|Year : 2016 | Volume
| Issue : 2 | Page : 56-59
Minimally invasive techniques for regenerative therapy
Ruchi Banthia, Manasi Dongre, Ruhi Ritika, Priyank Banthia
Department of Periodontics, Modern Dental College and Research Centre, Indore, Madhya Pradesh, India
|Date of Web Publication||5-Jan-2017|
Department of Periodontics, Modern Dental College and Research Centre, Indore, Madhya Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Patient-related outcomes are one of the primary concerns in the selection of periodontal surgical procedure. The need of less invasive and patient-friendly surgical procedures has led to invent of the concept of "minimally surgical techniques." These surgeries aim to produce minimal flap reflection, small wounds, and gentle handling of soft tissues. This review summarizes the rationale, indications, contraindications, and technique of various minimally invasive periodontal surgical procedures.
Clinical Relevance To Interdisciplinary Dentistry
Minimally invasive surgical techniques tend to enhance the outcome of periodontal regenerative procedures. As predictability of various restorative, orthodontic treatments as well as implants depend on successful regenerative therapy, minimally invasive surgery is an important step to achieve this goal.
Keywords: Microsurgery, minimally invasive periodontal surgery, papilla preservation technique, regenerative therapy, single tooth flap
|How to cite this article:|
Banthia R, Dongre M, Ritika R, Banthia P. Minimally invasive techniques for regenerative therapy. J Interdiscip Dentistry 2016;6:56-9
| Introduction|| |
Change is the only thing that is constant. The same holds true for periodontal surgical procedures. With the advent of new technologies and armamentarium over the years, periodontal surgery has undergone radical changes from pocket elimination to pocket reduction and now trending toward the era of regeneration. The renaissance in ideology further adds to the effect. The surgeons are now interested in more user-friendly, less invasive, esthetically favorable patient-oriented surgeries as they now aim at/prioritize patient comfort, satisfaction, and patient-centered outcomes. The concept of "extension for prevention" has now changed to "conserve to preserve."
The concept of "minimally invasive surgery (MIS)" is one such peculiar and innovative approach which aims to produce minimal wounds, minimal flap reflection, and gentle handling of the soft and hard tissues (Harrel et al. 2005). Wickham and Filtz described the techniques of using smaller incisions as "MIS" which were later defined by medical subject headings as those procedures that avoid the use of open invasive surgery in favor of closed or local surgery. Hunter and Sackier described the same as "the ability to minimaturize our eyes and extend our hands to perform microscopic and macroscopic operations in places that could previously be reached only by large incisions." 
MIS was first introduced into the periodontal field with intent to treat multiple and isolated periodontal intrabony defects in 1995. The use of microscope in periodontal surgeries for better visualization during manipulation and suturing of soft tissues was introduced by Tibbetts and Shanelec.  The techniques were then called as "periodontal microsurgeries" mainly to address the techniques aided by a specific technology such as microscopes.
A broader term "minimally invasive periodontal surgery" (MIPS) was introduced later to describe the smaller more precise surgical techniques that are possible through the use of operating microscopes and other technologies that are beginning to be available for the use in periodontal surgery.
This review focuses on various minimal invasive surgical techniques by critically evaluating their scope and limitations.
These include the gingival papilla preservation techniques which have been further modified lately so as to involve only buccal flap. Single flap approach, a novel simplified minimally invasive procedure was proposed so that unilateral mucoperiosteal flap could be elevated to retain intact adjoining soft tissues.
| Rationale And Objectives Of Minimally Invasive Surgery In Periodontal Regeneration|| |
Achieving primary closure
Two factors determine the successful outcome of periodontal reconstruction procedures:
- To eliminate or to a great extent, reduce the chances of postsurgical infection and contamination of blood clot, and possibly, the implanted biomaterial or biologic agent, which would unavoidably lead to impaired healing outcome
- To minimize the postoperative soft-tissue recession on the interproximal and buccal aspects of the treated tooth, with the result of compromising the preexisting esthetic appearance of the patient. In addition to esthetic impairments, loss of the interdental papilla may result in phonetic problems and food impaction Keeping this in mind, new surgical techniques, especially designed to optimize primary closure as well as functional and esthetic outcomes of reconstructive procedures, have been developed. Because conventional access flap surgery with reconstructive procedures namely guided tissue regeneration (GTR) may lead to a lack of primary closure of interdental space, flap dehiscence or membrane exposure may occur in 70%-80% of treated sites.
Minimum tissue manipulation
Minimally invasive surgical technique (MIST) also helps in reduction of the mesiodistal extension of the flap through elevation of only papilla overlying the intraosseous defect.
Improving regenerative potential
Success of periodontal regeneration mainly depends on utilizing the innate reference potential of local tissue as well as wound stabilization achieved by primary intention.
Various wound modification technologies using various biomaterials might find the osteogenic potential of periodontal tissues by causing osteo-obstructive effect.  Therefore, the advent of new surgical technology affecting flap designs as well as utilizing the innate potential of the tissues is need of the hour.
