Periodontal Surgery PDF

Periodontal surgery Learning objectives Analyze proficiently which of surgical technique is to be selected for management, Explain proficiently the clinical outcomes of surgical periodontal therapy, Classify the factors affecting clinical healing of surgical periodontal therapy. ADEE learning outc...

Periodontal surgery Learning objectives Analyze proficiently which of surgical technique is to be selected for management, Explain proficiently the clinical outcomes of surgical periodontal therapy, Classify the factors affecting clinical healing of surgical periodontal therapy. ADEE learning outcomes 3.1.1, 3.4.7 Selection of the surgical technique it must be understood that in most patients no single standardized technique alone can be applied when periodontal surgery is undertaken. In each surgical field, different techniques are often used and combined in such a way that the overall objectives of the periodontal surgical therapy are met. As a general rule, periodontal surgical techniques that preserve or induce the formation of periodontal tissue should be preferred over those that resect or eliminate tissue. (Sanz et al 2022) Gingivectomy The obvious indication for gingivectomy is the reshaping of abnormal gingival contours such as gingival craters and gingival hyperplasia. In these cases, the technique is often termed gingivoplasty. (Sanz et al 2022) Proximal soft tissue crater (Source Sanz et al 2022) Gingivectomy is usually not indicated since the external beveled incision will lead to the removal of the entire zone of gingiva. As an alternative, an internal beveled gingivectomy may be performed in situations with just soft tissue pockets (pockets not extending beyond the mucogingival junction), without the presence of bony craters or any infrabony lesion. These limitations, combined with the development of surgical methods which have a broader field of application, have led to less frequent use of gingivectomy. (Sanz et al 2022) Internal beveled gingivectomy (Source Sanz et al 2022) Flap procedures Flap operations can be used in all cases where surgical treatment of periodontitis is indicated. Periodontal flap procedures are particularly indicated at sites where pockets extend beyond the mucogingival junction and/or where treatment of bony defects and furcation involvements is required. The advantages of flap operations include: Existing gingival tissue is preserved Marginal alveolar bone is exposed allowing the identification of bony defects for their adequate treatment Furcation areas are exposed, and the degree of involvement and the “tooth–bone” relationship can be identified Flap can be repositioned at its original level or shifted apically, thereby making it possible to adjust the gingival margin to the local conditions Flap procedure preserves the oral epithelium and hence healing takes place mostly by primary intention. As a consequence, the postoperative period is usually less unpleasant to the patient when compared with gingivectomy. (Sanz et al 2022) Classifications of different flap modalities make distinctions between tissue‐eliminating (resective) and tissue preserving flaps (access/conservative). Flaps can be distinguished between those involving both buccal and lingual marginal tissues versus only buccal (standard versus single flaps) and those preserving or not the interdental tissues (standard versus papilla preservation flaps). (Sanz et al 2022) Appropriate to distinguish periodontal surgical therapy with regard to how to deal with (1) the soft tissue component and (2) the hard tissue component of the periodontal pocket at a specific tooth site (Sanz et al 2022) Surgical decisions. Treatment decisions with respect to the soft and the hard tissue component of a periodontal pocket. (Source Sanz et al 2022) Depending on the surgical technique used, the soft tissue flap would either be apically positioned at the level of the bone crest (apically positioned flap) or maintained in a coronal position (access and papilla preservation flaps) at the completion of the surgical intervention. The maintenance of the presurgical soft tissue height is of importance from an esthetic point of view. Long‐term results from clinical trials have shown that major differences in the final position of the soft tissue margin are not evident when comparing between access and resective surgical flap procedures. It may be of significance to position the flap coronally in the anterior tooth region in order to give the patient a prolonged time of adaptation to the inevitable soft tissue recession. In the posterior tooth region an apical position should be the standard. (Sanz et al 2022) Independent of flap position, the goal should be to achieve complete soft tissue coverage of the alveolar bone, not only at buccal/lingual sites but also at proximal sites. It is therefore of utmost importance to carefully plan the incisions in such a way that this goal is achieved at the termination of the surgical intervention once the flaps have been re‐positioned and sutured (Sanz et al 2022) The final positioning of the gingival margin between surgical techniques is also dependent on the degree of osseous recontouring performed (Townsend‐Olsen et al. 1985; Lindhe et al. 1987; Kaldahl et al. 1996; Becker et al. 2001). During conventional periodontal surgery, one would usually opt for the conversion of