Guided tissue regeneration for the treatment of intraosseous defects using a biabsorbable membrane. A controlled clinical study

Cytological Changes and Immunocytochemistry Expression of P53 in Oral Mucosa Among Waterpipe Users in the Kingdom of Saudi Arabia

Objective In this study, we aimed to assess cytological changes and p53 expression in oral mucosa among waterpipe users in the Kingdom of Saudi Arabia (KSA). Methodology A case-control study was conducted in KSA from January to October 2022. Two cytologic oral smear samples each were taken from 500 volunteers; 300 were waterpipe users (case) while 200 did not use a waterpipe (control). They were then stained using the Papanicolaou staining procedure and immunocytochemical method to show the expression of P53. Results The interpretation of the Papanicolaou staining outcomes showed the presence of four results with different proportions: inflammation, infection, atypia, and keratinization. Cytological inflammation was identified among 77/300 (25.6%) waterpipe smokers, which was higher than that among non-users (12/200, 6%). The reverse cytological infection and atypia were also higher in waterpipe smokers compared with controls (9% vs. 4.5% and 4.3% vs. 0.5%, respectively), and keratinization was detected only in waterpipe users (3.6%) compared with controls. Waterpipe users had higher p53 protein expression than non-users. Conclusion Using a waterpipe is an effective way to change the oral mucosa. In atypia and keratinization, there was high p53 expression. These results could indicate that p53 is involved in both the change from normal to cancerous cells and the growth of new cells, but the presence or absence of p53 staining could not be used to predict the outcome of potentially cancerous oral mucosal lesions.

Surgical Intervention is Effective for the Treatment of Crohn's related Rectovaginal Fistulas: Experience From A Tertiary Inflammatory Bowel Disease Practice

BACKGROUND AND AIMS

Rectovaginal fistula occurs in up to 10-20% of women with Crohn's disease, significantly affecting their quality of life. We sought to determine outcomes of single and repeat operative interventions.

METHODS

A retrospective review of all adult patients with a Crohn's related rectovaginal fistula who underwent an operation between 1995 to 2021 was performed. Data collected included patient demographics, Crohn's related medical treatment, surgical intervention, postoperative outcomes, and fistula outcomes.

RESULTS

A total of 166 patients underwent 360 operations; mean age was 42.8 (+/-13.2) years. Thirty-four (20.7%) patients were current and 58 (35.4%) former smokers. The most commonly performed procedure was a local approach (n=160, 44.5%) using fibrin glue, fistulotomy/fistulectomy or seton placement, followed by a transvaginal/transanal approach (n=113, 31.4%) with an advancement flap repair (including Martius advancement flap) and episoproctotomy, a transabdominal approach (n=98, 27.2%) including proctectomy or redo anastomosis and finally gracilis muscle interposition (n=8, 2.2%). The median number of operative interventions per patient was 2 (1.0-3.0) procedures. The overall fistula healing rate per patient was 71.7% (n=119) at a median follow-up of 5.5 (1.2-9.8) years. Factors that impaired healing included former smoking (OR 0.52 95%, CI 0.31 - 0.87, p=0.014) and seton insertion (OR 0.42 95%, CI 0.21-0.83, p=0.012).

CONCLUSION

Over two-thirds of Crohn's related rectovaginal fistulas can achieve closure with multiple surgical interventions. Smoking and seton usage negatively impact healing rates and should be avoided.

Evaluation of Surgical Treatment of Oroantral Fistulae in Smokers Versus Non-Smokers

