Int. J. Odontostomat.

,
17(3):245-250, 2023.

Injectable Composite Resin Technique: An Alternative

for Anterior Esthetic Restorations - Case Report

Técnica de Resina Compuesta Inyectable: Una Alternativa para

Restauraciones Estéticas Anteriores - Reporte de Caso

Tatiana Cursino Pereira1; Jefferson David Melo de Matos2;

Victor Ruano1; Marco Antonio Bottino2 & Eduardo Bresciani1

PEREIRA, T. C.; MATOS, J. D. M.; RUANO, V.; BOTTINO, M. A. & BRESCIANI, E. Injectable composite resin technique:
An alternative for anterior esthetic restorations - case report. Int. J. Odontostomat., 17(3):245-250, 2023.

ABSTRACT: This article aims to describe a clinical case of the use of the injectable restorative technique with
composite resin in a patient with an esthetic complaint in the anterior teeth. Producing direct restorations in anterior teeth
when performed with composite resin demands a long clinical time. Results often depend on the operator's ability to repro-
duce proper form, function, and esthetics. Lately, the versatility of composite resins has increased. As this material evolved,
new techniques were introduced to simplify the restorative process and save time. The restorative technique with injectable
fluid composite resin, in addition to delivering faster and with a certain ease, is capable of increasing the predictability of
treatment results. However, it is known that flowable resins have lower wear resistance and color stability compared to
conventional resins. Thus, a version of this material with a higher filler content in its composition was introduced to the
market, to improve wear resistance and gloss retention. Long-term studies evaluating the use of low-viscosity resins are
needed. The injectable technique can accurately reproduce the morphology obtained in the wax-up of the case, generating
a satisfactory esthetic and functional result. Despite simplifying the fabrication of restorations when compared to the
conventional technique, it is still necessary for the operator to have some experience and aptitude. The clinical time for the
production of restorations has been considerably reduced. The material showed good flow, shine, and polish in the immediate
result. However, the finishing and polishing of the restorations required a longer clinical period than usual and in the short-
term follow-up, flaws in the gingival margins and a new finishing and polishing procedure were necessary. Therefore, the
technique described in this article can be considered a restorative alternative, but it is still not able to replace the traditional
method of making previous esthetic restorations.

KEY WORDS: resin composite, flowable resin composite, injectable resin composite, injectable resin
technique, wax up.

INTRODUCTION

As an attempt to minimize the disadvantages mainly due to the bond strength of this material with
of acrylic resins used in the 1940s, composite resins the dental substrate. As their mechanical and optical
were introduced to conservative dentistry. In 1955, properties constantly evolve, resins have overcome
Buonocore improved the adhesion of acrylic resins limitations and become more versatile (Ikeda et al.,
to enamel through the use of phosphoric acid. In 2009; Coachman et al., 2020).
1962, Bowen developed the Bis-GMA monomer,
which was later polymerized by an ultraviolet light However, the use of this material for making
source (Hervás-García et al., 2006; Matos et al., direct restorations in anterior teeth demands a long
2021). The increase in composite resin use was clinical time. In addition, results are highly dependent

1
Department of Operative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos - SP,
Brazil.
2
Department of Biomaterials, Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology,
São José dos Campos - SP, Brazil.

Received: 2023-03-20 Accepted: 2023-04-22

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 PEREIRA, T. C.; MATOS, J. D. M.; RUANO, V.; BOTTINO, M. A. & BRESCIANI, E. Injectable composite resin technique: An alternative for anterior esthetic restorations - case
report. Int. J. Odontostomat., 17(3):245-250, 2023.

