interproximal stripping

1. 1 Inter Inter- -proximal stripping proximal stripping Prepared by: Prepared by: Dr Mohammed Alruby Dr Mohammed Alruby قح يلع مهنا لطابلا لها مهوت لطابلا نع قحلا لها تكس نيح I Inter nter- -proximal stripping proximal stripping Dr. Mohammed Alruby Dr. Mohammed Alruby

2. 2 Definition: selective reduction of proximal surfaces of certain teeth in order to reduce the mesiodistal width of the teeth to create space in the arch Names: Interproximal reduction Interproximal stripping Enamel re-approximation Enamel disking Odontoplasty Enamel plasty Slenderization Air-rotor stripping History: Was introduced by Ballard in 1944, it is used to improve areas of interdental gingival recession (Turverson1980) Indications: 1-Esthetic contouring of teeth malformed 2-When space requirement to correct the malocclusion below 2.5mm 3-If Bolton analysis shows mild tooth material discrepancy in either of arches 4-It can undertake in the lower anterior segment as an aid of retention 5-It can be undertaking as an adjunctive procedure in adult orthodontic 6-In the case of 1st premolar extraction to balance the Bolton ratio Contraindications: 1-In young patients as they possess large pulp chamber which increased risk of pulp exposure 2-Patients with high caries index and are susceptible to caries 3-Patient with bad oral hygiene 4-Poorly formed enamel because increased risk for exposure Advantages: 1-Avoid in border line cases where spaces required in minimal 2-Correct molars and incisors relationship by eliminate excess tooth material 3-More stable contact can be established Disadvantages: 1-Stripping procedure creates rough surface which attract plaque formation and is caries prone 2-Increase sensitivity of the tooth may occur 3-Alteration of tooth morphology giving un-natural appearance 4-Improper contact between the teeth may invite food impaction and hence periodontal breakdown Interproximal Procedure The procedure of enamel stripping involves the following steps: 1-Assessing space requirements: a-Model analysis: -Arch parameter in upper arch and Carey’s analysis in lower -Bolton analysis -Peck and Peck ratio = if arch discrepancy between 0 --- 2.5mm select stripping 2.5 ---5mm extraction of 2nd premolars 5mm and more, extraction of 1st premolars I Inter nter- -proximal stripping proximal stripping Dr. Mohammed Alruby Dr. Mohammed Alruby

3. 3 = it has been reported that 11----13.5% of populations have overall Bolton ratio problem and 22 ---30% of orthodontic populations have anterior Bolton ratio problem (tooth size discrepancy TSD) = estimate the mesiodistal dimension to the labiolingual thickness of lower incisors at cingulum that is 88% --- 92% -- for lower central, 90% ---95% ---- for lower lateral, long ratio need proximal re-contouring b-Radiographs: Intra-oral periapical radiograph gives an idea about enamel thickness and rough estimate of proximal enamel amount Panoramic radiograph to assess the proximity of roots c-Diagnostic set up: Help in treatment planning of alignment problems 2-Enamel thickness: amount of enamel: = there are gender and ethnic variation in enamel thickness = enamel thickness in anterior teeth is 0,6 --- 0.8mm, 50% reduction consider to be safe so reduction of 0.3 –0.4mm (300---400um) is recommended safe = mesial enamel is less thickness compared to distal side = enamel thickness of molars was significantly larger than premolars = total combined enamel thickness on 2 premolars and 2 molars was 10mm so reduction of posterior teeth make about 9.8mm of space 3-Enamel stripping procedure: The following precautions should be taken into consideration: -Hand or rotor stripping can produce heat so take care about cooling to prevent raise temperature of pulp -The procedure undertaken after have slight alignment to avoid reduction on the labial surface -Procedure should have done precisely -Excessive enamel reduction gives some sort of sensitivity -Used optimal instrument and polishing the enamel to prevent plaque accumulation -A bitewing radiograph of buccal segment provide a good view about enamel thickness and molars, but intra-oral periapical radiograph is more useful for anterior teeth Techniques & instruments: 1-Hudson 1966, recommend the fine metallic strip and thin followed by Harfin which recommend steel or diamond strip but the quality of enamel remaining optimal = Radlanski 1988 and Lundgren 1993: showing by scan microscope and profilometric analysis, that steel and diamond strip should be avoided because produce scratched and irregular enamel surface until polishing 2-Use of medium grit grant disk which mounted in contra angle hand piece with using anterior straight Elliot separator to control reduction of enamel and protect the interdental gingival papilla ------ this called Tuverson technique, polishing is made with fine sand and cut disc 3-Air rotor stripping the introduced by Sheridan 1985 – 1987 then followed by Sheridan and Hestiage in 1992 which depend on creating space by tungsten carbide bur Zhong et al 1999 –2000: carbide bur produces more scratch and groove then disc used 4-Chemical mechanical method: it is reported to be more physiologic use of 37% phosphoric acid in combination of micro abrasion using diamond coated metal strip and finishing strips I Inter nter- -proximal stripping proximal stripping Dr. Mohammed Alruby Dr. Mohammed Alruby