Background and Objectives: Smoking has been found to interfere with wound healing processes. Therefore, the purpose of this study was to compare surgical treatment of oroantral fistulae (OAFs) in smokers and non-smokers. Materials and Methods: Medical records of all consecutive patients who underwent surgical closure of OAFs between 2003 and 2016 at the oral and maxillofacial surgery department, Rabin Medical Center, Israel were reviewed. Patients' demographic data, preoperative signs and symptoms, surgical method of repair, and postoperative complications were recorded. Results: The cohort consisted of 38 smokers and 59 non-smokers. Age and gender distributions were similar in both groups. The main etiology in both groups was tooth extraction, followed by pre-prosthetic surgery in smokers and odontogenic infection in non-smokers (p = 0.02). Preoperative conditions were not significantly different between smokers and non-smokers in terms of size of soft tissue fistula and bony defect, chronic sinusitis and foreign bodies inside the sinus. OAFs were repaired by local soft tissue flaps without consideration of smoking status. Smokers experienced more moderate-severe postoperative pain (p = 0.05) and requested more weak opioids (p = 0.06). Postoperative complications included infection, delayed wound healing, residual OAF, pain, sensory disturbances and sino nasal symptoms. These were mostly minor and tended to be more frequent in smokers (p = 0.35). Successful closure of OAFs was obtained in all patients except one smoker who required revision surgery. Conclusions: Smokers may be more susceptible to OAFs secondary to preprosthetic surgery. In this cohort, there was no statistically significant difference in outcome between smokers and non-smokers in terms of failure. However, smokers tended to have more severe postoperative pain and discomfort and to experience more postoperative complications. Further studies with larger sample sizes should be conducted to validate these results.

Influence of smoking on periodontal healing one year after active treatment

OBJECTIVE

To investigate the impact of smoking on the reduction of pockets >4 mm deep and a composite variable of residual pockets >4 mm and bleeding on probing (BoP) after treatment.

METHODS

Eligible after exclusion due to missing records were 3,535 individuals, referred for periodontal treatment between 1980 and 2015. The number of teeth (NT), probing pocket depth (PPD), proportion of plaque (PLI) and BoP were registered before treatment and 1 year after treatment. To analyse the impact of smoking on PPD reduction, a mixed model adjusted for age, sex, type of therapy, baseline PPD, reduction of PLI, BoP and NT was used. Depending on residual PPD and BoP, two categories were created: good and poor responders.

RESULTS

PLI was reduced by 20% in non-smokers and by 18% in smokers, and BoP by 46% and 37%, respectively. In the adjusted mixed model, the mean reduction of PPD > 4 mm among smokers undergoing surgery was 14.4 versus 9.7 in non-smokers (p < .001). The odds ratio for being a poor responder was 2.40 (95% CI 1.99-2.91, p < .001) for smokers.

CONCLUSION

Although surgical treatment reduced PPD >4 mm in smokers more effectively than in non-smokers, significantly more non-smokers were good responders after periodontal therapy.

WITHDRAWN: Guided tissue regeneration for periodontal infra-bony defects

BACKGROUND

Conventional treatment of destructive periodontal (gum) disease arrests the disease but does not usually regain the bone support or connective tissue lost in the disease process. Guided tissue regeneration (GTR) is a surgical procedure that specifically aims to regenerate the periodontal tissues when the disease is advanced and could overcome some of the limitations of conventional therapy.

OBJECTIVES

To assess the efficacy of GTR in the treatment of periodontal infra-bony defects measured against conventional surgery (open flap debridement (OFD)) and factors affecting outcomes.

SEARCH METHODS

We conducted an electronic search of the Cochrane Oral Health Group Trials Register, MEDLINE and EMBASE up to April 2004. Handsearching included Journal of Periodontology, Journal of Clinical Periodontology, Journal of Periodontal Research and bibliographies of all relevant papers and review articles up to April 2004. In addition, we contacted experts/groups/companies involved in surgical research to find other trials or unpublished material or to clarify ambiguous or missing data and posted requests for data on two periodontal electronic discussion groups.

SELECTION CRITERIA

Randomised, controlled trials (RCTs) of at least 12 months duration comparing guided tissue regeneration (with or without graft materials) with open flap debridement for the treatment of periodontal infra-bony defects. Furcation involvements and studies specifically treating aggressive periodontitis were excluded.

DATA COLLECTION AND ANALYSIS

Screening of possible studies and data extraction was conducted independently. The methodological quality of studies was assessed in duplicate using individual components and agreement determined by Kappa scores. Methodological quality was used in sensitivity analyses to test the robustness of the conclusions. The Cochrane Collaboration statistical guidelines were followed and the results expressed as mean differences (MD and 95% CI) for continuous outcomes and risk ratios (RR and 95% CI) for dichotomous outcomes calculated using random-effects models. Any heterogeneity was investigated. The primary outcome measure was change in clinical attachment.

