free tracking

Laser Use in Dentistry

 

Laser Use in Dentistry

 

Lasers have been used in dentistry since 1994 to treat a number of dental problems. But, despite FDA approval, no laser system has received the American Dental Association's (ADA) Seal of Acceptance. That seal assures dentists that the product or device meets ADA standards of safety and efficacy, among other things. The ADA, however, states that it is cautiously optimistic about the role of laser technology in the field of dentistry. These lasers are different from the cold lasers used in phototherapy for the relief of headaches, pain, and inflammation.

Still, some dentists are using lasers to treat:

 

  • Tooth decay. Lasers are used to remove decay within a tooth and prepare the surrounding enamel for receipt of the filling. Lasers are also used to "cure" or harden a filling.
  • Gum disease. Lasers are used to reshape gums and remove bacteria during root canal procedures.
  • Biopsy or lesion removal. Lasers can be used to remove a small piece of tissue (called a biopsy) so that it can be examined for cancer. Laser are also used to remove lesions in the mouth; and relieve the pain ofcanker sores.
  • Teeth whitening. Lasers are used to speed up the in-office teeth whitening procedures. A peroxide bleaching solution, applied to the tooth surface, is "activated" by laser energy, which speeds up of the whitening process.

How Do Lasers Work in Dentistry?

All lasers work by delivering energy in the form of light. When used for surgical and dental procedures, the laser acts as a cutting instrument or a vaporizer of tissue that it comes in contact with. When used for "curing" a filling, the laser helps to strengthen the bond between the filling and the tooth. When used in teeth whitening procedures, the laser acts as a heat source and enhances the effect of tooth beaching agents.

What Are the Pros and Cons of Using a Laser in Dentistry?

Pros 
Compared to the traditional dental drill, lasers:

  • May cause less pain in some instances, therefore, reducing the need for anesthesia
  • May reduce anxiety in patients uncomfortable with the use of the dental drill
  • Minimize bleeding and swelling during soft tissue treatments
  • May preserve more healthy tooth during cavity removal

Cons 
The disadvantages of lasers are that:

  • Lasers can't be used on teeth with fillings already in place.
  • Lasers can't be used in many commonly performed dental procedures. For example, lasers can't be used to fill cavities located between teeth, around old fillings, and large cavities that need to be prepared for a crown. In addition, lasers cannot be used to remove defective crowns or silver fillings, or prepare teeth for bridges.
  • Traditional drills may still be needed to shape the filling, adjust the bite, and polish the filling even when a laser is used.
  • Lasers do not eliminate the need for anesthesia.
  • Laser treatment tends to be more expensive since the cost of the laser is much higher than a dental drill. Lasers can cost between $39,000 and $45,000 compared to about $600 for a standard drill.

 

 

 

Dentists use lasers to remove tooth decay, treat gum disease, biopsy tissue, and whiten teeth. Oftentimes, lasers cause less pain than traditional dental work, plus, they minimize bleeding and swelling. Unfortunately, lasers can't be used on teeth that already have fillings.

 

 

 

The current status of laser applications in dentistry

LJ Walsh*

Abstract

A range of lasers is now available for use in

dentistry. This paper summarizes key current and

emerging applications for lasers in clinical practice.

A major diagnostic application of low power lasers

is the detection of caries, using fluorescence elicited

from hydroxyapatite or from bacterial by-products.

Laser fluorescence is an effective method for

detecting and quantifying incipient occlusal and

cervical carious lesions, and with further refinement

could be used in the same manner for proximal

lesions. Photoactivated dye techniques have been

developed which use low power lasers to elicit a

photochemical reaction. Photoactivated dye

techniques can be used to disinfect root canals,

periodontal pockets, cavity preparations and sites of

peri-implantitis. Using similar principles, more

powerful lasers can be used for photodynamic

therapy in the treatment of malignancies of the oral

mucosa. Laser-driven photochemical reactions can

also be used for tooth whitening. In combination

with fluoride, laser irradiation can improve the

resistance of tooth structure to demineralization,

and this application is of particular benefit for

susceptible sites in high caries risk patients. Laser

technology for caries removal, cavity preparation

and soft tissue surgery is at a high state of

refinement, having had several decades of

development up to the present time. Used in

conjunction with or as a replacement for traditional

methods, it is expected that specific laser

technologies will become an essential component of

contemporary dental practice over the next decade.