4. 4 create relatively smooth surface enamel that has potential to heal in oral environment and artificial remineralization by using calcium fluoride solution that promote crystal growth 5-Modified Tuverson technique: less separation between incisors is needed when an ultrathin safe sided diamond disc rather than grant disc is used 6-Ortho- strip system: more recent development fine diamond –coated perforated disc for enamel stripping. Composed of: four double- sided diamond coated flexible metallic strip with grain size between 15 and 90um for enamel removal and polishing. The strips have the advantage of being flexible and adapting well to the shape and convexity of the teeth especially vertically = the multiple perforation of disc prevents clogging (blocked) = Josef et al 1992: it is appearing to be safe to remove enamel with disc than with tungsten or diamond bur, combined mechanical and chemical technique to restore the stripped enamel surface ** for optimal stripping technique: usually require a mechanical separator is recommended as a procedure of choice for routine enamel reduction ** an alternative to the separator, a wooden wedge can be used for the same purpose like separator, the wedge will also protect the interdental gingiva from damage during stripping (Poorman’s separator) How to maintain normal gingival papillae during orthodontic treatment: Location of the contact point and axial inclination of the teeth are the most important reasons why black triangle developed between neighboring teeth (Burke et al 1994, Kurth and Knkich 2001) Tarnow et al 1992: the decisive factor is the distance between the contact point and crest of bone, this distance should not exceed 5mm if an intact gingival papilla is to be maintained N: B: re-contouring by stripping is to relocate the contact point as much as required in an apical direction and ------ to increase the connector area between the teeth There is a distinction between the contact point and connector area: -The contact point between anterior teeth are generally small area -Connector area is larger border area that defined as zone in which two adjacent teeth appear to touch -The ideal connector area between the maxillary central incisors is defined as 50% of the length of the clinical crown of central incisors -The stripping must fulfill the following requirement: 1-Recontour the mesial surface to ideal shape 2-Relocate the contact point in gingival direction 3-Lengthen the connector area 4-Make the connector area parallel to facial midline 5-Eliminate the black triangle All these requirements can be met by careful stripping How to regain lost gingival papillae: = in patients with marked periodontal problems, the inter-dental gingival papillae between maxillary and mandibular incisors are normally lost I Inter nter- -proximal stripping proximal stripping Dr. Mohammed Alruby Dr. Mohammed Alruby

5. 5 = re-contouring tooth shapes by stripping and correcting the axial inclination of the incisors allow relocation of contact point and lengthening of the connector area so that the gingival papillae may return 4-Fluoride applications: This is an important step after stripping, the enamel roughness increase and hence caries susceptibility after proximal stripping also increase, this can prevented by fluoride application after the procedure. I Inter nter- -proximal stripping proximal stripping Dr. Mohammed Alruby Dr. Mohammed Alruby