating the proximal structures guided by the natural tooth and the neighbor teeth, and then adjust, based on said surrounding anatomical structures. An anatomical matrix was used to help develop the proximal walls.
The material was adapted with a low frequency vibration modeling instrument (Compovibes, Smile Line, Switzerland).
The material being vibrated adapts very easily thanks to its thixotropic properties. The moment the vibration is removed the composite goes back to a stiffer consistency.
Development of the marginal ridge, getting as much references as possible from the sound tissues into the restoration, this time from the buccal aspect. Same is done copying the palatal inclination.
The composite is cured while holding the matrix with the finger to its optimal positioning, it is imperative to be delicate, and to make sure there is no deformation of the matrix.
Correction of the generated freehand structures is mandatory. External correction is done with a disc at low speed.
Milling debris is easily removed by wetting with a universal bonding agent. Air is blown afterwards to remove both bonding and the dust now embedded in it.
The aim of the developed proximal structure is to create some support that will allow to determine the correct positioning of the finger to get a result that is good enough. Only then can we load a small and flat quantity of composite in the estimated position and place it in the cavity, remove the excess, and cure. When correctly done, it is possible to develop a rather good palatal wall. OA2 (Dentin A2) was used (Brilliant Everglow, Coltene Switzerland)
Composite is condensed with vibrations. Finger is held firmly in place trying not make excessive pressure. This is important not to create a subtractive defect on the palatal.
Preparing the modeling brush. It is imperative, if you like to use modeling liquids, not to have excess liquid that might change, and thus jeopardize the composite’s physical properties.
The final enamel layer is typically placed and manually modeled. In teeth that have increased texture, this task can be challenging. By passing a composite plugger as the thin end of the LM Arte Condensa (LM, Finland) with side-to-side movements and a burnishing like pressure, the composite will adapt to the buccal depressions guided by the instrument. The bigger size can be used as well.
Texture transfer strategy.
By simply passing the information from one surface (sound tooth) to the other (uncured composite) with the help of a modeling instrument, we can precisely recreate the buccal surface. Besides being compatible with almost every layering technique, the main advantage of this strategy is that the outcome is obtained effortlessly, thus giving precision to the modeling itself, and more time to focus on other features of the restoration. Rounded instruments are preferred such as LM Arte Condensa (LM, Finland), or the same shape but in a vibrating instrument such as Compo-Vibes (Smile Line, Switzerland) would be the first choice.
The shaping protocol, which will be treated in another article, starts by defining the incisal length.
Followed by primary anatomy.
Proximal finishing with a red coded finishing strip.
Finishing anteriors, Styleitaliano Sequence
STYF1 Secondary grooves depth
STYF3 Occlusion and anterior guidance
STYF4 Smoothening and tertiary anatomy
STYF5 Fine smoothening
Shapeguard spiral for pre-gloss.
The hybrid diamond paste is a single-step, super high-gloss compound. It doesn’t come off the tooth while working, but, as it is complete hydro soluble, it is incredibly easy to remove with water only.
Final gloss, darker aspect of the restoration is expected, and the patient should be warned of this before starting.
Check-up appointment shows an almost perfect integration, reason why we should never improvise the use of colors under the rubber dam isolation, or correct the restoration right after finishing it.
Following a well established protocol with the right instruments in hand is the way to make challenging restorations, such as class IVs, predictable. A few tricks can, of course, make the difference, as long as we use them to simplify our work throughout each step of the procedure.
1. Manauta J, Salat A, Putignano A, Devoto W, Paolone G, Hardan LS. Stratification in anterior teeth using one dentine shade and a predefined thickness of enamel: a new concept in composite layering – Part I. Odontostomatol Trop. 2014 Jun;37(146):5-16.
2. Manauta J, Salat A, Putignano A, Devoto W, Paolone G, Hardan LS., Stratification in anterior teeth using one den- tine shade and a predefined thickness of enamel: A new concept in composite layering – Part 2. Tropical Dental Journal vol. 37, n°147
3. Manauta J, Salat A. Layers, An atlas of composite resin stratification. Quintessence Books, 2012.
4. Mendoza A. García Ballesta C.Traumatología Oral; Diagnostico y Tratamiento integral, soluciones estéticas. ERGON, 2012 p. 68-92
5. Terry DA, Geller W, Tric O, et al. Anatomical form defines color: function, form, and aesthetics. Pract Proced Aesthet Dent 2002;14(1):59–67.
6. Kataoka S, Yoshimi N. Nature’s Morphology: An Atlas of Tooth Shape and Form. Chicago: Quintessence Publishing, 2002.
7. Afif Elossais A. Desenvolvimento e avaliação da efetividade de duas pastas polidoras empregadas a materiais restauradores estéticos. Análise comparativa por perfilometria digital e microscopia de força atômica. Araraquara : [s.n.], 2008. 198 f. ; 30 cm. (Doctoral Thesis In Portuguese).