Key words: Lasers, dental applications, débridement,

photosensitization, resin curing.

(Accepted for publication 6 February 2003.)

of the usefulness of lasers in the armamentarium of the

modern dental practice, where they can be used as an

adjunct or alternative to traditional approaches.

Traditionally, lasers have been classified according to

the physical construction of the laser (e.g., gas, liquid,

solid state, or semiconductor diode), the type of

medium which undergoes lasing (e.g., Erbium: Yttrium

Aluminium Garnet (Er:YAG)) (Table 1), and the degree

of hazard to the skin or eyes following inadvertent

exposure (Table 2). Lasers have been available

commercially for use in dental practice in Australia

since 1990, and the currently available systems

represent a high state of technical refinement in terms

of both performance and user features.

The purpose of this paper is to provide an overview

of various laser applications which have been

developed for dental practice, and to discuss in more

detail several key clinical applications which are

attracting a high level of interest.

Diagnostic laser applications

Low power laser energy has found numerous uses in

diagnosis, both in clinical settings (Table 3) and in

dental research (Table 4). By way of background, low

power lasers operate typically at powers of 100

milliwatts or less, and may produce energy in the visible

spectrum (400-700nm wavelength), or in the ultraviolet

(200-400nm), or near infrared regions (700-1500nm).

At the present time, there are few purpose built low

power lasers for the middle infrared (1500-4000nm) or

far infrared regions (4000-15000nm). Rather, lasers

operating in the middle and far-infrared regions are

used in health care primarily for hard and soft tissue

procedures.

Laser fluorescence systems for detection of dental

caries have been particularly popular in Australia. The

original technique employed visible blue light from the

argon laser, relying on the lack of fluorescence from

carious enamel and dentine to demonstrate the

presence of the lesion. Subsequent development of the

technique allowed visible red laser light from a

semiconductor diode laser to be used to elicit

fluorescence from bacterial deposits, and from calculus.

Combining a detection system with a therapeutic laser

has allowed automated removal of subgingival calculus

INTRODUCTION

The past decade has seen a veritable explosion of

research into the clinical applications of lasers in dental

practice, and the parallel emergence of organizations to

support laser dentistry with an international focus.

Once regarded as a complex technology with limited

uses in clinical dentistry, there is a growing awareness

*Professor of Dental Science, School of Dentistry, The University of

Queensland.

Australian Dental Journal 2003;48:(3):146-155

R E V I E Wfrom teeth and dental implants, a point discussed in

further detail below.

For detection of dental caries in pits and fissures,

laser fluorescence offers greater sensitivity than

conventional visual and tactile methods.

1,2

The

technique is also well suited to smooth surface lesions

on cervical surfaces of teeth,

3,4

and to recognition of

caries beneath clear fissure sealants.

5

Detection of

proximal lesions is technically more difficult, and in

this setting, argon laser-induced fluorescence offers a

valuable adjunct to conventional methods.

6-9

The

differential water content of early fissure caries and

sound occlusal enamel has also led to the development

of methods using the carbon dioxide laser to reveal

such lesions,

10-12

and to modify the fissure system to

increase resistance to future carious attack.

11

Two key advantages of laser-based systems are their

high sensitivity, and the lack of attendant risks of

ionizing radiation. This has allowed their frequent use

for monitoring lesions of dental caries and dental

erosion.

13-16

Extension of the principles of laser

fluorescence from the visible to the near infrared and

terahertz portions of spectrum opens the possibility for

more detailed analysis of the internal composition of

the tooth.

17

Moreover, the use of dyes in conjunction

with laser fluorescence holds promise for using the

method for delineating cavitated from non-cavitated

lesions in sites of poor clinical access, such as

approximal surfaces.