on the operator's ability to reproduce the proper form, composites (Kim et al., 2002; Karadas, 2016; Nair
function, and esthetics. Furthermore, the et al., 2017). With the constant evolution of flowable
reproduction of well-adapted battlements and resin formulations, a new version of this material with
contours using conventional resins can be a a high load in the composition was introduced into
challenge for clinicians. Therefore, professionals the market with the promise of increased wear
sometimes opt for the production of indirect resistance and gloss maintenance. However, there
restorations. However, working indirectly also has are rare studies in the literature that evaluate this
its disadvantages, as it increases the cost and time material over the long term (Terry & Powers, 2014).
required to resolve the case (Coachman et al., 2020; Thus, this article aims to report a clinical case of an
Ypei Gia et al., 2021). injectable resin composite restorative technique on
a patient with an esthetic complaint on the anterior
New clinical techniques were introduced to teeth.
facilitate the application of direct restorative
materials, save time, and obtain satisfactory esthetic
and functional results. Mockups using acrylic resin CASE REPORT
and transparent index with injected fluid resin have
become popular for making provisionals for anterior
teeth (Gouveia et al., 2017). Flowable resins have A 26-year-old male patient presented to São
low viscosity and offer high wettability of the tooth Paulo State University, in São José dos Campos.
surface, ensuring penetration into all irregularities The patient reported being dissatisfied with the
and the formation of layers of a minimum thickness esthetic of his anterior teeth. After clinical
(Hervás-García et al., 2006; Matos et al., 2021). examination, stained resin restorations, wear, and
Studies conducted to improve the mechanical fractures were observed (Figs. 1-6). As a treatment
properties of flowable resins resulted in the addition plan, it was determined to perform superior esthetic
of nanoparticles to their composition. Such an restorations by the injectable technique from teeth
improvement did not affect the material handling 13 to 23 and restorations by the conventional
characteristics. However, studies have concluded technique with composite resin in the premolars of
that such resins have good polishing but reduced both Hemi-arches.
wear resistance. Therefore, fluid resins are indicated
for low-stress areas (Coachman et al., 2020).

The injectable resin composite restorative

technique enables agility and simplicity of execution.
It consists of a copy of the wax-up that is reproduced
on a transparent matrix with small holes for the ma-
terial to flow into the tooth. The approach is
conservative and additive that is, there is no need
to remove healthy tooth structure (Terry & Powers,
2014). When compared to direct and indirect Fig. 1. Initial photos from the patient's teeth.
restoration techniques, the injectable technique is
the least sensitive. Therefore, a clinician's ability and
clinical time can be considerably decreased. Thus,
the cost of the procedure is also reduced (Coachman
et al., 2020; Yepi-Gia et al., 2020).

Some factors, such as gloss, surface

roughness, and color stability, are essential for an-
terior restoration success. An esthetic restorative
material must simulate natural tooth color and
maintain it over time (Lai et al., 2018). Although it is
known that some of the flowable resin's
disadvantages are low wear resistance and color Fig. 2. Wax-up performed for producing the transparent index
stability when compared to conventional resin for the restorations.

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 PEREIRA, T. C.; MATOS, J. D. M.; RUANO, V.; BOTTINO, M. A. & BRESCIANI, E. Injectable composite resin technique: An alternative for anterior esthetic restorations - case
report. Int. J. Odontostomat., 17(3):245-250, 2023.

Fig. 5. Created perforations to insert the tip of the syringe of

the flowable resin composite.

Fig. 3. Acetate plate.

Fig. 6. Isolation of the teeth to be restored and separation of

the other teeth with a Teflon band.

used, and it was photopolymerized for 20 seconds

(Emmiter A Fit – Schuster). The index was positioned
in the mouth and a flowable injectable resin syringe
was inserted into the incisal perforations created on
the index (Fig. 8). After the injection of the flowable
resin (G-aerial Universal Flo BW, GC Corporation) on
each tooth, photopolymerization was realized on the
labial and lingual faces for 30 seconds on each.

Before the procedure was repeated on the other

Fig. 4. A. silicone application on the acetate plate; B. acetate
group of teeth, the excess material was removed with
plate being adapted to the wax-up; C: silicone index adapted
to the wax-up guaranteeing 2mm thickness. a scalpel (no 12) and sandpaper so the injected resin
wouldn’t adhere to it. Protection of the already restored
tooth was made with Teflon (Isotape, TVD) and the
Previous restorations were removed with SofLex procedure described earlier was repeated. After the
discs (3M). Profilaxy was performed on the patient, as execution of it, finishing and polishing were performed,
well as modified isolation with a rubber dam on the as well as eventual occlusal adjustments. For finishing
superior teeth. After isolation, protection with Teflon and polishing, SofLex discs (3M) and interproximal
(Isotope, TVD) was made on the tooth that wasn't sandpaper (3M) were used. Occlusion was verified with
supposed to be restored at this moment. Enamel carbon paper 100 µm (Bausch, Colônia), where the
etching with phosphoric acid at 35 % (Ultra Etch, patient performed protrusive, retrieve, and lateral
Ultradent) (Fig. 7) was applied, rinsed, and dried. For movements. For polishing, finishing rubbers (Jiffy Ver-
the adhesion system, Single Bond Universal (3M) was de – Ultradent; Diacomp twist EVE-Odontomega) were
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 PEREIRA, T. C.; MATOS, J. D. M.; RUANO, V.; BOTTINO, M. A. & BRESCIANI, E. Injectable composite resin technique: An alternative for anterior esthetic restorations - case
report. Int. J. Odontostomat., 17(3):245-250, 2023.

