|Year : 2011 | Volume
| Issue : 4 | Page : 338-343
Minimally invasive periodontal therapy
Department of Periodontology, Faculty of Dental Medicine, Witten/Herdecke University, Witten, Germany
|Date of Submission||19-Jun-2010|
|Date of Acceptance||09-Nov-2011|
|Date of Web Publication||2-Feb-2012|
Breite Strasse 94, 58452 Witten
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Minimally invasive dentistry is a concept that preserves dentition and supporting structures. However, minimally invasive procedures in periodontal treatment are supposed to be limited within periodontal surgery, the aim of which is to represent alternative approaches developed to allow less extensive manipulation of surrounding tissues than conventional procedures, while accomplishing the same objectives. In this review, the concept of minimally invasive periodontal surgery (MIPS) is firstly explained. An electronic search for all studies regarding efficacy and effectiveness of MIPS between 2001 and 2009 was conducted. For this purpose, suitable key words from Medical Subject Headings on PubMed were used to extract the required studies. All studies are demonstrated and important results are concluded. Preliminary data from case cohorts and from many studies reveal that the microsurgical access flap, in terms of MIPS, has a high potential to seal the healing wound from the contaminated oral environment by achieving and maintaining primary closure. Soft tissues are mostly preserved and minimal gingival recession is observed, an important feature to meet the demands of the patient and the clinician in the esthetic zone. However, although the potential efficacy of MIPS in the treatment of deep intrabony defects has been proved, larger studies are required to confirm and extend the reported positive preliminary outcomes.
Keywords: Intrabony defect, microsurgery, minimally invasive, periodontology
|How to cite this article:|
Dannan A. Minimally invasive periodontal therapy. J Indian Soc Periodontol 2011;15:338-43
| Introduction|| |
For the past 150 years, mortality and morbidity for all surgical operations have been tacitly accepted as unavoidable parts of the therapeutic process, but since the early 1980s it has become evident that less invasive methods of interventional treatment in some areas have produced far fewer complications with a reduced risk of death and morbidity.  This realization has given rise to the idea of minimally invasive (MI) treatment with its general aiming at minimizing the trauma of any interventional process but still achieve a satisfactory therapeutic result.  More and more surgical and radiologic procedures are being re-evaluated worldwide with a view to reducing operative trauma.
Recently, many new procedures have been developed as a result of technologic advances and fundamental changes in hospital design and surgical training. This enhanced the reality of minimally invasive procedures in medicine.
According to Medical Subject Headings (MeSH), minimally invasive procedures in medicine can be defined as those procedures that avoid use of open invasive surgery in favor of closed or local surgery. These generally involve use of laparoscopic devices and remote-control manipulation of instruments with indirect observation of the surgical field through an endoscope or similar device. With the reduced trauma associated with minimally invasive surgery, long hospital stays may be reduced with increased rates of short stay or day surgery.
Minimally invasive surgery should have less operative trauma for the patient than an equivalent invasive procedure. It may be more or less expensive. Operative time is longer, but hospitalization time is shorter. It causes less pain and scarring, speeds recovery, and reduces the incidence of postsurgical complications, such as adhesions.
In this review, the concept of minimally invasive dentistry and minimally invasive periodontal surgery (MIPS) is firstly explained. An electronic search for all studies regarding the efficacy and effectiveness of MIPS between 2001 and 2009 was conducted. All studies are demonstrated and important results are concluded.
| Minimally Invasive Dentistry|| |
Due to the advantages mentioned above, physicians attempted to perform more procedures as minimally invasive procedures.
Minimally invasive dentistry (MID) was defined as a concept that preserves dentition and supporting structures.  Examples of minimally invasive dental treatments are as follows:
- Sealants: Good application of sealants can prevent further cutting of tooth structure. Placement of sealants in suspect teeth within 6 months of tooth eruption is highly effective in preventing the need for future tooth restoration or potential tooth removal at a later time. 
