Comparative evaluation of locally delivered probiotic paste and chlorhexidine gel as an adjunct to scaling and root planing in treating chronic periodontitis: A split-mouth randomized clinical trial.

Introduction: The etiological factors of periodontal diseases are the habitation of dysbiotic bacteria, absence of beneficial bacteria, and susceptibility of the host. Irresolute pattern in the periodontal diseases pathogenesis leads to the evolution of novel antimicrobial therapy. Objective: The objective of the study is to assess and compare the competency of locally delivered probiotic paste with chlorhexidine gel as a supplement to scaling and root planing (SRP) in chronic periodontitis patients. Materials and
Methods: A split-mouth randomized controlled trial was designed on 10 systemically healthy participants having chronic periodontitis at three distinct quadrants with 5-6-mm pocket depth. The sites in each participant were randomly selected for Group A (negative control), Group B (positive control), and Group C (test). In Group A, only SRP, Group B - SRP + chlorhexidine local drug delivery (LDD), Group C - SRP + probiotic LDD were done, respectively. Gingival index (GI) and bleeding index (BI) were determined at baseline, 3rd, 6th, and 9th weeks, whereas probing pocket depth (PPD), Russell's periodontal index, and clinical attachment level were checked at baseline and after 9 weeks.
Results: It shows a significant reduction in GI, BI, PPD, and gain of CAL in probiotic LDD group.
Conclusion: Nowadays, since microbes are rapidly developing resistance to antibiotics, the development of probiotics is a boon for the treatment of periodontal diseases. Diseases of the periodontium are not restricted to the oral cavity alone but also have strong systemic effects. Hence, probiotics give a natural and promising choice of therapy to establish both good oral and systemic health. Copyright:

INTRODUCTION

Periodontal disease is a chronic multifactorial microbial infection. Conventional treatment modalities include mechanical debridement and adjunctive antibiotic administration for entire elimination of the oral microflora.

Oral microbiota include two variants, one being symbiotic organisms seen in healthy periodontium and the other is dysbiotic organisms seen in diseased periodontium. Antimicrobial supplements in recent years include probiotics, photodynamic therapy, onestage fullmouth disinfection, and local drug delivery (LDD).

Goodson et al. in 1970[8] stated that local delivery system is more beneficial than systemic drug administration because of the following reasons: direct access to target disease, improvement of patient compliance, avoidance of gastrointestinal tract (GIT)-related issues, bypass of first-pass metabolism by the liver, enhanced therapeutic efficacy of the drug, and reduced treatment cost.

Therefore, LDD systems have been advanced as they maintain effective intrapocket levels of antibacterial agents for extended period of time that can alter subgingival flora and influence the healing of attachment apparatus.

Antibiotic resistance and recolonization by pathogenic bacteria led to the evolution of probiotics in LDD system. Elie Metchnikoff in 1907[15] introduced the concept of probiotics and the term probiotics were coined by Lilley - Stillwell in 1965.[15] The current definition for probiotics is given by the World Health Organization, which defines probiotics as live microorganisms, most often bacteria (sometimes fungi), which, when consumed, confer beneficial effects to the host (World Health Organization, 2002).[15] The most commonly used species of probiotics belong to the Lactobacillus, Bifidobacterium, Escherichia, Enterococcus, and Bacillus genera. These probiotic benefits oral health by defending the growth of harmful bacteria and by modulating mucosal immunity in the oral cavity.[16] Therefore, this study was designed to formulate a probiotic-based LDD material evaluating its in vitro pharmaceutical properties and to compare its clinical efficiency with chlorhexidine gel as a supplement to scaling and root planing in the treatment of chronic periodontitis patients.

MATERIALS AND METHODS

The in vitro pharmaceutical maneuvering of the novel probiotic LDD material was done under standardized protocol in Manipal College of Pharmaceutical Science, Manipal. Pharmaceutical armamentarium includes probiotic powder (Sporlac*), edible glycerol, glass slab, mixing spatula, measuring scale. Formulation of Lactobacillus sporogenes (250 mg) in five different proportions of glycerol (0.1 ml, 0.2 ml, 0.3 ml, 0.4 ml, and 0.5 ml) was prepared by taking Lactobacillus sporogenes powder and glycerol on a glass slab, and the powder was mixed with glycerol in geometric proportions until smooth consistency paste was obtained [Figure 1]. The formulated pastes were then evaluated for various parameters.

