Effect of daily vitamin C supplementation with or without flavonoid supplements on periodontal and systemic conditions before and after periodontal treatment

An important aim of the periodontal professional is to improve and promote
periodontal health as part of oral health, general health and well-being.
Research of the last decades showed that smoking, stress, and an unhealthy diet
have a detrimental effect on the periodontal condition. Periodontitis patients
have lower plasma levels of vitamin C compared to healthy controls. In
addition, a correlation has been found between the level of vitamin C in the
diet and the level of vitamin C in plasma of healthy controls. In periodontitis
patients this correlation was not found. The studies by Van der Velden et al.
(2006) on the natural history of periodontitis in people living in Java, who
had no access to dental care are well known. In this population the severity of
periodontitis appeared to be related to the consumption of guava fruit. The
more guava fruits were consumed, the less the severity of periodontitis. Guava
fruit contains an extremely high concentration of vitamin C and in addition
many flavonoids, among others quercetin. Quercetin has a number of
characteristics that could explain the possible positive effect of guava fruit
on the periodontal condition. The initial periodontal treatment is the most
important therapy for our periodontal patients. It consist of supra- and
subgingival plaque and calculus removal as well as thorough oral hygiene
instruction. An additional aim in the treatment of periodontitis is improving
the host resistance. In this respect smoking cessation and reduction of stress
have been studied extensively. Also, a healthy diet consisting of fruits and
vegetables contributes to an improved host resistance. On the basis of the
above it may be suggested that vitamin C with or without quercetin
supplementation could improve the periodontal resistance and thereby the
results of periodontal therapy.

To evaluate the inflammatory reducing effect, in the periodontal tissues and
systemically, of vitamin C with quercetin and other flavonoids in untreated
periodontal disease.
Secondly to evaluate the effect of vitamin C with quercetin and other
flavonoids compared to vitamin C alone on periodontal and systemic parameters
as an adjunct to initial periodontal therapy.

A single blind parallel randomized controlled longitudinal study.

The intervention will be the daily intake of vitamin C with flavonoids
supplements (capsules) (test group 1), or vitamin C only supplements (capsules)
(test group 2), compared to a negative control group. This negative control
group will be provided with non-active fibers only (capsules). The intake of
the supplements will be as long as the total duration of the study i.e. 5
months.

After informed consent is obtained, participants do not recieve any periodontal
treatment yet. Two months is the typical duration of 'waiting time' between
intake and the first appointments. Two months after intake all groups will
receive initial periodontal therapy, which will be performed within 2 weeks.
During the following 3 months, all groups will continue with taking the
supplements. All groups will receive oral hygiene reinforcement during this
period. Evaluation measurements will be carried out at intake (T0), start of
initial therapy (T1) and 3 months (T2) after the last initial treatment
session.

All groups recieve the regular treatment as they would when not taking part in
the study. This initial treatment is in fact the treatment for which patients
are referred. This is not considered as a burden nor involves any risks. For
all groups there is no difference compared to this normal treatment. The only
extra burden is three times venous blood drawing, and the daily intake of
supplements. Intake of these supplements is not associated with any risks.