Minimal dentistry and therapeutic concepts

Minimal dentistry and therapeutic concepts

Minimal Intervention Dentistry (MID): Definition

Minimal Intervention Dentistry (MID) is an indispensable element of modern dentistry focusing on preventive or non-surgical actions to preserve hard dental substances, thus avoiding any unnecessary sacrifice of dental tissues, ensuring the longest possible dental survival through increasingly early procedures (made possible by the evolution of diagnostic methods and materials) and less and less invasive.

Clinically, the practice of minimally invasive dentistry corresponds to the strict application of the principle: systematic respect for the original tissues.

Minimally invasive dentistry is becoming an operating concept applicable on a daily basis with the following common denominator for all techniques:

tissue preservation while prioritizing prevention over any form of therapy.

This involves a better understanding of the caries process, the use of increasing performance of adhesive systems and choosing from a wide range of tools: ozone therapy, sonic and ultrasonic inserts , etc. These new tools improve diagnosis for some and minimise the forms of preparation for others.

Minimal approach to carious lesion in dentistry

The ultra-conservative approach to carious lesions should include the following processes:

• Accurate diagnosis and assessment of risk, disease and injury

• Primary prevention

The a• Detect and treat early lesions

• Minimally invasive surgical procedures

• Secondary prevention

Benefits

There are several arguments in favor of restorative dentistry at a minimum:

• A limited survival rate of restorations: this type of practice limits the production of restorations as well as their volume

• A slowed rate of progression of carious disease

• The possibility of reversing and stabilizing the caries process

• New diagnostic and treatment methods

• The development of adhesive and restorative materials

This concept is preferable to conventional restorative dentistry, which is too destructive and destroys certain dental structures of interest (enamel bridge, peripheral marginal ridge).

It is important to clarify that minimal dentistry can only be used as a first-line treatment on patients at low risk of caries.

Principles of dentistry at a minimum

1. Early detection and diagnosis

The dentist, based on the clinical examination (after prior cleaning of the dental surfaces) and the X-rays (retro-alveolar and bite-wings), will assign a code to the carious lesion based on its location and extent according to the ICDAS II or SiSta classification.

Early diagnosis concerns early lesions. Visualization of lesions requires prior cleaning of dental surfaces with polishing pastes and brushes (see plaque removal and scaling if there is poor hygiene and tartar). Surfaces must be dry and clean . Hypoplasia and hypocalcification are not visible on wet surfaces, so drying is essential.

Use of optical aids is beneficial for better visibility of lesions.

The production of retro-coronal images (bite-wing) remains the basic examination, especially for the visualization of
proximal caries.

2. Classification of lesions:

2.1 The ICDAS II classification

The ICDAS II classification, created in 2005, allows carious lesions to be diagnosed based on visual criteria. As a result, it is easily and quickly applicable clinically and does not require an X-ray. This classification includes 6 scores (or codes):

Score 0 : Healthy tooth
Score 1 : First visual changes in the enamel visible after the tooth has dried:
Score 2 : Clear visual changes in enamel visible without drying of the tooth:
Score 3 : Characterized by enamel rupture (cavitation)
Score 4 : Dark area under the enamel: the practitioner may suspect a dentin lesion
Score 5: Cavity visible and dentin affected by the lesion
Score 6: Expandable cavity with visible dentin

2.2 The SiSta classification

This classification was proposed by Hume and Mount in 1997 and then modified by Professor Lasfargues in 2000. It is based on histological criteria and requires taking an X-ray to use it.

Three sites and five stadiums are worth remembering:

The sites:

Site 1: Pits and grooves (occlusal, palatine and vestibular)
Site 2: Interproximal zone
Site 3: Cervical and root parts of the tooth

The stadiums:

Stage 0 : Enamel damage without cavitation and which can reach the enamel-dentin junction (reversible by enamel remineralization)
Stage 1 : Involvement of the outer third of the dentine with cavitation
Stage 2 : Involvement of half of the dentine without major cusp weakening.
Stage 3 : Involvement of the inner third of the dentine with weakening of the cusps
Stage 4 : Juxtapulpal lesion with total or partial cusp destruction

Therapeutic choice in restorative dentistry at a minimum

The practitioner will be able to direct his care and actions to treat the lesion. The operator will then oscillate between protocols

MID-1: focused on prevention and non-surgical procedures
MID-2: using microsurgery techniques

The MID-1 (Minimal Intervention Dentistry-1)

Allows the treatment of enamel and enamel-dentin lesions without preparation (apart from tissue conditioning), provided that there is no surface cavitation.