an intrabony defect into a suprabony defect, which then is eliminated by apical repositioning of the soft tissue flap(s). Osseous recontouring of angular bony defects and craters is an excisional technique, which should be used with caution and discrimination. (Sanz et al 2022) There are a number of factors that should be considered in the treatment decision, of deciding whether or not to eliminate an angular bony defect, such as: Esthetics Tooth/tooth site involved Defect morphology (intrabony component and defect angle) Amount of remaining periodontium. (Sanz et al 2022) Since alveolar bone supports the soft tissue, bone recontouring will result in recession of the soft tissue margin. For esthetic reasons, one may therefore be restrictive in eliminating interproximal bony defects in the anterior tooth region. Defect morphology is a variable of significance for repair/regeneration during healing (Rosling et al. 1976; Cortellini et al. 1993, 1995). Whereas two‐ and, especially, three‐wall defects may show great potential for repair/regeneration, one‐wall defects and interproximal craters will rarely result in such resolution. (Sanz et al 2022) The removal of intrabony connective tissue/granulation tissue during a surgical procedure will always lead to crestal resorption of bone, especially in sites with thin bony walls. This results in reduction of the vertical dimensions of the bone tissue at the site. (Sanz et al 2022) The treatment options available for the hard tissue defect may include: Eliminating the osseous defect by resecting bone (osteoplasty and/or ostectomy). In cases of an approximal crater of limited depth, it may often be sufficient to reduce/eliminate the bone wall on the lingual side of the crater, thereby maintaining the bone support for the soft tissue on the facial aspect. (Sanz et al 2022). In addition to esthetics, the presence of furcation lesions may limit the extent to which bone recontouring can be performed (Oschenbein 1986). Maintaining the area without osseous resection and either using regenerative procedures or minimally invasive flap procedures aimed to preserve the marginal tissues and provide maximum blood clot stability and protection of self‐periodontal regeneration (Sanz et al 2022). Clinical outcomes of surgical periodontal therapy Surgical periodontal treatment must be seen within the context of a sequential step of treatments in which the surgical options might not be needed in all cases (Graziani et al. 2017). The performance of periodontal surgical treatment is moreover influenced by the bone anatomy associated with the residual pockets (Graziani et al. 2012, 2014, 2015; Sanz‐Sanchez 2020). Tooth survival The amount of tooth loss is the most relevant criterion in an evaluation of the relative importance of surgical periodontal therapy in the overall treatment of periodontal disease. Overall tooth retention after surgery is high if appropriate supportive treatment is provided as shown in a systematic review taking into account long‐term results of periodontal surgery on teeth associated with intrabony defects (Graziani et al. 2012). When comparing periodontal surgery with repetition of non‐surgical instrumentation in residual pockets of 7 mm, more tooth retention was seen in the former in a 13‐year follow‐up period (0.6 teeth lost versus 1.6, respectively) (Serino et al. 2001). Plaque and gingival inflammation The most commonly used outcome criteria in clinical research have been resolution of gingivitis (BoP), probing pocket depth (PPD) reduction, and clinical attachment level change. However, with regard to post‐treatment plaque accumulation and gingivitis resolution, there is no evidence to suggest that differences exist between non‐surgical or surgical treatment or between various surgical procedures. (Sanz et al 2022) Probing pocket depth reduction Periodontal surgical therapy is remarkably effective in reducing PPD. It generally creates greater short-term reduction of probing depth than non‐surgically performed scaling and root planing (Sanch‐Sanchez et al 2020) which are significantly more pronounced in deeper pockets. In moderately deep pockets differences are noted only in the short term. Overall, the differences tend to become less apparent in the long-term follow‐ups (over 12 months). (Sanz et al 2022) Clinical attachment level change In sites with shallow initial probing depth, both short and long‐term data demonstrate that surgery creates a greater loss of clinical attachment than non‐surgical treatment, whereas in sites with initially deep pockets (≥7 mm), a greater gain of clinical attachment is generally obtained (Knowles et al. 1979; Lindhe et al. 1984; Ramfjord et al. 1987; Kaldahl et al. 1996; Becker et al. 2001). Based on data generated from a clinical trial comparing non‐surgical and surgical (modified Widman flap) approaches to root debridement, Lindhe et al. (1982) developed the concept of critical probing depth (CPD) in relation to clinical attachment level change. For each treatment approach, the clinical attachment change was plotted against the initial pocket depth and regression lines were calculated. Gain and loss of clinical attachment (y axis) at incisors, premolars, and molars, calculated from measurements taken prior to and 6 months after treatment. The non‐surgical approach (RPL) consistently yielded lower critical probing depth values than the surgical approach. RPL, scaling and root planing; MWF, modified Widman flap surgery. (Source:Lindhe et al. 1982).  