MAIN RESULTS

The search produced 626 titles, of these 596 were clearly not relevant to the review. The full text of 32 studies of possible relevance was obtained and 15 studies were excluded. Therefore 17 RCTs were included in this review, 16 studies testing GTR alone and two testing GTR + bone substitutes (one study had both test treatment arms).No tooth loss was reported in any study although these data are incomplete where patient follow up was not complete. For attachment level change, the mean difference between GTR and OFD was 1.22 mm (95% CI Random Effects: 0.80 to 1.64, Chi2 for heterogeneity 69.1 (df = 15), P < 0.001, I2 = 78%) and for GTR + bone substitutes was 1.25 mm (95% CI 0.89 to 1.61, Chi2 for heterogeneity 0.01 (df = 1), P = 0.91). GTR showed a significant benefit when comparing the numbers of sites failing to gain 2 mm attachment with risk ratio 0.54 (95% CI Random Effects: 0.31 to 0.96, Chi2 for heterogeneity 8.9 (df = 5), P = 0.11). The number needed to treat (NNT) for GTR to achieve one extra site gaining 2 mm or more attachment over open flap debridement was therefore 8 (95% CI 5 to 33), based on an incidence of 28% of sites in the control group failing to gain 2 mm or more of attachment. For baseline incidences in the range of the control groups of 3% and 55% the NNTs are 71 and 4.Probing depth reduction was greater for GTR than OFD: 1.21 mm (95% CI 0.53 to 1.88, Chi2 for heterogeneity 62.9 (df = 10), P < 0.001, I2 = 84%) or GTR + bone substitutes, weighted mean difference 1.24 mm (95% CI 0.89 to 1.59, Chi2 for heterogeneity 0.03 (df = 1), P = 0.85).For gingival recession, a statistically significant difference between GTR and open flap debridement controls was evident (mean difference 0.26 mm (95% CI Random Effects: 0.08, 0.43, Chi2 for heterogeneity 2.7 (df = 8), P = 0.95), with a greater change in recession from baseline for the control group.Regarding hard tissue probing at surgical re-entry, a statistically significant greater gain was found for GTR compared with open flap debridement. This amounted to a weighted mean difference of 1.39 mm (95% CI 1.08 to 1.71, Chi2 for heterogeneity 0.85 (df = 2), P = 0.65). For GTR + bone substitutes the difference was greater, with mean difference 3.37 mm (95% CI 3.14 to 3.61).Adverse effects were generally minor although with an increased treatment time for GTR. Exposure of the barrier membrane was frequently reported with a lack of evidence of an effect on healing.

AUTHORS' CONCLUSIONS

GTR has a greater effect on probing measures of periodontal treatment than open flap debridement, including improved attachment gain, reduced pocket depth, less increase in gingival recession and more gain in hard tissue probing at re-entry surgery. However there is marked variability between studies and the clinical relevance of these changes is unknown. As a result, it is difficult to draw general conclusions about the clinical benefit of GTR. Whilst there is evidence that GTR can demonstrate a significant improvement over conventional open flap surgery, the factors affecting outcomes are unclear from the literature and these might include study conduct issues such as bias. Therefore, patients and health professionals need to consider the predictability of the technique compared with other methods of treatment before making final decisions on use. Since trial reports were often incomplete, we recommend that future trials should follow the CONSORT statement both in their conduct and reporting.There is therefore little value in future research repeating simple, small efficacy studies. The priority should be to identify factors associated with improved outcomes as well as investigating outcomes relevant to patients. Types of research might include large observational studies to generate hypotheses for testing in clinical trials, qualitative studies on patient-centred outcomes and trials exploring innovative analytic methods such as multilevel modelling. Open flap surgery should remain the control comparison in these studies.

Early wound healing outcomes after regenerative periodontal surgery with enamel matrix derivatives or guided tissue regeneration: a systematic review

BACKGROUND

Proper wound healing after regenerative surgical procedures is an essential issue for clinical success. Guided tissue regeneration (GTR) and application of enamel matrix derivatives (EMD) are common means to regenerate periodontal tissues. Both methods bear considerable advantages due to their special characteristics, but also go along with certain disadvantages. Today, there is no consensus in the literature whether GTR or EMD show better results regarding early wound healing, which is considered a crucial stage in periodontal regeneration. Therefore, the aim of the present systematic review was to compare the early wound healing after regenerative periodontal surgery with either EMD or GTR treatment.