MID-1 uses a set of techniques aimed at:

sterilize,
remineralize,
reverse and seal the carious process

Prevention

To eliminate or minimize caries risk factors by modifying diet, lifestyle habits and increasing the pH of the oral environment.

Teaching oral hygiene and plaque control
HAS reminds us of the importance of brushing teeth at least twice a day with a fluoride toothpaste with a fluoride content appropriate for age. (HAS, 2010)

The UFSBD supports these recommendations: it recommends brushing for at least two minutes twice a day using the BROS technique.

This brushing will be completed in the evening by flossing as soon as there is a point of contact between two teeth. However, there is no recommendation regarding the electric toothbrush.

Nutritional advice

The relationship between fermentable sugars and caries having been demonstrated, the prevention of carious lesions therefore involves reducing the quantity of sugar consumed but above all the frequency of this consumption, it is therefore recommended to:

Reduce the frequency of food intake between meals (snacking, including sugary drinks). In this sense, the morning snack in the community should be eliminated
Promote a varied and balanced diet during meals and the
consumption of pure water.
Use chewing gum containing xylitol after each
meal or consumption of sugary drinks that cannot be followed by
brushing your teeth.
The widespread use of sugar as a sweetener in medicines; as well as the use of iodized and fluoridated salt rather than non-fluoridated salt

Remineralization

To arrest and reverse early lesions, using appropriate topical agents including fluorides and casein phosphopeptides-amorphous calcium phosphate (CPP-ACP).

Remineralization by fluorinated agents

Fluoride is the most widely studied agent in the scientific literature for the remineralization of hard tissues demineralized by acid attacks from bacteria, but also the most used .

Topical application of fluoride

Daily topical use at home: The most common and widely used is fluoride toothpaste, which can be supplemented with a mouthwash.

Brushing with fluoride toothpaste not only prevents the formation of a carious lesion, but also stops its progression and even repairs the damage caused in some cases. However, the remineralization action takes a long time and requires rigorous plaque control.

Professional application

Professional application of remineralizing agents such as fluoride varnishes should be done twice a year. They have an undeniable preventive effect on caries; their remineralizing effect on non-cavitary lesions remains to be proven.

New remineralization agents, derived from calcium phosphate, have recently appeared. Calcium phosphate is a molecule that has the effect of increasing the calcium concentration in the oral cavity. The natural remineralization capacity of saliva is therefore improved.
Among these agents:

Casein phosphopeptide-amorphous calcium phosphate or CPPACP, (topical remineralization paste). Also exists CPP-ACP with added fluoride or CPP-ACPF.
Unstabilized amorphous calcium phosphate or ACP, called EnamelonTM, (toothpaste).
A bioactive glass containing sodium calcium phosphosilicate or Novamin
CPP-ACP and CPP-ACPF are promising products in the remineralization of non-cavitary lesions

Casein Phosphopeptin-Amorphous Calcium Phosphate

These are peptides derived from milk casein. It affects the process of demineralization remineralization. The CPP-ACP complex is a reservoir of calcium and phosphate, this nano-complex adheres to the bacterial wall of microorganisms and dental surfaces. During an acid attack, these ions are released and the saliva is then saturated with calcium and phosphate compared to the dental enamel: inhibiting demineralization and promoting remineralization

It comes in the form of a cream or gel to be applied twice a day to the teeth after brushing. This cream must act for at least 3 minutes on all the teeth. It is during this period that the complex will act as a restorative agent. For an effective action, it will be necessary to avoid eating, drinking or rinsing for at least 30 minutes after application.

