The Adjunctive Role of Vitamin C on Pigment Recurrence (Randomized Clinical and Histological Trial)

The goal of this clinical trial is to determine the role of vitamin C on recurrence of gingival pigment after patients who are healthy and esthetically concerned with it received surgical removal of this pigment. The main question\[s\] it aims to answer are:

* Pigment recurrence after one year.
* Patient satisfaction and histological response of tissues.

Participants will be asked to come on regular follow up visits one group will receive vitamin C injection other will be asked to apply topical vitamin C on a specific regimen.

Researcher will compare the groups who received injectable vitamin C with those who topically applied it to see the effect of each.

Esthetic dentistry is currently concerned with the pivotal role of the gingival tissue along with the teeth color, shape and position to achieve a harmonious attractive smile.

Physiological gingival hyperpigmentation is attributed to the increased activity of melanocytes rather than the increased number; consequently the gingiva in these individuals reveals increased density of melanophores. There are several pigments that contribute to physiological gingival hyper pigmentation, the main contributory pigment is melanin that is synthesized by melanocytes. Melanocytes form melanosomes granules from the amino acid tyrosine converting it into a molecule called dehydroxyphenylalanine (DOPA) through a hydroxylation process catalyzed by tryosinase enzyme.

Surgical and non-surgical approaches have been utilized to treat gingival hyperpigmentation. De-epithelizing of the target region is the main concept for most of the surgical interventions using different techniques as de-epithelizing using surgical blade or bur abrasion, cryosurgery and laser.

Among the minimal invasive non-surgical approaches of treating gingival hyperpigmentation was vitamin C that yielded promising results in the previous few years as proved in different clinical trials and have been recently documented in systemic review by .Vitamin C binds to melanin effectively once introduced into the tissues with a consequent deficient in calcium and copper affecting both melanin formation and transportation.

One of the main challenges after treating gingival hyperpigmentation is pigment recurrence. Different theories tried to explain the reasons for recurrence, some attributed it to the three dimensional shape of rete pegs, others attributed it to the migration theory and capability of cells to migrate from existing neighboring areas . Recurrence of pigment had shown to be inevitable occurring with nearly equal ranges in the previously illustrated techniques.

Sheel et al illustrated no recurrence of gingival pigmentation was observed after 9 months follow up with the topical application of vitamin C after surgical gingival depigmentation in a case report. This case report highlighted the ancillary role of vitamin C in decreasing the recurrence rate of gingival pigment after depigmentation.

According to the researcher knowledge, up to this time, there were no further studies investigating the long-term effect of using vitamin C to gain gingival color stability after depigmentation. This study was conducted to compare efficacy of vitamin C either locally injected or topically applied after surgical gingival depigmentation on recurrence of pigment and patient satisfaction over one-year follow up.

Eligibility Criteria:
Inclusion Criteria:

Both genders aged from 18-40. Systemically free patients from any disease as evidenced by the health questionnaire, using modified Cornell medical index and classified as ASA class I.

Patients who were diagnosed to have physiological gingival melanin pigmentation on the maxillary or mandibular keratinized gingiva with Dummett oral pigmentation score 2 or more.

Patients with thick gingival phenotype ≥ 1.5 mm.

Exclusion criteria:

Pregnant or lactating females Smokers (water pipe, cigar or cigarette smoking). Patients taking or have taken any drug that may cause gingival depigmentation as chloroquine, minocycline, zidovudine, chlorpromazine, ketoconazole and bleomycin .

Any cause for supplemental intake of vitamin C. Reported allergy to ascorbic acid or to any of its derivatives as reported in health questionnaire .

Clinically diagnosed periodontitis regarding the following criteria probing depth \>3mm, clinical attachment loss ≥ 1mm and bleeding on probing \> 10% .

Patients with poor oral hygiene, incompliant to treatment and persistence gingival inflammation after phase I periodontal therapy.