Figure 1

Formulated paste (F1-F5) with different concentrations of glycerine

The pH of the drug solution in 3 different solvents, i.e., water, glycerol, and methanol was determined using pH meter [Figure 2]. The pH values were found ranging from 3 to 6.5. The viscosity of all 5 formulations was determined using Brookfield viscometer at 0.01 rpm and temperature of 27°C. The viscosity of all 5 formulations was identified to be >30,650 centipoises [Figure 3]. Spreadability of the formulations was evaluated by measuring the spreading diameter of 1 g of sample placed between two horizontal glass plates after 1 min. The standard weight applied to the upper plate was 25 g. It was found that with increasing the amount of glycerol, the spreadability of the formulation increased [Figure 4]. Homogeneity and texture were tested by pressing a small quantity of the formulation between the thumb and index finger. The consistency of the formulations and the presence of coarse particles were used to determine the texture and homogeneity of the formulations. All the five formulations (F1-F5) showed that the formulated paste had appealing appearance and smooth texture, and they were all homogenous as indicated by the absence of gritty particles.

Figure 2

pH determination

Figure 3

Brookfield viscometer (a) and (b)

Figure 4

Spreadability test indicating (a) original diameter before addition of weights and (b) increased diameter after addition of 25 g weights

Lambda max (λmax) value is the wavelength at which a substance has its strongest photon absorption. At this wavelength, the drug shows maximum absorption. λmax of LS was determined in different solvents such as glycerol and phosphate buffer (pH-6.8) and it was found to be 208 nm and 205 nm, respectively [Figure 5]. The stock solution (1000 mg/ml) of Lactobacillus sporogenes was prepared, and further dilutions were made in the concentration range of 50–500 mg/ml using phosphate buffer pH-6.8 as diluent. All samples were analyzed by ultraviolet (UV) spectrophotometer by measuring the absorbance at 205 nm with phosphate buffer pH 6.8 used as a reference standard. The absorbance readings obtained were plotted against concentration to get standard calibration curve of Lactobacillus sporogenes. Slope of graph was calculated for estimating the drug released in receptor compartment during diffusion studies using UV/visible spectroscopic method [Figure 6]. In vitro drug release studies were carried out by using vertical diffusion cell with a nominal volume of the acceptor compartment of 20 ml of phosphate buffer (pH 6.8). Cellophane membrane was fixed between donor and receptor compartment. In the donor compartment, 250 mg of formulation was added. The experiments were conducted at temperature of 37°C and 900 rpm for 12 h. Samples were withdrawn from the receptor compartment at different time points, and the amount of drug released in receptor solution was estimated by using UV spectrophotometer at 205 nm. The image of the diffusion cell used in the present study is shown in Figure 7. The drug release from the formulated paste was by diffusion mechanism and was found to be increased, and almost 100% release was observed at the end of 12 h.

Figure 5

Ultraviolet-visible spectrum of LS in glycerol. LS – Lactobacillus sporogenes; Abs – Absorbance

Figure 6

Calibration curve. y – linear regression calculated; r2 – Correlation coefficient

Figure 7

Vertical diffusion cell

The present study was a split-mouth randomized clinical trial conducted under standardized protocol after obtaining ethical clearance by the college ethical clearance committee, Mahe Institute of Dental Sciences and Hospital, Mahe. A total of 10 participants from the department of periodontics who were diagnosed as systemically healthy having chronic periodontitis in at least three different quadrants with 5–6 mm pocket depth were selected for the study.

Inclusion criteria for the study were patients with chronic generalized periodontitis (AAP 1999 classification), probing pocket depth (PPD) of 5–6 mm (all the surface of the tooth was evaluated and the highest measure of the pocket depth was considered for categorizing the tooth for respective group), and the exclusion criteria include patients undergone any periodontal therapy previously, systemic disease or medication, patients with any bone disorders, vitamin D deficiency, postmenopausal women.

Clinical armamentarium includes chlorhexidine gel (Hexigel*-1.0%w/w), probiotic formulation (Sporlac * Powder + Glycerol), glass slab, mixing spatula, plastic filling instrument, coie-pack. Three sites in each participant were randomly selected as Group A (control), Group B (positive control), and Group C (test).

Parameters analyzed at baseline, 3 weeks, 6 weeks, and 9 weeks are gingival index (GI) (Loe and Silness) and bleeding index (BI) (mSBI Mombelli 1987) and at baseline and after 9 weeks are PPD, Russell's Periodontal Index (RPI), and clinical attachment level.

