Periodontal Regeneration: Management of Periodontal Osseous Defects by the Periodontist-Dental Hygienist Team

Periodontal health can be restored through assessment, diagnosis, treatment and management of periodontal osseous defects by the periodontist-dental hygienist team.Background and PurposeTreatment of periodontitis has evolved over time, with regenerative periodontal therapy at the forefront in cutting-edge periodontal care. While the techniques and materials available today are allowing therapists to push the limits of periodontal regeneration and achieve success in increasingly more difficult cases, the principles of successful regeneration remain the same. Case selection, identification and resolution of etiologic and contributing factors, proper surgical technique, follow-up and patient education are keys to obtaining a successful outcome. The impact of the dental hygienist in assessment and maintenance is highlighted.MethodsLiterature review of the key research studies evaluating the etiology and contributing factors in the development osseous defects, osseous defect and tooth-related characteristics, and principles of successful regenerative therapy. The authors draw upon their experience with patient care and clinical research to synthesize the evidence relevant to today's dental hygienist.ConclusionsPeriodontal regeneration is a well-supported and predictable therapy that can be utilized to restore periodontal support and health. The dental hygienist is key in assessing and caring for the periodontal health of patients over time. Identifying who may benefit from regenerative periodontal therapy is an essential skill for today's practicing dental hygienist.     

120 infrabony defects treated with regenerative therapy: long-term results

Background: The aim of this study is to evaluate the long‐term benefits of regenerative therapy and which factors (i.e., smoking, oral hygiene, radiographic angle, tooth, clinical center, and biomaterial) influence results. Methods: A total of 120 infrabony defects were treated with guided tissue regeneration using bioabsorbable and non‐resorbable membranes with grafts or enamel matrix derivative (EMD) proteins. At baseline, smoking, x‐ray angle, probing depth (PD), recession, and clinical attachment level (CAL) were recorded. CAL was measured 1 year post‐surgery and every 2 years for ≤16 years. The participation of patients in oral hygiene protocols was recorded. Results: The mean ± SD baseline CAL was 8.5 ± 2.3 mm, baseline PD was 7.8 ± 2.1 mm, and baseline x‐ray angle was 31.8° ± 8.9°. One year post‐surgery, CAL gain was 4.1 ± 2.1 mm. EMD was used in 47 defects, bioabsorbable membranes with deproteinized bovine bone were used in 41 cases, non‐resorbable membranes were used in seven defects, bioabsorbable membranes and autogenous bone were used in five defects, and a combination was used in 20 defects. A total of 10% of subjects were smokers, and 20% of subjects did not participate in an oral hygiene program. The average follow‐up was 9 years. A total of 90% teeth survival was achieved at 13 years, and CAL gain was maintained at 82% for 11 years. Statistical analyses demonstrated that smoking and oral hygiene maintenance influenced long‐term outcomes. The x‐ray angle, tooth, clinical center, and biomaterials did not influence results. Conclusions: Regenerative therapy provided a high percentage of long‐term success. Smoking and non‐participation in oral hygiene maintenance negatively influenced the prognosis, whereas other factors did not affect long‐term results.     

Effect of cigarette smoking on periodontal healing following GTR in infrabony defects

Abstract This retrospective study examined the effect of cigarette smoking on the healing response following guided tissue regeneration (GTR) in deep infrabony defects. 71 defects in 51 patients underwent GTR with teflon membranes. 20 patients (32 defects) smoked more than 10 cigarettes per day, while 31 patients (39 defects) did not smoke. Clinical measurements were available at baseline, at membrane removal and at the 1-year follow-up. The oral hygiene of both groups was good, but smokers had significantly higher full mouth plaque scores. No significant differences were observed between smokers and non-smokers in terms of % of tissue gained at membrane removal. At the 1-year follow up, however, smokers gained significantly less probing attachment level than non-smokers (2.1 ± 1.2 mm compared with 5.2 ± 1.9 mm). A multivariate model, correcting for the oral hygiene level of the patients and the depth of the infrabony component, indicated that smoking was in itself a significant factor in determining the clinical outcome. A risk-assessment analysis indicated that smokers had a significantly greater risk than non-smokers to display a reduced probing attachment level gain following GTR. It is concluded that cigarette smoking is associated with a reduced healing response after GTR treatment, and may be responsible, at least in part, for the observed results.     