18,19

Bacterial porphyrins in dental calculus give a strong

fluorescence signal,

20

which can be used to control

lasers used for scaling. The same principle could be

applied to lesions of dental caries, where a targeting

laser could induce fluorescence and provide feedback to

the user as to the presence of residual bacteria (i.e., the

presence of infected carious dentine), and could also

control the action of a pulsed laser to achieve

automated caries removal. There are already data on

the spectral changes which occur during infrared laser

treatment of enamel and dentine

21,22

which could

similarly be applied clinically when assessing the

presence or absence of carious tooth structure during

laser-based cavity preparation.

Photoactivated dye disinfection using lasers

Low power laser energy in itself is not particularly

lethal to bacteria, but is useful for photochemical

activation of oxygen-releasing dyes. Singlet oxygen

released from the dyes causes membrane and DNA

damage to micro-organisms. The photoactivated dye

(PAD) technique can be undertaken with a range of

visible red and near infrared lasers, and systems using

low power (100 milliwatt) visible red semiconductor

diode lasers and tolonium chloride (toluidine blue) dye

are now available commercially (Fig 1). The initial

work which demonstrated the PAD technique used

helium-neon lasers.

23

However, such units have been

surpassed with high efficiency diode lasers which

operate at the same wavelength.

The PAD technique has been shown to be effective

for killing bacteria in complex biofilms, such as

subgingival plaque, which are typically resistant to the

action of antimicrobial agents.

24-26

It can be used

effectively in carious lesions, since visible red light

transmits well across dentine,

27

and can be made

species-specific by tagging the dye with monoclonal

147

Australian Dental Journal 2003;48:3.

Table 1. Common laser types used in dentistry

Laser type Construction Wavelength(s) Delivery system(s)

Argon Gas laser 488, 515nm Optical fibre

KTP Solid state 532nm Optical fibre

Helium-neon Gas laser 633nm Optical fibre

Diode Semiconductor 635, 670, 810, Optical fibre

830, 980nm

Nd:YAG Solid state 1064nm Optical fibre

Er,Cr:YSGG Solid state 2780nm Optical fibre

Er:YAG Solid state 2940nm Optical fibre,

waveguide,

articulated arm

CO2 Gas laser 9600, 10600nm Waveguide,

articulated arm

Table 2. Laser classification according to potential

hazards

Class Risk Example

I Fully enclosed system Nd:YAG laser welding system

used in a dental laboratory

II Visible low power laser Visible red aiming beam of a

protected by the blink reflex surgical laser

IIIa Visible laser above No dental examples

1 milliwatt

IIIb Higher power laser unit Low power (50 milliwatt)

(up to 0.5 watts) which diode laser used for

may or may not be visible. biostimulation

Direct viewing hazardous

to the eyes

IV Damage to eyes and skin All lasers used for oral surgery,

possible. Direct or indirect whitening, and cavity

viewing hazardous to preparation

the eyes

Table 3. Diagnostic laser applications for clinical practice

Argon Helium-neon Diode Diode CO2

488nm 633nm 633nm 655nm 10600nm

Laser fluorescence detection of dental caries ✔ ✔

Laser fluorescence detection of subgingival calculus ✔

Detection of fissure caries lesions by optical changes ✔

Laser doppler flowmetry to assess pulpal blood flow ✔ ✔

Scanning of phosphor plate digital radiographs ✔

Scanning of conventional radiographs for teleradiology ✔148 Australian Dental Journal 2003;48:3.

antibodies.

28

Photoactivated dye can be applied

effectively for killing Gram-positive bacteria (including

MRSA), Gram-negative bacteria, fungi and viruses.

29,30

Major clinical applications of PAD include

disinfection of root canals, periodontal pockets, deep

carious lesions, and sites of peri-implantitis.

31,32

In such

locations, PAD does not give rise to deleterious thermal

effects,

33

and adjacent tissues are not subjected to

bystander thermal injury. Photoactivated dye treatment

does not cause sensitization and killing of adjacent

human cells such as fibroblasts and keratinocytes.