MIS seems to achieve primary intention healing as well as provides pro-regenerative conditions rendering additional protocols unnecessary (Liu, Trombelli, Cortellini). In 2009, Cortellini and Tonetti  preliminarily evaluated the outcomes of a microsurgical approach in the regenerative therapy of deep intrabony defects by means of GTR membranes. Closure was achieved in all treated defects and was maintained in 92.3% of cases for the entire healing period. The procedure resulted in clinically important amounts of CAL gains and minimal recessions.
| Indications|| |
- An ideal site for bone grafting using MIPS is an ISOLATED, usually interproximal defect that does not extend significantly beyond interproximal site. Steffer et al.  concluded that MIPS provides comparable outcome as the conventional surgery in the management of intrabony periodontal defects
- Less than ideal site is a defect that extends to buccal and/or lingual from interproximal area
- Defects that border on an edentulous area
- MIPS can be used for patients who have many isolated defects, so long as the incision at one site does not connect with incisions at other sites to become a continuous incision.
| Contraindications|| |
Generalized horizontal bone loss or multiple interconnected vertical defects are thought to be contraindicated for MIPS and are best handled with more traditional surgical approaches. 
| Advantages|| |
- MIPS has a high potential for achieving and maintaining primary closure leading to less contamination from oral environment 
- Soft-tissue height and contour are mostly preserved leading to minimal gingival recession meeting the demands of patients and clinician in the esthetic zone. These distinguishing features of MIS might be attributed to decreased tissue manipulation, lessened overall trauma, and enhanced blood supply to the surgical sites ,
- This technique allows for minimization of soft-tissue trauma and removal of granulation tissue using much smaller surgical incision than standard surgical procedure 
- Gentle handling of tissue leads to less postsurgical complications such as pain, swelling, and flap dehiscence. Perumal et al. (2015)  concluded that in open flap debridement, a microsurgical flap approach can substantially improve early healing and include less postoperative pain as compared to macroscopic approach. Lack of embarrassment of blood supply to the flap is the reason for improved soft-tissue healing
- Uninvolved areas can be spared by decreasing surgical area span. 
| Disadvantages|| |
According to Jaffray, disadvantages of MIS, in general, are related to the fact that it requires special expensive equipment and training, slightly longer duration. Resistance to newer techniques has also been a disadvantage which can be attributed to normal human behavior. 
| Armamentarium|| |
Principles of microsurgery are based on three essential components forming the triad of microsurgery. These include magnification, illumination, and instruments. 
The most popular MIS techniques are as follows:
Conventional papilla preservation flap 
Takei et al. introduced this technique to keep the papilla intact in areas with more than 3 mm interdental spaces. This method uses sulcular incisions around each tooth with no incision being made through the interdental papilla facially, but the lingual/palatal flap involves a sulcular incision along each tooth with a semilunar incision made across each interdental papilla that dips apically from the line angles of the tooth so that the papillary incision line angle is at least 5 mm from the gingival margin allowing the interdental tissues to be dissected from the lingual or palatal aspect so that it can be elevated intact with facial flap. 
Modified papilla preservation flap 
Cortellini et al. proposed this design as a modification of conventional papilla preservation flap. It was popularized by Cortellini as MIST. A horizontal incision is traced in the buccal gingiva of the interdental space at the base of the papilla, and the papilla is elevated toward the palatal aspect. It is mostly suitable for thick interdental papilla in wide interdental spaces. 
Simplified papilla preservation flap (modified minimally invasive surgical technique ) 
Cortellini further modified the above technique so that it was suitable for narrow interdental spaces (≤2 mm). An oblique incision instead of horizontal incision is traced across the buccal aspect of the interdental papilla, and the papilla is elevated toward the palatal aspect. 
Single incision to harvest subepithelial and de-epithelized connective tissue graft 
This is a technique to harvest connective tissue graft. It uses only one incision placed at 90° to the bone with no epithelium removed facilitating the readaptation of the separated tissue. 
Pinhole surgical technique 
Chao designed pinhole surgical technique to overcome the problems associated with conventional periodontal plastic surgical procedures such as the need of releasing incisions, coronal approach for the entry incision, elevation of flap, and graft placement. A minimal horizontal incision of 2-3 mm is made in the alveolar mucosa near the base of the vestibule, apical to the recipient site(s). A full-thickness flap is raised which is extended coronally and horizontally such that four papillae are involved. Suture is not required at the entry incision. 
Buttonhole technique 
This technique is used for correction of mild ridge deficiencies in sites of implant or tooth-supported fixed partial dentures. This leads to reduced flap tension allowing for more precise primary incision closure and lesser vestibular extension. 
Single tooth flap technique 
Single tooth flap approach consists of a mucoperiosteal flap elevated on one side (buccal or oral), leaving the soft tissues on the opposite side intact. It is indicated in intraosseous defects involving the interproximal aspect and exhibiting limited to no extension on the lateral/palatal side. 
Tunnel technique 
The procedure aims at creating a multi-envelope supraperiosteal bed for the placement of connective tissue graft under a pedicle flap without any external incision. 
Flapless punch approach for socket preservation 
This technique is preferred in areas with insufficient amounts of keratinized tissue. The rationale for flapless approach is to isolate implant and/or grafted socket from oral cavity obtaining an inclusive GBR effect while preserving circulation and esthetic soft-tissue contours. 
Indirect sinus lift procedure for sinus augmentation 
The technique involves 1-3 mm wide osteotomy site, minimal instrumentation with closed graft thereby requiring less time and expertise. However, there is more probability of error with this technique as it is a blunt procedure, and the sinus is not exposed. 
| Conclusion|| |
Although the periodontal microsurgery (MIS) was introduced in the field of periodontics as a part of pushback technology adopted from the medical practice, these techniques have appear promising in having a clear-cut advantage over conventional methods in terms of more patient acceptance and improved regenerative outcomes. In spite of obvious advantages of the new techniques, there still exists ambivalence to the acceptance of these as routine procedure. Deficient literature related to these techniques might deter clinicians from adapting these techniques; time is not far when these techniques will become an inseparable part of periodontal surgical practice.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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