University Ave. Regenerative periodontal therapy comprises techniques which are particularly designed to restore those parts of the tooth-supporting structures which have been lost due to periodontitis or gingival trauma. Procedures aimed at restoring lost periodontal tissues favor the creation of new attachment, including the formation a new periodontal ligament with its fibers inserting in newly formed cementum and alveolar bone.
Deep infra-bony defects associated with periodontal pockets are the classic indication for periodontal regenerative therapy. Additionally, different degrees of furcation involvement in molars and upper first premolars are a further indication for regenerative approaches as the furcation area remains difficult to maintain through instrumentation and oral hygiene. A third group of indications for regenerative periodontal therapy are localized gingival recessions and root exposure since they may cause a significant esthetic concern for the patient.Periodontal Surgery with Regeneration for Lower Teeth
The denuding of a root surface with resultant root sensitivity represents a further indication to apply regenerative periodontal therapy in order to achieve both the reduction of root sensitivity and the improvement of esthetics.
Professional periodontal therapy and maintenance, combined with risk factor control, are shown to effectively reduce periodontal disease progression.
In contrast to the conventional approaches of anti-inflammatory periodontal therapy, however, the regenerative procedures aimed at repairing lost periodontal tissues, including alveolar bone, periodontal ligament and root cementum, remain more challenging Periodontal research in the past few decades has attempted to systematically determine predictably successful clinical procedures to regenerate periodontal tissues.
Hence, various methods in combination with regenerative biomaterials, such as hard- and soft-tissue grafts, or cell occlusive barrier membranes used in guided tissue regeneration procedures, have been pursued to regenerate lost tooth support Periodontal regeneration is assessed by probing measures, radiographic analysis, direct measurements of new bone and histology Many cases that are considered clinically successful, including cases with significant re-growth of alveolar bone, may histologically still show an epithelial lining along the treated root surface instead of newly formed periodontal ligament and cementum In general, however, the clinical outcome of periodontal regenerative techniques is shown to depend on 1 patient associated factors such as plaque control, smoking habits, residual periodontal infection, or membrane exposure in guided tissue regeneration procedures, 2 effects of occlusal forces that deliver intermittent loads in axial and transverse dimensions, as well as 3 factors associated with the clinical skills of the operator such as lack of primary closure of the surgical wound Even though modified flap designs and microsurgical approaches are shown to positively affect the outcome of both soft and hard tissue regeneration, the clinical success for periodontal regeneration still remains limited in many cases.
Moreover, the surgical protocols for regenerative procedures are skill-demanding and may therefore lack practicability for a number of clinicians. Consequently, both clinical and pre-clinical research continues to evaluate advanced regenerative approaches using either new barrier membrane techniques 67cell-growth stimulating proteins 264268 or gene delivery applicationsrespectively, in order to simplify and enhance the rebuilding of missing periodontal support.
The aim of our review is to compare these advanced regenerative concepts for periodontal hard and soft tissue repair with conventional regenerative techniques Table 1. While a focus will be given on clinical applications with the delivery of growth factors, the applications for gene delivery of tissue growth factors are also reviewed.
Research on periodontal wound healing in the past was able to provide the basic understanding of the mechanisms favoring periodontal tissue regeneration. A number of valuable findings at both the cellular and molecular levels was revealed and subsequently used for the engineering of regenerative biomaterials available in periodontal medicine today. In order to provide an overview of the cellular and molecular events and their relation to periodontal tissue regeneration, the course of periodontal wound healing is briefly reviewed in this article.
The biology and principles of periodontal wound healing have previously been reviewed Based on observations following experimental incisions in periodontal soft tissues, after blood clot formation, the sequence of healing is commonly divided into the following phases: 1 soft tissue inflammation; 2 granulation tissue formation; and 3 intercellular matrix formation and remodeling 20 Plasma proteins, mainly fibrinogen, dominate rapidly in the bleeding wound and provide an initial basis for the adherence of a fibrin clot The inflammatory phase of healing in the soft tissue wound is initiated by polymorphonuclear leukocytes infiltrating the fibrin clot from the wound margins shortly followed by macrophages The major function of the polymorphonuclear leukocytes is to debride the wound by removing bacterial cells and injured tissue particles through phagocytosis.
