INTRODUCTION:

The primary etiologic agents in periodontitis are bacterial plaque and calculus. Correlation of supragingival plaque and calculus with gingivitis and periodontitis has been demonstrated in several studies^1-5Scaling and root planing are widely used techniques in periodontal therapy to remove all kind of from tooth surface and also to reduce tooth surface roughness which may facilitate the accumulation of irritants. It has become increasingly evident that the most important aspect of periodontal therapy is the removal of all accretions from tooth surfaces. Scaling and root planing (SRP) with manual and ultrasonic instruments is the most established treatment of periodontal disease and has been shown to be effective in improving clinical parameters.

The SRP procedures may lead to rough areas caused by instrumentation. This roughened tooth surface caused either by instrumentation or disease in turn may influence the bacterial colonization and increase the rate of plaque formation and calculus deposition. The efficacy of periodontal therapy is directly related to the ability of treatment to lower levels and/or prevalence of one or more pathogenic bacterial species. Also, Loss of tooth substance may cause _exposureof the contents of dentinal tubules and lead to hypersensitive surfaces.⁶ Earlier, investigators studied root surface texture changes following different instrumentation like curettes and ultrasonic instruments. They found that curettes and ultrasonic instruments were equally effective in removing calculus. And also showed that curettes produce smoother sub gingival root surface than ultrasonic instruments.^7-11

Scanning electron microscope is widely used to study any surface topography. A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. This mechanism of action is by interaction toms and electrons in the sample which produce signals that contain information about the sample's surface topography and composition.¹²In this investigation analysis of root surfaces was made utilizing the scanning electron microscope as it provides, to date, the greatest magnification and detail of surface morphology available.

The newest addition to the vision enhancement arena in dentistry is the operating microscope. The surgical microscope was introduced to dentistry by Apothekar in 1981.¹³At present the use of an operating microscope in periodontics is confined to plastic surgery, but it can help the clinician with diagnostic procedures, nonsurgical and surgical periodontal therapy. Macroscopic versus microscopic vision determines the degree to which surgeons can handle soft and hard tissue for primary wound closure and rapid, non-traumatic healing. Subtle basic micro suturing techniques offer vast improvement in wound closure through magnification and good visual feedback. Hence, this study aims to analyze the morphological characteristics of the root surfaces and remaining calculus with scanning electron microscope after scaling and root planing with curettes under microscope, dental loupes, and naked eye.

MATERIAL AND METHODS:

The study was conducted in the dental research lab in Saveetha institute of medical and technological sciences with approval from the Institutional Review Board. Eighteen freshly extracted single or multi-rooted human teeth due to periodontal disease (attachment loss of more than one third of the root) from non-smoking patients, with calculus present on surfaces were selected for the study. Teeth without apparent surface defects such as extraction marks or root grooves were only included. Both single rooted and multi rooted teeth were included in this study. After extraction, the teeth were washed in distilled water to remove blood and other deposits and kept at room temperature in PBS of pH 7.0, to keep the teeth hydrated up till the experiment.

Experimental procedure:

All the samples were treated by SRP, comprising 50 traction movements in the cervico-occlusal direction with hand curettes (Gracey curettes, Hu-Friedy). The different groups in this study were: Group 1 (SRP was done under naked eye) N=6, Group 2 (SRP was done with dental loupes of x3.5 magnification) N=6, Group 3 (SRP was done under dental microscope of x12 magnification) N=6. Single rooted and multi-rooted teeth were equally distributed among the three groups.

A single trained operator performed all treatments. The working distance and position was standardized by sitting with back straight, arms at 90 degree angle, elbows close to the body and working distance of about 25-30 mm between the eye and the operating field. All specimens were examined by The Quanta 200 FEG scanning electron microscope (SEM).

Evaluation of specimen:

The SEM micrographs were analyzed by a previously trained blinded single operator, who described the morphology of the root surfaces in terms of Presence or absence of smear layer, Remaining calculus index, Roughness and loss of tooth substance index.

