Article title : Periodontal regeneration –an analytical puzzle ?
Authors : Dr. Sumit Shende1, Dr. Salman Ansari2, Dr. Deepti Gattani3, Dr. Girish Bhutada4,
Dr. Sabahat Ansari5, Dr. Sanjana Jirafe6.
1,6- PG student, Department of Periodontology, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital, Nagpur.
2-Reader and Guide, Department of Periodontology, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital, Nagpur.
3-Professor and HOD, Department of Periodontology, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital, Nagpur.
4-Professor, Department of Periodontology, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital, Nagpur.
5-Dental practioner, MDS in Oral Medicine, Diagnosis and Radiology, Nagpur.
Corresponding author : Dr. Sumit Shende , Email id – .
Phone no. – 9665292327
Abstract :
Periodontal regeneration is a challenging scenario in periodontology. There are various factors which ultimately decides the prognosis and treatment outcome of periodontal regeneration. Periodontal regeneration is complex procedure which also depends on operator’s skills and materials which are used for regenerative procedure. Healing after periodontal regeneration and plaque control maintained by the patient are important in an order to obtain the success of periodontal regeneration. Hard tissue and soft tissue regenerative procedures involves the use of resorbable and nonresorbable membranes, bone grafts including autogenous bone grafts and allografts. Tooth and root anatomy and time needed for the periodontal regeneration are the other scenarios which have to be taken into consideration while doing periodontal regeneration.
Systemic conditions, growth factors and immune host response to periodontal treatment decides the relative outcome of periodontal regeneration. There are other factors like space provision, tissue occlusion and wound healing stability.Knowledge obtained from core principles that should guide us in the development of new therapeutic approaches to benefit our patients and, ultimately, our society. But still further research is needed on a large scale to overcome the difficulties and to avoid limiting factors which may affect the prognosis, treatment outcome, maintenance and ultimately success of periodontal regeneration.
Introduction :
Periodontitis is an infectious and multifactorial disease. Periodontitis if left untreated may lead to various problems such as increased attachment loss, severe bone loss, tooth mobility and finally leading to tooth loss. But to the knowledge provided, it has been said that periodontitis can be treated surgically and nonsurgicaly depending upon patient compliance, maintenance care and treatment therapy.
“Regeneration Is Something That Is Accompanied By God”
“A Dead Man Cannot Raise Himself from The Dead”
Periodontal regeneration surgical procedures are by definition, supposed to restore all three tooth supporting tissues i.e. periodontal ligament fibers, alveolar bone and the cementum. Periodontal tissue regeneration is very complex and elusive procedure including soft and hard tissue formation. There are various consequences of advanced periodontal diseases like rollercoaster soft- and hard-tissue anatomy; a barren landscape of gingival clefts and fissures; exposed root surfaces; loss of a keratinized attached gingiva; and alveolar valleys, ridges, craters, ravines and caves1. Regenerative procedures include use of autogenous bone grafts, synthetic bone grafts , resorbable and non resorbable membranes.
In perspective, periodontal regeneration remains a challenge. Periodontal regeneration includes complete regeneration of alveolar bone, cementum and soft tissues.There are various factors which should be undertaken into consideration such as materials used for periodontal regeneration, tooth and root anatomy, type of bone loss whether it is horizontal , angular or vertical bone loss, periodontal wound healing, growth and differentiation factors, systemic diseases and microorganisms.
We herein focus on critical issues related to periodontal wound healing ⁄ regeneration.