34

Neither the dye nor the reactive oxygen species

produced from it are toxic to the patient. Tolonium

chloride is used in high concentrations for screening

patients for malignancies of the oral mucosa and

oropharynx,

35,36

and does not exert toxic effects at the

low concentrations used in the PAD technique.

Moreover, residual reactive oxygen species are rapidly

dealt with by the enzyme catalase, which is present in

all tissues and in the peripheral circulation,

37

and by

lactoperoxidase, which is a normal component of

saliva.

Photodynamic therapy

A more powerful laser-initiated photochemical

reaction is photodynamic therapy (PDT), which has

been employed in the treatment of malignancies of the

oral mucosa, particularly multi-focal squamous cell

carcinoma. As in PAD, laser-activation of a sensitizing

dye in PDT generates reactive oxygen species. These in

turn directly damage cells and the associated blood

vascular network, triggering both necrosis and

apoptosis.

38

Of interest, while direct effects of PDT destroy the

bulk of tumour cells, there is accumulating evidence

that PDT activates the host immune response, and

promotes anti-tumour immunity through the activation

of macrophages and T lymphocytes.

37

For example,

there is direct experimental evidence for photodynamic

activation of the production of tumour necrosis factoralpha,

39

a key cytokine in host anti-tumour immune

responses.

Clinical studies have reported positive results for

PDT treatment of carcinoma-in-situ and squamous cell

carcinoma in the oral cavity, with response rates

approximating 90 per cent.

40,41

The treated sites

characteristically show erythema and oedema, followed

by necrosis and frank ulceration. The ulcerated lesions

typically take up to eight weeks to heal fully, and

supportive analgesia is required in the first few weeks.

Other than short-term photosensitivity, the treatment is

tolerated well.

39

Other photochemical laser effects

The argon laser produces high intensity visible blue

light (488nm) which is able to initiate photopolymerization of light-cured dental restorative

materials which use camphoroquinone as the

photoinitiator.

42-44

The temperature increase at the level

of the dental pulp is much less with argon laser curing

than when conventional quartz tungsten halogen lamp

units are used.

45,46

Argon laser radiation is also able to

alter the surface chemistry of both enamel and root

surface dentine,

47,48

which reduces the probability of

recurrent caries. This clinical benefit is arguably more

important than the reduced curing time and improved

depth of cure achieved with the argon laser.

A further photochemical effect produced by high

intensity green laser light is photochemical bleaching

(Table 5). This effect relies upon specific absorption of

a narrow spectral range of green light (510-540nm)

into chelate compounds formed between apatites,

Table 4. Diagnostic laser applications used as research tools

Nd:YAG Er:YAG Argon Helium-neon Diode

1064nm 2940nm 488 and 515nm 633nm 633 and 670nm

Raman spectroscopic analysis of tooth structure ✔

Terahertz imaging of internal tooth structure ✔

Breakdown spectroscopic analysis of tooth structure ✔ ✔

Confocal microscopic imaging of soft and hard tissues ✔

Flow cytometric analysis of cells and cell sorting ✔

Profiling of tooth surfaces and dental restorations ✔ ✔

Fig 1. Laser system for photo-activated dye therapy, which uses a

diode laser (635nm) and tolonium chloride dye (SaveDent, Asclepion

Meditec, Fife, UK).

Table 5. Laser-enhanced tooth whitening

Argon KTP Diode CO2

515nm 532nm 810-980nm 10600nm

Photochemical bleaching ✔ ✔

Photothermal bleaching ✔ ✔porphyrins, and tetracycline compounds.

49

The argon

laser (515nm) and potassium titanyl phosphate (KTP)

laser (532nm) can both be used for photochemical

bleaching, since their wavelengths approximate the

absorption maxima of these chelate compounds (525-

530nm).

50

Argon and KTP lasers can achieve a positive

result in cases which are completely unresponsive to

conventional photothermal ‘power’ bleaching (Fig 2).