Periodontal healing following reconstructive surgery: effect of guided tissue regeneration

Abstract Clinical healing following guided tissue regeneration (GTR) in deep intrabaony pockets was compared to healing following gingival flap surgery alone (GFS). 15 patients received the GTR treatment including an expanded polytetrafluoroethylene membrane. 13 other patients received the control treatment GFS. A postsurgery protocol emphasizing wound stability and infection control was used. Treatment effects were evaluated 6 months postsurgery. Mean pre-surgery probing depth for the GTR and control treatments was 7.5±1.0 and 7.7±1.5 mm. respectively. Significant probing depth reduction (3.8±1.2 and 2.9±1.1 mm), attachment level improvement (2.4±2.1 and 2.2±1.2 mm) and bone fill (2.0±2.0 and 2.4±0.9 mm) followed the GTR and control protocols, respectively (p < 0.01) Significant differences between GTR and control treatments were observed in probing depth reduction (p < 0.01) and in gingival recession increase (1.7±1.5 and O.7±0.9 mm. respectively; (p < 0.05). The results suggest that GTR procedures compared to GFS have similar clinical potential in intrabony pockets, under the present protocol.     

The use of regenerative techniques in apical surgery: A literature review

Apical surgery has become a standard of care for tooth maintenance if conventional endodontic retreatment is not possible or associated with risks. However, in certain situations, the outcome of apical surgery may be compromised due to the extent or location of the periapical or periradicular lesions. The present review article including clinical and experimental studies reports and discusses the outcome of regenerative techniques (RT) in conjunction with apical surgery, with regard to the type of periradicular lesions:

Apical lesions

The majority of studies have shown no benefit for healing in test sites treated with RT compared to control sites treated without RT. The use of a radio-opaque bone filler/substitute may even compound the radiographic interpretation of periapical healing. Currently, the use of RT for lesions <10 mm limited to the apical area is not warranted.

Through-and-through lesions

All reviewed studies demonstrated a better outcome for test sites with RT compared to the control sites without RT; hence the use of RT for treatment of tunnel lesions in apical surgery is recommended.

Apico-marginal lesions

All clinical studies assessed cohorts without controls, and, therefore, no firm conclusion about the benefit of RT for treatment of apico-marginal lesions in conjunction with apical surgery can be drawn. However, the experimental animal studies have shown that healing of teeth with apico-marginal lesions appears to benefit from RT.     

牙周再生性手术联合正畸移动治疗垂直型骨缺损

牙周再生性手术能够使牙周炎患者的垂直型骨缺损获得最佳的治疗效果,正畸患者在牙周手术后炎症得到控制,正畸牙齿的移动也相对安全。牙周再生性手术后,可通过早期牙齿移动,使牙根在不牺牲安全性的情况下尽早进入移植部位,手术过程中使用的骨替代物或屏障膜等移植材料可能会阻碍牙齿移动,但是另一方面也会降低牙根吸收发生的概率。牙周再生性手术联合正畸治疗垂直型骨缺损能否维持长期较好的临床效果,受到牙周维护频率、正畸加力频率及大小等多方面因素的影响,术后疗效有待进一步观察和研究。     

Evaluation of the effect of tooth vitality on regenerative outcomes in infrabony defects

