The wounds of the oral environment are regularly contaminated with saliva as well as food, exacerbated by movements of cheek and tongue. Previous studies have reported that frequency of infection and contracture degree are extensively decreased when wounds are covered as opposed to left uncovered. Studies have reported that dressings make a physiological interface between wound surface and environment, thus permitting repair [2, 7].

Efforts are continuously being made to develop newer treatment methods that are less invasive with minimal side effects. Our study evaluated two modalities in reconstruction of oral cavity post-operative defects: collagen, used as reconstruction material to cover the surgical wound, and platelet-derived growth factor which enhances wound healing. As an alternative material to mucosal or skin grafts, collagen can be used to cover surgical defects intraorally. Since collagen is an actual component of the skin, it has beneficial effect throughout the wound healing process. As compared to tissue grafts, collagen membrane is easily available commercially and hence obviates the need for a second surgery for graft harvesting and its associated morbidity [2, 3, 8].

Many studies have focused on methods to improve healing in oral cavity defects, and there is an increasing interest in growth factor to aid this process. PDGF-BB is a blood product containing a lot of growth factors which do not have side effects. It helps in cell proliferation, differentiation, chemotaxis and matrix synthesis. Its effects are important in the initial phases of healing and tissue regeneration [5, 6].

Collagen is a very efficient haemostatic agent. The platelets adhere to collagen, followed by swelling and release of substances that initiate haemostasis. Our study noted good haemostasis in 25 out of 30 (83.3%) patients and fair in five patients (16.7%) [9].

Collagen provides coverage for open nerve endings and hence diminishes the intensity of pain when used over raw wounds. However, some degree of pain can be present post-surgery which is usually attributable to post-surgical traumatic inflammation. Our study showed good pain relief in 18 cases (60%) and fair in 12 cases (40%) [3].

Although collagen can undergo collagenolysis, collagen membranes are robust enough to allow formation of granulation tissue, which appeared uniform and clinically healthy. Our study showed good granulation formation in 16 cases (53.35%) and fair in 14 cases (46.65%) two weeks post-operatively [2, 10].

Collagen triggers the adhesiveness of platelets and stimulates the release phenomenon, leading to aggregation of nearby platelets. The collagen membrane can achieve early epithelisation. The same was noted in our study with good epithelialisation in 19 cases (63.35%) and fair in 11 cases (36.65%) [11].

Scar contracture can be prevented by controlling infection and accelerated re-epithelialisation of wound, and it can be fulfilled with the help of collagen and rhPDGF-BB. In our study, we had with 23 cases with good contracture and 7 with fair contracture.

We also tried to assess the role of rhPDGF-BB when used along with collagen grafting. We noticed that patients in group I who underwent collagen grafting along with rnPDGF had better granulation tissue response, better epithelialisation and lesser tissue contracture in comparison with group II, although this was not statistically significant (p value = 0.464, 0.705 and 1.000, respectively). Haemostasis and post-operative pain were similar among both the groups.

The use of collagen as a wound dressing material was shown to be benefical in all aspects of wound healing in our study similar to what has been noted in previous studies. Although augmentation with rhPDGF was associated with better granulation tissue response, epithelialisation and lesser scar contracture, the results were not statistically significant compared to grafting with collagen alone. This could probably be attributed to the relatively small sample size, and hence, the authors recommend further studies in larger size sample to observe the effects.