- Mini-implants versus standard-size dental implants: Three general categories of implant diameters are available: The mini-implant (≈1.8 mm), the standard-sized implant (≈3.75 mm), and the wide-body implant (≈6.0 mm), with all sizes in between. Use of minidiameter implants is increasing, and more research publications and clinical technique articles about them are becoming available. ,, The results of using mini-implants in terms of MID would be more patients who would be served successfully at reduced cost with minimized pain and trauma.
- Placement of veneers instead of crowns: In many cases, full crowns can be avoided in the treatment plan and replaced by veneer placement. Here, teeth must be first acceptable in anatomy and occlusion.  Crowns are invasive. They hold a potential threat to tooth vitality. They require replacement after only a few years, and in most practices they seldom simulate natural teeth on a long-term basis.
- Digital radiography instead of conventional radiography: Digital radiography reduces the amount of radiation dental patients receive by at least 80%, with the obvious advantages of less cumulative radiation exposure during therapy. , Moreover, good quality can be obtained by means of this technique. 
It could be stated that in recent years there have been a number of technological advances in equipment and dental material, which have lead to enhancement of MID concepts. Specifically, advances in adhesive dentistry have made it possible to preserve more tooth structure by utilizing bonded restorations.
| Minimally Invasive Periodontal Therapy|| |
Periodontitis is mostly a chronic disease of the periodontal tissue, caused by pathogenic bacterial strains present in the dental plaque that induce an inflammatory response of the alveolar bone and soft periodontal tissue. The inflammation cascade causes breakdown of periodontal connective soft and hard tissue and represents an important cause of tooth loss. Regeneration of lost periodontal tissues has always been the ultimate goal of periodontal therapy.
Periodontal regeneration of intrabony defects has been achieved with different principles: These include barrier membranes, , demineralized freeze-dried bone allograft,  a combination of barrier membranes and grafts, , and enamel matrix derivative (EMD). , Data from controlled clinical trials and meta-analyses from systematic reviews demonstrate that those approaches provide added benefits in terms of clinical attachment level (CAL) gain and probing pocket depth reduction as compared with access flap alone. ,,,
In the last decade, a special emphasis has been focused on the design and performance of surgical procedures for periodontal regeneration. Specific surgical approaches have been proposed to preserve the soft tissues and to reach a stable primary closure of the wound in order to seal the area of regeneration from the oral environment. ,
In fact, flap dehiscence at regenerative sites is a frequent occurrence with barrier membranes, ,, bone grafts,  combination of barriers and grafts  and, to a lesser extent, with EMD. , Exposure and thus contamination of the regenerative material is a critical issue because it has been associated with reduced clinical outcomes. ,
Thus, in order to further increase surgical effectiveness, the use of operating microscopes and microsurgical instruments in terms of MIPS has been suggested, and the use of a microsurgical approach in combination with different regenerative materials resulted in maintenance of primary wound closure in more than 92% of the treated sites for the whole healing period. ,
We believe that the term "minimally invasive" in periodontal therapy is just limited within periodontal surgery. Therefore, the term MIPS as well as "periodontal microsurgery (PM)" can be frequently found in the literature rather than other less-descriptive terms (eg, minimally invasive periodontal treatment/therapy).
MIPS technique allows for minimization of soft tissue trauma and the removal of granulation tissue from periodontal defects using a much smaller surgical incision than that used in standard bone graft techniques.
Periodontal microsurgical techniques have been described by Tibbetts and Shanelec, , and have primarily concentrated on soft tissue regeneration and augmentation procedures where visualization is improved with the use of a surgical operating microscope with the aim to produce minimal wounds, minimal flap reflection, and gentle handling of the soft and hard tissues in periodontal surgery. Data from case reports showed clinical improvements in terms of pocket depth reduction, attachment level gain, and minimal increase of recession after application of MIPS in different types of defects. ,
An ideal site for bone grafting using MIPS is an isolated, usually interproximal, defect that does not extend significantly beyond the interproximal site.  MIPS may also suit a periodontal defect that borders on an edentulous area. A less ideal site for MIPS, but one where the technique can be used, is a defect that extends to the buccal and/or lingual from the interproximal area. 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. 