Laser applications in the dental laboratory

There is a range of laboratory-based laser

applications (Table 6). Laser holographic imaging is a

well established method for storing topographic

information, such as crown preparations, occlusal

tables, and facial forms. The use of two laser beams

allows more complex surface detail to be mapped using

interferometry,

51,52

while conventional diffraction

gratings and interference patterns are used to generate

holograms and contour profiles.

53-56

Laser scanning of casts can be linked to

computerized milling equipment for fabrication of

restorations from porcelain and other materials. An

alternative fabrication strategy is to sinter ceramic

materials, to create a solid restoration from a powder

of alumina or hydroxyapatite.

57

The same approach can

be used to form complex shapes from dental wax and

other materials which can be sintered, such that these

can then be used in conventional ‘lost wax’ casting. A

variation on this theme is ultraviolet (helium-cadmium)

laser-initiated polymerization of liquid resin in a

chamber, to create surgical templates for implant

surgery and major reconstructive oral surgery. These

templates can be coupled with laser-based positioning

systems for complex reconstructive and orthognathic

surgical procedures.

Laser procedures on dental hard tissues

Cavity preparation using lasers has been an area of

major research interest since lasers were initially

developed in the early 1960s. At the present time,

several laser types with similar wavelengths in the

middle infrared region of the electromagnetic spectrum

are used commonly for cavity preparation and caries

removal. The Er:YAG, Er:YSGG and Er,Cr:YSGG lasers

operate at wavelengths of 2940, 2790, and 2780nm,

respectively. These wavelengths correspond to the peak

absorption range of water in the infrared spectrum 

(Fig 3), although the absorption of the Er:YAG laser

(13,000cm-1

) is much higher than that of the Er:YSGG

(7000cm-1

) and Er,Cr:YSGG (4000cm-1

)

58-60

Since all

three lasers rely on water-based absorption for cutting

enamel and dentine, the efficiency of ablation

(measured in terms of volume and mass loss of tooth

structure for identical energy parameters) is greatest for

the Er:YAG laser.

58,60

These laser systems can be used for effective caries

removal and cavity preparation without significant

thermal effects, collateral damage to tooth structure, or

patient discomfort.

61-64

Normal dental enamel contains

sufficient water (approximately 12 per cent by volume)

that a water mist spray coupled to an Er-based laser

Australian Dental Journal 2003;48:3. 149

Fig 2. KTP laser photochemical bleaching. A. Initial clinical

appearance of the dentition in a 9-year-old patient with intense

discolouration of the incisor teeth caused by prolonged childhood

illnesses and associated medications. B. The situation immediately

after three 60-minute appointments of power bleaching using a

conventional quartz tungsten halogen curing lamp and 35 per cent

hydrogen peroxide gel. The incisal enamel shade has improved

somewhat, but the areas of discolouration at the gingival third are

unchanged. The arrow indicates a residue of the protective gingival

dam. C. Clinical appearance immediately after one session of

photochemical bleaching using the KTP laser and proprietary

alkaline hydrogen peroxide (Smartbleach ®) gel. The laser treatment

was targeted to the gingival third. The patient and her parents were

pleased with the immediate post-operative result and did not request

any additional treatment.150 Australian Dental Journal 2003;48:3.

system can achieve effective ablation at temperatures

well below the melting and vapourization temperatures

of enamel.

61

Er-based dental lasers can also be used to

remove resin composite resin and glass-ionomer cement

restorations, and to etch tooth structure (Fig 4).

A characteristic operating feature of Er-based laser

systems is a popping sound when the laser is operating

on dental hard tissues. Both the pitch and resonance of

this sound relate to the propagation of an acoustic

shock wave within the tooth, and vary according to the

presence or absence of caries. This feature assists the

user in determining that caries removal is complete.

