Evaluation of postsurgical clinical outcomes with/without removal of pocket epithelium: A split mouth randomized trial.

BACKGROUND: Periodontitis is bacteria-related chronic inflammatory condition characterized by pocket formation, loss of clinical attachment, gingival recession, mobility, and eventual loss of teeth. The purpose of this study was to clinically evaluate the need for elimination of the pocket epithelium during mucoperiosteal flap surgery aimed at reattachment or re-adaptation.
MATERIALS AND METHODS: A split mouth design was done to compare modified Widman flap (MWF) with removal of the pocket epithelium and crevicular mucoperiosteal flap (CMF) without removing the pocket epithelium. The following measurements were taken after 1 month of completion of nonsurgical phase gingival index (Loe and Silness), plaque index (Silness and Loe), mobility, furcation involvement, level of attachment, pocket depth, gingival recession, gingival contour index, and dentinal hypersensitivity (ice stick test). In addition to these measurements, which were taken immediately prior to the surgery (baseline), 1- and 3-month and 6 months postsurgical measurements were also recorded.
RESULTS: The results of this study showed a greater reduction of mean probing depth in the test group (MWF). The control group (CMF) showed greater mean gingival recession compared to the test group throughout the study period. The test group showed more gain in the clinical attachment levels compared with the control group. The difference between the two groups was statistically significant (P < 0.001).
CONCLUSIONS: The results of this study demonstrate that MWF surgery was more effective in reducing mean probing depth, showed greater gain in clinical attachment, and demonstrated less gingival recession.

RCT Entities:   Population Interventions Outcomes

INTRODUCTION

Periodontitis is a bacteria-related inflammatory disease leading to the destruction of tooth supporting tissues caused by interaction of bacteria present in the dental plaque and the host. One of our prime objective in periodontal therapy is to eliminate the bacterial deposits (oral biofilm) adhering to tooth/root surface and other plaque retentive factors, which can be achieved by nonsurgical and surgical therapies.[123]

The limitations of nonsurgical therapy[4] led to the development of the various surgical procedures which were directed primarily at the reduction/elimination of periodontal pocket. Over time the removal of pocket lining with the intention to achieve connective tissue attachment in preference to long junctional epithelium attachment has been a desirable goal.[456789101112131415] Recognizing this importance Ramfjord and Nissle (1974) proposed the modified Widman flap (MWF) surgery.[45]

However, the limitations of MWF including postsurgical gingival recession, dental hypersensitivity, root caries, poor esthetic outcomes, and formation of long junctional epithelium with minimal connective tissue attachment gain let to the introduction of a more conservative crevicular mucoperiosteal flap (CMF).[59]

Thus, with the conflicting data in the literature about the superiority of the surgical procedure the present study was done to assess the postsurgical clinical outcomes of surgical techniques that either retained or removed the gingival sulcular epithelium.

MATERIALS AND METHODS

Source of data

This study was conducted on 18 paired posterior sextants (13 patients) from June 2011 to September 2012. The patients in the age group of 22-60 years were selected from the outpatient department of Periodontics, Dr. Syamala Reddy Dental College Bangalore based on the following inclusion criteria's: (1) Compliant patients in the age group of 22-60 years. (2) Patients with moderate to advanced periodontitis. (3) Patients with pocket depth of ≥5 mm. (4) Patients with bilaterally similar bone loss. Patients who had undergone periodontal treatment 6 months prior to the study, pregnant women and lactating mothers, patients who were known smokers, medically compromised patients, patients on the long-term use of drugs which could affect the treatment and final outcome of the surgery and patients with aggressive periodontitis were excluded from the study.

The measurements were recorded using a pressure sensitive UNC-15 periodontal probe and customized acrylic stents at six surfaces of the teeth, which were grouped into interproximal and buccolingual measurements.

Study design

In this split mouth[16] clinical study, a total of 18 paired posterior sextants (13 patients; 4 females and 9 males) with identical bone defects on either sides in maxilla or mandible, which required periodontal flap surgery were selected. All patients were informed about the study and a written consent was obtained.

Though gingival recession at baseline was not an exclusion criterion for the study, but care was taken not to sacrifice any additional tissue. Thus, if a sextant allocated to the test group displayed teeth with gingival recession at baseline such teeth only received a crevicular incision and was hence excluded from the statistical analysis thereafter.