MIPS can be used for patients who have many isolated defects, so long as the incision at one site does not connect with the incisions at other sites to become a continuous incision.
| Features of Minimally Invasive Periodontal Surgery|| |
The incisions for MIPS are designed to conserve as much of the soft tissue as possible. Incisions used for an interproximal defect in the maxillary anterior, for example, must be firstly designed as intrasulcular incisions made on the teeth adjacent to the defect. These incisions should be made as separate incisions and should not be continuous across the interproximal tissue as in most other routine periodontal surgical procedures. By not making these incisions continuous, more of the interproximal papillary tissue and tissue height can be retained. The 2 intrasulcular incisions are connected with a single horizontal incision that is placed 2-3 mm from the crest of the papilla. When the surgery is being performed in an esthetic area, such as the maxillary anterior, this horizontal incision will usually be placed on the palatal aspect of the papilla. This will help to preserve the shape of the papilla as well as cover the grafted site with soft tissue. In a nonesthetic area, the horizontal incision can be placed either buccally or lingually as needed to better cover the grafted site with soft tissue.
The use of Tunnel Technique (TT) in periodontal surgery is considered an important element of MIPS.  This technique is originated primarily from the Envelope Technique (ET) developed by Raetzke in 1985 for the treatment of single gingival recessions.  In the TT, intrasulcular incisions are first initiated and then followed by supraperiosteal preparation of a tunnel through the defect areas. This will allow the transplantation of subepithelial connective tissue graft (SECTG) in the sulcular areas.
In terms of MIPS, and talking about SECTG, it is important to mention that the Single Incision Technique (SIT), described by Hurzeler and Weng,  for the extraction of SECTG from the palate, is more preferable than using Trap Door Incision Technique (TDIT).
In MIPS, the tissue is elevated utilizing sharp dissection only. This could be achieved by means of Orban knives that have been reshaped to one third to one fourth of their original size. The use of the small Orban knives will allow the blade to be placed into the previously made intrasulcular incision and, with the tip of the knife angled toward the center of the papilla, perform a thinning and undermining incision. The stiffness of the shaft of the Orban knife allows the papilla to be pulled to the buccal or lingual while the thinning incision is made. When blunt dissection has been used to elevate MIPS flaps, obvious blanching of the reflected tissue has been noted. This often leads to a darkened bruised appearance of the flap at the time of closure. When this bruised appearance is present, an increased incidence of postsurgical flattening of the papilla, interproximal cratering, and loss of soft tissue height is observed compared with when only sharp dissection has been used. It is supposed that the use of sharp dissection minimizes trauma to the flap and preserves much of the blood supply to the soft tissue. The lack of embarrassment of the blood supply to the flap is a probable reason for the improved soft tissue healing and the minimization of postoperative soft tissue changes that have been reported following the use of MIPS. 
It is always recommended to achieve the incisions for flap elevation in the form of "splitting," so that the periosteum tissue is left on the bone surface. By leaving the periosteum in its original position, a coronally tension-free reflection of the flap will be more possible, and moreover, less postsurgical bone loss and edema are to be expected. 
Specific surgical approaches have been reported to prevent or reduce an excessive apical displacement of the gingival margin in the treatment of periodontal defects.
Takei et al.  proposed a new surgical approach called the papilla preservation technique. The buccal aspect of the flap is designed with a sulcular incision around each tooth, with no incisions made through the interdental papilla. The lingual/palatal flap design consists of a sulcular incision along the lingual or palatal aspect of each tooth, with a semi-lunar incision across each interdental papilla. This incision dips apically from the line angles of the tooth so that the papillary incision line is at least 5 mm from the gingival margin. This allows the interdental tissue to be dissected from the lingual/palatal aspect so that it can be elevated intact with the facial flap. After treatment of the bony defect, the buccal flap, including the palatal/lingual aspect of the papilla, is repositioned. The palatal/lingual papilla is sutured with the palatal/lingual flap.
Cortellini et al.,  published a modification of Takei's technique as a new approach for interproximal regenerative procedures called (the modified papilla preservation technique).