_{Remaining Calculus index was estimated in accordance with
the following criteria of the Remaining calculus Index (RCI):14}

_{0: No calculus
remaining on the root surface}

_{1: Small patches
of calculus}

_{2: Defined
patches of calculus confine to smaller areas}

_{3: Considerable
amounts of remaining calculus appearing as one or a few voluminous patches or as
several smaller patches scattered on the treated surface.}

Roughness and loss of tooth substance were evaluated by the following index, formulated as a modification and combination of the scanning roughness index (SRI) and the Loss of tooth Substance Index (LTSI)¹¹

0: Smooth and even root surface without  marks from the instrumentation and with no loss of tooth substance.

1: Slightly roughened or corrugated local areas confined to the cementum

2: Definitely corrugated local areas where the cementum may be completely removed, although most of the cementum is still present.

3: Considerable loss of tooth substance with instrumentation marks into the dentin. The cementum is completely removed in large areas, or it has a considerable number of instrumentation marks.

The statistical testing of the differences between the scores for the various groups were made by means of chi square test to compare the presence or absence of smear layer, Remaining calculus index (RCI) and Roughness and loss of tooth substance index (RLTSI) between the groups.

RESULTS:

Remaining calculus Index:

The amount of remaining calculus varied among the specimens. In terms of RCI, SRP under microscope showed significantly better result when compared to naked eye (p=0.007) whereas dental loupe was not statistically significant when compared with naked eye (p =0.10) or dental microscope (p=0.32).

Table 1: Comparison of difference in Remaining Calculus Index between the groups by One-way ANOVA

		N	Mean	Std. Deviation	Sig.
RCI	Group 1	6	2.1667	.75277	.007
	Group 2	6	1.1667	.98319
	Group 3	6	.5000	.54772
	Total	18	1.2778	1.01782

Table 2: Comparison of difference in Remaining Calculus Index between the groups by POST HOC

Dependent Variable	(I) Groups	(J) Groups	Mean Difference (I-J)	Std. Error	Sig.
Dependent Variable	(I) Groups	(J) Groups	Mean Difference (I-J)	Std. Error	Sig.
RCI	Group 1	Group 2	1.00000	.45134	.101
	Group 1	Group 3	1.66667^*	.45134	.006
	Group 2	Group 1	-1.00000	.45134	.101
	Group 2	Group 3	.66667	.45134	.329
	Group 3	Group 1	-1.66667^*	.45134	.007
	Group 3	Group 2	-.66667	.45134	.329

Roughness and Loss of tooth substance:

Scanning electron microscope revealed that specimens planed under Naked eye displayed relatively few small but deep instrumentation marks. Specimens planed under microscope and dental loupes showed less frequent instrumentation marks in the specimens. One-way ANOVA test revealed significant differences between the groups in regards to scores of roughness and loss of tooth substance. SRP under microscope (p=0.000) and dental loupe (p=0.004) was statistically significant when compared with SRP under naked eye. Whereas Dental microscope was not statistically significant when compared with Dental loupe group (p=0.10).

Table 3: Comparison of difference in Roughness and Loss of tooth substance index between the groups by One-way ANOVA

		N	Mean	Std. Deviation	Sig.
RLTSI	Group 1	6	2.1667	.75277	.000
	Group 2	6	1.0000	.00000
	Group 3	6	.3333	.51640
	Total	18	1.1667	.92355

Table 4: Comparison of difference in Roughness and Loss of tooth substance index between the groups by POST HOC

Dependent Variable	(I) Groups	(J) Groups	Mean Difference (I-J)	Std. Error	Sig.	95% Confidence Interval
Dependent Variable	(I) Groups	(J) Groups	Mean Difference (I-J)	Std. Error	Sig.	Lower Bound	Upper Bound
RLSI	Group 1	Group 2	1.16667^*	.30429	.004	.3763	1.9571
	Group 1	Group 3	1.83333^*	.30429	.000	1.0429	2.6237
	Group 2	Group 1	-1.16667^*	.30429	.004	-1.9571	-.3763
	Group 2	Group 3	.66667	.30429	.105	-.1237	1.4571
	Group 3	Group 1	-1.83333^*	.30429	.000	-2.6237	-1.0429
	Group 3	Group 2	-.66667	.30429	.105	-1.4571	.1237

