Classification of Dental Surface Defects PDF

J Periodontol June 2010 Classification of Dental Surface Defects in Areas of Gingival Recession Giovanpaolo Pini-Prato,* Debora Franceschi,* Francesco Cairo,* Michele Nieri,* and Roberto Rotundo* Background: A clinical classification of surface defects in gingival recession area is propos...

J Periodontol June 2010 Classification of Dental Surface Defects in Areas of Gingival Recession Giovanpaolo Pini-Prato,* Debora Franceschi,* Francesco Cairo,* Michele Nieri,* and Roberto Rotundo* Background: A clinical classification of surface defects in gingival recession area is proposed. Methods: Two factors were evaluated to set up a classifica- tion system: presence (A) or absence (B) of cemento-enamel junction (CEJ) and presence (+) or absence (-) of dental sur- face discrepancy caused by abrasion (step). Four classes (A+, A-, B+, and B-) were identified on the basis of these variables. T he Glossary of the American Acad- To validate the classification three different calibrated exam- emy of Periodontology defines gin- iners applied the proposed classification system to 46 gingival gival recession as ‘‘the apical recessions and k statistics were performed. The classification migration of the gingival margin beyond was used on 1,010 gingival recessions from 353 patients to the cemento-enamel junction.’’1 As a con- examine the distribution of the four classes. sequence, the damage to soft tissues Results: The k statistics for intrarater agreement ranged leads to exposed root along with loss of from 0.74 to 0.95 (almost perfect agreement), whereas inter- attachment and bone loss. To categorize rater agreement ranged from 0.26 to 0.59 (moderate agree- these defects, Miller2 proposed four clas- ment). Out of 1,010 exposed root surfaces associated with ses of marginal gingival recessions based gingival recession, 144 showed an identifiable CEJ associated on the degree of involvement of the peri- with a root surface defect (Class A+, 14%); 469 an identifiable odontal tissues (mucogingival junction CEJ without any associated step (Class A-, 46%); 244 an un- and underlying alveolar bone). This clin- identifiable CEJ with a step (Class B+, 24%); and 153 an un- ically useful classification evaluates dif- identifiable CEJ without any associated step (Class B-, 15%). ferent degrees of damage to periodontal Conclusion: The proposed classification describes the tissues, but does not consider the condi- dental surface defects that are of paramount importance in tion of the exposed root surface: presence diagnosing gingival recession areas. J Periodontol 2010;81: of an identifiable cemento-enamel junc- 885-890. tion (CEJ) and presence of root abrasion. Sometimes these lesions may be associ- KEY WORDS ated with enamel abrasion. Cemento-enamel junction; classification; dental enamel; The CEJ serves as the reference point diagnosis; gingival recession; tooth abrasion. for the diagnosis and treatment of such defects. The anatomic and esthetic suc- * Department of Periodontology, University of Florence, Florence, Italy. cess of a procedure is based on a gingival margin located slightly more coronally to the CEJ after surgery3-6 and in a good in- tegration of the grafted gingival tissue with the adjacent teeth.7 However, the CEJ is not identifiable in some cases be- cause of dental abrasion caused by tooth brushing trauma or cervical caries.3,8 In this situation, clinicians encounter diffi- culties in accurately measuring the depth and the width of recessions during the diagnostic phase. Other problems may arise during the surgical procedure be- cause the lack of an identifiable CEJ does doi: 10.1902/jop.2010.090631 885 Classification of Dental Surface Defects Volume 81 Number 6 not allow for the precise location of the gingival mar- gin when suturing. Where does the clinician place the margin of the flap or graft? In fact, after surgery the coronal position of the gingival margin with respect to the CEJ is a fundamental requirement for obtaining complete root coverage using coronally advanced flap.9,10 More serious surgical problems may occur in the presence of a pronounced root surface discrepancy caused by traumatic abrasion and erosion of hard tis- sue (step). These conditions impair the proper posi- tioning of the flap (coronally advanced flap) or the graft (connective tissue graft) on the dental surface.8 In addition, the accurate evaluation of the clinical out- come of the root coverage procedure is difficult at the end of the treatment if the CEJ is lacking. In this situ- ation, it is not possible to establish whether or not complete root coverage has been achieved. In many Figure 1. articles dealing with root coverage procedures, gingi- Gingival recession associated with an identifiable cemento-enamel val recessions with no identifiable CEJ are excluded junction without a surface discrepancy (step) (Class A-). Histologic (A) from the study as selection criteria.10-12 and clinical (B) views. On the basis of these considerations, complete root coverage might not be obtained even in Miller Class I and II recession defects associated with root and crown abrasion. Therefore, an accurate evaluation of the dental hard tissues associated with Miller’s2 periodontal classification could be useful for a com- plete