A horizontal incision is performed on the buccal papillary tissue at the base of the papilla. A full-thickness palatal flap, which includes the interdental papilla, is elevated. A buccal full-thickness flap is elevated with vertical releasing incisions and/or periosteal incisions, when needed. A barrier membrane is positioned to cover the defect. The interdental tissues are repositioned and sutured to completely cover the membrane. A horizontal internal crossed mattress suture is placed beneath the mucoperiosteal flaps between the base of the palatal papilla and the buccal flap. This suture relieves all the tension of the flaps. A second suture (vertical internal mattress suture) is placed between the buccal aspect of the interproximal papilla and the most coronal portion of the buccal flap to ensure primary closure. This technique is applicable in wide interdental spaces (2 mm), especially in the anterior dentition. This technique allows for achieving primary closure of the tissue and preserving the papilla in 75% of cases.
Cortellini et al.  proposed the simplified papilla preservation flap (SPPF).
It is initiated with an oblique incision across the defect-associated papilla, from the gingival margin at the buccal line angle of the involved tooth to the midinterproximal portion of the papilla under the contact point of the adjacent tooth. A full-thickness palatal flap, including the papilla, and a split-thickness buccal flap are then elevated. The interdental tissues are positioned and sutured to obtain primary closure of the interdental space. The SPPF is applicable in narrow interdental spaces (2 mm).
It could be stated that the papilla preservation technique, the modified papilla preservation technique, and the simplified papilla preservation flap are important elements in terms of MIPS since they can guarantee minimal access to the periodontal defect.
An important element of MIPS is the use of suitable microsuturing.  This includes the materials to be used as well as the suturing technique itself.
From minimally invasive point of view, monofilament suturing materials are atraumatic, whereas polyfilament suturing materials may carry the "wicking-action" and therefore contribute to wound contamination from saliva. Histologic studies showed higher infiltration of inflammatory cells around polyfilament suturing materials when compared with monofilament suturing materials. , Those concepts should be taken into consideration when planning MIPS.
In the anterior areas, it is recommended to use the vertical matrix suture. In the premolar and/or molar areas, the use of modified matrix suture is a better choice. These techniques help removing the collapse of gingiva and enhancing optimal adaptation of wound edges. Continuous suturing may be achieved wherever releasing-incisions have been done. 
The use of microscope
Along with other advantages, the use of magnification and optimal illumination of the surgical field in MIPS greatly improves the visual acuity and the control of the surgical instruments, making it possible to perform surgery with reduced flap reflection. This could confer several potential advantages for the surgery, the healing process, and the patient's perception of the procedure. The surgery could be less invasive, shorter in time and less demanding, the healing process could be favored by the improved wound stability of minimally mobilized flaps, and the patients could benefit from a procedure with potentially reduced intraoperative and postoperative morbidity.
However, while a surgical microscope can be used for magnification, the present configuration of these microscopes makes their use troublesome.  During MIPS, it is often necessary to visualize the defect from several angles to verify the debridement areas of the osseous defect or the root surfaces. It is difficult to move a surgical microscope from one visualization angle to another rapidly. We believe that the easiest method to achieve a good magnification of the surgical field is a head-banded microscope, which could be placed on the head of the surgeon and can be easily directed during surgery. An appropriate lightening can be also added to the head-band.
In order to guarantee atraumatic surgical approach in the MIPS, the use of miniaturized operation instruments is considered to be of great importance. 
Generally, a useful microsurgical tray for the routine use in MIPS should include: (1) microraspatorium, (2) bone scraper, (3) papilla elevatorium, (4) microscalpel holder, (5) needle holder, (6) microscissor, and (7) a dental microforceps.
Efficacy, effectiveness, and disadvantages of MIPS
An electronic search for all studies regarding efficacy and effectiveness of MIPS between 2001 and 2009 was conducted. For this purpose, suitable key words from MeSH on PubMed were used to extract the required studies. All studies are demonstrated and important results are concluded.
In 2001, Cortellini and Tonetti  preliminarily evaluated the outcomes of a microsurgical approach in the regenerative therapy of deep intrabony defects in a case cohort of 26 patients by means of guided tissue regeneration membranes. Closure was achieved in all treated defects and was maintained in 92.3% of cases for the entire healing period. Associated gains in CAL were 5.4 mm on average, corresponding to a CAL gain of 82.8% of the initial intrabony component of the defect. The procedure resulted in clinically important amounts of CAL gains and minimal recessions.