Recaldent® Toothpaste with CPP-ACP

Prophylactic sealing of pits and fissures
Definition

” A non-invasive procedure to fill the grooves with a fluid adhesive material. It creates a smooth, flat, waterproof physical barrier that prevents the accumulation of bacterial plaque on contact with the protected enamel surface and prevents acid demineralization at this level.”

Indication

The HAS issued in 2005 stipulate that they must be systematized in:

Subjects at high risk of caries ,
Low-risk subjects , in the case of anfractuous occlusal morphology of permanent molars characterized by main grooves that are deeper than they are wide.
Since the mechanical characteristics of the sealing materials are not optimal, the choice of this interceptive treatment should be reserved for people who can commit to regular monitoring.

Materials

The materials that can be used for sealing are:

Photopolymerizable composite resins containing or not an addition of fluorine,
Self-curing composite resins
Glass ionomer cements (GIC).

Photopolymer or self-curing resins appear to have the same retention. CVI, as well as fluorine-containing photopolymer resins, have less retention.

Operating protocol

The HAS recommends

E) dry mechanical cleaning (without pumice stone, which reduces material retention) or air-polishing cleaning,

F) conditioning of the enamel with acid before placing the sealing resin.

G) The installation of sealants must be subject to regular monitoring, which varies depending on

function of the RCI.

H) During the inspection visits, the RCI is reassessed and the integrity of the material is checked. In the event of partial loss, the material is repaired and in the event of total loss,

it is reapplied based on the RCI

The MID-2
1. Indications:

It is intended for the treatment of early enamel-dentin lesions with surface cavitation affecting only the external or middle third of the dentin. This type of dentistry requires minimal dental preparation.

Clinical phases

The common points of minimal restorative techniques are:

The operating field;
Clinical antisepsis procedures;
Optical aids.

Disinfections

It is possible to disinfect hard-to-reach areas typical in microdentistry (e.g. SISTA 2.1 cavity) by brushing the dentin surface with an aqueous solution of chlorhexidine, fluorinated derivatives (SnF2, Silver-Diamin-F, fluorinated amines).

Other techniques exist such as the application of tetracycline-based preparations (Ledermix, Riemser) on the dentine but which requires a 2-stage intervention incompatible with the minimal techniques in first intention. Their use can be recommended peroperatively before or after tissue conditioning with phosphoric acid

Only two techniques have proven antibacterial power: laser and Carisolv® (Medi Team, Gothenburg, Sweden), with a synergy of action.

Classically, we can distinguish the following intervention phases, even if they often overlap with each other during the operating procedures:

Access to the lesion;
Removal and destruction of pathological tissues;
Finishing of cavity contours for watertight adaptation of the obturation

Clinical applications of the SI/STA concept

4.1. Clinical options for site 1 lesions

4.1.1 SI/STA 1•0

A. Diagnosis:

The presence of opaque white spots of demineralization (white spots) at the bottom and/or on the banks of the pits, grooves and occlusal dimples

Absence of cavity in the enamel

Therapeutic option

Sono-abrasive and aero-abrasive techniques offer an interesting action here.

They allow selective elimination of damaged tissues, which are more fragile than healthy enamel.

Tissue removal must then be limited to the affected area but complete,

Individual dental prophylaxis measures should be introduced in addition to these therapies,

Application of fluoride varnish or glass ionomer cement.
Installation of sealant.

Stage 0, non-invasive treatment with sealant.

4.1.2 SI/STA 1•1

A. Diagnosis: based on the following clinical elements:

Change in enamel color (white opacities or brown colorations) with the appearance of gray shadows

Rough enamel on probing (indicating micro-cavitations); or occasional cavity beginning after enamel rupture

Therapeutic option

Creation of mini occlusal cavities (without opening the network of adjacent grooves) by rotary preparation (micro-burrs), kinetic (air abrasion), vibratory (sonoa-brasion and ultra-sono-abrasion) or photoablation (lasers)
Preventive fillings at a minimum

stage 1, preventive filling

When curettage is necessary, it should be limited to the dentinal lesions, without connecting them together, and without extending the cavity to all the grooves.

Prolonged aero-abrasive action allows suitable removal of altered dentin.