diagnosis of gingival recession areas. The aim of this article is to propose a clinical clas- sification of surface defects in gingival recession areas by evaluating two factors: presence or absence of CEJ, and presence or absence of dental surface dis- crepancy (step). MATERIALS AND METHODS The buccal aspect of the exposed root associated with gingival recessions was the object of this study. Identification of Hard Tissue Variables and Classification The evaluation was performed on both frontal and lat- eral views using a ·4 magnification lens, a periodontal Figure 2. Gingival recession associated with an identifiable cemento-enamel probe (PCP UNC 15), and a dental explorer. Two vari- junction and a surface discrepancy (step) (Class A+). Histologic (A) and ables were considered: CEJ and cervical discrep- clinical (B) views. ancies. Considering the presence of the CEJ on the buccal surface, two classes were identified: Class A, identifiable CEJ on the entire buccal surface; and Class Validation Session B, unidentifiable CEJ totally or partially. Considering Three periodontal examiners (GPP, RR, and FC), the presence of cervical discrepancies (step), mea- with >10 years of periodontal practice, were required sured with a periodontal probe perpendicular to the to attend a calibration session on 46 recession defects long axis of the tooth in the deepest point of the abra- aimed at the validation of the proposed classification. sion, two classes were identified: Class (+), presence of Under the guidance of one statistical operator (MN) cervical step (>0.5 mm) involving the root or the crown the examiners twice evaluated, independently and and the root; and Class (-), absence of cervical step. blindly, the presence or absence of CEJ and of step Therefore, a working classification identifies four dif- after an interval of 1 hour. The considered variables ferent conditions (Figs. 1 through 4 ; Table 1). were recorded directly by the statistician. 886 J Periodontol June 2010 Pini-Prato, Franceschi, Cairo, Nieri, Rotundo Table 1. Classification System of Four Different Classes of Root Surface Discrepancies CEJ Step Descriptions Class A - CEJ visible, without step (Fig. 1) Class A + CEJ visible, with step (Fig. 2) Class B - CEJ not visible, without step (Fig. 3) Class B + CEJ not visible, with step (Fig. 4) least one gingival recession were examined between January 2008 and May 2009 at the Department of Periodontology, University of Florence, Florence, Italy. A sample of 1,010 consecutive maxillary and Figure 3. mandibular gingival recessions was included in the Gingival recession associated with an unidentifiable cemento-enamel study. Informed written consent was obtained from junction without a surface discrepancy (Class B-). Histologic (A) and all subjects who participated in the study. The princi- clinical (B) views. ples set forth in the Helsinki Declaration on experi- mentation involving human subjects were fully respected in obtaining the informed consent and in the conduct of the study. A descriptive statistic anal- ysis was also performed. RESULTS Four classes of dental surface defects in areas of gin- gival recession were identified on the basis of the pres- ence (Class A) or absence (Class B) of CEJ and of presence (Class+) or absence (Class-) of surface dis- crepancy (step). The intrarater and interrater agreement (k statis- tics) among the three examiners referring to the presence or absence of the CEJ and of the step is shown in Tables 2 and 3. The k statistics for intra- rater agreement ranged from 0.74 to 0.95 (almost perfect agreement), whereas interrater agreement ranged from 0.26 to 0.59 (moderate agreement) ac- Figure 4. cording to the guidelines proposed by Landis and Gingival recession associated with an unidentifiable cemento-enamel Koch.13 junction with a surface discrepancy (Class B+). Histologic (A) and clinical The distribution of the four classes was observed (B) views. within a population of 1,010 gingival recessions in 359 patients, 175 males and 184 females, between 10 and 64 years of age (33.7 – 10.9). A total of 612 k statistics were performed to analyze the intrarater recessions were located in the maxillary arch and and interrater agreement among the three examiners. 398 in the lower jaw. A descriptive statistical analysis The interrater agreement was calculated using the first is given in Table 4. Out of 1,010 exposed root surfaces measurement by each examiner, whereas intrarater associated with gingival recession, 144 showed an agreement was assessed using both measurements. identifiable CEJ associated with a root surface defect The training results were evaluated according to (Class A+, 14%); 469 an identifiable CEJ without any Landis and Koch.13 associated step (Class A-, 46%); 244 an unidentifi- Distribution of Hard Tissue Defects able CEJ with a step (Class B+, 24%); and 153 an un- To observe the distribution of the four classes of the identifiable CEJ without any associated step (Class present classification, 359 patients presenting at B-, 15%). 