The International Journal of Periodontics & Restorative Dentistry

Transcription

1 The International Journal of Periodontics & Restorative Dentistry

2 87 Orthodontic Extrusion With or Without Circumferential Supracrestal Fiberotomy and Root Planing Cássio Volponi Carvalho, DDS, MS* Flávio Paim Falcão Bauer, DDS, MS** Giuseppe Alexandre Romito, DDS, MS, PhD*** Cláudio Mendes Pannuti, DDS, MD, PhD* Giorgio De Micheli, DDS, MS, PhD*** The aim of this randomized clinical trial was to carry out a biometric comparison between the orthodontic extrusion (OE, group B) technique and OE combined with fiberotomy and root planing (OEFRP, group A). Twenty single-root teeth were extruded and assigned to two different groups. In both groups, fixed orthodontic appliances were activated weekly during the course of 3 weeks. After activation, the extruded teeth were maintained in retention for a period of 8 weeks. In group A, along with weekly activation, fiberotomy and root planing were carried out on the top of the alveolar bone crest. Statistical analysis revealed that the amount of dental structure exposed was greater in group A, where the gingival margin and bone tissue remained stable (P <.05). Group B presented coronal migration of the gingival tissue and bone tissue of 2 mm and 1.5 mm, respectively. (Int J Periodontics Restorative Dent 2006;26:87 93.) *Resident, Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, Brazil. **Private Practice, São Paulo, Brazil. ***Assistant Professor, Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, Brazil. Correspondence to: Dr Cássio Volponi Carvalho, Av. Professor Lineu Prestes no. 2227, Cidade Universitária, CEP , São Paulo, S.P., Brazil; volpcarv@terra.com.br. Forced eruption, or orthodontic extrusion, was proposed by Heithersay 1 for the treatment of horizontal fractures in the middle third of the root. Simon et al 2 described techniques for dental extrusion for endodontic purposes. These authors mentioned that orthodontic extrusion requires 1 to 3 weeks of activation and 8 to 12 weeks of retention for the stabilization of the tooth in its new position. Ingber 3,4 reported the need for surgical crown lengthening after the retention phase. The purpose of surgical crown lengthening is to re-establish biologic width 5 through the removal of gingival and bone tissues that follow the tooth in its coronal trajectory, thus permitting appropriate prosthetic therapy. The coronal migration of periodontal tissues in dental extrusion is induced by the tension provoked by gingival fibers and by the periodontal ligament. 6 In clinical case reports, Edwards 6 described the use of tattooing of gingival tissue as a reference for measuring its deformation during dental movement and suggested the application of gingival fiberotomy to reduce the possibility of relapse. Volume 26, Number 1, 2006

3 88 Pontoriero et al 7 described an orthodontic extrusion technique associated with supracrestal fiberotomy (SCF). During the period of forced eruption, intrasulcular incisions were performed weekly through the junctional epithelium and connective tissue to eliminate the tension produced by supracrestal fibers. In doing so, the authors reported that only minor correction of the gingival tissue outline was necessary after extrusion, because intra-sulcular incisions prevented the bone tissue from migrating coronally. Partial migration, especially that of gingival tissue, can be justified by the study by Levine and Stahl, 8 who demonstrated that the supracrestal fibers, when incised, remain inserted into the root surface and will reinsert into soft tissue, thus reconstructing the gingival fiber apparatus. Kozlovsky et al 9 studied a variation of the orthodontic extrusion technique associated with SCF. 7 During the process of extrusion, teeth were submitted to SCF associated with root planing every 2 weeks. This technique prevented the coronal migration of bone tissue and gingival tissue. The aim of the present randomized clinical trial was to carry out a biometric comparison of the orthodontic extrusion (OE) technique and the OE technique combined with fiberotomy and root planing (OEFRP). Method and materials This study was approved by the Ethics Committee in Research, School of Dentistry, University of São Paulo, Brazil. For this study, 20 single-root teeth (maxillary incisors), obtained from 18 patients (9 men and 9 women, mean age years), were used. A periapical radiograph of each selected tooth was obtained. Based on radiographic and clinical evaluation, crown lengthening was indicated. All patients were nonsmokers and presented with no systemic factors that could compromise their periodontal condition. The selected teeth did not present periodontal pockets, and their adjacent teeth possessed a clinical attachment of at least two-thirds of the root length, thus permitting adequate support for orthodontic movement. Teeth that presented with crown destruction received fixed provisional restorations, when clinical conditions permitted, and only then were partial fixed orthodontic appliances applied. Movement was performed using a 0.14-mm stainless steel orthodontic wire, with a constant pressure of not more than 50 g. All patients were provided with initial periodontal treatment and received professional plaque control treatment every 2 weeks. All measurements were taken by a single trained blinded examiner and were standardized to an acrylic resin stent. Six marks were made around the tooth to be extruded to serve as guides so that measurements would always be carried out at the same point: distobuccal (DB), buccal (B), mesiobuccal (MB), distolingual (DL), lingual (L), and mesiolingual (ML). A periodontal probe (North Carolina, PCPUNC 15, Hu- Friedy) and a digital caliper (Absolute- Digimatic model CD-6 C, Mitutoyo) were used to perform the measurements. The measurements used were: 1. Guide mark healthy tooth structure (M-T) 2. Guide mark gingival margin (M- GM) 3. Guide mark top of alveolar bone crest (M-AC) The third measurement (M-AC) (Fig 1) was obtained via transsulcular probing (Jardini and Pustiglioni 10 ). To accomplish this, local anesthesia was applied to the papillae, and then, using the fixed point of the stent, the periodontal probe was introduced into the gingival sulcus, and light pressure was exerted until the top of the alveolar bone crest was reached. The aforementioned parameters were measured three times: (1) at baseline (time 0), (2) after extrusion (21 days; time 1), and (3) after retention (8 weeks after the end of extrusion; time 2). After the initial measurements, the teeth were randomly assigned to 2 groups. The International Journal of Periodontics & Restorative Dentistry