Wachtel et al.  assessed the clinical effect of the microsurgical access flap and EMD treatment with an emphasis on the evaluation of early wound healing in 11 patients. Both test and control treatment resulted in a statistically significant mean CAL gain of 2.8 and 2.0 mm at 6 months, and 3.6 and 1.7 mm at 12 months, respectively. Two weeks after surgery, primary closure was maintained in 89% of the test sites and in 96% of the control sites. In terms of probing pocket depth reduction and CAL gain, the combination with EMD application appeared to be superior to the microsurgical access flap alone.
Harrel et al.  showed CAL gains of 4.05 mm following application of MIPS and EMD in 16 patients presenting multiple sites with deep pockets associated with different defect morphologies, including furcation involvements.
Bokan et al.,  conducted a study to compare the 12-month clinical results of two regenerative treatment methods using either Emdogain® alone or Emdogain® in combination with Cerasorb® with the results of conventional flap surgery. Both EMD treatments showed similar clinical effects, with significant probing attachment level gain and a significantly lower recession increase in comparison with conventional surgical treatment. It was suggested that the microsurgical access flap, in terms of MIPS, might have both influenced treatment outcomes in this study in favor of Emdogain® -treated groups, yielding similar results in both Emdogain® -treated groups.
Cortellini and Tonetti  described and evaluated preliminarily the clinical performance and patient perception of MIPS associated with the application of EMD in the treatment of isolated deep intrabony defects in 13 patients. The preliminary case cohort resulted in a CAL gain of 4.8-1.9 mm and an 88.7-20.7% fill of the intrabony component of the defects at 1 year. Besides a decrease in the surgical time, there were indications of a decrease in patient morbidity as the postoperative period was uneventful for 77% of the patients. It has been indicated that MIPS associated with EMD resulted in excellent clinical improvements while limiting patient morbidity.
Similarly, Cortellini et al.  conducted a case cohort study to evaluate the clinical performance and the intraoperative and postoperative morbidity of MIPS associated with the application of an EMD in the treatment of multiple deep intrabony defects in a single surgical procedure. The 1-year CAL gain was 4.4-1.4 mm. Seventy-three percent of defects showed CAL improvements ≥4 mm. Residual probing pocket depths (PDs) were 2.5 ± 0.6 mm. A minimal increase of 0.2 ± 0.6 mm in gingival recession between baseline and 1 year was recorded. Twelve patients reported a mild perception of the hardship of the surgical procedure. Primary closure was obtained and maintained in all treated sites over time. Only 6 subjects reported moderate postoperative pain that lasted for 21 ± 5 h.
Jepsen et al.  compared the outcomes of a combination of an EMD and a synthetic bone graft (EMD/SBC) with EMD alone in wide intrabony defects by means of MIPS. In this study, both treatment modalities led to significant clinical improvements. Change in bone fill 6 months after surgery was 2.0 mm in the test group and 2.1 mm in the control group. No differences in patients' perceptions were found.
More recently, Cortellini and Tonetti described a modified surgical approach of the minimally invasive surgical technique (modified minimally invasive surgical technique, M-MIST) to evaluate its applicability and clinical performances in the treatment of isolated deep intrabony defects in combination with amelogenins.  The M-MIST consisted of a buccal incision of the defect-associated papilla, according to the principles of the papilla preservation techniques. Only a buccal flap was raised while the interdental papilla was left in situ. The granulation tissue filling the defect was dissected and removed, leaving the interdental and palatal tissues untouched. Root instrumentation and application of the regenerative material were performed before suturing. Primary closure of the flaps was attained with a single internal modified mattress suture. Surgery was performed with the aid of an operating microscope and microsurgical instruments. In summary, M-MIST associated with EMD resulted in improved clinical outcomes with no or minimal patient morbidity. It was easily applicable to isolated interproximal intrabony defects with a prevalent interdental component with no or minimal involvement of the lingual/palatal side. It seems to be that MIPS significantly enhances the clinical outcomes of periodontal treatment.