Table 5: Comparison of difference in presence or absence of smear layer between the groups by One-way ANOVA

		Groups			Total
		Group 1	Group 2	Group 3	Total
Smear layer	Absent (.00) Present	0	2	4	6
Smear layer	(1.00)	6	4	2	12
Total		6	6	6	18

Smear Layer:

Smear layer was seen in all the samples planed under naked eye. When compared between groups, Pearson Chi-square test showed statistically significant difference (p=0.050) favoring root planing under dental microscope.

DISCUSSION:

This study aimed to assess the the morphological characteristics of the root surfaces with scanning electron microscope after scaling and root planing with curettes under microscope, dental loupes, and naked eye. The one-way ANOVA test showed statistically significant differences favoring group 3, as to RCI on root surfaces (p = 0.007) and RLTSI (p=0.00). The Chi-square test also showed statistically significant difference favoring group 3 (SRP was done under dental microscope of x12 magnification, p=0.05) as to the presence or absence of smear layer.

Many studies has confirmed the effect of root planning with curettes in non-surgical periodontal therapy.^15-17 Root planning is more significant than subgingival scaling alone, as the root surface morphology contributes to plaque and calculus deposition. Schaffer ¹⁷ in his study scaled one group of teeth and root planed other group of teeth. After extraction, he found significantly more remaining calculus on the root surface of scaled teeth than the root planed teeth. This shows the significance of root planning over sub-gingival scaling.

Consequently, a micro- surgical approach for periodontal regeneration was introduced and it was reported that the rate of secondary wound closure could be further limited to 8% of all reported cases.^18,19Cortellini and colleagues showed in two recent case series with a total of 53 deep intra-bony defects that a minimally invasive, high-power magnification- assisted surgical technique using EMD yielded clinically significant improvements (CAL gains of 4.8 1.9 mm). ^20,21Cairo et al ²²performed the periodontal pocket treatment with shallow to moderate bony defects in the the esthetic zone with preservation of the attached gingival fibers and maintenance of the interdental papilla using microsurgical flap access. The results in terms of attachment level gain and residual pocket depth showed that use of microsurgical approach helped to minimize marginal tissue recession and improve esthetics. The present investigation corroborates these results that the effect of root planning under microscope can be significantly better than root planing under naked eye.

Once the working end of the instrument is placed sub gingivally, proprioception and tactile sensation may be more critical to the outcome of the periodontal therapy than visual acuity. Proprioceptive guidance is of little value under a microscope, so visual guidance is used to make a midcourse correction of the operating hand position to maximize operator dexterity and fine movements required for the treatment procedure. There is no clinical evidence to differentiate the effect of root planning under naked eye, dental loupes or dental microscope. This study is the first of its kind. Though this study showed that scaling and root planing with curettes under microscope of x12 magnification provided smoother root surface with nearly no smear layer remaining calculus, the clinical significance related to use of dental microscope has to be evaluated.

CONCLUSION:

Considering the obtained results and methodology used in this study, it may be concluded that scaling and root planing with curettes under microscope of x12 magnification provided smoother root surface with nearly no smear layer and remaining calculus when compared with SRP done under naked eye and dental loupes of x3.5 magnification.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

ACKNOWLEDGEMENT:

We are most grateful to the dental research lab in Saveetha Institute of medical and technological sciences for the immense effort in performing the research.

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Received on 04.10.2018 Modified on 29.11.2018

Research J. Pharm. and Tech. 2019; 12(4):1547-1550.

DOI: 10.5958/0974-360X.2019.00256.7