887 Classification of Dental Surface Defects Volume 81 Number 6 DISCUSSION CEJ and presence (Class+) or absence (Class-) of The aim of this study is to propose a classification of dental surface discrepancy (step). surface defects in gingival recession areas. This clas- Miller’s2 classification for gingival recessions al- sification is based on the evaluation of two clinical fac- lows for identifying different conditions based on the tors that may be observed on hard dental tissues amount of soft periodontal tissues around the affected following the occurrence of gingival recession: pres- teeth. However, a gingival recession is also character- ence (Class A) or absence (Class B) of identifiable ized by an involvement of dental hard tissues with the exposure of the root surface and of the CEJ. The ex- posed root surface may be further damaged by trau- Table 2. matic tooth brushing or by root caries capable of causing a formation of surface discrepancies along Cemento-Enamel Junction: Intrarater and with the disappearance of the original CEJ. During Interrater Agreement (k statistics) the daily practice routine, recording an identifiable CEJ or the presence of a tooth surface discrepancy Examiner Examiner #1 Examiner #2 Examiner #3 is of paramount importance for measuring recession Examiner #1 0.78 (0.09) 0.48 (0.12) 0.26 (0.14) depth1 and evaluating the outcome after treatment (i.e., partial or complete root coverage).3 Therefore, Examiner #2 0.95 (0.04) 0.52 (0.12) a complete diagnosis of a gingival recession defect Examiner #3 0.74 (0.10) requires not only the evaluation of the periodontal tissues, according to Miller’s2 classification, but also k statistic (standard error) the assessment of the hard dental tissue conditions. The condition of the exposed root surface may also be important for the prognostic evaluation of muco- Table 3. gingival surgery. For instance, in case of a Miller Class Step: Intrarater and Interrater Agreement I or II associated with a deep surface abrasion the pre- (k statistics) dictability of achieving 100% root coverage might not be ensured because of the difficulty in stabilizing the Examiner Examiner #1 Examiner #2 Examiner #3 flap on the exposed root surface, In this study the surface discrepancy (step) was Examiner #1 0.85 (0.10) 0.53 (0.12) 0.29 (0.13) measured with a periodontal probe perpendicular to Examiner #2 0.81 (0.09) 0.59 (0.12) the long axis of the tooth in the deepest point of the abrasion. The choice of a step >0.5 mm (Fig. 5) Examiner #3 0.86 (0.08) is justified by a clinical observation that flap thickness k statistic (standard error) >0.8 mm is associated with complete root coverage.14 Table 4. Distribution of the Four Classes Within a Population of 1,010 Gingival Recessions Maxillary teeth #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14 #15 Class A+ 3 4 8 13 8 4 8 15 12 10 7 4 Class A- 4 22 30 27 28 35 41 35 20 21 11 4 Class B+ 3 8 14 18 6 2 6 9 32 26 13 1 1 Class B- 1 3 7 11 15 4 8 8 8 13 14 6 1 Mandibular teeth #31 #30 #29 #28 #27 #26 #25 #24 #23 #22 #21 #20 #19 #18 Class A+ 2 2 6 3 5 6 4 6 6 5 1 2 Class A- 3 10 12 15 17 30 38 23 21 12 8 2 Class B+ 2 9 13 10 5 9 10 6 15 16 9 1 Class B- 1 7 7 3 1 4 3 2 7 11 8 888 J Periodontol June 2010 Pini-Prato, Franceschi, Cairo, Nieri, Rotundo CONCLUSION The classification of dental surface defects in conjunc- tion with the classification of periodontal tissues is useful for reaching a more precise diagnosis in areas of gingival recession. ACKNOWLEDGMENT The authors report no conflicts of interest related to this study. REFERENCES 1. American Academy of Periodontology. Glossary of Periodontal Terms, 4th edition. Chicago, IL; 2001: Figure 5. 44. Lateral view of a surface discrepancy (step) >0.5 mm measured with 2. Miller PD Jr. A classification of marginal tissue re- a periodontal probe. cession. Int J Periodontics Restorative Dent 1985;5:8- 13. 3. Zucchelli G, Testori T, De Sanctis M. Clinical and anatomical factors limiting treatment outcomes of In this case, a thick flap may fill the cervical root dis- gingival recession: A new method to predetermine crepancy at the end of its coronal position. the line of root coverage. J Periodontol 2006;77:714- To validate the reliability of the classification, three 721. different examiners applied it to a sample of gingival 4. Miller PD Jr. Root coverage with the free gingival graft. Factors associated with incomplete coverage. J Peri- recessions showing k statistics for intrarater agree- odontol 1987;58:674-681. ment ranging from 0.74 to 0.95 (almost perfect) 5. 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Pini-Prato G, Baldi C, Rotundo R, Franceschi D, Muzzi L. the ‘‘moderate’’ k statistics values found for interrater The treatment of gingival recession associated with agreement, these results are similar to those reported deep corono-radicular abrasions (CEJ step) – A case in the clinical evaluations of root coverage proce- series. Perio–Periodontal Practices Today 2004;1:57- dures.17 66. Available at: http://www.quintpub.com/journals/ Following the validation of the system, a sample of perio/archive_display_abstract.php3?journalArt=6947. Accessed April 14, 2010. 1,010 gingival recessions were collected to assess the 9. Pini-Prato G, Baldi C, Pagliaro U, et al. Coronally distribution of the four classes of this classification. It advanced flap procedure for root coverage. Treatment should be noted that 46% of gingival recessions of root surface: Root planing versus polishing. 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