66

In

contrast to the popping sound during caries removal,

one current generation Er,Cr:YSGG laser system creates

a loud snapping sound even when not in contact with

any structure in the mouth. This seeming paradox can

be explained by an effect termed ‘plasma de-coupling’

of the beam, in which incident laser energy heats the air

and water directly in front of the laser handpiece. In the

Er,Cr:YSGG laser, this is done intentionally in order to

deliver energy onto the rear surface of atomized water

molecules, with the aim of accelerating them to a higher

speed (so-called ‘HydroKinetic cutting’).

67

Detailed

studies of the cutting mechanisms of Er:YAG and

Er,Cr:YSGG lasers have revealed that the mechanism

by which enamel is removed is basically the same for

both laser systems, namely explosive subsurface

expansion of interstitially trapped water.

65

The same

investigations also failed to show Er,Cr:YSGG laser

cutting of a variety of materials which were free of

water, which the authors stated was ‘contradictory to

the existence of the hydrokinetic phenomenon’.

65

An important theoretical extension to the principle

of water-based laser ablation of tooth structure is the

recently described effect of ‘laser abrasion’, in which

Er:YAG laser energy is used to accelerate the movement

of particles of sapphire 30-50 micrometers in diameter

in aqueous suspension. As in air abrasion, the impact of

these particles causes brittle splitting, resulting in tooth

substance removal. In the laser abrasion method, high

speed photography has documented particle velocities

in the range of 50-100 metres per second, which enable

a rate of enamel removal ‘higher than that of high speed

turbines’ with a very low volume of abrasive particles.

68

This technique could be employed with current

generation lasers once a suitable dispensing system for

the suspension of particles has been developed. As well

as the potential of even more rapid cutting rates than

conventional rotary instrumentation, laser abrasion

offers the promise of laser-based cutting of structures

which are not otherwise amenable to this, such as

ceramic restorations.

Intensive research over the past three decades on

other non-Erbium laser-based cavity preparation

systems has yet to be translated to direct clinical

application. To date, alternative laser systems,

including super-pulsed CO2, Ho:YAG, Ho:YSGG,

Nd:YAG, Nd:NLF, diode lasers and excimers, have not

proven feasible for use for cavity preparation in general

practice settings.

Other than caries removal, this is a range of other

well established laser hard tissue procedures include

desensitization of cervical dentine (using Nd:YAG,

Er:YAG, Er,Cr:YSGG CO2, KTP, and diode lasers),

laser analgesia (using Nd:YAG, Er:YAG, and

Er,Cr:YSGG lasers), laser-enhanced fluoride uptake

(using Er:YAG, Er,Cr:YSGG, CO2, argon, and KTP

lasers). Furthermore, there is a considerable range of

periodontal procedures (Table 7), and endodontic

procedures (Table 8) which can be undertaken with

lasers as an alternative to conventional approaches.

Soft tissue laser procedures

There are numerous soft tissue procedures which can

be performed with lasers.

69-71

Two key features of these

are reduced bleeding intra-operatively and less pain

post-operatively compared to conventional techniques

such as electrosurgery. The degree of absorption in key

tissue components dictates the type of effect gained by

the laser on soft tissues, and in this regard the content

of water and haemoglobin in oral tissues is important

Table 6. Laser applications in the dental laboratory

Helium neon Diode Nd:YAG CO2 Helium-Cadmium

633nm 635nm 1064nm 10600nm 300nm

Scanning of models for orthodontics or holographic storage ✔ ✔

Scanning of crown preparations for CAD-CAM ✔ ✔

Welding of metals (Co:Cr, titanium) ✔

Sintering of ceramics ✔

CAD-sintering fabrication ✔

CAD-polymer fabrication of splints or surgical models ✔

Cutting of ceramics ✔

Fig 3. The absorption curve of water in the middle infrared region.

Data on the vertical axis are units of absorption, while the horizontal

axis shows wavelength in micrometers. The plot shows the position

of two laser wavelengths used for cavity preparation: Er,Cr:YSGG

2.78 micrometers, and Er:YAG 2.94 micrometers. The figure is based

on data from reference 59.

