01 June 2022

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Immediate or delayed dentin sealing with or without flowable resin reinforcement

Co-authors: A. Comba, F. Florenzano

Lorenzo Breschi

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IDS (immediate dentin sealing) consists of applying a dentin bonding agent (DBA) immediately after dentin preparation, to avoid contamination with oral fluids and impression or provisional materials. In the last decade, it has been demonstrated that there are plenty of benefits connected to this technique and among them, decreasing in postoperative sensitivity and increasing in bond strength are of great importance. However, the original IDS   technique  was performed with a highly filled adhesive system, such as Optibond FL (Kerr), while today lots of clinicians feel more confident by using self-etch DBAs . Therefore, to increase the  mechanical performance of self-etch adhesive De Carvalho et al. considered to add a layer of flowable resin composite to protect and strengthen the hybridized dentin, and created the so called “reinforced IDS”   approach.

The authors conducted and in vitro study aimed to evaluate the microtensile bond strength of unfilled/lightly filled   DBAs   compared to the traditional IDS technique with  filled Optibond FL and no  IDS as well as the influence of reinforcement with a flowable resin coating.

Materials and methods: 

To conduct the study the authors selected seventy-five extracted human molars free of caries and divided them in  fifteen groups (n=5) according to the combination of the five   DBAs and three application modes: delayed dentin sealing (DDS) , immediate dentin sealing (IDS)   and immediate dentin sealing  with flowable resin coating. All the samples were tested according the microtensile bond strength method.

Results: 

From the data obtained by the test, de Carvalho et al. found out that IDS improve bond strength of all tested adhesives. In addition, the researchers discovered that the use of a flowable resin coating reinforcement after immediate dentin sealing   increased the microtensile bond strength of all unfilled/lightly filled adhesives (from 233% of increase for ScotchBond MP, up to 560% for Clearfil SE Bond) and maintained the performance of the 3-step gold standard adhesive. The authors claimed that Optibond FL used with (52.51 MPa) or without (54.75 MPa) additional flowable resin coating and Clearfil SE Bond (45.64 MPa) used with flowable resin coating provided the best results.

Conclusions: 

De Carvalho and his group affirmed that IDS improved the microtensile bond strength (μTBS) to dentin when a filled DBA   was used and when using SBMP;  IDS did not increase the μTBS when unfilled/lightly filled DBAs   were used except when using SBMP; Unfilled/lightly filled DBAs should be reinforced with a flowable resin coating to improve the μTBS to dentin for IDS .

For more information: Significance of immediate dentin sealing and flowable resin coating reinforcement for unfilled/lightly filled adhesive systems.