The point where the regression line crossed the horizontal axis (initial probing depth) was defined as the CPD, that is, the level of pocket depth below which clinical attachment loss would occur as the result of the treatment procedure performed. The CPD was consistently found to be greater for the surgical approach than for the non‐surgical treatment. Furthermore, at incisors and premolars, the surgical therapy showed superior outcome only when the initial probing depth was >6–7 mm, while at molars the corresponding cut‐off point was 4.5 mm. The interpretation of the latter finding is that, in the molar tooth regions, the surgical approach to root debridement offers advantages over the nonsurgical approach. (Sanz et al 2022) When comparing clinical attachment levels following various types of surgery, either no difference was found between therapies, or flap surgery without osseous/ tissue resection produced a greater gain, especially in shallow sites (Polak et al. 2020). In addition, there was no difference in the longitudinal maintenance of clinical attachment levels between sites treated non‐surgically and those treated surgically, with or without osseous resection (Kaldahl et al. 1996) Longitudinal changes over 7 years in recession (top) and clinical attachment levels (bottom) at sites with an initial probing pocket depth of >6 mm following three different periodontal treatment modalities. BL, baseline; FO, flap and osseous surgery; MWF, modified Widman flap procedure; RPL, scaling and root planing. (Source Kaldahl et al. 1996 ) In residual pockets associated with intrabony defects, surgical therapy resulted in an attachment gain of approximately 2 mm in the long‐term. Interestingly, an important flap‐dependent gradient indicating that papilla preservation flaps and minimally invasive flaps determined a higher extent of attachment gains compared with conventional open flap debridement in such defects was noted (Graziani et al. 2012). Gingival recession Gingival recession is an inevitable consequence of periodontal therapy. Because it occurs primarily as a result of resolution of the inflammation in the periodontal tissues, it is seen both following non‐surgical and surgical therapy. Irrespective of treatment modality used, initially deeper pocket sites will experience more pronounced signs of recession of the gingival margin than sites with shallow initial probing depths (Badersten et al. 1984; Lindhe et al. 1987; Becker et al. 2001). A general finding in short‐term follow‐up studies of periodontal therapy is that non‐surgically performed scaling and root planning causes less gingival recession than surgical therapy, and that surgical treatment involving osseous and soft tissue resection results in the most pronounced recession (Polak et al. 2020). In general, surgical root instrumentation without tissue resection determines approximately 1 mm of recession 12 months after surgery of residual pockets associated with intrabony, suprabony, and furcation defects. However, data obtained from long‐term studies reveal that the initial differences seen in amount of recession between various treatment modalities diminish over time caused by a coronal rebound of the soft tissue margin following surgical treatment (Kaldahl et al. 1996; Becker et al. 2001) Bone fill in angular bone defects The potential for bone formation in angular defects following surgical access therapy has been demonstrated in a number of studies. Rosling et al. (1976) studied the healing of two‐ and three‐wall angular bone defects following a modified Widman flap procedure, including careful curettage of the bone defect and proper root debridement, in 24 patients with multiple osseous defects. Following active treatment, patients assigned to the test group received supportive periodontal care once every 2 weeks for a 2‐year period, while the patients in the control group were only recalled once a year for prophylaxis. Re‐examination carried out 2 years after therapy demonstrated that the patients who had been subjected to the intensive professional tooth‐cleaning regimen had experienced a mean gain of clinical attachment in the angular bone defects amounting to 3.5 mm. Measurements performed on radiographs revealed a marginal bone loss of 0.4 mm, but the remaining portion of the original bone defect (2.8 mm) was refilled with bone. The results from the studies Rosling et al. (1976) and Polson and Heijl (1978) demonstrate that a significant bone fill may be obtained in two‐ and three‐wall intrabony defects at single‐rooted teeth, provided the postoperative supportive care is of very high quality. Two reviews (Laurell et al. 1998; Lang 2000), focusing on the outcome of surgical access therapy in angular bone defects, gave additional information regarding expected bone regeneration in angular defects following open‐flap debridement (modified Widman flap). This data was further confirmed by a recent meta‐analysis indicating an average bone fill was 1 mm (Graziani et al. 2012). Factors affecting clinical healing Periodontal surgical treatment shows heterogenous healing influenced and explained by numerous factors that a clinician should consider when planning an intervention because many of these factors may be changed by