used. The patient returned after a week for eventual DISCUSSION

adjustments and the confection of the premolar
restorations. Finally, extra oral registers were made with
a digital camera (Fig. 9). Based on the possibility of performing a
diagnostic wax-up, the injectable resin technique
After a week, the patient returned for a follow- increases the predictability of results. The fidelity to
up appointment. There could be observed some the dental anatomy achieved by the transparent matrix
staining in the cervical area, near the gingival margin. and its reproduction through the use of low impression
A new finishing and polishing procedure was executed precision corroborates the high precision results
with the same materials described before. Regions that (Coachman et al., 2020). Fluid resins have the
presented a lack of material were sealed with the advantage of adapting the material to the margins and
flowable resin. These procedures were performed to filling the compost materials. However, despite all the
improve the restoration’s esthetic and longevity. continuous efforts to improve the resin's properties, they
present a reduced number of fillers when compared to
conventional resin. This characteristic interferes with
the mechanical properties of this material, causing
greater susceptibility to wear and reduced polishing
quality and color stability (Terry & Powers, 2014;
Karadas, 2016; Nair et al., 2017).

The injectable resin has higher flexural strength

compared to other fluid materials, as well as lower
flexural modulus and greater resilience (Imai et al.,
Fig. 7. Phosphoric acid etching. 2019). However, the success of restorations mainly
depends on their appearance and color stability. One
of the most common esthetic flaws encountered by
clinicians is the discoloration of anterior restorations.
Situations like this generate patient dissatisfaction and
the need for retreatment. This fact is an inconvenience
caused, given the extra time and money that is spent
on both sides (Abd-Elhamid & Mosallam, 2010).
Discoloration of restorations can be extrinsic or intrinsic.
Extrinsic causes include plaque buildup and surface
staining, which degrades the restoration surface and
generates penetration and absorption of coloring
agents into the composite resin. Intrinsic causes can
be related to physicochemical reactions that take pla-
ce inside the restoration (Powers et al., 1978; Dietschi
et al., 1994).
Fig. 8. Silicone index and the tip of the
flowable resin positioned on the incisal’s The degree of color change can also be affected
perforations. by the structure of the composite resin, the
characteristics of the filler particles, the degree of
polymerization, and the water sorption of the material.
If the composite resin can absorb water, then it is also
capable of absorbing other fluids that cause
discoloration (Garoushi et al., 2013; Karadas, 2016).
For the removal of surface stains from composite resin
restorations, tooth hygiene and the execution of
polishing protocols performed by the dentist are the
most frequently used options. However, sometimes
Fig. 9. Final photos of the patient's teeth after finishing and polishing procedures are not able to achieve the origi-
polishing. nal appearance of the restoration. This is because the
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 PEREIRA, T. C.; MATOS, J. D. M.; RUANO, V.; BOTTINO, M. A. & BRESCIANI, E. Injectable composite resin technique: An alternative for anterior esthetic restorations - case
report. Int. J. Odontostomat., 17(3):245-250, 2023.

