Keywords
prosthodontics - dental tissue - no-prep - oral health - oral rehabilitation - porcelain
veneers - aesthetic
Introduction
Prosthodontics is a specialized branch of dentistry that focuses on designing, fabricating,
and fitting artificial replacements for missing teeth and other structures in the
oral cavity. Prosthodontics aims to restore the patient's oral function, esthetics,
and overall quality of life. No-prep techniques in dentistry are a relatively recent development that has revolutionized the field
of prosthodontics.[1] These techniques use innovative materials and procedures to create dental restorations
requiring little or no natural tooth structure preparation. This approach is attractive
to patients because it often eliminates the need for injections and drilling, resulting
in a more comfortable and less invasive treatment experience.
Some examples of no-prep techniques include using porcelain veneers, which can be bonded directly to the tooth's surface,
and dental crowns that are milled using computer-aided design and manufacturing (CAD/CAM)
technology. No-prep techniques can offer a range of benefits, such as preserving more
of the natural tooth structure, reducing the risk of post-treatment sensitivity, and
producing more predictable and aesthetically pleasing results.[2] Dental anterior restoration refers to repairing or replacing damaged or missing
teeth in the front of the mouth. One of the newer techniques used for anterior restoration
is the no-prep approach. The no-prep technique involves placing a dental veneer directly
onto the existing tooth without removing any natural tooth structure. This approach
is often used for minor cosmetic improvements or repairing small chips and cracks
in the front teeth. One advantage of the no-prep technique is that it is minimally
invasive, meaning less disruption to the natural tooth structure. This can help preserve
the tooth's health and reduce the risk of postoperative sensitivity. Another advantage
is that the no-prep technique often requires only one visit to the dentist, as opposed
to traditional dental veneers, which may require multiple visits. This can save time
and reduce the overall cost of the procedure. However, the no-prep technique may only
be suitable for some.
In some cases, the existing tooth may need more surface area to support a veneer without
removing some natural tooth structure. In these cases, a traditional veneer may be
necessary.[3] The no-prep technique may not provide as long-lasting results as conventional veneers.
This is because the veneers may only bond as strongly to the tooth, removing some
of the natural tooth structure. The new mode of operation for many practitioners is
to exploit healthy tooth tissue through partial adhesive restorations rather than
preparing teeth for full coverage restorations. In particular, porcelain veneers are
a minimally invasive aesthetic restoration option with a high success rate for color
stability, biocompatibility, mechanical properties, and good aesthetic results.[4]
[5]
[6] In selected cases, it is possible to obtain all the advantages of ceramics, especially
its high bond strength to the enamel, without preparing the tooth,[7]
[8] achieving various clinical benefits: no form of postoperative sensitivity, maximum
bond strength to the enamel, function and aesthetics at the long term and possibility
of reversibility. The main indications for this type of aesthetic restoration are
as follows:
-
Teeth with a previous minor additive composite restoration whose removal gives the
technician the necessary space for the realization of the ceramic restoration;
-
Teeth with anatomical alterations that allow insertion for ceramic veneers.
The latter indication fits perfectly with the clinical case in the following article.
Case Report
The no-prep technique in dentistry typically involves the following phases:
-
Consultation: The first step is to consult with your dentist to assess your dental
needs and determine if the no-prep technique is appropriate.
-
Preparation: Once it is determined that the no-prep technique is the best option,
the dentist will take impressions of your teeth to create a custom-fit veneer.
-
Bonding: On your next visit, the dentist will clean and prepare the surface of the
tooth to be restored. The veneer is then bonded to the tooth's surface using a unique
dental adhesive.
-
Polishing: After the veneer has been bonded, the dentist will polish and shape it
to match the surrounding teeth.
-
Follow-up: The dentist will schedule a follow-up appointment to ensure the veneer
functions correctly and make any necessary adjustments.
The no-prep technique is a minimally invasive and efficient way to restore damaged
or discolored teeth. Choosing a skilled and experienced dentist is essential to ensure
the best outcome.
