The restorative procedures of posterior areas are the most frequent in our daily practice. Despite the fact that composites are used in posteriors since more than twenty years, there’s still a lot of confusion about when to choose a direct technique or an indirect one, and when to do surgery or not. At the same time, indeed, when restoring we must have a perfect isolation, that means that we do not have to select shortcuts: when surgery it’s mandatory, we have to perform it, to obtain a proper isolation, good impressions, and a perfect sealing. This Article clarifies how and when to chose a direct approach or an indirect one, depending on the clinical indications.
A male patient, 27 years old, came to my attention by a sharp pain spread to the lower left arch. He referred to not be able to locate the pain, although he realized to perceive the presence of a cavity, of large size, in one of the lower left molars. The patient also reported having non regular eating habits, to consume sugary food and drinks, just to wash and rinse his teeth, not flossing. In the picture, the initial situation of the upper arch.
Initial situation of the lower arch.
Details of the 3rd quadrant.
Details of the 4th quadrant.
Bitewing and periapical X-rays of the 3rd and 4th quadrants. A lot of decays are present on the lower arch. Little spots on the upper too.
Isolation of the 3rd quadrant.
After the cleaning of the biggest decay, it was necessary to perform a root canal treatment: the patient was referred to my brother and partner Dr. Paolo Marchetti, for the endodontic procedures. A provisional build up was done by me on the distal wall in order to contain the irrigating liquids.
After the removal of the decay it is clear that the rubber dam will not isolate properly. In these situations we do not have to try to put in place a matrix, with the rubber dam on it, because this will lead to a failure, due to the impossibility to control the moisture coming from the gingival sulcus. On the other hand it is clear at the same time that the only removal of gum, with radio-surgical procedure, burrs or else, is not the solution, because this will probably cause periodontal problems, if not immediately, in a second time, for the nearness between the bone and the restoration. The correct clinical solution is to remove the dam and do a fast and conservative crown lengthening.
A minimally invasive crown lengthening was performed by the periodontal surgeon, (again my team-mate Dr. Paolo Marchetti) and the right biological width was re-gained.
Details of the suture. The gutta-percha was protected with flowable composite without doing adhesion.
Immediately after the surgery, the rubber dam was placed and the build up performed.
The cusps were reduced with a big grained diamond bur. The correct reduction is 1.5-2 mm for the composites overlays. Less than this will probably cause the fracture of the restoration. It is a butt joint prep, with no external bevels, because they would reduce the thickness of the material and cause its fracture. Instead with a flat preparation we will not risk to fracture our work, during the chewing loads, due to the insufficient thickness.
Details of the finishing of the cervical step, with sonic tips.
Details of the cervical margin finishing with sonic tips.
The prep is polished with a brownie rubber.
Details of the Overlay preparation of 37.
Details of the Overlay preparation of 37.
At this point we can do the direct restorations where needed. Details of 35 and 36.
The interproximal caries on 35 and 36 are accessed from the occlusal surface.
A caries detector was used to ensure all the infected tissue removal.
After only 10 seconds after its application is rinsed off . The dentin affected by the decay will remain colored.
Details of the preps for direct restorations. The preps must be done in a way that the matrices will fit passively.
Detail of the distal preparation on 36.
A sectional matrix blocked with a wooden wedge. In order to increase the fitting on the cervical margin sometimes is necessary to place PTFE (Teflon tape), between the matrix and the wedge.
A separating ring is also placed. Details of the cervical margin and of the matrix fitting.
We proceed for the adhesion steps with a self-etching technique. Only the enamel is etched for 30 seconds, after dentin cleaning with glycine powder, and its disinfection with 2% chlorhexidine.
The self etch product is applied both on dentin and enamel, it is brushed for 40 seconds and light cured for 40 seconds as well.
Details of the build up of the distal wall with a dentin mass (to increase opacity and contrast of the ridge). Before the removal of the matrix a little amount of flowable composite is used between the dentin and the distal wall, in order to stabilize the wall for matrix removal safety.
With the same dentin mass we do 70% of the volume of the distal restoration and start insinuating the anatomy with the modeling.
A enamel is chosen and used in order to do the micro anatomy of the occlusal surface. This strategy is optional, when we want to have the best chromatic outcome. In fact, most of the times in the posterior region we can use just one body mass to reproduce the anatomy and have almost the same perfect outcome.
Details of the matrix placement in the mesial of 36.
Details of the direct restorations of both cavities of 36 after a fast finishing stage.
Matrix and ring placement on 35.
We can use a little amount of tints on the occlusal surface if we want to. Then with sonic tips we start doing the finishing.
A supercharged diamond paste is used to polish the restorations.
The two direct restorations on 35 and 36 after the finishing and polishing procedures.