To avoid any discrepancy in the number of teeth evaluated in the test and control posterior sextants the contra lateral teeth in the control group were also eliminated from statistical analysis in the study. The clinical parameters which were assessed at baseline, 1, 3, and 6 months included gingival recession, plaque index,[1718] gingival index, gingival contour index,[10] dentinal hypersensitivity,[19] and tooth mobility[20] while probing pocket depth, clinical attachment levels and furcation involvement would be assessed at baseline, 3 and 6 months, respectively.

Surgical procedure

The surgical procedure was performed under local anesthesia using 2% lignocaine hydrochloride containing adrenaline at a concentration of 1:80,000. The choice of flap surgery technique, that is, MWF (test group) or CMF (control group) was decided by the toss of a coin method.

Statistical analysis

The Excel and SPSS (SPSS Inc., Chicago, USA, Version 10.5) software packages were used for data entry and analysis. One-way analyses of variance were used to test the difference between groups, Student's ‘t’-test was used to determine whether there was a statistical difference between two groups in the parameters measured and proportions were compared using Chi-square test of significance. The P ≤ 0.05 were taken to be statistically significant.

The statistical evaluation in this study stresses upon probing depth reduction, changes in clinical attachment levels and gingival recession as they were considered as the primary outcome variables for the study.

RESULTS

The present split mouth study was aimed to compare the postsurgical outcomes between MWF (test) and CMF (control).[21]

This study was conducted over a period of 6 months. Thirty posterior sextants; 15 each in test and control groups 3 months follow-up, 12 posterior sextants completed 6 months follow-up while the remaining with six posterior sextants did not complete 3 months follow-up. None of the patients reported any postsurgical complications.

For all the clinical parameters considered in the study only the mean values of buccolingual and interproximal measurements are reported for simplicity of data presentation and statistical evaluation.

Evaluation of probing pocket depth at baseline, 3 and 6 months

The mean probing depths for the control group in the buccolingual area reduced from 4.1 mm at baseline to 2.9 at 6 months while in the interproximal areas 6.8 mm at baseline 3.6 mm at 6 months (P < 0.05) [Table 1 and Graph 1]. While in the test group the pocket depths reduced from 4.2 mm at baseline to 2.3 at 6 months and 7.1 mm at baseline to 3.0 mm at 6 months in buccolingual and interproximal areas respectively (P < 0.05) Table 1, and Graph 1]. The test group showed a greater reduction of mean probing depth in buccolingual and interproximal areas, which was highly statistically significant (P < 0.001) Table 2, and Graph 2].

Table 1

Intra-group comparison of mean probing depth on interproximal and buccal and lingual surfaces at different visits

Graph 1

Comparison of probing depth on various surfaces between the groups

Table 2

Inter-group comparison of mean probing depth changes on interproximal and buccal and lingual surfaces at different visits

Graph 2

Comparison of gingival recession on various surfaces between the groups

Evaluation of gingival recession at baseline, 1, 3 and 6 months

The mean recession in the control group increased from 0.5 to 1.2 mm at all areas over 6 months (P < 0.001) [Table 3, Graph 3]. While there was no gingival recession seen in the sites treated with MWF during 6 months of the study period [Tables 3 and 4, Graphs 3 and 4].

Table 3

Intra-group comparison of gingival recession depth on interproximal and buccal and lingual surfaces at different visits

Graph 3

Comparison of clinical attachment level on various surfaces between the groups

Table 4

Inter-group comparisons of mean gingival recession changes on interproximal and buccal and lingual surfaces at different visits

Graph 4

Inter-group comparision of gingival contour index

Evaluation of clinical attachment level at baseline, 3 and 6 months: Intra-group comparison

Similar to improvements in probing pocket depth there was gain in clinical attachment levels with both the procedures in both buccolingual control: (4.6-3.7 mm); test: (4.1-2.4 mm) and interproximal areas control: (7.5-4.3 mm); test (7.0-3.1 mm) from baseline to 6 months, though the gain was more in the test group (P < 0.001) [Tables 5 and 6, Graphs 5 and 6].

Table 5

Intra-group comparison of clinical attachment depth on interproximal and buccal and lingual surfaces level at different visits

Table 6

Inter-group comparisons of CAL changes on interproximal and buccal and lingual surfaces at different visits

Graph 5

Inter-group comparison of plaque index

Graph 6

Inter-group comparison of gingival index

Other parameters evaluated showed improvement with both procedures, but did not reach statistical significance over 6 months and between the two groups. The gingival contour index showed better results with the test group though values were not statistically significant.