Case Presentation
After orthodontic therapy with a straight-wire technique, the female patient wanted
to restore the harmony of her smile with minimally invasive treatment. The disharmony
was related to the genesis of element 1.2 and the anomaly of the shape and volume
of element 2.2. To evaluate the case, intra- and extraoral photos were taken to discuss
the case with the patient and the technician and choose the most appropriate treatment
plan for the clinical case ([Figs. 1]
[2]). Subsequently, impressions were taken in polyvinylsiloxane on nonperforated commercial
impression trays to create the diagnostic wax-up in the laboratory.
Fig. 1 Intraoral preoperative photo.
Fig. 2 Extraoral preoperative photo with relaxed and smiling lips.
Diagnostic Wax-Up
In the laboratory, the impressions were developed with extra-hard plaster for the
diagnostic wax-up involving elements 1.4-1.3-2.2-2.3; on the 1.4, a shape similar
to a canine was given on the buccal side, on the 1.3, a shape more similar to a lateral
incisor, on the 22nd an increase in volume to close the distal diastema. Finally, in 2.3, a shape and
volume in harmony with the contralateral 14 ([Fig. 3]). Based on the wax-up, a transparent silicone key was made for the mockup.
Fig. 3 Additive diagnostic wax-up.
Mockups
The composite mockup makes it possible to evaluate the diagnostic wax-up volumes and
modify its shapes, dimensions and lengths if they are not congruous with the patient's
smile and face ([Fig. 4]).
Fig. 4 Intraoral previsualization of final rehabilitation.
A softer, oval shape of the teeth harmonizes well with the patient's face. The smile
line follows the lower and upper lip trend, and the occlusal plane is symmetrical
with the median lines and the bipupillary line ([Fig. 5]).[9]
Fig. 5 The extraoral figure of the mockup.
After removing the mockup, a definitive polyvinylsiloxane impression was taken with
the single-phase bi-paste technique with commercially available nonperforated impression
trays.
Technical and Laboratory Phases
The veneers were made of feldspar ceramic and sintered on the platinum sheet with
the alveolar model technique ([Fig. 6]). The translucency of the material characterizes these ceramic restorations to obtain
highly aesthetic restorations with very thin ceramic layers, up to 0.5 mm, with or
without preparation ([Fig. 7]).
Fig. 6 Feldspathic ceramic platin-synthesized.
Fig. 7 Feldspathic ceramic restorations.
The only weak point remains the resistance to fracture with an elastic modulus ranging
between 50 and 120 Mpa, which classifies it as a brittle ceramic. However, the brittleness
of these ceramic materials can be considered before the adhesive cementation stage
of the restorations. The distribution and interaction of crystals within the glass
matrix change the mechanical properties, and the finer the crystals, the higher the
fracture resistance[10]
[11]([Fig. 8]).
Fig. 8 Final restoration on the plaster model.
Results
After isolation with a rubber dam ([Fig. 9]), the teeth were cleaned with brushes and pumice. The final restorations were tried
in for fit, shape, and color. Subsequently, the intaglio surfaces of the repairs were
etched with 9% hydrofluoric acid for 20 seconds to enhance the micromechanical retention
of the ceramic artefacts. Crystalline precipitates are produced during acid etching,
which could decrease the adhesive strength of the restorations,[12] which is removed by immersing the frameworks in an ultrasonic bath for 5 minutes.
After rinsing and drying, a silane agent was applied for 1 minute. The dental substrate
was etched with phosphoric acid for 60 seconds ([Fig. 10]), rinsed and air-dried.[13] Without curing, an unfilled, hydrophobic universal bonding agent was applied to
the framework and dental substrate. For the cementation of the veneers, a dual aesthetic
resinous definitive cement was used, chosen based on its mechanical properties and
the restorative material used, and, after careful removal of the excess, the product
was polymerized with a LED lamp for 40 seconds with low power mode. Afterward, glycerin
gel was applied to block the air and light-cured again for 40 seconds with a high-power
method on all surfaces.
Fig. 9 Dental dam isolated field.
Fig. 10 Acid etching with a dental dam.