Er,Cr:YSGG

Er:YAG

14000

12000

10000

8000

6000

4000

2000

0

2.6 2.65 2.7 2.75 2.8 2.85 2.9 2.95 3 3.05 3.1 3.15 3.2 3.25 3.3for the efficient absorption of many commonly used

dental lasers.

72

Certain procedures in patients with

bleeding disorders are better suited to lasers with

greater haemostatic capabilities (Table 9). Examples of

simple soft tissue procedures are presented in Fig 5.

CONCLUSIONS

Laser technology for caries detection, resin curing,

cavity preparation and soft tissue surgery is at a high

state of refinement, having had several decades of

development up to the present time. This is not to say

that further major improvements cannot occur. Indeed,

as is in the case with laser abrasion, the fusion of

concepts from differing technologies may open the

door to novel techniques and treatments. The field of

laser-based photochemical reactions holds great

promise for additional applications, particularly for

targeting specific cells, pathogens or molecules. A

further area of future growth is expected to be the

combination of diagnostic and therapeutic laser

techniques in the one device, for example the detection

and removal of dental caries or dental calculus. For

Australian Dental Journal 2003;48:3. 151

Fig 4. Restorative procedures using the Er:YAG laser, in anxious dental patients, without local anesthesia. The Er:YAG laser was used with a 

non-contact handpiece. A. Pre-operative appearance of a 22-year-old male with salivary dysfunction, and associated cervical and approximal

caries. B. Areas of caries and defective resin composite have been removed. The intense white appearance of the margins is typical of laser etching.

C. The restored teeth immediately post-operatively. The etched appearance of the margins disappears once bonding resin has been placed.

D. 30-year-old female patient with areas of hypoplastic enamel. E. The enamel surface has been ‘peeled’ using a series of pulses from the laser. 

F. The two areas have been restored with resin composite. G. 65-year-old female patient undergoing anti-cancer chemotherapy, with recurrent

caries at the margins of several restorations. H. Areas of caries and undermined resin composite have been removed. I. The cavity preparations

have been restored.152 Australian Dental Journal 2003;48:3.

example, an ‘autopilot’ system for subgingival

d´ebridement has been developed (for detailed review,

see ref 73), and the potential exists to extend this

concept further.

There is a large research effort internationally

focused on developing new laser applications for dental

practice, and each year several large meetings are held

which bring together this research. Examples include

the International Society for Lasers in Dentistry (ISLD),

the European Society for Oral Laser Applications

(ESOLA), and the Academy of Laser Dentistry (ALD).

With the further development of laser dentistry as an

area of clinical pursuit, there will be considerable

opportunity for clinicians to become involved in these

research meetings and in specific research projects. The

Australasian region has played a substantial role in the

development of hard tissue laser applications,

74,75

and

this level of involvement is expected to continue in the

future, as various research groups examine uses for

lasers in conjunction with or as a replacement for

traditional methods.

There is little argument that over recent years the use

of lasers in dentistry in Australia has moved beyond

academic centres and specialist units into the

mainstream of general practice. Looking to the future,

it is expected that specific laser technologies will

become an essential component of contemporary dental

practice over the next decade.

ACKNOWLEDGMENTS

I thank the dental practitioners who have referred

patients to the Laser Clinic over the past 12 years, and

the numerous staff and students who have contributed

to the dental laser research programme at the

University of Queensland.

REFERENCES

1. Shi XQ, Welander U, Angmar-Månsson B. Occlusal caries

detection with KaVo DIAGNOdent and radiography: an in vitro

comparison. Caries Res 2000;34:151-158.

2. Lussi A, Megert B, Longbottom C, Reich E, Francescut P. Clinical

performance of a laser fluorescence device for detection of

occlusal caries lesions. Eur J Oral Sci 2001;109:14-19.

3. Shi XQ, Tranaeus S, Angmar-Månsson B. Validation of

DIAGNOdent for quantification of smooth-surface caries: an in

vitro study. Acta Odontol Scand 2001;59:74-78.

4. Shi XQ, Tranaeus S, Angmar-Månsson B. Comparison of QLF

and DIAGNOdent for quantification of smooth surface caries.