The macrophages, in addition, have an important role to play in the initiation of tissue repair. The inflammatory phase progresses into its later stage as the polymorphonuclear leukocyte infiltrate gradually decreases while the macrophage influx continues. These macrophages contribute to the cleansing process by phagocytosis of used polymorphonuclear leukocytes and erythrocytes.
Additionally, macrophages release a number of biologically active molecules such as inflammatory cytokines and tissue growth factors, which recruit further inflammatory cells as well as fibroblastic and endothelial cells, thus playing an essential role in the transition of the wound from the inflammation into the granulation tissue formation.
The influx of fibroblasts and budding capillaries from the gingival connective tissue and the periodontal ligament connective tissue initiate the phase of granulation tissue formation in the periodontal wound approximately two days after incision.
At this stage, fibroblasts are responsible for the formation of a loose new matrix of collagen, fibronectin, and proteoglycans Eventually, cells and matrix form cell-to-cell and cell-to-matrix links that generate a concerted tension resulting in tissue contraction.
The phase of granulation tissue formation gradually develops into the final phase of healing in which the reformed, more cell-rich tissue undergoes maturation and sequenced re-modeling to meet functional needs 20 The morphology of a periodontal wound comprises 1 the gingival epithelium, 2 the gingival connective tissue, 3 the periodontal ligament, and the hard tissue components such as 4 alveolar bone and 5 cementum or dentin on the dental root surface Fig.
This particular composition ultimately affects both the healing events in each tissue component as well as in the entire periodontal site. While the healing of gingival epithelia and their underlying connective tissues concludes in a number of weeks, the regeneration of periodontal ligament, root cementum and alveolar bone generally only occur within a number of weeks or months.Dental College and Hospital, J.
Dental College and Hospital, S. There are recent advances in periodontal surgical techniques, from resection to regeneration, the focus of surgical access has shifted to regeneration of lost tissues. To achieve goals of periodontal surgical therapy, minimal invasive surgery can be considered as a potential future for the treatment of periodontal disease with the concept of being minimal in our treatment approaches.
This article reviews the various techniques, its applications, and future prospects of minimal invasive periodontal surgery. Users Online: Schluger S.
Osseous resection; a basic principle in periodontal surgery. Garrett S. Periodontal regeneration around natural teeth. Ann Periodontol ; Long-term evaluation of periodontal therapy: I. Response of four treatment modalities. J Periodontol. Granulation tissue removal in routine and minimally invasive procedures. Compend Contin Educ Dent ;, Harrel SK. A minimally invasive surgical approach for periodontal regeneration: Surgical technique and observations.
J Periodontol ; Gingiva thickness in guided tissue regeneration and associated recession at facial furcation defects. Minimally invasive surgery. Br J Surg ; Minimally invasive high tech surgery; into the 21 st century. In: Minimally Invasive Surgery.Periodontal regenerative technologies are applied to improve short- and long-term clinical outcomes of periodontally compromised teeth, presenting with deep pockets and reduced periodontal support.
The persistence of deep pockets following active periodontal therapy has been associated with an increased probability of tooth loss in patients attending supportive periodontal care programs . Teeth with deep pockets associated with deep intrabony defects are considered a clinical challenge: periodontal regeneration has been shown to be effective in the treatment of one- two- and three-wall intrabony defects or combinations thereof, from very deep to very shallow, from very wide to very narrow [2—5].
Therefore, the application of regenerative procedures, including minimally invasive procedures, is suited in deep and shallow intrabony defects. Regeneration is a healing outcome that can occur when the systemic and local conditions are favorable.
The systemic conditions include the control of periodontitis, a low total bacterial load in the mouth and cessation of smoking habits: high percentages of bleeding on probing and high bacterial loads as well as cigarette smoking have been associated with reduced clinical outcomes [6—12].
The local conditions include the presence of space for the formation of the blood clot at the interface between the flap and the root surface [12—17], the stability of the blood clot to maintain a continuity with the root surface avoiding formation of a long junctional epithelium [13,18—20], and the soft tissue protection to avoid bacterial contamination [10,21—23].