Evaluation of gingival contour index at baseline, 1, 3 and 6 months

The gingival contour was estimated by using of gingival contour index proposed by Newman in 1984.

Intra-group comparison

The mean gingival contour index score for the 18 sextants receiving CMF at baseline, 1, 3, and 6 months were 2.1, 1.8, 1.6, and 1.5, respectively. The control group (18 sextants) showed an improvement in the gingival contour scores over the baseline values, which was statistically significant (P < 0.01) Table 7 and Graph 7].

Table 7

Intra-group comparison of gingival contour index at different visits

Graph 7

Inter-group comparison of dentinal hypersensitivity

The mean gingival contour index score for the test group (18 sextants) at baseline, 1, 3, and 6 months were 2.1, 1.7, 1.2, and 1.3, respectively. The test (18 sextants) group showed an improvement in the gingival contour over the baseline value, which was statistically significant (P < 0.01) [Table 7 and Graph 7].

Inter-group comparison

The difference of means between the control (18 sextants) and test group (18 sextants) at baseline, 1, 3, and 6 months were 0.03, 0.03, 0.4, and 0.2, respectively. The test group showed better gingival contour compared to the control group at 3 months, which was statistically significant (P < 0.05) [Table 8, Graph 8]. The difference in the gingival contour between the control and test groups at 1 and 6 months was not statistically significant [Table 8 and Graph 8].

Table 8

Inter-group comparisons of mean values of gingival contour index at different visits

Graph 8

Inter-group comparison of furcation grades

Evaluation of plaque index at baseline, 1, 3, and 6 months

The plaque scores were calculated using plaque index proposed by Silness and Loe.

The mean plaque scores for the control group (18 sextants) recorded at baseline, 1, 3, and 6 months were 1.4, 1.4, 1.3, and 1.3, respectively. The control group showed an improvement in the plaque scores over the baseline values which was statistically significant (P < 0.004) [Table 9 and Graph 9].

Table 9

Intra-group comparison of plaque index at different visits

Graph 9

Inter-group comparison of mobility grades

The mean plaque scores for the 18 sextants (MWF) at baseline, 1, 3, and 6 months were 1.5, 1.3, 1.3, and 1.3, respectively. The test group showed an improvement in the plaque scores over the baseline values, which was highly statistically significant (P < 0.001) Table 9 and Graph 9].

The difference of means between the control (18 sextants) and the test group (18 sextants) at baseline, 1, 3, and 6 months were 0.02, 0.02, 0.02, and 0.05, respectively. The difference between the control and the test group was not statistically significant at 1, 3, and 6 months [Table 10 and Graph 10].

Table 10

Inter-group comparison of mean plaque index at different visits

Graph 10

Comparison of probing depth (overbaseline) between the groups

Evaluation of gingival index at baseline, 1, 3 and 6 months

The gingival changes were recorded with the help of gingival index proposed by Loe and Silness.

The mean gingival index score for the control group (18 sextants receiving CMF) at baseline, 1, 3, and 6 months were 1.4, 1.3, 1.2, and 1.3, respectively. The control group showed improvement in gingival index scores over the baseline values, which was highly statistically significant (P < 0.001) [Table 11 and Graph 11].

Table 11

Intra-group comparison of gingival index at different visits

Graph 11

Comparison of gingival recession (over baseline) between the groups

The mean gingival index score for the test group (18 sextants) at baseline, 1, 3, and 6 months were 1.4, 1.3, 1.2, and 1.3, respectively. The test group showed improvement in gingival index scores over the baseline values, which highly statistically significant (P < 0.001) [Table 11 and Graph 11].

The difference of means between the control (18 sextants) and test groups (18 sextants receiving MWF) at baseline, 1, 3, and 6 months were 0.003, 0.022, 0.009, and 0.013, respectively. The difference between the control and the test group was not statistically significant at 1, 3, and 6 months Table 12 and Graph 12].

Table 12

Inter-group comparison of mean gingival index at different visits

Graph 12

Comparison of clinical attachment level (over baseline) between the groups

Evaluation of dentinal hypersensitivity at baseline, 1, 3 and 6 months

The presence/absence of dentinal hypersensitivity was tested using a blast of air. The finding was recorded as a dichotomous parameter.