The baseline parameters were recorded after obtaining consent from the patient for participating in the study, and periodontal therapy was done based on the group allotment.

Group A was advised SRP alone, Group B was advised SRP + LDD (chlorhexidine gel), and Group C was advised SRP + LDD (probiotic LDD material). All the data were statistically analyzed using SPSS is Statistical Package for the Social Sciences. It is a software used for statistical analysis of the present study. Descriptive analysis was done and independent sample t-test was employed between the groups. Two-way analysis of variance tests was applied for intergroup comparison. For all tests, a P < 0.05 was considered as statistically significant.

RESULTS

The results for the present investigation were estimated based on the parameters analyzed. The GI score [Tables 1 and 2] and BI score [Tables 3 and 4] were assessed at base, 3 weeks, 6 weeks, and 9 weeks showed gradual improvement in all three groups with significant improvement for GI in Group B from score 3.1 to 2.2 and in Group C from score 3.4 to 1.9 and in case of BI in Group B from score 2.9 to 2.2 and in Group C from score 3 to 1.9, respectively.

Table 1

Mean gingival index score (Loe and Silness)

Site (tooth number)	Baseline	3rd week	6th week	9th week	Guidelines
Group A (SRP)	3	2.8	2.6	2.6	0. Normal
Group B (CHX)	3.1	2.6	2.4	2.2	1. Mild inflammation, no bleedin
Group C (probiotic)	3.4	2.4	2.4	1.9	2. Moderate inflammation, bleeding on probing
					3. Severe inflammation, spontaneous bleeding

SRP – Scaling and root planing; CHX – Chlorhexidine

Table 2

Intergroup comparisons of gingival index

Groups	Mean	SD	Comparison group	Mean difference	P	95% CI
						Lower bound	Upper bound
A	2.75	0.157	B (CHX)	0.175	0.439	−0.282	0.632
			C (probiotic)	0.225	0.321	−0.232	0.682
B	2.58	0.157	A (control)	−0.175	0.439	−0.632	0.282
			C (probiotic)	0.050	0.824	−0.407	0.507
C	2.53	0.157	A (control)	−0.225	0.321	−0.682	0.232
			B (CHX)	−0.050	0.824	−0.507	0.407

SD – Standard deviation; CI – Confidence interval; CHX – Chlorhexidine; P – Probability value; P < 0.05 was considered as statistically significant

Table 3

Mean bleeding index score (mSBI Mombelli 1987)

Site (tooth number)	Baseline	3rd weeks	6th week	9th week	Guidelines
Group A (SRP)	2.8	2.7	2.6	2.6	0. No bleeding when probe is passed along marginal gingiva
Group B (CHX)	2.9	2.6	2.4	2.2	1. Isolated bleeding spots visible
Group C (probiotic)	3	2.4	2.4	1.9	2. Blood from a confluent red line on margin
					3. Heavy or profuse bleeding

SRP – Scaling and root planing; CHX – Chlorhexidine

Table 4

Intergroup comparisons of bleeding index score

Groups	Mean	SD	Comparison group	Mean difference	P	95% CI
						Lower bound	Upper bound
A	2.68	0.132	B (CHX)	0.150	1.000	−0.326	0.626
			C (probiotic)	0.250	0.574	−0.226	0.726
B	2.53	0.132	A (control)	−0.150	1.000	−0.626	0.326
			C (probiotic	0.100	1.000	−0.376	0.576
C	2.43	0.132	A (control)	−0.250	0.574	−0.726	0.226
			B (CHX)	−0.100	1.000	−0.576	0.376

CI – Confidence interval; SD – Standard deviation; P – Chlorhexidine; CHX – Probability value; P < 0.05 was considered as statistically significant

In case of PPD [Tables 5 and 6], RPI [Tables 7 and 8] and clinical attachment level [Tables 9 and 10] measured at baseline and after 9 weeks showed gradual gain in the clinical attachment level with significant improvement for PPD in Group B from 5.6 mm to 4.2 mm and in Group C from 5.6 mm to 3.9 mm, for RPI in Group B from score 3.3 to 2.2 and in Group C from score 3.5 to score 1.9, finally in case of CAL in Group B from 1.4 mm to 1.2 mm and in Group C from 1.5 mm to 1.2 mm, respectively.