Development of periodontal regenerative medicine in the past 25 years has followed two distinctive, though totally interlaced paths. The interest of researchers has thus far focused on regenerative materials and products on the one side and on novel surgical approaches on the other side.
In the area of materials and products, three different regenerative concepts have been explored: i barrier membranes, ii grafts, and iii wound healing modifiers, plus many combinations of the aforementioned concepts . Specifically, flap designs attempted to achieve passive primary closure of the flap combined with optimal wound stability. In the s, the modified papilla preservation technique MPPT  and the simplified papilla preservation flap SPPF  have been tested and proposed.
Further enhancements of clinical outcomes were achieved when an operative microscope was adopted [25,26]. Other authors reported improved outcomes using operative microscopes in different areas of periodontal surgery, from flap surgery to mucogingival surgery [27—32]. In the past decade, a growing interest for more friendly, patient-oriented surgery have urged clinical investigators to focus their interest in the development of less invasive approaches [33—35].
Cohort studies and randomized controlled clinical trials reporting outcomes on the application of minimally invasive surgical approaches are reported in Tables 8. Table 8. This approach is supported by three cohort studies [36,37,39] and two controlled studies [40,41]. This approach is supported by a cohort study  and three controlled studies [42—44]. The reported outcomes raise a series of hypotheses that focus on the intrinsic healing potential of a wound when ideal conditions are provided with the surgical approach.
In other words, the outcomes of these studies challenge clinicians with the possibility to obtain substantial clinical improvements without using products or materials applying surgical techniques that do enhance per se blood clot and wound stability. In particular, the advanced flap design of the M-MIST greatly enhances the potential to provide space and stability for regeneration by leaving the interdental papillary soft tissues attached to the root surface of the crest-associated tooth and by avoiding any palatal flap elevation.
The hanging papilla prevents the collapse of the soft tissues, thereby maintaining space for regeneration. The minimal flap extension and elevation also minimizes the damages to the vascular system favoring the healing process of the tiny soft tissues.
Delivering periodontal surgery in general and regenerative treatment in particular requires knowledge, skills, experience, and a well-defined step-by-step approach. The first step of periodontal therapy is always cause-related therapy, aimed at obtaining patient compliance, reduction of oral bacterial loads, and control of gingival infection.
At completion of nonsurgical cause-related therapy, patients have to be carefully reevaluated. A full periodontal evaluation should be performed to check for Flow chart 8. The presence of residual deep pocket probing depths might indicate the need for periodontal surgery. Clinical goals of regenerative surgery are to i reduce pocket probing depth through attachment gain while limiting the gingival recession and ii increase the functional support of the involved teeth.
However, periodontal regeneration is not always applicable  Flow chart 8. Ample evidence shows that it is highly predictable in the treatment of pockets associated with deep and shallow intrabony defects.Your periodontist may recommend a regenerative procedure when the bone supporting your teeth has been destroyed due to periodontal disease.
These procedures can reverse some of the damage by regenerating lost bone and tissue. During this procedure, your periodontist folds back the gum tissue and removes the disease-causing bacteria.
Membranes filtersbone grafts or tissue-stimulating proteins can be used to encourage your body's natural ability to regenerate bone and tissue. Eliminating existing bacteria and regenerating bone and tissue helps to reduce pocket depth and repair damage caused by the progression of periodontal disease. With a combination of daily oral hygiene and professional maintenance care, you'll increase the chances of keeping your natural teeth — and decrease the chances of other health problems associated with periodontal disease.
Periodontal Plastic Surgery Procedures Periodontists are often considered the plastic surgeons of dentistry. If you are Michigan Ave. Search form Search. Regenerative Procedures Procedures that regenerate lost bone and tissue supporting your teeth can reverse some of the damage caused by periodontal disease. Members Only Content:.Assessment of Periodontal Wound Healing. Reconstructive Surgical Techniques. Factors That Influence Therapeutic Success.
Future Directions for Periodontal Regeneration. When the periodontium is damaged by inflammation or as a result of surgical treatment, the defect heals either through periodontal regeneration or repair.
Although the stability of periodontal repair is not clear, the ideal goal of periodontal surgical therapy is periodontal regeneration. This chapter summarizes our current understanding of therapy that results in periodontal regeneration and examines how regenerative approaches used for correcting intrabony defects have changed over the years. It is sometimes difficult in clinical and experimental situations to determine whether regeneration or new attachment has occurred and the extent to which it has occurred.