Disadvantages of MIPS are probably similar to those related to any MIST in the medical field.
According to Jaffray,  disadvantages of minimally invasive surgery, in general, are related to the fact that
- it requires special equipment,
- specialist training is probably required,
- some additional equipments could be more expensive, and
- some procedures may take longer than usual, compared with conventional surgeries.
Thus, although techniques of MIPS may encounter further advantages, other disadvantages of such methods should also be taken into consideration.
| Conclusion|| |
Applying microsurgical concepts in the field of periodontal surgery is found to be of great importance.
The main objectives of MIPS are the following:
(1) reduce surgical trauma, (2) increase flap/wound stability, (3) allow stable primary closure of the wound, (4) reduce surgical chair time, and (5) minimize patient discomfort and side effects.
While many studies did assure the effectiveness of MIPS by the enhancement of clinical parameters and reducing patient morbidity, there is still a need to confirm the effectiveness of such techniques in periodontal surgery when compared with other traditional ones.
| References|| |
|1.||Wickham J. Endoscopic surgery. Br Med Bull 1986;42:221-339. |
|2.||Wickham J. Minimally invasive therapy. Health Trends 1991;23:6-9. |
|3.||Christensen GJ. The advantages of minimally invasive dentistry. J Am Dent Assoc 2005;136:1563-5. |
|4.||Beauchamp J, Caufield PW, Crall JJ, Donly K, Feigal R, Gooch B, et al. Evidence-based clinical recommendations for the use of pit-and-fissure sealants: A report of the American Dental Association Council on Scientific Affairs. J Am Dent Assoc 2008;139:257-68. |
|5.||Christensen GJ. Critical appraisal: Mini implants: Good or bad for long-term service? J Esthet Restor Dent 2008;20:343-8. |
|6.||Chaddad K, Ferreira AF, Geurs N, Reddy MS. Influence of surface characteristics on survival rates of mini-implants. Angle Orthod 2008;78:107-13. |
|7.||Baek SH, Kim BM, Kyung SH, Lim JK, Kim YH. Success rate and risk factors associated with mini-implants reinstalled in the maxilla. Angle Orthod 2008;78:895-901. |
|8.||Christensen GJ. What is a veneer? Resolving the confusion. J Am Dent Assoc 2004;135:1574-6. |
|9.||Brennan J. An introduction to digital radiography in dentistry. J Orthod 2002;29:66-9. |
|10.||Christensen GJ. Why switch to digital radiography? J Am Dent Assoc 2004;135:1437-9. |
|11.||Wang FQ, Huang W, Qin YL, Qin XD, Jiang YF, Tu XN, et al. Evaluation of direct digital radiography image quality in dentistry. Shanghai Kou Qiang Yi Xue 2008;17:552-4. |
|12.||Gottlow J, Nyman S, Lindhe J, Karring T, Wennstrom J. New attachment formation in the human periodontium by guided tissue regeneration: Case reports. J Clin Periodontol 1986;13:604-16. |
|13.||Nyman S, Lindhe J, Karring T, Rylander H. New attachment following surgical treatment of human periodontal disease. J Clin Periodontol 1982;9:290-6. |
|14.||Bowers GM, Chadroff B, Carnevale R, Mellonig J, Corio R, Emerson J, et al. Histologic evaluation of new attachment apparatus formation in humans: Part II. J Periodontol 1989;60:675-82. |
|15.||Camelo M, Nevins ML, Schenk RK, Simion M, Rasperini G, Lynch SE, et al. Clinical, radiographic, and histologic evaluation of human periodontal defects treated with Bio-Oss and Bio-Gide. Int J Periodontics Restorative Dent 1998;18:321-31. |
|16.||Mellonig JT. Human histologic evaluation of a bovine-derived bone xenograft in the treatment of periodontal osseous defects. Int J Periodontics Restorative Dent 2000;20:19-29. |
