VOLUME 18 NO.10 THE NATION'S LEADING CLINICAL NEWS MAGAZINE FOR DENTISTS OCTOBER 1999

Figure 1.

could be used for dental purposes,the Er, Cr:YSGG wavelength(2780nm), found in the MillenniumLaser (Biolase Technology, Inc).This unique crystal generates pho-tons through a fiber delivery systememitting from a handpiece with asapphire crystal that is bathed inan air and water atomization spray.The system emits photons at awavelength of 2780nm and a repeti-tion rate of 20Hz. The power outputcan vary from O to 6 W. The beamspot size is O.442mm2 with the useof the 750~m fiber. There are sever-al unique properties possessed bythis system that make it entirely

appropriate for dental practice.A major feature of the Er,

Cr: YSGG system includes a previous-ly unknown method of cutting tissues,called laser hydrokinetics. Hydro-kinetics is the process of removingbiocalcified tissue through optimizedabsorption ofEr, Cr:YSGG laser ener-gy by atomized water particles thatresult in energized microparticlescapable of precise tissue cutting.Water particles are the energizedagent which remove the target tissue.

If the power of the laser is low-ered significantly, and most or all ofthe water is eliminated while apply-ing a small amount of air co-axially

F ew professions have worked

as hard as dentistry to con-

vince the public of the valueof its services and especial-

ly to make these services as attrac-tive as possible. Of no minor impor-tance is the realization that pa-tients want and appreciate den-tistry's efforts to make dental visitsmore pleasant. Efforts to communi-cate advancement in dentistry isseen in written advertisements, aswell as television coverage of justhow painless and high-tech a visitto the dentist has become. Helpingimprove the public's perception thatdentistry has come a long way sincethe "old-fashioned drill" is the addi-tion of lasers to the dentists' arma-mentarium.

Our practice has had an associa-tion with various dental lasers sincethey were introduced to dentistry.At one time or another, we haveessentially incorporated most wave-lengths into patient treatment. Wehave used CO2, Nd:YAG and diodelasers for soft tissue applicationsand use argon technology for curingand power bleaching. Each havehad unique features that allowed usto improve the manner in which wedo dentistry.

Recently, we became interestedin a totally new wavelength that

Approach to ""

By Ronald E. Goldstein, DDS

Figure 3.Figure 2

Chart 1

Figure 4.

As previously stated, a majoradvantage of the Er, Cr:YSGG laseris the ability to be able to treat bothhard and soft tissues with the sameinstrument, thus saving time andproviding the patient with a highlyefficient dual procedure. Presentedhere are two cases using the Er,Cr: YSGG in its dual capacity treatinghard and soft tissue. N o anesthesiawas required in either case. One ofthe advantages of using this laser inits hard tissue mode is that toothstructure can be preserved by elimi-nating only the diseased portion andnot causing microfractures. The Er,Cr:YSGG laser leaves no smearlayer, eliminating the need to etch.However, if acid is used in conjunc-tion, a stronger bond is developedthan using either one alone.

laser as it should be used in the oper-atory.

The laser, resembling a commondental handpiece, makes the prepa-ration. After the laser was used toprepare the tooth, it was noted thatthe gingival tissue had grown intothe disto-gingival defect (Figure 2).

The hard tissue was cut using thedosimetries shown in chart 1.

The Er, Cr:YSGG laser incorpo-rates presets, and it is easy to gofrom one tissue dosimetry toanother by pushing one button(Figure 3).

The laser is used in the soft tis-sue mode with 14% air and 1.25 Wof power and no water. Occasionally,5% to 7% water might be used forpatient comfort. However, in thiscase, due to its hyperemic nature,no water was used (Figure 4). Thedisto-gingival margin is now mucheasier to see and finish (Figure 5).The adjacent teeth (Nos. 26 and 27)are prepared using the dentin set-ting for hard tissue removal. Again,

to the tip for patient comfort, thelaser can usually effectively cut softtissue without anesthesia. There isseldom discomfort because the fluidat the cellular level absorbs theenergy and not the nerve endings.There is photo-ablation, truly a va-porization of the cells. Where otherfiber-delivered soft tissue lasersneed to be initiated or enhanced atthe tip to make them effective(essentially making the tip a hotknife) the Er, Cr:YSGG laser needsno initiation at the tip due to itsabsorption into water.

Although the original deliverysystem with the Er, Cr:YSGG laserdid not have replaceable tips anddid not rotate, the new MVP-HS(Micro Versa Prep -HydroKinetic)delivery system has remedied theseissues. The MVP has the look andfeel of a traditional dental hand-piece, rotates 360°, has a range ofdisposable tip sizes (400 to 750 JIm)that can be used for different proce-dures and can be autoclaved.

CASE 1The first case was a geriatric patientwith advanced caries in need of adisto-occlusal restoration on tooth No.28. Figure 1 shows the position of the

Figure 5. Figure 6.

Figure 7. Figure 8.

Figure 9. Figure 10.

the patient felt no sensitivity(Figure 6). Undercuts and precisioncutting are easy to obtain with thenew handpiece (Figure 7). The finalrestoration of the right lateral (No.26), cuspid (N 0. 27) and first bicus-pid (No.28) are restored using ahybrid composite resin (Figure 8).