The further excesses of resinous cement were removed with scalpel n.12, which does
not damage the ceramic restorations ([Fig. 11]). The veneers were cemented one at a time. The finishing was carried out with interproximal
abrasive strips, and finally, the rubber dam was removed to carry out the occlusal
registration ([Figs. 12] and [13]).
Fig. 11 Cemented veneers.
Fig. 12 Intraoral final result.
Fig. 13 Extraoral final result.
Fi-index Tool
This manuscript has been checked with the Fi-index tool and obtained a score of 0
on the date 19/12/22 according to Scopus for the first author only.[14]
[15]
Discussion and Conclusions
Discussion and Conclusions
Veneers are thin ceramic plates cemented onto the teeth's outer surface to improve
aesthetics (dark, chipped teeth, closed spaces between teeth or restore function;
teeth worn out due to wear, abrasion, and erosion). The no-prep technique is often
combined with the creation of partial restorations called “additional”: if it is not
necessary to cover the entire surface of one or more teeth, it is possible to manufacture
small ceramic fragments that can be cemented. This is necessary to fill a space or
restore, for example, a fractured cusp. Similarly, today it is also possible to make
very thin lithium disilicate crowns (“full veneers”) in cases where it is necessary
to completely cover the tooth surface (teeth heavily destroyed by caries, teeth consumed
by wear or abraded by chemical substances, such as food acids, etc.). The small thickness
of these crowns (up to 0.3 mm) allows you to make minimally invasive preparations
or not touch the teeth with the burs. This will enable you to save the amount of enamel
and dentin and not devitalize the teeth for prosthetic crowns.[16]
[17]
[18]
The ceramic veneers allow correcting anomalies of shape and volume (closing of black
interdental triangles and diastemas, conoid teeth), pigmentations, and dyschromia
such as nicotine and/or caffeine stains, yellowed, composite restorations, malpositions,
and congenital enamel defects (e.g., fluorosis, imperfect amelogenesis), giving harmony
to the smile even with a nonoptimal position of the teeth. Modern material technologies
today allow various types of ceramics to create veneers, from traditional highly translucent
feldspathic ceramics to the more recent highly resistant lithium disilicate-based
ceramics. It is evident that a microscope or magnifying system is almost indispensable
for rehabilitations carried out with these materials. The optimal mechanical properties
and the high fracture resistance of the disilicate allow for the creation of definitive
veneers in biomechanically nonideal situations, such as in patients with bites or
the case of severe wear of the incisal edges. Since veneer preparation is a noninvasive
technique that does not involve the gingival space, it is now possible to use intraoral
scanners to take a digital impression of veneers. Compared to traditional ones, digital
impressions do not require pastes, impression materials, or impression trays, which
are often bulky and uncomfortable for patients. Intraoral scanners are high-resolution
cameras that allow you to detect the shape of the teeth and gums and the color of
the tissues, creating the veneers in a wholly digital way. This technique is very
comfortable and quick and allows you to check the precision of the preparations in
real time.[2]
[19]
[20]
The treatment has no absolute contraindications and can be performed at any age. In
the case of young patients who have not yet completed their growth (about 16 years
for females and 18 for males), it is preferable to use dental veneers in composite
resin. This material can be modified and/or removed more easily over time.[21]
Ceramic dental veneers can be made in the presence of composite reconstructions (frequent
in patients who have chipped or worn teeth), provided the filling material does not
show infiltrations (dark coloring of the margins) or secondary caries. The indirect
restoration in the anterior sectors still today remains the gold standard for restoring
a smile respecting the canons of aesthetics, function and durability over time compared
to direct composite restorations in the anterior sectors, which have the advantage
of requiring a single session, lower costs, and no tooth preparation.[3]
[16]
[19]
[22] In fact, among the disadvantages of indirect restorations, the need to prepare the
tooth to give the correct thickness to the product would not meet today's concepts
of minimally invasive dentistry. No-prep techniques in dentistry have several advantages
that make them an attractive option for patients who require dental restorations.[23] Here are some of the critical benefits of no-prep techniques:
-
Minimally invasive: No-prep techniques typically require little or no removal of natural
tooth structure, meaning patients can undergo treatment with less pain and discomfort.