Micro-round or “pear” burs on a contra-angle are also suitable for performing selective curettage in this softened tissue.

Mini occlusal cavities (SISTA 1/1) and minimal sulcus preparation

Site lesion 1 stage 1 Preparation by air abrasion of the occlusal lesion Obturation of the preparation with a microhybrid composite

4.1.3 SI/STA 1•2

Diagnosis:

Enamel color changes and gray shadows (underlying dentin damage);
Loss of enamel surface integrity detectable without optical aids;
Localized enamel cavity assessable by probing (hard dentin in depth).
The lesion is of moderate size and does not weaken the peripheral structures of the dental crown

Therapeutic option

Minimal preparation with limited access to affected grooves

Direct cavity filling by layering of micro-hybrid composite resins.

Stage 2: small, punctate fillings not connected to each other

Stage 2 (involvement of the middle third of the dentin)

Access to the lesion is achieved with spherical diamond instruments (ball or pear), the action of which begins on sites presenting a clear cavitation.

Opening the infiltrated grooves with a fine instrument without trying to connect the cavities together.

The edges of the cavity are smoothed using a rotary finishing instrument (generally a fine-grain diamond burr)

2. Clinical applications of the SI/STA concept : Site 2 lesions

a. Stage 0: lesions confined to the enamel

Only individual prophylactic measures need to be implemented, they are identical to sites 1.

b. Stage 1 (involvement of the outer third of the dentin)

The major difficulty in treating proximal sites is the poor accessibility, both instrumental and visual.

Radiological information being more reliable than that obtained with sites 1.

2.1 SI/STA 2•0

Diagnosis:

Radiolucency localized to the enamel with, at most, an involvement of the enamel-dentine junction, on the retrocoronary image

Therapeutic option

Non-invasive remineralization treatment combined with monitoring

2.2. SI/STA 2•1

Diagnosis:

Extended enamel radiolucency below the enamel-dentin junction, in the outer third of the dentin. The image remains difficult to interpret in terms of the absence or presence of a cavity.

On clinical examination:

Change in translucency of the marginal ridge
Microcavitations of the proximal surface can be revealed by tearing of dental floss.

Therapeutic option

Ultraconservative preparations with preservation of marginal ridges and preservation of interproximal enamel contact.

Make small fillings by injecting an adhesive material (CVIMAR and composites)

Site 2 preparations in “tunnel”: open or closed, depending on whether or not the proximal zone is opened during preparation.

These preparations are contraindicated:

On patients whose caries risk is not stabilized;
If the thickness of the marginal ridge is less than 1 mm;
If, following preparation, the marginal ridge shows visible cracks;
If the operative difficulty reduces the control of the preparation shape and its obturation.

Operating sequence

Protect the adjacent proximal face with a metal matrix.

Open the marginal ridge fossa using a ball diamond bur which will already be oriented towards the proximal area (45° angle).

Complete the preparation using a sonic diamond ball insert (angled insert) or ultrasonic insert so that visibility is sufficient.

Remove infected dentin

Set up the operating field and disinfect the preparation.

Set up a metal stamping,

Inject into the bottom either a flowable composite or, preferably, a CVIMAR.

Leave the occlusal cavity free so that a classic microhybrid composite can be inserted using the “up” composite technique.

Mini “tunnel” cavity, preparation in an oblique direction towards the proximal lesion and preservation of the marginal ridge over 2 mm (SISTA 2/1).

“Funnel” or “slot” preparations: Operating sequence.

Start the preparation using a diamond ball bur on the accessible surface (vestibular or palatine).

Use diamond half-ball inserts (smooth non-working side)

Once the infected dentin is reached, use a full ball insert to finalize the preparation

Site preparations 2 for adhesive restoration

Preparations to be carried out when the marginal ridge is no longer salvageable or when the carious stage is level 2/3 (middle third/inner third of dentin).

Operating sequence

Protect the adjacent proximal face with a metal matrix.

Creation of an occlusal access cavity with micro burs.

Minimal opening of the marginal ridge either with a diamond bur or with an ultrasonic insert

Removal of infected dentin

Setting up the surgical field, conditioning the tissues and obturation