Table 5

Mean probing pocket depth

Site (tooth number)	Baseline	9th week	Guidelines
Group A (SRP)	5.5	4.9	At baseline - 5-6 mm
Group B (CHX)	5.6	4.2	Six points probing (mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, distolingual)
Group C (probiotic)	5.6	3.9

SRP – Scaling and root planing; CHX – Chlorhexidine

Table 6

Intergroup comparisons of probing pocket depth

Group	Mean	SD	Comparison group	Mean difference	P	95% CI
						Lower bound	Upper bound
A	5.20	0.179	B (CHX)	0.300	0.737	−0.345	0.945
			C (probiotic)	0	0.259	−0.195	1.095
B	4.90	0.179	A (control)	−0.300	0.737	−0.945	0.345
			C (probiotic)	0.150	1.000	−0.495	0.795
C	4.75	0.179	A (control)	−0.450	0.259	−1.095	0.195
			B (CHX)	−0.150	1.000	−0.795	0.495

CI – Confidence interval; SD – Standard deviation; P – Probability value; CHX – Chlorhexidine; P < 0.05 was considered as statistically significant

Table 7

Mean Russell’s periodontal index score

Site (tooth number)	Baseline	9th week	Guidelines
Group A (SRP)	3.1	2.7	Negative. There is neither overt inflammation in the investing tissues nor loss of function due to destruction of supporting tissue Mild gingivitis. There is an overt area of inflammation in the free gingivae which does not circumscribe the tooth Gingivitis. Inflammation completely circumscribes the tooth, but there is no apparent break in the epithelial attachment Gingivitis with pocket formation. The epithelial attachment has been broken and there is a pocket (not merely a deepened gingival crevice due to swelling in the free gingivae). There is no interference with normal masticatory function, the tooth is firm in its socket, and has not drifted Advanced destruction with loss of masticatory function. The tooth may sound dull on percussion with a metallic instrument; may be depressible in its socket.
Group B (CHX)	3.3	2.2
Group C (probiotic)	3.5	1.9

SRP – Scaling and root planing; CHX – Chlorhexidine

Table 8

Intergroup comparisons of Russell’s periodontal index

Group	Mean	SD	Comparison group	Mean difference	P	95% CI
						Lower bound	Upper bound
A	2.90	0.173	B (CHX)	0.150	1.000	−0.476	0.776
			C (probiotic)	0.200	1.000	−0.426	0.826
B	2.75	0.173	A (control)	−0.150	1.000	−0.776	0.476
			C (probiotic)	0.050	1.000	−0.576	0.676
C	2.	0.173	A (control)	−0.200	1.000	−0.826	0.426
			B (CHX)	−0.050	1.000	−0.676	0.576

CI – Confidence interval; SD – Standard deviation; P – Probability value; CHX – Chlorhexidine; P < 0.05 was considered as statistically significant

Table 9

Mean clinical attachment level

Site (tooth number)	Baseline	9th week	Guidelines
Group A (SRP)	1.5	1.5	The CAL is the measurement of the position of the soft tissue in relation to the CEJ that is a fixed point
Group B (CHX)	1.4	1.2
Group C (probiotic)	1.5	1.2

CAL – Clinical attachment level; CEJ – Cementoenamel junction; SRP – Scaling and root planing; CHX – Chlorhexidine

Table 10

Intergroup comparisons of clinical attachment level

Groups	Mean	SD	Comparison group	Mean difference	P	95% CI
						Lower bound	Upper bound
A	1.50	0.144	B (CHX)	0.200	1.000	−0.321	0.721
			C (probiotic)	0.150	1.000	−0.371	0.671
B	1.30	0.144	A (control)	−0.200	1.000	−0.721	0.321
			C (probiotic	−0.050	1.000	−0.571	0.471
C	1.35	0.144	A (control)	−0.150	1.000	−0.671	0.371
			B (CHX)	0.050	1.000	−0.471	0.571

CI – Confidence interval; SD – Standard deviation; P – Probability value; CHX – Chlorhexidine; P < 0.05 was considered as statistically significant

DISCUSSION

The prevailing concept for etiology of periodontal disease includes three main factors – a susceptible host, the presence of pathogenic species, and the absence of socalled “beneficial bacteria which determine whether an active periodontal disease will occur.”[1]