|17.||Mellonig JT. Enamel matrix derivative for periodontal reconstructive surgery: Technique and clinical and histologic case report. Int J Periodontics Restorative Dent 1999;19:8-19. |
|18.||Yukna RA, Mellonig JT. Histologic evaluation of periodontal healing in humans following regenerative therapy with enamel matrix derivative: A 10-case series. J Periodontol 2000;71:752-9. |
|19.||Murphy KG, Gunsolley JC. Guided tissue regeneration for the treatment of periodontal intrabony and furcation defects: A systematic review. Ann Periodontol 2003;8:266-302. |
|20.||Needleman I, Tucker R, Giedrys-Leeper E, Worthington H. Guided tissue regeneration for periodontal intrabony defects: A Cochrane Systematic Review. Periodontol 2000 2005;37:106-23. |
|21.||Tonetti MS, Fourmousis I, Suvan J, Cortellini P, Bragger U, Lang NP. Healing, post-operative morbidity and patient perception of outcomes following regenerative therapy of deep intrabony defects. J Clin Periodontol 2004;31:1092-8. |
|22.||Trombelli L, Heitz-Mayfield LJ, Needleman I, Moles D, Scabbia A. A systematic review of graft materials and biological agents for periodontal intraosseous defects. J Clin Periodontol 2002;29(Suppl 3):117-35; discussion 60-2. |
|23.||Cortellini P, Prato GP, Tonetti MS. The modified papilla preservation technique. A new surgical approach for interproximal regenerative procedures. J Periodontol 1995;66:261-6. |
|24.||Cortellini P, Prato GP, Tonetti MS. The simplified papilla preservation flap: A novel surgical approach for the management of soft tissues in regenerative procedures. Int J Periodontics Restorative Dent 1999;19:589-99. |
|25.||Cortellini P, Pini Prato G, Tonetti MS. Periodontal regeneration of human infrabony defects, II: Re-entry procedures and bone measures. J Periodontol 1993;64:261-8. |
|26.||Cortellini P, Tonetti MS, Lang NP, Suvan JE, Zucchelli G, Vangsted T, et al. The simplified papilla preservation flap in the regenerative treatment of deep intrabony defects: Clinical outcomes and postoperative morbidity. J Periodontol 2001;72:1702-12. |
|27.||Tonetti MS, Cortellini P, Suvan JE, Adriaens P, Baldi C, Dubravec D, et al. Generalizability of the added benefits of guided tissue regeneration in the treatment of deep intrabony defects: Evaluation in a multi-center randomized controlled clinical trial. J Periodontol 1998;69:1183-92. |
|28.||Sanders JJ, Sepe WW, Bowers GM, Koch RW, Williams JE, Lekas JS, et al. Clinical evaluation of freeze-dried bone allografts in periodontal osseous defects, Part III: Composite freeze-dried bone allografts with and without autogenous bone grafts. J Periodontol 1983;54:1-8. |
|29.||Tonetti MS, Cortellini P, Lang NP, Suvan JE, Adriaens P, Dubravec D, et al. Clinical outcomes following treatment of human intrabony defects with GTR/bone replacement material or access flap alone: A multicenter randomized controlled clinical trial. J Clin Periodontol 2004;31:770-6. |
|30.||Sanz M, Tonetti MS, Zabalegui I, Sicilia A, Blanco J, Rebelo H, et al. Treatment of intrabony defects with enamel matrix proteins or barrier membranes: Results from a multicenter practice-based clinical trial. J Periodontol 2004;75:726-33. |
|31.||Tonetti MS, Lang NP, Cortellini P, Suvan JE, Adriaens P, Dubravec D, et al. Enamel matrix proteins in the regenerative therapy of deep intrabony defects. J Clin Periodontol 2002;29:317-25. |
|32.||De Sanctis M, Zucchelli G, Clauser C. Bacterial colonization of barrier material and periodontal regeneration. J Clin Periodontol 1996;23:1039-46. |
|33.||Nowzari H, Matian F, Slots J. Periodontal pathogens on polytetrafluoroethylene membrane for guided tissue regeneration inhibit healing. J Clin Periodontol 1995;22:469-74. |