Although there are various evidences of reconstruction, the proof of principle for the type of healing is determined by histological studies. Once defined, the evidence found subsequently by clinical, radiographic, and surgical reentry findings is implied.
A comparative analysis of regenerative approaches is detailed in Table It is only through histological analysis can one define the nature of the reparative tissue Figure In periodontal reconstructive surgery, the goal is to achieve periodontal regeneration.
Classically, experimental animal model systems 36are used whereby reference notches are placed at the base of bony defects or at the apical extent of calculus deposits.
Periodontal regeneration is considered to have occurred when the newly formed functionally aligned periodontium is coronal to the apical extent of the notches. Reparative tissue response dominated may include long junctional epithelium, connective tissue adhesion, and root resorption associated with ankylosis. It should be noted that the healing may be predominated by periodontal regeneration; there may be localized areas of repair. On rare circumstances, human histology is available if the tooth is to be extracted in conjunction with orthodontic or restorative therapy Figure Clinical methods to evaluate periodontal reconstruction consist of comparisons between pretreatment and posttreatment pocket probings and determinations of clinical gingival findings.
The probe can be used to determine pocket depth, attachment level, and bone level Figure Clinical determinations of attachment level are more useful than probing pocket depths because the latter may change as a result of displacement of the gingival margin see Chapter Several studies have determined that the depth of penetration of a probe in a periodontal pocket varies according to the degree of inflammatory involvement of the tissues immediately beneath the bottom of the pocket Figure Therefore, even though the forces used may be standardized with pressure-sensitive probes, there is an inherent margin of error in this method that is difficult to overcome.
Fowler et al 71 have calculated this error to be 1. Bone probing performed with the patient under anesthesia is not subject to this error and has been found to be as accurate as bone height measurements made on surgical reentry. Measurements of the defect should be made before and after treatment from the same point within the defect and with the same angulation of the probe.
This reproducibility of probe placement is difficult and may be facilitated in part by using a grooved stent to guide the introduction of the probe Figure The simplest distribution would list every value of a variable and the number of persons who had each value. For instance, a typical way to describe the distribution of college students is by year in college, listing the number or percent of students at each of the four years. Or, we describe gender by listing the number or percent of males and females.
In these cases, the variable has few enough values that we can list each one and summarize how many sample cases had the value. But what do we do for a variable like income or GPA.
With these variables there can be a large number of possible values, with relatively few people having each one. In this case, we group the raw scores into categories according to ranges of values. For instance, we might look at GPA according to the letter grade ranges. Or, we might group income into four or five ranges of income values. One of the most common ways to describe a single variable is with a frequency distribution.
Depending on the particular variable, all of the data values may be represented, or you may group the values into categories first (e. Rather, the value are grouped into ranges and the frequencies determined. Frequency distributions can be depicted in two ways, as a table or as a graph.
Table 1 shows an age frequency distribution with five categories of age ranges defined. The same frequency distribution can be depicted in a graph as shown in Figure 1. This type of graph is often referred to as a histogram or bar chart. Frequency distribution bar chart. Distributions may also be displayed using percentages. For example, you could use percentages to describe the:Central Tendency. The central tendency of a distribution is an estimate of the "center" of a distribution of values.
There are three major types of estimates of central tendency:The Mean or average is probably the most commonly used method of describing central tendency. To compute the mean all you do is add up all the values and divide by the number of values.
For example, the mean or average quiz score is determined by summing all the scores and dividing by the number of students taking the exam. For example, consider the test score values:The Median is the score found at the exact middle of the set of values. One way to compute the median is to list all scores in numerical order, and then locate the score in the center of the sample. Since both of these scores are 20, the median is 20. If the two middle scores had different values, you would have to interpolate to determine the median.
The mode is the most frequently occurring value in the set of scores. To determine the mode, you might again order the scores as shown above, and then count each one. The most frequently occurring value is the mode. In our example, the value 15 occurs three times and is the model. In some distributions there is more than one modal value. For instance, in a bimodal distribution there are two values that occur most frequently.We liked that you tailored the trip to meet our requirements.
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