4 Relining Techniques

7/30/2019 4 Relining Techniques

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Relining techniques for complete denturesFinn Tengs Christensen, L.D.S.*University of Bergen, School of Dentistry, Bergen, Norway

1 he term reline is defined as, To resurface the tissue side of a denture with newbase material to make it fit more accurately. The term rebase is defined as, Aprocess of refitting a denture by the replacement of the denture base material with-out changing the occlusal relation of the teeth.l

Commonly used relining techniques will be discussed in this article. In addition,a reliable laboratory relining technique for complete and removable partial dentureswhich is simple to execute and offers a high degree of precision will be described.RELINE, REBASE, OR NEW DENTURES

The main purpose for either relining or rebasing is to re-establish adequateadaptation of the denture base to the bearing area and to re-establish the originaljaw relations. Lack of knowledge and technical skill regarding relining and rebasinghave caused disappointments, and consequently, these procedures have often beenomitted where indicated.

Some dentists recommend making new dentures, others reline, and still othersprefer to reprocess the old denture on a cast from a new impression.3l New den-tures are indicated when the residual ridges have resorbed extensively with greatloss of vertical height or when proper occlusion is difficult to establish.3

When only one jaw has resorbed extensively, the rebasing method described bySwenson5 may be used if the occlusion is acceptable. The thickness of the layer ofimpression material is not increased, but the intermaxillar distance is established bymeans of an interoccusal record; and the vertical change is accomplished by re-occluding the teeth after the dentures have been mounted on the articulator. Nagleand Sear9 recommend filling the alveolar groove of the denture with softened waxto determine the new vertical dimension of occlusion prior to making the impres-sion.

Van den Berg7 prefers to increase the vertical dimension of occlusion without*Head of the Prosthetic Department.

373


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374 Christensenchanging the fit of the denture base. Histologic findings indicate that balance GIIIoccur between the denture base and the ridge which should not bc disturb(sd. lhismethod may be advantageous when an increase of the vertical height is t~cccssar!and the patient is satisficcl M.ith the fit of the dcxnturc*.TIME FOR RELINING

The best time for and the frequency of relining depend on the amount andrapidity of resorption of thcb residual ridges. Disharmony of fit and occlusion a~important factors in the degree and rapidity of the resorption. AccordinK toSchiile, the resorption is Icast ivhen the dentures arcs relined within a short time.

Immediate dentures usually must br relined about three months following sur-gery. If thr patient has difficulties M.ith retention prior to this time. the dentureshould be relined earlier.DIAGNOSIS AND PREPARATION OF THE ORAL CAVITY

The tissue underlying the dentures JnUSt br examined carefully, and irritationcaused by the denture must be eliminated beforc relining procedures can be initi-ated. According to Lytlc, I1 frequent consfhcutivr temporary relines with tissue con-ditioning material ha\se to be made until complete tissue recovery is achieved. Sup-porting therapy includes massage of soft tissues with a soft toothbrush or finger, re-moval of dentures during the night, and use of soft food during the healing period.In addition, the dentures must be removed from thr mouth for 48 hours before thefinal impressions are made.If the supporting bone is badly drstroycd, surgicai corrections may be necessary.Plastic surgery to drepcn the sulcus or surgical treatment of the mylohyoid ridg-cmay also bc nrcrssary.EXAMINING THE OCCLUSION

When dentures are relined, it must be assumed that the occlusion was satisfac-tory when they were made. With cusp teeth, the rock test (Wipp-probe) may btused.12 The occlusal surfaces of opposing teeth are put against each othrr with th(*dentures in the hand, and where there is disharmony of the occlusion, thcl dentur-thwill rock on the high spots.A relining in connection with faulty occlusion will only give tcnjporary ill]-provemcnt. The occlusal disharmony will cause resorption, and the fit of the denturewii1 again be fadty. No rclinin g can bc accurate or complete without a IIVM Inollnt-inF: of the dentures on the articulator and ;1 regrindin,g of the occlusion.PREPARING THE DENTURE BASE FOR RELINING

All undercuts on the denture base must be eliminated before impression pro-cedures are started to avoid locking the denture to the cast. The bordrrs of thedenture may be cut down if too long or built up with a suitable n~atrrial if tooshort to make theul harmonious with the surrounding tissues. The vibratinSg lineis checked, and the posterior border of the denturr is corrected, if necessary. todevelop the posttarior palatal seal.


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~~%Fre Relining techniques for complete dentures 375The palatal and labial flange of the upper denture should be perforated to de-

crease pressure inside the denture during the impression-making procedure whichmight displace soft tissue. The perforations also prevent air bubbles from formingon the surface of the impression and may prevent anterior displacement of the den-ture. A moderate pressure with a balancing finger against the labial surface of theupper denture as the jaws are closed will assist in maintaining the denture in itsproper position. When the vertical relation has been established, the lips and cheeksare constricted to mold the borders.