Caries Res 2001;35:21-26.

Table 7. Periodontal laser procedures

Er:YAG Er,Cr:YSGG KTP Argon 488 Diode Nd:YAG Helium-neon Diode 635, CO2

2940nm 2780nm 532nm and 515nm 810-980nm 1064nm 633nm 670 or 830nm 10600nm

Calculus removal ✔

Periodontal pocket

disinfection ✔ ✔ ✔ ✔  ✔ ✔

Photoactivated dye

disinfection of

pockets ✔ ✔

De-epithelialization to

assist regeneration ✔ ✔ ✔

Table 8. Endodontic laser procedures

CO2

Erbium:YAG Er,Cr:YSGG KTP Argon 488 Diode Nd:YAG Helium-neon Diode 635,

10600nm 2940nm 2780nm 532nm and 515nm 810-980nm 1064nm 633nm 670, or 830nm

Direct pulp capping ✔ ✔

Drying of the

root canal ✔ ✔  ✔

Removal of

smear layer ✔ ✔

Root canal

disinfection ✔  ✔ ✔ ✔  ✔ ✔

Photoactivated dye

disinfection of pockets ✔ ✔

Table 9. Surgical laser applications

Er:YAG 2940nm Er,Cr:YSGG CO2 KTP Diode Argon 488 Nd:YAG 1064nm

(least haemostasis) 2780nm 10600nm 532nm 810-980nm and 515nm (most haemostatis)

Minor soft

tissue surgery ✔ ✔ ✔ ✔  ✔ ✔

Major soft

tissue surgery ✔

Surgical treatment

of large

vascular lesions ✔

Bone cutting ✔ ✔

Implant exposure

with bone removal ✔ ✔ ✔5. Takamori K, Hokari N, Okumura Y, Watanabe S. Detection of

occlusal caries under sealants by use of a laser fluorescence

system. J Clin Laser Med Surg 2001;19:267-271.

6. Bjelkhagen H, Sundström F, Angmar-Månsson B, Ryden H. Early

detection of enamel caries by the luminescence excited by visible

laser light. Swed Dent J 1982;6:1-7.

7. Angmar-Månsson B, ten Bosch JJ. Optical methods for the

detection and quantification of caries. Adv Dent Res 1987;1:14-

20.

8. Hafström-Bjorkman U, Sundström F, Angmar-Månsson B. Initial

caries diagnosis in rat molars, using laser fluorescence. Acta

Odontol Scand 1991;49:27-33.

9. Hafström-Bjorkman U, Sundström F, de Josselin de Jong E,

Oliveby A, Angmar-Månsson B. Comparison of laser fluorescence

and longitudinal microradiography for quantitative assessment of

in vitro enamel caries. Caries Res 1992;26:241-247.

10. Longbottom C, Pitts NB. CO2

laser and the diagnosis of occlusal

caries: in vitro study. J Dent 1993;21:234-239.

Australian Dental Journal 2003;48:3. 153

Fig 5. Soft tissue procedures using middle and far infrared lasers. A. Pre-operative clinical appearance of a 22-year-old female with marked gingival

overgrowth from nifedipine and cyclosporin. The patient has received a kidney transplant, is immuno-suppressed, and has a bleeding tendency. 

B. the immediate post-operative appearance following gingivoplasty with the carbon dioxide laser. Complete haemostasis is maintained during the

procedure. C. Initial clinical appearance of a 16-year-old female patient with marked gingival overgrowth, which has obscured the orthodontic

brackets and caused the cessation of fixed orthodontic treatment. D. Immediate post-operative view of quadrant 1 following gingival recontouring

with the carbon dioxide laser. E. Immediate post-operative view of quadrant 2 following recontouring with the Er:YAG laser in contact mode.

Note the different appearance of the tissues compared to quadrant 1. Both segments were treated at the same appointment. F and G. Clinical

appearance of the two sites two weeks following surgery. The tissue contours are identical to those determined at the time of surgery

 

 

 

 

 

 

 

Enhanced by Zemanta