Factors affecting periodontal regeneration –
Historically, it is seen that debridement of periodontal defect, removal of polymicrobial biofilm and decontamination of root surfaces if done thoroughly ,then wound healing occurs to include some regeneration or remodeling of crestal alveolar bone.1,2 Bowers et al (1989) gives a study on periodontally compromised teeth by submerging them after an open flap debridement in combination or not with a demineralized bone matrix.The histological evaluation showed that periodontal regeneration was successful in submerged teeth and it fails in nonsubmerged teeth. The results obtained from this study showed that there is always innate regenerative potential responsible for periodontal regeneration.1
Innate regenerative potential:
Dickinson et al (2012)stated that there are local and systemic factors responsible for innate potential which is required for periodontal regeneration.3Various clinical and preclinical studies showed that the there are various conditions responsible for periodontal regeneration such as innate potential of the periodontal tissues, optimal conditions for wound healing, the site and specific patient characteristics and local and systemic factors. These factors always poses a problem for a clinician for success of periodontal regeneration.3
Postoperative healing outcomes :
After the periodontal surgical procedures, the epithelial cells of the gingival flap will migrate apically along the instrumented root surface, creating a long junctional epithelium precluding periodontal regeneration. Given the perception that epithelial cells proliferate at a higher rate than other cell populations in the periodontal wound, it would be inevitable that after just a few days a large proportion of the periodontal wound would be effectively blocked by epithelium.4
Techniques responsible for periodontal regeneration:
Alterations in flap design and repeat gingival curettage were among other protocols used to hinder the epithelial lining of the periodontal pocket. These procedures were eventually found not to support periodontal regeneration. There are various technique generally used for periodontal regeneration such as guided tissue regeneration using resorbable and non resorbable membranes and open flap debridement. Healing of resorbable and non resorbable membranes always poses a challenge, as after healing , there is apical migration of gingival epithelium which is the limiting factor in periodontal regeneration. In an order to prevent the apical migration of epithelium if the membranes are placed close to flap margin and occlusally, it will result in reduced nutritional supply to gingival tissues as well as there are chances of infection and wound dehiscence which will ultimately result in failure.4,5
Slow and time consuming procedure :
There is generalized concept based on the clinical and radiographic findings following surgical, nonsurgical and reconstructive periodontal therapy that periodontal regeneration is a slow and time consuming procedure.Dickinson et al, 2012using the critical size “supraalveolar periodontal defect model”, assessed early (2 and 5 days), intermediate (9 and 14 days) and late (4 and 8 weeks) healing events.4
Studies have assumed that cell activation in the periodontal ligament and alveolar bone was observed in the early phase upon clot formation.Periodontal regeneration occurs within weeks, whereas periodontal tissue maturation requires a longer time for completion.5
Biomaterials used for periodontal regeneration :
Biomaterials used for periodontal regeneration provides cell scaffolding as well as wound stability. Biomaterials could also serve as a matrix, or release active molecules and thus enhance the formation of new tissue. Studies indicate that most of the biomaterials currently used in periodontics remain sequestered in dense connective tissue without major evidence of active bone formation.Trombelli et al 2008 concluded that osteo obstruction is the main event in the use of biomaterials.Biomaterials like demineralized bone matrices provide biocompatibility along with osteoconductive and osteoinductive properties . But, at the same time, there is no such any miracle material which will give 100% results in periodontal regeneration.5,6,7
Continuing the theme of periodontal regeneration, Hynes et al present an outstanding summary of the state of the art in periodontal regeneration using stem cells. However, the most exciting development appears to be the research focussing on induced pluripotent stem cells, which are generated from somatic cells through the forced expression of key transcription factors, thereby negating the need to harvest stem cells from elsewhere. This offers huge potential for revolutionizing periodontal therapeutic strategies. There are clearly important questions still to be answered relating to the use of stem cells, however, such as ensuring that the correct cell type develops in the correct location and with appropriate anatomical orientation and correct physiological and homeostatic functions.7,8
Data obtained from various studies have shown that biomaterials which are currently being used for regeneration depends upon factors like donor age, variability in commercial preparations and particle size. In context, most of todays biomaterials will probably interfere with, rather than support, the wound-healing process. Potentially, biologic factors could be used to alleviate negative effects, while at the same time stimulate the migration and the proliferation of targeted periodontal cell populations.8,9
Tooth and root anatomy :
Tooth and root anatomy is one of the major factor in regeneration potential, factors like cervical-enamel projections, furcation areas,root convexities and concavities, developmental tooth anomalies are the limiting factors which may affect the prognosis and success rate of periodontal regeneration. Furcation areas are always difficult to access and for debridement and instrumentation which may affect the outcome of periodontal regeneration.6,7
Systemic factors :
Periodontal regeneration as it is contraindicated in systemic diseases like diabetes, HIV, hepatitis B, bronchial asthama. Systemic condition of the patient worsens the prognosis and treatment outcome in periodontal regeneration. Healing is compromised in systemic conditions which affects the prognosis. At the same time, as the innate regenerative potential of the body is also compromised and chances of postoperative infections are greater. Finally, treatment outcome is also compromised.8,9,10
Growth and differentiation factors :
Growth and differentiation factors may affect the role and treatment outcome of periodontal regeneration as well as controls the cell activity, chemo taxis and cell differentiation. Growth and differentiation factors used for periodontal regeneration are insulin-like growth factors, fibroblast growth factors, epidermal growth factor, platelet-derived growth factors, vascular endothelial growth factor, parathyroid hormone, transforming growth factor-b and bone morphogenetic proteins, recombinant DNA growth factors.Critical issues with the use of growth and differentiation factors are complexity of periodontium, enormous cost , high dose of bone morphogenetic proteins and non-availability of ideal carrier.A long history of preclinical evaluation with promising results, the routine use of growth factors as therapeutic agents for periodontal regeneration is not yet a reality.7,8
Other factors -
a.Space provision, wound stability and healing by primary intention are necessary, but not always sufficient, to achieve periodontal regeneration.