4 89 Fig 1 Transsulcular probing with acrylic resin stent. Fig 2a Pretreatment clinical appearance of maxillary right central incisor in group A. Fig 2b Root planing performed after fiberotomy. Fig 2c Before extrusion. Fig 2d After 3 weeks of extrusion and 8 weeks of stabilization. Fig 2e Final appearance with provisional restoration. Group A teeth In these teeth, the forced extrusion technique was combined with circumferential supracrestal fiberotomy and root planing, 8 and fixed orthodontic appliances were activated weekly, with a force of approximately 50 g, for 3 weeks. The weekly activations were performed with fiberotomy using a scalpel and a 15C blade (Swann- Morton) jointly with root planing from the top of the alveolar bone crest using curettes (Gracey 5/6, Hu-Friedy). The incisions were made under papillary anesthesia, using the smallest possible quantity of anesthetic. Following the active period of extrusion, the teeth were maintained for 8 weeks, using the same fixed orthodontic appliance with a 0.18-inch wire (Dentaurum) to prevent relapse. In this group, there was no need for complementary surgery (Figs 2a to 2e). Group B teeth In these teeth, only the forced extrusion technique was applied. Fixed orthodontic appliances were activated weekly with a force of approximately 50 g for 3 weeks. From this moment on, the extruded teeth were maintained for 8 weeks. After this stage, the teeth in this group received surgical crown lengthening to re-establish biologic width (Figs 3a to 3d). Volume 26, Number 1, 2006

5 90 Fig 3a (left) Pretreatment clinical appearance of maxillary right central incisor in group B. Fig 3b (right) After forced eruption. Fig 3c (left) An osseous resection is performed to establish normal biologic width. Fig 3d (right) Final appearance with provisional restoration. Statistical analysis The chi-squared association test was performed to determine whether there was an association between the groups studied and the qualitative variable gender. To analyze the difference between the mean ages of both groups, the Student t test was performed. The homogeneity of variances was assessed by the Levene test, and distribution normality was evaluated with the Komolgorov-Smirnov test. 11 To determine whether there were differences between the values obtained for the measurements taken at the three different time points, the Student t test was applied for two independent groups (time 0 time 1, time 0 time 2, and time 1 time 2). A statistical software package was used (Statistical Package for the Social Sciences, SPSS) and the criterion for statistical significance was P <.05. Results There was no statistically significant association between experimental group and sex (P = 1.00), which means that both groups were homogenous as to this variable. According to the t test, the difference between the mean ages of each group (group A, 37.8 ± 7.3 years; group B, 32.7 ± 12.1 years) was not considered to be significant (P =.27). The differences between the initial and final values for the time assessed are presented in Tables 1 to 3. We chose to analyze the differences, because if we started off with the initial values for each tooth, the variability among the teeth would lead to a mathematical difference that would not represent the reality from a clinical standpoint. The values in Tables 1 to 3 represent how much dental, gingival, and bone tissue was extruded. Negative values correspond to the amount of tissue that drifted away from the probing guide in comparison to a previous measurement. Tables 1 and 2 reveal that statistically significant differences were seen between the groups in the three parameters assessed from baseline. Group A teeth obtained a greater amount of extrusion with respect to measure M- T than did group B teeth. With respect to other measurements (M-GM and M-AC), group A teeth did not show differences between the values for the two time periods represented. Table 3 presents the values of the differences found between times 1 and 2 that is, after the period of 8 weeks of retention for stabilization. Between those times, statistical testing did not reveal significant differences between groups A and B for any of the measurements considered. The International Journal of Periodontics & Restorative Dentistry