Subgingival debridement, surgical interventions, and supplemental use of antibiotics and antiseptics are contemporary methods to decrease the pathogenic bacteria. According to Quirynen et al., 2002; Teughels et al.,[7] 2011, these treatments result in a temporary decline in the bacterial load and associated inflammation and are often not sufficient to control the disease. Therefore, the administration of beneficial bacteria, probiotics with antimicrobial and anti-inflammatory properties, is one of the novel supplemental approaches for periodontal therapy. The mechanism of probiotics in humans involves direct interaction, competitive exclusion, and modulation of host immune response.[3]

Various studies have been published investigating the effective health benefits of probiotics on systemic health, but investigations regarding their use in oral health are limited. These vary in terms of probiotics strains used, its concentrations, and vehicles for the application including cheese, lozenges, milk, kefir, ice cream, gum, drops, powder, and mouthwash.[7]

In periodontal disease, studies on the role of probiotics in gingivitis reported a significant decrease of plaque and gingival indices, bleeding on probing, and gingival inflammation in the probiotic groups.[11] The results of the animal and clinical periodontitis studies support the concept of probiotics in the management of periodontitis and thereby offer a low-risk, inexpensive, easy-to-use prevention, or treatment option for treating periodontal disease.

Glycerol is a colorless, odorless, and sweet compound with cryoprotectant activity. Based on a study conducted by Hafiz Shehzad Muzammil, Barbara Rasco and Shyam Sablani, Glycerol supplementation with probiotic frozen yogurt, increased the stickiness from 2.4% to 18.7%, and decreased the hardness from 8.0% to 14.5%, respectively.[16]

The present investigation focused primarily on the formulation of a paste incorporating probiotic and glycerol, with sustained drug release capacity, ideal pH, viscosity, homogeneity, and spreadability for ease in delivering the formulation into the pocket.

After testing various concentrations and formulations, we developed a mix of materials that represent satisfactory pharmaceutical property for a material to be used as LDD material. The formulation with 250 mg of probiotic powder and 0.1 ml of edible glycerol was found to have ideal properties for a LDD material. The formulated drug is professionally applied (in dental office) biodegradable material with sustained drug release ability. These are delivery systems whose action lasts for <24 h and therefore require multiple applications. It follows the first-order kinetics.[8] Various drug delivery systems are available for treating periodontitis, the material prepared in our study is a paste.

A systematic review by Cosyn J & Wyn I in 2006 has reported that treatment of periodontal pocket with adjunctive use of chlorhexidine gel with scaling and root planning results in a significant improvement of probing depth while reducing the microbial load. However, in the present study, adjunctive use of probiotics led to significant improvement in GI and BI, which are in accordance with the reported observations of Krasse et al.,[2] Noordin and Kamin,[4] Twetman et al.,[5] and Vivekananda et al.,[6] where they found a remarkable decrease in gingivitis scores with the use of probiotics along with scaling and root planing (SRP).

Further, in the current study, a significant reduction in periodontal pocket depth and improvement in clinical attachment level were found, which are in agreement with the reported observations of Vicario et al.,[9] Ince et al.,[10] Tekce et al.,[14] Laleman et al.,[12] suggesting the potent role of probiotic-based LDD paste as an adjunct to SRP in chronic periodontitis patient.

In the present study, using a negative (SRP alone) and a positive control (chlorhexidine gel), we were able to state that the probiotic LDD (Sporlac) has shown to be a potential LDD material in comparison to chlorhexidine. Chlorhexidine seldom caused local side effects including brown staining, taste alterations, increased supragingival calculus formation, and rarely desquamation of the oral mucosa, irrespective of which type of vehicle is used.[13] Sporlac probiotic LDD paste shows a very effective and economical substitute for patients with periodontal disease

CONCLUSION

Sustained drug release devices are proving to be more effective, more convenient, and easier to use than regular systemic administration of medicines. This development definitely paves the way for future trademarking of novel, economically feasible, and physiologically acceptable intrapocket-targeted drug delivery systems.

The multifactorial and complex microbial nature of periodontal and peri-implant infections, consisting of both erobic and anerobic bacteria, renders difficulty in predicting all the restrictions with the clinical use of drug formulated in the present study. However, based on the positive results from in vitro pharmaceutical analysis (the pH is suitable for use in oral cavity, viscosity was suitable for a paste material with adequate spreadability, homogeneous and smooth texture, and the drug was completely absorbed in 12 h) and the clinical trial (significant reduction in GI, BI, PPD, and gain of CAL) of the drug formulated in the present study suggest a definitive platform for further welldesigned clinical studies with larger sample sizes, administering a booster dose and long-term follow-ups.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.