MANAGING THE ARCH CIRCUMFERENCE

Band Adaptation and Impressions

Stainless Steel Preformed Bands

Bands are made by several manufacturers, excellent results are achieved with Unitek bands. Permanent first molar bands are used for fabricating the lingual arch and palatal (Nance) arch, and pedodontic molar bands are used for fabricating the band and loop.

Select the Band

• From a kit of preformed bands, select the appropriate size band by estimation.

• If the band completely seats with finger pressure it it too large and a smaller size should be selected.

• If it is too small it will not be able to be seated such that the occlusal margin seats past the marginal ridge of the tooth.

• The proper size will fit snugly and and a band seater must be used to seat it completely.

Seat the Band

• With finger pressure, push the band as far as it will go onto the tooth.

• Care should be taken to match the buccal of the band to the buccal of the tooth. The groove in the band occurs on the buccal of maxillary teeth and the lingual of mandibular teeth.

Seat the Band

• Place the band seater on the top of the band and have the patient close, forcing the band farther onto the tooth.

• As the patient bites intermittently the band seater is moved around the band beginning with the lingual of the mandibular teeth and buccal of the maxillary until the band is completely seated.

Seat the Band

When properly seated:

• the band should fit tightly,

• the occlusal margins should be just below the proximal marginal ridges, and

• the gingival margins should be in the gingival sulcus.

Adapt the Margins

Use the side of the band pusher and adapt the margins of the band into the larger grooves.

Adapt the Margins

• Use the end of the pusher to adapt the margins into the smaller accessory grooves so that the margins of the band adapt closely to the tooth.

• The band pusher should be used carefully with appropriate finger rests in order that it does not accidentally slip injuring the gingival tissues.

Adapt the Margins

With adaptation properly accomplished:

• the band is adapted to the morphology of the tooth,

• the explorer cannot easily engage any open margins, and

• the band is not in occlusal contact. (occlusal forces on the band will dislodge it)

ImpressionA compound impression is preferred to an alginate one for two reasons:

1. It is difficult to lute the band in place in an alginate impression. Luting the band to the impression is necessary to prevent dislodgment of the band while pouring the stone, with it subsequently being in a distorted position on the working.

2. The sharp edge of the band can cut through the alginate when being prepared for pouring, resulting in an inaccurate positioning of the band on the working case.

Impression

• Soften red cake compound in a compound heater and place in an impression tray.

• Use quadrant tray for band and loop, and full arch tray for lingual/palatal arch.

• Allow the compound to harden completely before it is removed from the teeth.

• The impression is satisfactory if the anatomic structures to be contacted by, or adjacent to, the appliance are accurately reproduced.

Band Removal

• A posterior band removing pliers and/or excavator is used to remove the band.

• A cotton roll should be place on the occlusal surface of the tooth unless the particular band removing pliers you are using has a soft plastic covering.

• The cotton roll or plastic tip prevents potential fracturing of occlusal cusps.

Cast Recovery

Remove the band from the tooth and place it into the compound impression in the position it occupied on the tooth. If not stable, lute the band to the impression with sticky wax.

Sequencing Band Adaptation and Impression in the

Treatment Plan

• Whenever possible, the space manitainer should be fabricated and ready for insertion at the time the primary tooth is extracted.

• Restorations required on the tooth to be banded must be accomplished prior to the comentationof the space maintainer. A common situation is the placement of a lingual arch on two first permanent molars requiring occlusal and buccal restorations.

Typical Treatment Plan

• One Appointment:

#19 O, B amalgam or composite

#19/#30 Bands adapted and impression for lingual arch

#L Extraction

• Next Appointment

#30 O, B amalgam or composite

# S Extraction

# T Extraction

#19#30 Cement lingual arch