6 91 Table 1 Mean differences (mm) between variables M-T (healthy tooth structure), M-GM (gingival margin), and M-AC (top of alveolar bone crest) between time 0 (baseline) and time 1 (after extrusion) Buccal measurements Lingual measurements Parameter/ group Mesiobuccal Buccal Distobuccal P Mesiolingual Lingual Distolingual P M-T Group A 2.7 ± ± ± ± ± ± 0.50 <.05 <.05 Group B 2.10 ± ± ± ± ± ± 0.33 M-GM Group A 0.01 ± ± ± ± ± ± 0.13 Group B 1.82 ± ± ± ± ± ± 0.60 M-AC Group A 0.09 ± ± ± ± ± ± 0.19 Group B 1.51 ± ± ± ± ± ± 0.69 Table 2 Mean differences (mm) between variables M-T (healthy tooth structure), M-GM (gingival margin), and M-AC (top of alveolar bone crest) between time 0 (baseline) and time 2 (after retention) Buccal measurements Lingual measurements Parameter/ group Mesiobuccal Buccal Distobuccal P Mesiolingual Lingual Distolingual P M-T Group A 2.68 ± ± ± ± ± ± 0.53 <.05 <.05 Group B 2.07 ± ± ± ± ± ± 0.33 M-GM Group A 0.01 ± ± ± ± ± ± 0.19 Group B 1.78 ± ± ± ± ± ± 0.64 M-AC Group A 0.09 ± ± ± ± ± ± 0.19 Group B 1.53 ± ± ± ± ± ±0.76 Table 3 Mean differences (mm) between variables M-T (healthy tooth structure), M-GM (gingival margin), and M-AC (top of alveolar bone crest) between time 1 (after extrusion) and time 2 (after retention) Buccal measurements Lingual measurements Parameter/ group Mesiobuccal Buccal Distobuccal P Mesiolingual Lingual Distolingual P M-T Group A 0.01 ± ± ± ± ± ± 0.10 Group B 0.03 ± ± ± ± ± ± 0.12 M-GM Group A 0.02 ± ± ± ± ± ± 0.12 Group B 0.04 ± ± ± ± ± ± 0.10 M-AC Group A 0.00 ± ± ± ± ± ± 0.09 Group B 0.02 ± ± ± ± ± ± 0.11 Volume 26, Number 1, 2006

7 92 Discussion The purpose of this study was to measure possible morphologic alterations in dental and periodontal tissues after the execution of the two different techniques employed, as in the studies by Pontoriero et al 7 and Kozlovsky et al. 9 All parameters evaluated (M-T, M- GM, and M-AC) were separately measured at six points on each tooth. To reduce the possibility of error inherent in the procedure of probing, we used a guide made specifically for each patient. The use of this apparatus has an advantage over the use of radiologic evaluation, because the latter does not permit the analysis of the free surfaces of each tooth; in addition there are distortions inherent in the radiographic technology itself. The statistical analysis of our results highlighted the changes that occurred in the position of the structures evaluated at the three studied times that is, the amount of structure, if any, that moved within each increment of time. The results regarding the first time period (Table 1) clearly indicate that teeth were extruded more in group A, in which OEFRP was carried out. Moreover, it is clear that the gingival margin maintained itself unaltered in this group, demonstrating that the procedure is capable of dissociating movement of teeth from periodontal support structures. One of the most important points is the analysis of the position of the gingival margin in the studied procedures. Tables 1 and 2 clearly show that when OEFRP was not carried out, there was coronal migration of the gingival tissue, as had been demonstrated in the studies by Ingber. 3,4 This is very important, because if a clinical situation demands surgical crown lengthening and the area has important esthetic involvement, coronal dislocation from the gingival margin will lead to the need for surgical crown lengthening. However, when we carried out SCF without root scaling, there was no significant accompanying migration. Nonetheless, Pontoriero et al 7 drew attention to the fact that in some situations, there may be a need for gingival plastic surgery, which would require additional treatment time. Our results show that if we consider the amount of exposed dental tissue (M-T) after 21 days of movement, group A (OEFRP group) had a greater exposure than group B (OE group). When we analyze the amount of bone tissue that followed dental movement in a coronal direction, the results we obtain are the same as those reported elsewhere. 7,9 In group B, we observed an osseous dislocation of approximately 1.48 mm (mean of all sites) during the period studied. This result corroborates those of van Venrooy and Yukna, 12 who evaluated the potential of orthodontic movement for the gain of osseous structure in teeth with advanced periodontal disease and reported a mean of 2.00 mm (for all sites) of crestal bone deposition. An important finding of this study was that in the group who received OEFRP, there was a small osseous resorption (represented by negative values in Tables 1 and 2). From a clinical standpoint, the values found are not very significant. However, some histologic considerations could be made, since it was only after SCF and root planing that the subjacent bone tissue suffered some kind of modification. Naturally, during the period evaluated, there remains some doubt about whether this result is associated with an actual loss or if the tissue was still in a process of reparation; also, a probing error is possible. Ruben et al 13 reported that by 14 to 18 days after gingivectomy, which is a far more invasive procedure than that carried out in the current study, a welldefined osteoblastic layer had been formed. When this happens, osseous remodeling starts somewhere around that period. Hill et al 14 compared four different root treatments in shallow pockets and observed that there was clinical loss of insertion with all four treatments. The possibility of these values being related to an eventual osseous resorption is justifiable, because negative values appeared only in the group where the invasive procedure was carried out (group A). If a probing error was in fact responsible, one would expect more surfaces to present a positive value. In group B, coronal migration of the gingival and bone tissues was approximately 1.5 and 2.0 mm, respectively. Recent studies have demonstrated the importance of this technique when executed on hopeless teeth prior to the placement of osseointegrated implants, resulting in a more esthetic rehabilitation. 15,16 Another important aspect is that between time 1 and time 2 (retention), there were no statistically significant changes for all the parameters. This is in agreement with the findings of Simon et al, 2 who recommend a min- The International Journal of Periodontics & Restorative Dentistry