Then the rubber dam was removed and with the sutures still in place we took and impression with VPS (Imprint 4) in order to do the composite Overlay on 37.
After the try-in and small occlusal check of the restoration without the rubber dam, the composite build up is sandblasted to improve adhesion.
Enamel etching for 30 seconds.
Adhesive application on the inner surface of the composite overlay which was already sandblasted after try-in.
The overlay is bonded with heated composite from a carpule, which are generally softer than those of syringes.
Final gloss is done with this new polishing products (Spiral).
Details of the anatomy of the direct and indirect restorations
Details after the polishing procedure.
Final X-rays of the 3rd quadrant.
Details after one month
Details of the morphology and buccal margin aspect after one month. The soft tissues after the surgery are growing and healing properly.
Details after one month from a lingual view
Isolation of the 4th quadrant and the protection of 47.
Details of the pulp exposure of 46.
We proceeded with a root canal therapy on the 4th quadrant and crown lengthening as well. We opt for this strategy every time that we have less than 3mm from the healthy cervical margin to the bone.
Immediately after suturing the rubber dam is placed back and the build up and the prep of the overlay on 46 is performed.
Details of the decay on the disto lingual surface of 47.
Details of the decay on the disto lingual surface of 48.
Again we used a caries detector to be sure to remove all the carious lesion.
Details of the caries detector on 47.
The caries completely removed.
On the distal of 48 a build up and a prep for a composite only was done. To avoid losing all the inner sound tissue of the occlusal surface of 4.8 i did a direct restoration on the mesial surface.
Details of the matrix on the mesial surface of 48.
The direct restoration was done with the same strategy we used in the 3rd quadrant.
Details of the restoration on the mesial of 48 after a fast finishing stage in order to put in place the matrix of 47 properly.
Details of the matrix on the distal of 47.
The application of the flowable with the Fissura Instrument (LM Arte by Style Italiano instrument Kit).
The direct restorations of 47 and 48 after the application of the stains.
The mesial cavity is done directly from the mesial surface due to the possibility to have a perfect view and access.
Final polishing procedures with Spiral.
Details of the polished restorations at the end of the procedure.
The distal decay of 45 is treated directly in the same way, with a distal access.
The finished distal restoration of 45.
Occlusal check before impressions taking
Impressions done with a Polyether material.
Try in and occlusal check before bonding 46, 48.
The final aspect of the direct and the indirect restorations after the polishing procedures under the dam.
The final occlusal check
Details of the soft tissues and the restorations after one month.
Details of the restored 4th quadrant after one month, the tissues keep maturing and growing.
Final x rays of the 4th quadrant.
One year control of the upper arch after the interproximal direct restorations (will be shown in a upcoming article) and of the lower arch with directs and indirects that were shown in this same article.
A modern restorative approach of the posterior teeth, that uses direct techiques as a first choice, and partial restorations (not crowns) in endo treated teeth, with the full respect and preservation of the remaning sound dental tissues and the periodontal ones, allows us to obtain ideal results, from a morphological-functional and biological point of view, which can be predictable and long lasting in time.
I want to thank my partner, team mate and brother Dr. Paolo Marchetti, for the endo and perio therapies and Sebastiano Nardo for the lab work.
1. Devoto W. Clinical procedure for producing aesthetic stratified composite resin restorations. Pract Proced Aesthet Dent. 2002 Sep;14(7):541-3
2. Saboia VP, Nato F, Mazzoni A, Orsini G, Putignano A, Giannini M, Breschi L. Adhesion of a two-step etch-and-rinse adhesive on collagen-depleted dentin. J Adhes Dent. 2008 Dec;10(6):419-22
3.Veneziani M. Adhesive restorations in the posterior area with subgingival cervical margins: new classification and differentiated treatment approach. Eur J Esthet Dent. 2010 Spring;5(1):50-76
4. Manauta J, Salat A, Layers, an Atlas of composite resin stratification, Quintessence 2012
5. Vanini L. Restoration with composite materials: Class 2. Attual Dent. 1986 Apr 20;2(15):8-9, 11-3, 16-9
6.Bichacho N. The centripetal build-up for composite resin posterior restorations. Pract Periodontics Aesthet Dent. 1994 Apr;6(3):17-23
7.Dietschi D, Spreafico R. Evidence-based concepts and procedures for bonded inlays and onlays. Part I. Historical perspectives and clinical rationale for a biosubstitutive approach. Int J Esthet Dent. 2015 Summer;10(2):210-27
8.Mangani F, Marini S, Barabanti N, Preti A, Cerutti A. The success of indirect restorations in posterior teeth: a systematic review of the literature. Minerva Stomatol. 2015 Oct;64(5):231-40