Nagle and Sears? recommend boiling the dentures for 5 minutes before reliningthem to minimize the internal strains in the base material.IMPRESSION MATERIALS AND IMPRESSION METHODS

A thin layer of impression material usually causes more pressure on the tissuesthan a thick layer and a low degree of flow. Therefore, to avoid tissue distortion,the impression material should possess a certain thickness and a high degree offlow and have sufficient time to flow at mouth temperature.r3

ChaseI uses a thin layer of rubber-base impression material with a closed-mouthtechnique, making the impression with little pressure. Escape holes are madethrough the labial flange to prevent the forward displacement of the maxillary den-ture. The occlusal relationship is preserved by relining and finishing the maxillarydenture first so that it will control the position of the mandibular denture. Thepatient is cautioned to use slight force and only tap the teeth together again.Increased occlusal pressure may squeeze too much of the impression material outof the dentures resulting in sore points from the completed dentures.

Buchmanl recommends using a central bearing point and a needlepoint (Gothicarch) tracing in connection with the relining procedure.

Impression materials for relines must reproduce fine surface detail, If tissue-conditioning impression materials are used, they can be used for the final impres-sion. However, each dentist should use the material which is most suitable for histechnique and his experience.RELININGSoft-base materials in relining

Usually a cold-curing acrylic resin is used as the relining material. However,elastic-base materials may have advantages for patients with extremely resorbedresidual ridges when the interarch distance is great* or where the underlying tissueis especially tender and sensitive.17 According to Sauer,ls the denture lined with asoft material may be especially desirable when mechanical shock to the supportingareas should be reduced. The indications for this reduction include ( 1) ridges withmultiple osseous undercuts, (2) ridges with thin, nonresilient, mucosal coverage,(3) persistent denture sore mouth, (4) knife-edge mandibular ridges, (5) relief forthe median palatine suture or torus palatinus, and (6) prosthodontic restorations forcongenital or acquired oral defects.

Most patients seem to be very comfortable with the soft acrylic resins. AS occlusalpressures are distributed over the entire underlying area, retention seems to be in-


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DH ihl) 3 I .ioSS rh) 31.60SS (hi) 26.50DH (11) 26.50

DH (hl)NH (h2)Three measurements were made before (L-M-R) and after (LI-Ml-R,) the relining procedurecold-curing resin during relining.

creased and problems with food accumulatin,c underneath the denture are reduced.The reduction of mechanical shock resulting from occlusal pressure tends to reduce.destructive changes in the supporting tissues.!

Soft acrylic resin may cover the whole base or may be surrounded by rigid


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Volume 26Number 4 Relining techniques for complete dentures 377during relining

BeforeM

FfOTUAfterMl

Right side- -Difference Before After DiBerenceM-MI R Ri R-RI

38.65 38.8038.73 38.8030.0530.05

30.0530.10

32.40 32.3532.40 32.4026.90 26.9026.90 26.9036.5036.6037.3537.3530.5030.45

36.6036.7037.4037.4030.6030.50

28.4028.3531.7031.75

28.3528.4031.7031.80

34.3034.20

34.2034.10

29.1.529.15

29.1029.05

34.4034.40

34.4534.50

31.1031.20

31.1531.20

30.1030.15

30.2530.30

34.80 34.8534.80 34.8025.3025.30

25.2325.30

+0.15+0.05

0to.05-0.05

000

+0.10to.10+0.05+0.05to.10to.05-0.05to.05+0.05to.05-0.10-0.10-0.05-0.10to.05+0.10+0.05

0+0.15to.15to.05

0-0.05

0

36.0036.1027.5027.50

36.00 036.0025.6027.55

32.35 32.5032.35 32.4027.30 27.3027.30 27.2026.40 26.2026.35 26.2029.6029.6528.9028.90

29.7029.7029.0029.00

24.80 24.8024.80 24.8033.4533.50 33.4533.4531.1031.10

31.1531.10

25.75 25.7025.70 25.6.33.60 33.6533.60 33.6032.05 32.0032.10 32.0026.30 26.406.3.5 26.4035.5035.50

35.5035.50

23.30 23.3023.30 23.30

-0.10to.10+O.O.ito. 1 ito.05

0-0.10-0.20-0.15+O.lOto.05to.10+O.lO

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0-0.0.5-0.10+O.lOto.05

0000

L-L,, M-M,, and R-R,, indicate the difference in measurements before and after the curing of the

acrylic resin which forms the border of the denture. The soft resins will only besatisfactory for a limited time (up to three years), 3p16, *O because they harden andstain and white nodules appear in the silicone rubber materialszl Therefore, pa-tients should be informed that relining must be repeated periodically.