All the 36 posterior sextants (18-test; 18-control) evaluated for dentinal hypersensitivity did not show any statistically significant difference between the two groups and when compared with the baseline findings at 1, 3, and 6 months (P > 0.05) [Table 13 and Graph 13].

Table 13

Inter-group comparison of dentinal hypersensitivity at different visits

Graph 13

Intra-group comparison (over baseline)of gingival contour index

Evaluation of furcation involvement at baseline, 3 and 6 months

The involvement of the furcation area was evaluated using a Nabers probe and graded according to Glickman's index.

All the 36 posterior sextants (18-test; 18-control) evaluated for furcation involvement did not show any statistically significant difference between the two groups and when compared with the baseline findings at 3 and 6 months (P > 0.05) [Table 14 and Graph 14].

Table 14

Changes in furcation involvement grades comparing the MWF and CMF

Graph 14

Intra-group comparison (over baseline) of plaque index

Evaluation of mobility at baseline, 1, 3, and 6 months

The mobility of teeth was recorded and graded according to Muhlemann's method.

All the 36 posterior sextants (18-test; 18-control) evaluated for tooth mobility did not show any statistically significant difference between the two groups and when compared to the baseline findings at 1, 3, and 6 months (P > 0.05) [Table 15 and Graph 15].

Table 15

Changes in severity mobility grades comparing the MWF and CMF

Graph 15

Intra-group comparison (over baseline) of gingival index

In five paired posterior sextants bone graft material was placed on encountering contained intrabony defects. The clinical parameters when assessed for these five paired sextants did not show any difference in results at 3 and 6 months, respectively.

DISCUSSION

In the present split mouth study, 13 patients (36 posterior sextants) having moderate to severe periodontitis with bilaterally symmetrical disease pattern were selected. After the completion of phase I therapy all of them demonstrated persistent pockets when evaluated after 4 weeks[89] and thus was selected for periodontal flap surgery.

The results of the present study showed that both the periodontal flap surgical procedures were highly effective in achieving significant improvement in all the clinical parameters over the baseline values when evaluated at 1, 3, and 6 months postsurgically. The results of this study are in agreement with the previous studies.[22232425]

In our study, the mean probing depth reduction with both the techniques was statistically significant (P < 0.001). This reduction was consistently seen at all intervals and on all three surfaces, which is in agreement with previous studies.[22232425262728] When the MWF (test group) was compared to the CMF (control group) the former showed greater reduction in mean probing depth both buccolingually and interproximally, which was highly statistically significant[922232425262728] (P < 0.001). The reduction in probing depth obtained in the present study were greater compared to previous studies due to higher baseline probing depths.[22232425]

The mean gingival recession seen in our study was more with the CMF compared to the MWF a (P < 0.05). This observation was also reported by other authors[922232425262728] and this could be possibly explained by the fact that the retention of pocket epithelium in the CMF prevented the fibrin clot to retain the flap in the desired position and an apical shift could have occurred because of shrinkage in the healing period[9] or due to the coronal rebound of soft tissue margin after surgical treatment.[29]

This study showed a gain in clinical attachment level for both the treatment groups which was statistically significant (P < 0.05). The MWF group showed greater gain in clinical attachment than the CMF group at 3 and 6 months both bucco-lingually and interproximally, which was highly statistically significant (P < 0.001). The results obtained were in accordance to the previous studies.[9] The greater gain in clinical attachment levels with MWF surgery could be speculated because of re-attachment[922232425262728] happening with inverse bevel incision as opposed to healing by long junctional epithelium in control group. However, this finding should be taken with caution as no histological analysis was done in the present study.

Both surgical techniques exhibited improved gingival contour postsurgically.[3031323334] However, the test group exhibited slightly better results over the control group at 6 months though this difference was not statistically significant (P > 0.05). Zamet et al. in their study also reported a similar finding, but in contrary Newman did not report any improvement in gingival contour with inverse bevel incision.[10]

CONCLUSIONS

The results from this study have shown that both MWF and CMF were effective to reduce mean probing depth and to gain clinical attachment. However, lower probing depth, higher clinical attachment gain and less recession were observed at sites where a MWF was used compared to sites treated with a CMF.

Though further studies with better methodology and sample size are required to draw any conclusive inference over this long standing controversy.