8 93 imum of 8 to 12 weeks of retention to stabilize the root in its new position. In conclusion, the OEFRP technique is indicated when crown lengthening is desired without alteration in the position of the gingival margin. This aspect is of great importance, especially in those cases in which esthetic involvement is a decisive factor in therapeutic choice. Extrusion without fiberotomy and root planing can be used with success when aiming for coronal dislocation of the periodontal tissues together with the tooth. References 1. Heithersay GS. Combined endodonticorthodontic treatment of transverse root fractures in the region of the alveolar crest. Oral Surg Oral Med Oral Pathol 1973;36: Simon JK, Kelly WH, Gordon DG, Ericksen GW. Extrusion of endodontically treated teeth. J Am Dent Assoc 1978;97: Ingber JS. Forced eruption: Part I. A method of treating isolated one- and twowall infrabony osseous defects Rationale and case report. J Periodontol 1974;45: Ingber JS. Forced eruption: Part II. A method of treating nonrestorable teeth Periodontal and restorative considerations. J Periodontol 1976;47: Nevins M, Skurow HM. The intracrevicular restorative margin, the biologic width and the maintenance of the gingival margin. Int J Periodontics Restorative Dent 1984;4: Edwards JG. A surgical procedure to eliminate rotational relapse. Am J Orthod 1970;57: Pontoriero R, Celenza F, Ricci G, Carnevale G. Rapid extrusion with fiber resection: A combined orthodontic-periodontic treatment modality. Int J Periodontics Restorative Dent 1987;7: Levine HL, Stahl SS. Repair following periodontal flap surgery with the retention of gingival fibers. J Periodontol 1972;43: Kozlovsky A, Tal H, Lieberman M. Forced eruption combined with gingival fiberotomy. A technique for clinical crown lengthening. J Clin Periodontol 1988;15: Jardini MAN, Pustiglioni FE. Estudo biométrico do espaço biológico em humanos por meio de sondagem transulcular. R P G Rev Pós Grad 2000;7: Kirkwood BR. Essentials of Medical Statistics. Oxford: Blackwell, van Venrooy JR, Yukna RA. Orthodontic extrusion of single-rooted teeth affected with advanced periodontal disease. Am J Orthod 1985;87: Ruben M, Smukler H, Shulman S, Kon S, Bloom A. Healing of periodontal surgical wounds. In: Goldman H, Cohen W (eds). Periodontal Therapy, ed 6. St Louis: Mosby, 1980: Hill R, Ramfjord S, Morrison E, et al. Four types of periodontal treatment compared over two years. J Periodontol 1981;52: Mantzikos T, Shamus I. Forced eruption and implant site development: soft tissue response. Am J Orthod Dentofacial Orthop 1997;112: Buskin R, Castellon P, Hochstedler J. Orthodontic extrusion and orthodontic extraction in preprosthetic treatment using implant therapy. Pract Periodontics Aesthet Dent 2000;12: Volume 26, Number 1, 2006