b.Periodontal wound-modification strategies should be a target at the early phase of wound healing.
c.Tissue occlusion promotes some additional periodontal regeneration but it also increases the likelihood of wound failure.
d.An ideal construct for periodontal wound healing ⁄ regeneration would encompass a combination of biologics with an ease-of-use, moldable, space-providing, biocompatible, bioadhesive, porous and biodegradable matrix for local applications.
Question arises , whether periodontal regeneration gives 100 % results or not ? Periodontal regeneration, as with most medical developments may evolve with time. New treatments, based on biological and ⁄ or clinical concepts, are developed. Knowledge obtained from core principles that should guide us in the development of new therapeutic approaches to benefit our patients and, ultimately, our society. But still further research is needed on a large scale to overcome the difficulties and to avoid limiting factors which may affect the prognosis , treatment outcome , maintenance and ultimately success of periodontal regeneration.9,10
While wound healing is largely a universal event, the compromised periodontium offers unique challenges. It is probably fair to say that when the profession embarked on this journey some three decades ago, most would have imagined that by now periodontal regenerative therapy would be an everyday activity. Perhaps the advent of oral implant osseointegration, in perspective an easier pursuit, somehow shifted our focus? Nevertheless, researchers and clinicians have never been better positioned to make clinically meaningful advances toward periodontal regeneration, an objective well worth pursuing.8,9
References :
- Bowers GM, Chadroff B, Carnevale R, Mellonig J, Corio R, Emerson J, Stevens M, Romberg E. Histologic evaluation of new attachment apparatus formation in humans. Part III. J Periodontol 1989: 60: 683–693.
- Bowers GM, Granet M, Stevens M, Emerson J, Corio R, Mellonig J, Lewis SB, Peltzman B, Romberg E, Risom L. Histologic evaluation of new attachment in humans. A preliminary report. J Periodontol 1985: 56: 381–396.
- Dickinson DP, Coleman BG, Batrice N, Lee J, Koli K, Pennington C, Susin C, Wikesjo ME. Events of wound healing ⁄ regeneration in the canine supraalveolar periodontal defect model. submitted. J Clin Periodontol 2012: doi: 10.1111/jcpe.12055.
- Froum S, Stahl SS. Human intraosseous healing responses to the placement of tricalcium phosphate ceramic implants. II. 13 to 18 months. J Periodontol 1987: 58: 103–109.
- Hiatt WH, Schallhorn RG. Intraoral transplants of cancellous bone and marrow in periodontal lesions. J Periodontol 1973: 44: 194–208.
- Schallhorn RG, Hiatt WH, Boyce W. Iliac transplants in periodontal therapy. J Periodontol 1970: 41: 566–580.
- Caton J, Nyman S, Zander H. Histometric evaluation of periodontal surgery. II. Connective tissue attachment levels after four regenerative procedures. J Clin Periodontol 1980: 7: 224–231.
- Dickinson DP, Coleman BG, Batrice N, Lee J, Koli K, Pennington C, Susin C, Wikesjo ME. Events of wound healing ⁄ regeneration in the canine supraalveolar periodontal defect model. J Clin Periodontol 2012: doi: 10.1111/jcpe.12055
- Karring T, Nyman S, Lindhe J. Healing following implantation of periodontitis affected roots into bone tissue. J Clin Periodontol 1980: 7: 96–105
- Nyman S, Gottlow J, Karring T, Lindhe J. The regenerative potential of the periodontal ligament. An experimental study in the monkey. J Clin Periodontol 1982: 9: 257–265.