Real-Time PCR Quantification of Red Complex Bacterial DNA and Periodontal Status in Removable Partial Denture Wearers

Summary

Real-time polymerase chain reaction (PCR) was used to quantify red complex bacteria DNA in removable partial denture (RPD) wearers. This study promises a novel approach to future implant prosthetic treatment strategies for these patients, considering the role of these bacteria in the development of peri-implantitis.

Abstract

The insertion of removable partial dentures (RPDs) in the oral cavity is associated with changes in the oral microflora over time. However, there is a paucity of literature examining the presence of red complex bacteria (RCB) in these patients. Given RCB's established role in the development of periodontitis, peri-implantitis, and various systemic diseases, investigating the impact of RPDs on these bacteria is crucial. This study aims to quantify the subgingival burden of RCB-Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola-in abutment teeth of partially edentulous patients rehabilitated with RPDs, using real-time polymerase chain reaction (RT-PCR). A secondary objective was to assess the periodontal status of abutment and non-abutment teeth and to determine the correlations between microbial load and clinical periodontal indices.

Thirty participants requiring RPDs were enrolled. Deoxyribonucleic acid (DNA) was isolated from bacterial samples obtained from abutment teeth before (T0) and 3 months post-insertion (T3). RCB quantification was performed via RT-PCR and expressed as "Lg (genome equivalents/sample)". Clinical parameters-plaque index (PI), gingival index (GI), probing depth (PD), and tooth mobility (TM)-were recorded for abutment and non-abutment teeth at both timepoints.

Abutment teeth demonstrated statistically significant increases in RCB loads across all three target species from T0 to T3: P. gingivalis (1.99 ± 2.01 vs 3.64 ± 2.21, p = 0.00003), T. forsythia (2.20 ± 2.17 vs 3.56 ± 2.33, p = 0.00009), and T. denticola (0.82 ± 1.41 vs 2.35 ± 2.21, p = 0.0001). While periodontal parameters were elevated in abutment versus non-abutment teeth post-treatment, differences did not reach statistical significance. Among pathogens, T. forsythia exhibited the strongest positive correlation with periodontal indices.

Short-term use of RPDs is associated with a significant increase in RCB colonization of abutment teeth, suggesting early microbial and inflammatory shifts that may precede clinically evident periodontal breakdown.

Introduction

The oral cavity harbors a dynamic microbiome whose ecological balance is critical to maintaining periodontal health¹. Disruption of this microbial homeostasis, due to endogenous and exogenous factors, can disrupt the microbial homeostasis, creating favorable conditions for the growth of pathogenic bacteria, including periodontal pathogens such as Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, collectively termed the red complex bacteria (RCB)². These pathogens are pivotal in the pathogenesis of periodontitis and peri-implantitis, working synergistically to evade host d....

Protocol

This study included 30 partially edentulous patients who sought prosthodontic care at the Clinic of Dental Prosthetics, University Dentistry Clinical Center of Kosovo, between September 2021 and March 2022. Ethical approval was obtained from the institutional review board (Approval No. 378/19), and all procedures adhered to the principles of the Declaration of Helsinki. Written informed consent was secured from all participants.

The sample size was determined based on prior research, which indicates that 11 to 30 participants are sufficient to obtain significant results in microbial and periodontal parameters among RPD wearers

Results

Participant demographic

Table 1 presents the distribution of demographic parameters. Among the 30 participants, 16 were male (53.3%), and 14 were female (46.7%). The average age of participants was 64.6 years, with a range from 48 to 76 years. Additional details regarding the social demographics are provided in Table 1.

Clinical examination

Table 2 shows .......

Discussion

Maintaining optimal oral hygiene becomes increasingly challenging with age, due to diminished immune responsiveness and the mechanical limitations imposed by prosthetic appliances such as clasp-retained RPDs. These conditions favor the accumulation of pathogenic biofilms, particularly around abutment teeth, which serve as critical load-bearing structures but are also vulnerable to periodontal deterioration. This study sought to address these concerns by quantifying red complex bacteria (RCB) loads and assessing associate.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
1.5 mL Microcentrifuge Tubes with Safety Lock	Biotek	MT1.5/100
Dental Tweezers	Bader	17/4021-1
DTprime Real-Time Thermal Cyclers	DNA-Technology		Real-Time Thermal Cyclers
IBM SPSS	IBM Corp	Version 21.0
Microsoft Excel	Microsoft Office 2010
Paper points (no. 35; 04 tapered)	DiaDent	MP210-602
ParodontoScreen REAL-TIME PCR Detection Kit	DNA-Technology	R1-P808-S3/5EU
Periodontal probe	MEDESY	548/9PT
PREP-GS PLUS	DNA-Technology	P-003/2EU	DNA extraction kit
RealTime software	DNA-Technology	Version 7.9
Sodium Chloride 0.9%	VIOSER