penetration is deep and the stains are not superficial. restoration close to the gingival margin, suggesting low
In some cases, polishing can even lead to the removal strength when in thinner thickness. It was also observed
of layers from the resin surface, increasing the surface that there was a need for regular follow-ups to
roughness of the restoration (Türkün & Türkün, 2004; guarantee color stability and greater treatment
Abd-Elhamid & Mosallam, 2010). longevity. Therefore, the technique described in this
article can be considered a restorative alternative, but
Fluid materials can have different amounts of it is still not able to replace the traditional restorative
inorganic content, ranging from 61 to 71 % of their technique for anterior teeth.
composition. The resin used in this clinical case has a
higher amount of filler than other fluid resins available
on the market and, for this reason, covers a greater ACKNOWLEDGMENTS. This research was funded by
number of indications to be used. However, despite São Paulo Research Foundation (FAPESP – grant
having a higher number of fillers and showing an numbers 2019/24903-6, and 2021/11499-2).
indication of universal use, studies observed that when
simulating occlusal stress, flowable resins showed
significantly reduced values when compared to bulk- PEREIRA, T. C.; MATOS, J. D. M.; RUANO, V.; BOTTINO,
fill resins (Ujiie et al., 2020). Therefore, low-viscosity M. A. & BRESCIANI, E. Técnica de resina compuesta
resins need to have their clinical performance and inyectable: Una alternativa para restauraciones estéticas
longevity investigated and compared to regular anteriores - reporte de caso. Int. J. Odontostomat., 17(3):245-
250, 2023.
viscosity materials (Torres et al., 2014). Directly
fabricated restorations, whether injectable or not, have RESUMEN: Este artículo tiene como objetivo descri-
limitations in terms of wear. In this case, the patient bir un caso clínico del uso de la técnica restauradora
had bruxism. Thus, before treatment, the professional inyectable con resina compuesta en un paciente con una
explained the limitations of the case to the patient, and queja estética en los dientes anteriores. Producir restaura-
a plate to protect the teeth was made at the end of the ciones directas en dientes anteriores cuando se realizan con
treatment. resina compuesta demanda un largo tiempo clínico. Los re-
sultados a menudo dependen de la capacidad del operador
Although the technique aims to simplify the para reproducir la forma, la función y la estética adecuadas.
Últimamente, la versatilidad de las resinas compuestas ha
restorative process, some limitations were observed.
aumentado. A medida que este material evolucionó, se in-
The technique consists of a series of steps that, if the trodujeron nuevas técnicas para simplificar el proceso de
operator is inexperienced, can take a long time to restauración y ahorrar tiempo. La técnica restauradora con
perform. The adequacy of the interproximal spaces and resina compuesta fluida inyectable, además de una entrega
the removal of excess material that is generated after más rápida y segura, es capaz de aumentar la previsibilidad
the light curing of the material can consume a lot of de los resultados del tratamiento. Sin embargo, se sabe que
clinical time (Gesˇtakovski, 2019). If a lot of finishing is las resinas fluidas tienen menor resistencia al desgaste y
needed, it can lead to a de-characterization of the estabilidad del color en comparación con las resinas con-
anatomy produced by the wax-up. vencionales. Así, se introdujo en el mercado una versión de
este material con un mayor contenido de relleno en su com-
posición, con el objetivo de mejorar la resistencia al desgas-
Final considerations te y la retención del brillo. Se necesitan estudios a largo
plazo que evalúen el uso de resinas de baja viscosidad. La
It can be concluded from this study that: The técnica inyectable es capaz de reproducir fielmente la mor-
injectable technique can accurately reproduce the fología obtenida en el encerado del caso, generando un re-
morphology obtained in the wax-up of the case, sultado estético y funcional satisfactorio. A pesar de simplifi-
generating a satisfactory esthetic and functional result. car la fabricación de restauraciones en comparación con la
Despite its simplification when compared to the técnica convencional, todavía es necesario que el operador
conventional technique, it is still necessary for the tenga cierta experiencia y aptitud. El tiempo clínico para la
producción de restauraciones se ha reducido considerable-
operator to have some skill. The clinical time for making
mente. El material mostró buena fluidez, brillo y pulido en el
the restorations was considerably reduced. However, resultado inmediato. Sin embargo, el acabado y pulido de
much of the service was spent on achieving the final las restauraciones requirió de un período de tiempo clínico
finishing and polishing, which was considered ideal. más largo de lo habitual y en el seguimiento a corto plazo,
The fluid resin used showed good flow, gloss, and fueron necesarios defectos en los márgenes gingivales y un
polishing in the immediate result. However, in the short- nuevo procedimiento de acabado y pulido. Por lo tanto, la
term follow-up, failures can be observed in the técnica descrita en este artículo puede considerarse una al-

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 PEREIRA, T. C.; MATOS, J. D. M.; RUANO, V.; BOTTINO, M. A. & BRESCIANI, E. Injectable composite resin technique: An alternative for anterior esthetic restorations - case
report. Int. J. Odontostomat., 17(3):245-250, 2023.

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Terry, D. & Powers, J. Using injectable resin composite: part one.
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