CASE 2The patient presented with a disto-lingual carious defect in the upperleft lateral incisor (No.10) andincisal edge of the cuspid (No.11).The upper teeth will eventually betreated with porcelain laminatesthat will overlap the incisal edges

(Figure 9).The Er, Cr:YSGG system was

used on the enamel setting to par-tially prepare the lingual lesion.The laser is readjusted to the softtissue setting to remove the excesstissue (Figure 10).

Once the tissue is removed, the

Figure 12.Figure 11.

laser is instantly readjusted to thedentin setting to finish the prepara-tion and the defect is bonded with ahybrid composite resin (Figure 11).

The patient returned 7 days post-operative. Notice how well the tissuehas healed (Figure 12).

public opinion concerning dentaltreatments. .

11. Pick RM, Miserendino LJ. Lasers in den-tistry: an overview. Laser Medicine &Surgery News and Advances. 1989; (June):33-42.

12. Pick RM. Lasers in soft tissue dental surgery.Laser surgery: advanced characterization,therapeutics, and systems II. Progress inBiomedical Optics, Society of Photographicand Instrumentation Engineers. 1990;416.

13. Pick RM, Pecaro BC. Use of the CO2 laser insoft tissue dental surgery. Laser Surg Med.1987; 7:207-213.

14. Powell GL, Morton TH, Whisenant BK.Argon laser oral safety parameters for teeth.Lasers Surg Med. 1993;13:548-552.

15. Rizoiu IM, Eversole LR, Kimmel AI. Theeffects of an erbium laser system onmucosa, skin, bone, dental hard tissues andpulp. Oral Surg Oral Med Oral Pathol.1996;82(10):386-395.

16. Stern RH, Sognnaes RF. Laser beam effectson dental hard tissues. J Dent Res.1964;43:873.

17. Stern RH, Renger HL, Powell FV. Lasereffects on vital dental pulps. Br Dent J.1969;127(1):26-28.

18. Wigdor HA, Walsh JT Jr, et al. Lasers in den-tistry. Lasers Surg Med. 1992;9:521-532.

19. Vu D, Powell GL, Higuchi WI, et al.Comparison of three lasers on dental pulpchamber temperature changes. J Clin LaserMed Surg. 1993;11:119-122.

Recommended Reading1. Eversole LR, Rizoiu I, Kimmel AI. Pulpal

response to cavity preparation by an erbium,chromium YSGG pulsed laser hydrokineticsystem. JADA. 1997;128:1099-1106.

2. Garber DA. Dental Lasers -Myth, Magic, &Miracles? Compend Contin Educ Dent.

1991;12(7):448-454.3. Garber DA. Dental Lasers -Myth, Magic, &

Miracles? Part 2. Compend Contin EducDent. 1991;12(10): 698-706.

4. Goldstein RE, Miller MC. Role of high tech-nology in maintaining esthetic restorations.J Esthetic Dentistry. 1996;8(1):39-46.

5. Goldstein RE, Garber, DA. Equipping thecomplete dental practice. Dent Today. 1994;

13(1):34-37.6. Goldstein RE, Garber DA. Building the per-

fect esthetic practice. Dent Today.

1991;10(9).7. Goldstein RE. Change Your Smile. 3rd ed.

Chicago,lll: Quintessence Publishing Co.

1997; 201,275,277,307.8. Gutknecht N. Enamel and dentin cutting

efficacy of Er:YAG, Er, Cr:YSGG hydrokineticsystem and dental bur [abstract]. DeutschGesellschaft f r laser Zahnheilkunde e.V.

9. Hadley J, Young D, Javid N, et al. Theeffects of a laser powered hydrokineticdevice for cavity preparation on human den-tal pulp. J Oper Dent. 1998, Submitted.

10. Pick RM, Pecaro BC, Silberman CJ. The lasergingivectomy: the use of the COz laser forthe removal of phenytoin hyperplasia. JPeriodontol. 1985;56:492-496.

DISCUSSIONFirst the high-speed drill, then airabrasion, and now the "cutting" laseradd up to a complete range of tech-nology to prepare teeth in a preciseand often painless method. What isexciting about this newest of lasersis its usefulness in preparing virtu-ally any classification of cavities aswell as its ability to help treat anadjunctive soft tissue problem thatmay be discovered.

Approximately 50% of the U .8.population fails to see a dentist rou-tinely. This is partially caused by theperception that dentistry is painful,so should be avoided at all costs.With the development and imple-mentation of this new technology,dentistry has another valuable aidthat can certainly help to improve

Dr. Goldstein is president of the International Federation of

Esthetic Dentistry, and is cofounder of the American

Academy of Esthetic Dentistry. He is clinical professor of

Oral Rehabilitation at the medical collage in Georgia School

of Dentistry, and adjunct clinical professor of Prosthodontics

at Boston University School of Dental Medicine. He is an

author and co-author of seven published texts, including the

best seller consumer book, Change Your Smile. He can be

reached at (404) 261-4941 or send e-mail to goldsteingar-

ber@goldsteingarber.com .