|34.||Cortellini P, Tonetti MS. Microsurgical approach to periodontal regeneration: Initial evaluation in a case cohort. J Periodontol 2001;72:559-69. |
|35.||Cortellini P, Tonetti MS. Clinical performance of a regenerative strategy for intrabony defects: Scientific evidence and clinical experience. J Periodontol 2005;76:341-50. |
|36.||Tibbetts LS, Shanelec D. Periodontal microsurgery. Dent Clin North Am 1998;42:339-59. |
|37.||Tibbetts LS, Shanelec DA. An overview of periodontal microsurgery. Curr Opin Periodontol 1994. p. 187-93. |
|38.||Harrel SK. A minimally invasive surgical approach for periodontal bone grafting. Int J Periodontics Restorative Dent 1998;18:161-9. |
|39.||Harrel SK, Nunn ME. Longitudinal comparison of the periodontal status of patients with moderate to severe periodontal disease receiving no treatment, non-surgical treatment, and surgical treatment utilizing individual sites for analysis. J Periodontol 2001;72:1509-19. |
|40.||Harrel SK. A minimally invasive surgical approach for periodontal regeneration: Surgical technique and observations. J Periodontol 1999;70:1547-57. |
|41.||Allen EP. Advances in mucogingival surgery. Tex Dent J 1984;101:26-30. |
|42.||Raetzke PB. Covering localized areas of root exposure employing the "envelope" technique. J Periodontol 1985;56:397-402. |
|43.||Hurzeler MB, Weng D. A single-incision technique to harvest subepithelial connective tissue grafts from the palate. Int J Periodontics Restorative Dent 1999;19:279-87. |
|44.||Gassmann G, Grimm WD. Minimal-invasive regenerative und plastisch-rekonstruktive Parodontalchirurgie. Dent Implant Parodontol 2006;10:90-7. |
|45.||Takei HH, Han TJ, Carranza FA Jr, Kenney EB, Lekovic V. Flap technique for periodontal bone implants: Papilla preservation technique. J Periodontol 1985;56:204-10. |
|46.||Leknes KN, Roynstrand IT, Selvig KA. Human gingival tissue reactions to silk and expanded polytetrafluoroethylene sutures. J Periodontol 2005;76:34-42. |
|47.||Selvig KA, Biagiotti GR, Leknes KN, Wikesjo UM. Oral tissue reactions to suture materials. Int J Periodontics Restorative Dent 1998;18:474-87. |
|48.||Wachtel H, Schenk G, Bohm S, Weng D, Zuhr O, Hurzeler MB. Microsurgical access flap and enamel matrix derivative for the treatment of periodontal intrabony defects: A controlled clinical study. J Clin Periodontol 2003;30:496-504. |
|49.||Harrel SK, Wilson TG, Nunn ME. Prospective assessment of the use of enamel matrix proteins with minimally invasive surgery. J Periodontol 2005;76:380-4. |
|50.||Bokan I, Bill JS, Schlagenhauf U. Primary flap closure combined with Emdogain alone or Emdogain and Cerasorb in the treatment of intra-bony defects. J Clin Periodontol 2006;33:885-93. |
|51.||Cortellini P, Tonetti MS. A minimally invasive surgical technique with an enamel matrix derivative in the regenerative treatment of intra-bony defects: A novel approach to limit morbidity. J Clin Periodontol 2007;34:87-93. |
|52.||Cortellini P, Nieri M, Prato GP, Tonetti MS. Single minimally invasive surgical technique with an enamel matrix derivative to treat multiple adjacent intra-bony defects: Clinical outcomes and patient morbidity. J Clin Periodontol 2008;35:605-13. |
|53.||Jepsen S, Topoll H, Rengers H, Heinz B, Teich M, Hoffmann T, et al. Clinical outcomes after treatment of intra-bony defects with an EMD/synthetic bone graft or EMD alone: A multicentre randomized-controlled clinical trial. J Clin Periodontol 2008;35:420-8. |
|54.||Cortellini P, Tonetti MS. Improved wound stability with a modified minimally invasive surgical technique in the regenerative treatment of isolated interdental intrabony defects. J Clin Periodontol 2009;36:157-63. |
|55.||Jaffray B. Minimally invasive surgery. Arch Dis Child 2005;90:537-42. |