BACKGROUND, AIMS: This investigation was designed to evaluate the null hypothesis of no differences in GTR outcomes in intrabony defects at vital and successfully root-canal-treated teeth. METHOD: 208 consecutive patients with one intrabony defect each were enrolled. Based on tooth vitality, the treated population was divided at baseline into 2 groups: one with 41 non-vital teeth and the other with 167 vital teeth. The 2 groups were similar in terms of patient and defect characteristics. RESULTS: A slight unbalance in terms of depth of the intrabony component was observed in the non-vital group compared to the vital group (6.9+/-2.1 mm versus 6.2+/-2.3 mm, p=0.08). All defects were treated with GTR therapy. At 1 year, the non-vital and the vital groups showed a clinical attachment level (CAL) gain of 4.9+/-2.2 mm and of 4.2+/-2 mm, respectively. The difference was statistically significant (p=0.03). To correct for the baseline unbalance in defect depth, data were expressed as a % of clinical attachment level gains with respect to the original intrabony depth of the defect. % CAL gains were 72.8+/-42.2% and 73+/-26.4% for vital and non-vital teeth, respectively: the difference was not statistically significant (p=0.48). Average residual pocket depths were 2.8+/-1 mm in the vital and 2.8+/-0.9 mm in the non-vital group. Tooth vitality was assessed at baseline, at 1-year and at follow-up (5.4+/-2.8 years after surgery): all teeth vital at baseline were still vital at follow-up with the exception of 2 teeth that received endodontic treatment for reconstructive reasons and for caries. At follow-up visit, the difference in CAL with respect to 1-year measurements was -0.9+/-0.8 mm in the vital group and -0.7+/-0.8 mm in the non-vital group, indicating stability of the regenerated attachment at the majority of sites. CONCLUSIONS: Data from this study demonstrate that root canal treatment does not negatively affect the healing response of deep intrabony defects treated with GTR therapy; furthermore GTR therapy in deep intrabony defects does not negatively influence tooth vitality.     

Healing of horizontal circumferential periodontal defects following regenerative surgery in beagle dogs

Regenerative surgery of dog teeth with reduced periodontal support was undertaken to determine: if new connective tissue attachment could be predictably attained back to the level of the cemento-enamel junction; and to what extent the new attachment would be accompanied by bone regeneration, root resorption, and ankylosis. The alveolar bone around mandibular premolars was surgically reduced up to 6 mm from the cementoenamel junction. The denuded root surfaces were exposed to the oral environment during a period of 3 months without plaque control. Regenerative surgery was then carried out employing citric acid root conditioning and coronally positioned flaps. 6 months later, histologic evaluation of the midbuccal and midlingual areas of mesial and distal roots revealed new attachment over extended portions of the root surfaces. In 91 of 120 available surfaces, there was no epithelial downgrowth apical to the cemento-enamel junction. Bone regeneration varied from negligible amounts to complete reformation. However, root resorption and ankylosis were prevalent features. 2 different types of resorptions could be distinguished: those occurring near the cemento-enamel junction (cervical resorption), and those occurring more apically in areas of newly formed bone (ankylosis-associated resorption). Resorption of either or both types was noted for 92 of the 120 surfaces.     

The effect on osteogenesis of type I collagen applied to experimental bone defects

Abstract –  The purpose of the present investigation was to evaluate the effects of type I collagen sponge on the healing of bone defects. In this study, six adult male rabbits were used. After the induction of general anesthesia with intraperitoneal kethamine, the anterior surfaces of tibias of the rabbits were surgically exposed, and two holes with 4 mm in diameter were prepared on each tibia for the investigation. Only one hole in each tibia was filled with type I collagen, the other unfilled hole was used as control. During the study, radiopacity changes in the radiographs of the tibias of the rabbits were evaluated. The animals were killed on the 28th day, and histologic sections of the tibias were prepared. On the 28th day, it was histopathologically observed that collagen cavities were filled with new bone. In addition, it was determined that there was an increase in radiopacity of the defect areas from 14 to 28 days in both groups, and there were statistically a significant difference between control and collagen groups ( P  = 0.0001). In this study, consequently, it was determined that type I collagen sponge in the experimental cavities provides a more rapid regeneration of bone defects compared with non-filled cavities.     

Periodontal regeneration in aggressive periodontitis patients: A systematic review of the literature

The aim of the present study was to systematically review the existing literature on periodontal regenerative procedures in individuals affected by aggressive periodontitis (AgP). An electronic and manual search was performed using an ad hoc prepared search string. All types of study designs were considered acceptable for inclusion. Data about treated patients, baseline clinical parameters, type of surgery, and outcomes were extracted and recorded. A narrative evaluation of the results was performed. After the article‐selection process, a total of 22 full‐texts were included in the qualitative synthesis. Twelve papers were case reports; one was a retrospective study; six were non‐randomized, comparative studies; and three papers were published on two randomized, controlled trials (RCT). Various biomaterials and surgical techniques were described in the included papers. Based on the existing literature, even considering the relatively low level of evidence, periodontal regenerative surgery could be successfully performed in patients affected by AgP. There is a substantial need of high‐quality RCT to support this.