-
Preservation of tooth structure: By preserving more of the natural tooth structure,
no-prep techniques help maintain the tooth's structural integrity and reduce the risk
of complications in the future.
-
Aesthetic appeal: No-prep techniques can produce highly aesthetic, natural-looking,
and long-lasting results.
-
Speed: These techniques are often quicker than traditional dental procedures, meaning
patients can complete treatment in fewer visits and spend less time in the dentist's
chair.
-
Reduced sensitivity: Because no-prep techniques do not require injections or drilling,
patients may experience less post-treatment sensitivity and discomfort ([Table 1]).
Table 1
Pros and cons of no-prep techniques
|
Pros
|
Cons
|
|
Minimally invasive: The no-prep technique preserves more natural tooth structure than
traditional restorations, resulting in a minimally invasive approach. This can help
maintain tooth health and reduce the risk of postoperative sensitivity
|
Limited indications: The no-prep technique may not be suitable for all cases. In situations
where more extensive tooth surface area is required to support a restoration or when
significant tooth structure needs correction, a traditional preparation approach may
be necessary
|
|
Aesthetic results: No-prep restorations can provide highly aesthetic and natural-looking
results, enhancing the patient's smile and overall appearance. The use of advanced
materials and bonding techniques contributes to improved aesthetics
|
Long-term durability: While no-prep restorations can provide aesthetically pleasing
results, they may not offer the same long-term durability as traditional restorations.
The bonding strength of veneers without tooth preparation may be lower, potentially
affecting the restoration's longevity
|
|
Time-efficient: No-prep techniques often require fewer dental visits, as the restorations
can be fabricated and placed in a single appointment. This saves time for both the
patient and the dentist
|
Case selection complexity: Choosing the appropriate cases for the no-prep technique
requires careful evaluation and case selection. Dentists need to consider factors
such as the patient's oral health, occlusion, and aesthetic goals to determine if
the no-prep approach is suitable
|
|
Patient comfort: The absence of injections and drilling associated with the no-prep
technique makes it a more comfortable and less invasive treatment option. Patients
may experience less anxiety and discomfort during the procedure
|
Expertise and training: Performing successful no-prep restorations requires expertise
and training in adhesive techniques and materials
|
In the future, no-prep techniques will become even more sophisticated and effective.
Advances in materials science and digital technology allow dentists to create more
durable, functional, and aesthetic restorations than ever before. Additionally, as
more dentists adopt these techniques, they will likely become more widely available
and affordable, making them accessible to a more significant number of patients. Overall,
no-prep techniques represent an exciting development in the field of dentistry that
has the potential to significantly improve the patient experience and the quality
of care provided by dental professionals. But today, the technological evolutions
of materials, both the artefacts and the resinous types of cement, make it possible
to save healthy dental tissue by exploiting the no-prep technique when the correct
diagnosis is made and when we have the clinical indication, as in the case presented
in this article. The field of prosthodontics is continually evolving, and the future
holds promising developments for no-prep techniques in dentistry. Advancements in
material science can lead to the development of advanced dental restoration materials,
offering improved aesthetics, durability, and bond strength for no-prep restorations.
Integrating digital dentistry and CAD/CAM technology will play a significant role,
with advancements in intraoral scanners and CAD/CAM systems streamlining the fabrication
process for more precise and efficient restoration production. Researchers are exploring
biocompatible and biomimetic materials that mimic natural tooth properties, enhancing
aesthetics and functionality while promoting long-term oral health. Advancements in
digital technology may enable highly customized and personalized restorations based
on patient-specific data, leading to improved treatment outcomes and patient satisfaction.
Future developments may further reduce tooth preparation, with minimally invasive
techniques such as regenerative approaches and bioactive materials promoting natural
tooth regeneration and reducing the need for restorative interventions. In conclusion,
the no-prep technique for anterior dental restoration is a relatively new and minimally
invasive approach that can provide quick and straightforward solutions for minor cosmetic
improvements. However, it is essential to assess each case individually to determine
the best course of treatment.