the clinician in order to improve the overall surgical prognosis. Patient factors Plaque levels Plaque levels influence healing of surgical debridement significantly. In a landmark study, patients in the test group received, after surgical debridement of intrabony defects, repeated oral hygiene instructions and professional tooth cleaning once every 2 weeks during the postoperative period (Rosling et al. 1976). The patients maintained the surgically reduced pocket depth throughout the 2‐year follow‐up period and important clinical attachment level gains and bone fill were observed for most of the surgical procedures evaluated. The control group that was assessed and polished only once a year (i.e. with high plaque score), showed a significant and important deterioration of clinical attachment level and bone levels. The fact that the standard of postoperative oral hygiene is decisive for the outcome of surgical pocket therapy is further underlined by data from a 5‐year longitudinal study by Lindhe et al. (1984) which showed that patients with a high standard of infection control maintained clinical attachment levels and probing depth reductions following treatment more consistently than patients with poor plaque control. On the other hand, professional tooth cleaning, including subgingival scaling every 3 months, may partly compensate for the negative effects of variations in self‐performed plaque control (Ramfjord et al. 1982; Isidor & Karring 1986). Gingival inflammation The overall level of inflammation influences the outcome of surgical debridement of intrabony defects in terms of attachment gain when full mouth bleeding scores reach >12% (Tonetti et al. 1996). Therefore, careful decontamination and reduction of inflammation is needed before surgery. (Sanz et al 2022) Smoking Smoking, despite not being a contraindication for surgery, has an important negative impact on the outcome after periodontal surgery, as shown by the negative influence on both probing pocket depth (PPD) reduction and clinical attachment levels (CAL) (Labriola et al. 2005). Smoking does lessen the impact in both outcomes 6 months after surgery. The chance of obtaining a postsurgical pocket reduction of >3 mm is nearly three times lower in patients who smoke (Scabbia et al. 2010). Local factors Type of periodontal defect Periodontal defects are classically divided in intrabony, suprabony, and inter‐radicular defects. Most knowledge is derived from the literature on intrabony defects. Conservative surgical debridement of an intrabony defect determines a clinical attachment gain of approximately 1.5 mm and a probing depth reduction of 3 mm, 12 months after surgery (Graziani et al. 2012). Suprabony defects do not heal as well compared with healing achieved after surgical debridement of intrabony defects with a 1.4 probing depth reduction and 0.5 mm of clinical attachment gain (Graziani et al. 2014). Furcation defects also show important reductions in clinical healing if compared with intrabony defects. A meta‐analysis analyzing the control group of trials in which periodontal regeneration was applied indicated that the average CAL gain of degree II mandibular furcation was 0.5 mm 6 months after debridement and a PPD reduction of 1.4 mm. This highlights the complexity of surgical access in furcation defects (Graziani et al. 2015). Periodontal defect morphology The morphology of the defect has important repercussions for healing after surgery. When a residual pocket is associated with an intrabony defect, some factors such as the number of walls of the defect, and the depth and width of the defect, influence significantly the surgical outcome. The deeper the intrabony component the larger is the postsurgical clinical attachment gain in access flaps (Cortellini et al. 1998). Three‐wall intrabony defects have a 269% higher chance of showing a clinical attachment gain of at least 3 mm than a 1‐wall defect after surgical debridement (Tonetti et al. 2002). Moreover, the wider the defect, the lower the healing (Sanz et al 2022). Clinician factors Experience and surgical dexterity Clinical experience and capabilities have an obvious impact on healing. In a multicenter trial, clinicians operating on identical periodontal defects at baseline with the same surgical access showed a difference of more than 1 mm of clinical attachment gain (Tonetti et al. 1998). Flap choice The evolution of flap design contributed significantly to the clinical outcome after surgical debridement. The performance of access flaps in intrabony defects changed abruptly within 10 years, indicating an increase in performance of control sites (access flap) of 1 mm between 1996 and 2006 (Tu et al. 2008). This has been further confirmed in a meta‐analysis indicating that if conservation of the papillary area during surgery is performed, a higher postsurgical clinical attachment gain is achieved (Graziani et al. 2012). Papilla preservation flaps appear to improve clinical attachment gain compared with conventional surgery, and also appear to be effective for suprabony defects (Graziani et al. 2014). This can be explained by the fact that the choice of papilla preservation flaps increase vascularization, as noted in laser flow doppler studies, which results in improved primary closure and better protection from postsurgical bacterial contamination in the wound (Retzepi et al. 2007).