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378 Christensen

Fig. 1 . Thr impression material has been removed from the denture. and the t,rrtl of cac,hresin wing (A. B, and C) has been rut flush with thr surrounding plaster in order to forma definite border between the resin and plaster. The junction between the ~Y~CIVC~and thl,wings is marked with ink (B) for visual control of the relining material.

Disadvantage of the relining proceduresThe greatest disadvantage of all relining methods has been the problem of in-creasing the vertical dimension of occlusion during thr laboratory procedures. Often,

this problem can be corrected by intraoral occlusal grinding or by remounting thedentures on the articulator and correcting the processing changes. However, theproblem may be eliminated or minimized by means of the wing relining laboratoryprocedure.Wing relining laboratory technique

The wing relining technique *2 incorporates a. simple but effective control foralterations in the vertical dimension of occlusion during laboratory procedures bythe use of resin wings Lvhich are added to the denture. The resin wings fit intocorresponding grooves in the land of the cast (Fig. 1 ) and allow the denture to btbaccurately repositioned and maintained following rclnoval of the impression ma-terial. The vertical dimension is controlled by clamps during the addition of cold-curing acrylic resin to replace the impression material.Accuracy of the wing relining laboratory technique

Changes in the vertical dimension of occlusion during relinings were investigatedbefore and after laboratory procedures using the wing technique. Measurementswere made from the occlusal surfaces o f the teeth to the base of the cast with iisliding caliper. One measurement was made in the anterior region and the otherson either side in the molar region.

The sliding caliper was developed by soldering a plate to a Boley gauge (Fig. 2 j .The plate functions as a supporting plane and must fit the base of the cast without


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Volume 26Xumher 4 Relining techniques for complete dentures 379

Fig. 2. (P) The supporting plane added to the sliding caliper. The supporting plane fits thebase of the cast without rocking. (A) The tracing of the supporting plane to permit its re-placement for subsequent measurements after the curing process is complete.

rocking. Consequently, the base of the cast must be made even by means of a casttrimmer. When measuring, the upper arm of the sliding gauge is placed on one ofthe selected points, and the supporting plane is placed on the base of the cast (Fig.2). The border of the supporting plane is marked on the base of the cast with asharp pencil. and the lines are accentuated with a sharp instrument. In this way,the supporting plane can be accurately replaced for repeated measurements afterthe curing process.

The denture with the impression material and with the resin wings added wasfirst measured on the cast at the three selected locations before the denture wasseparated from the cast (Table 1). The measurements at the same three locationswere repeated after curing the autopolymerizing (cold-curing) resin but before thedenture and cast were separated. Altogether, at least six measurements were madefor each denture during the relining procedure, and each of the measurements wasrepeated by another person for a total o f twelve measurements for each reliningprocedure.

The measurements with the impression material in the denture before its separa-tion from the cast are listed in the cdumns Iabeled L, M, and R in Table I. Themeasurements after curing but before the denture was separated from the cast arelisted in columns L,, MI, and R,. Differences between the first and second measure-ments indicate the alterations in the vertical height before and after processing(Differences L-L,, M-M,, R-R,).STATISTICAL EVALUATION OF MEASUREMENTS

The change in vertical dimension is equal to d (Table I) ; the mean change ofthe vertical dimension is equal to z n is equal to 96 measurements.


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300 Christensen

The standard deviation (Sd)Consequently, changes in thr vertical dimension of occlusion N~FII dining dyll-

tures using the xving relining laboratory twhniyue varies with x-i- Sd -m 0.01 ? 0.71nIn. That is, fi8 per cent of the variation in vertical changes during the laboratol.!relining procedure lie between -0.06 and 4-0.08 mm.. c\.hilf: 9.5 per cent art situatedhetmwn -0.13 and +O. 15 IIIIII.According to Swenson, the relining prowdurr is time consm~iing when usingan exacting technique. Hr states that thf. work involved requires about half of thttime necessary to construct new dentures. Hol\.cver. cvhcrl using the \\.ing rchinc!technique. an a\craSye dcnturr can bc rplillcd in Ir~ss than t\vo hol~r.~ including ~111procedures.

Measurements rnadc in this stud!. indicate that dirrlcnsion may be dcweascd drtl--ing the laboratory proccduI-es of rclininc. IIlereforc*. only n gcntlt: prwsurc shouldbe used during the c,uring procedure or t1w ;rryIir r&J, w,ings GUI 1~5 I)rcssyd intothe plaster.

Prcssurc: on the dcnturc itself should be nvoidcd durin,g processing. The pressuwcausrs the denture base to act as a spring, and too much of the new relining materialmay be squwzcd out. Whcu the pressure i\ rcGe,ml bcforr the c,llring process ha5been conlplcted. air will be drawn bot\t.c~c~n he drnturc and the cast resultinK in aiibubbles in the acrylic resin. I f the prc~ssurc on thtx occlusal surfaw is milintainrduntil the acrylic resin is cur&. chan,qcs Illa!- occur irr the oc~clusion. Pol~rr~rrizatio~~of cold-curing acrylic twin in a pressl~re box improws quality of c111w1 resin ;ihcompared with resin cured without prcssuw. Howm.fI. correctly treatc~l cold-curin?acrvlic resins procmscd without a prcssurc box also qi\.fs good results.SUMMARY AND CONCLUSION

I>ifferent relining techniques for rcnm~ablc dentures have beer1 discussc*tl. 1%~.wing relining method for wrnplete clcntures is an rrtcctivc laboratory wlining pro-.cedure that permits control of thr I-ertical dirlrension of occlusion during prows+ing. Statistical analysis indicates that the wing relinin% laboratory proccdurcss reflecteda variation in changes in th(. \.crtical dimension or owlusion that IILIX less th;tlliO.l mm. in 68 per cent of the dentures relined.

References

2. Hardy, I. R.: Rebasing the Maxillary Detlturc. Dent. Dig. 55: 23, 1949.3. Rehm, H.: Erfolgr und Miswrfolge bei Tot&n Protbespn, Heidelberg, 196.5, Dr. ,4]frczr(

Hiithig Verlag.


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Volume 26Number 4 Relining techniques for complete dentures 3814. Coburn, W. il.: Century of Standard Maxillary and Mandibular Impressions With Re-

finements, J. PROSTHET. DENT. 3: 29, 1953.5. Swenson, M.: Improving Immedia te Dentures in General Practice, J. Am. Dent. Assoc.

47: 550, 1953.6. Nagle, R. J., and Sears, V. H.: Remodeling and Refitting Dentures, St. Louis, 1962, TheC. V. Mosby Company.

7. van den Berg, E. J.: Partial Dentures as Seen by a General Practitioner. IX. Interna-tionalen Zahnarztekongrez der F.D.I., Wien, 1936, Urban und Schwarzenberg, p. 1133.

8. Van Thiel, H.: Alteration in Tissue Underlying Complete Dentures, Int. Dent. J. 10:518, 1960.

9. Schiile, H.: Untersuchungen tiber den Einfluss van Alveolarkammplastik und Immtdia-tprothese auf Form und Beschaffenkeit des Prohtesenlagers, Dtsch. Zahnaerztl. Z. 12:1451, 1957.

10. Frohlich, E.: Gewebsveranderungen als Folge Schleimhautgetragener Prosthesen. Dtsrh.Zahnaerztl. Z. 7: 107, 1952.

11. Lytle, R. B.: The Management of Abused Oral Tissues in Complete Denture Construc-tion, J. PROSTHET. DENT. 7: 27, 1957.12. Kiihler, L.: Die Vollprothese, in Scheff und Pichler, editors: Handbuck der Zahnheil-

kunder, Band IV, Berlin and Wien, 1929, Urban und Schwarzenberg.13. Sandermann-Olsen, Th.: Karakteristik af Dentale Aftrykspastaer, Tandlaegebladet 57:

333,1953.14. Chase, W. W.: Adaptation of Rubber-base Impression Materials to Removable Denture

Prosthetics, J. PROSTHET. DENT. 10: 1043, 1960 .15. Buchman, J.: Relining Full Upper and Lower Dentures, J. PROSTHET. DENT. 2: 703,

1952.16. Kuck, M.: Die Physiologische Protheses im Zahnlosen Unterkiefer, Dtsch. Zahnaerztl.

Z. 9: 1352, 1954.17. Langer, H.: Die Unterfiitterung van Kunstoffplatten als Prothetische Aufgabe, dsterr.Z. Stomatol. 55: 244, 1958,

18. Sauer, J. L., Jr.: A Clinical Evaluation of Silastic 390 as a Lining Material for Dentures,J. PROSTHET.DENT. 16:650, 1966.

19. Voss, R.: Die Theoretischen Grundlagen der Verwendung van Weichbleibender Kunstof-fen, Stoma 15: 153, 1962.

20. Hildestad, P.: Anvendelse af Blodtblivende Protesematerialer, Tandlaegebladet 71: 1189,1967.

21. Bascom, P. W.: Resilient Denture Base Materials, J. PROSTHET. DENT. 16: 646, 1966.22. Christensen, F. T.: The Wing Relining Technique, J. PROSTHET. DENT. 22: 268, 1969.

IXSTITUTE OF ODONTOLOCYUNIVERSITY OF BERGEN5000 BERGES,NORWAY

4 Relining Techniques

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