METHODS

An electronic literature search in PubMed was performed to identify randomized clinical trials (RCTs) or clinical trials (CTs) comparing regenerative surgery employing EMD and/or GTR in patients with chronic periodontitis. Among the finally included studies, a qualitative and quantitative data extraction regarding early wound healing parameters was performed. Primary outcome parameters were early wound healing index (EWH), flap dehiscence, membrane exposure, suppuration and abscess formation during the first 6 weeks. As secondary parameters, swelling and allergic reactions were assessed.

RESULTS

Seven studies reporting 220 intrabony periodontal defects in 199 patients were analysed. Flap dehiscence was observed in two studies in 12% of the GTR treated sites and in 10.3% of those treated with EMD. Membrane exposure was evaluated in five studies and was registered in the 28.8% of the defects, while no dehiscence was reported on the EMD group. Swelling was reported only in one study in 8/16 GTR sites and 7/16 EMD sites. Due to considerable heterogeneity of parameters no meta-analysis was possible.

CONCLUSIONS

Due to considerable heterogeneity of the published studies a clear beneficial effect of the EMD on the early wound healing outcomes after surgical treatment of periodontal intrabony defects cannot be confirmed. Standardized RCT studies are needed in order to allow for proper comparison of early wound healing after both types of surgical approaches.

The influence of smoking on radiation-induced bystander signal production in esophageal cancer patients

The relevance of radiation-induced bystander effects in humans is unclear. Much of the existing data relate to cell lines but the effect of bystander signals in complex human tissues is unclear. A phase II clinical study was untaken, where blood sera from 60 patients along with 15 cancer-free volunteers were used to detect whether measurable bystander factor(s) could be found in the blood following high dose rate (HDR) brachytherapy. Overall, there was no significant change in bystander signal production (measured in a human keratinocyte reporter system) before and after one treatment fraction of HDR brachytherapy (p>0.05). Further assessment of patient characteristics and environmental modifiable factors including smoking were also analyzed. Similar to previously published data, samples taken from smokers produced weaker signals compared to non-smokers (p<0.05). Although the number of non-smoking subjects was low, there was a clear decrease in cloning efficiency observed in keratinocyte cultures for these patients that requires further study. This study found that samples taken from smokers do not produce bystander signals, whereas samples taken from non-smokers can produce such signals following HDR brachytherapy. These findings highlight the importance of studying the interactions of multiple stressors including environmental modifiers with radiation, since some factors such as smoking may elicit protection in tumor cells which could counteract the effectiveness of radiation therapy.

Clinical evaluation of hydroxyapatite and β-tricalcium phosphate composite graft in the treatment of intrabony periodontal defect: A clinico-radiographic study

Background and Objective:

Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) grafts have shown to be effective in promoting the clinical signs of periodontal regeneration in intrabony defects. The aim of our study was to clinically and radiographically evaluate the efficacy of HA and β-TCP composite bone graft material in the treatment of intrabony three-wall defect.

Materials and Methods:

Twenty patients participated in this study. Interproximal bony defects were surgically treated with a combination of HA–βTCP (biphasic calcium phosphate). Changes in clinical parameters such as gingival status, probing pocket depth, clinical attachment, and radiographic estimation of the amount of bone fill were evaluated after 6 months postoperatively.

Statistical Analysis Used:

Student's “t” test.

Results:

This treatment modality resulted in significant pocket depth reduction and clinical attachment gain which were observed to be 2.938 mm (47.04%) and 3.188 mm (29.09%), respectively. The defect fill as seen radiographically was 3.204 mm (63.195%). All the differences were highly significant and in favor of postoperative group.

Conclusion:

The results of this study suggest that HA–βTCP (biphasic calcium phosphate) provides an added regenerative effect in promoting the clinical resolution of intrabony three-wall defects in patients with periodontitis.

AB, Taba Jr. M, Palioto DB, Grisi MFM, Souza SLS. Treatment of Intrabony Defects with Anorganic Bone Matrix/P-15 or Guided Tissue Regeneration in Patients with Aggressive Periodontitis

Intrabony periodontal defects present a particular treatment problem, especially in patients with generalized aggressive periodontitis (G-AgP). Regenerative procedures have been indicated for this clinical situation. The aim of this study was to compare treatment outcomes of intrabony periodontal defects with either anorganic bone matrix/cell binding peptide (ABM/P-15) or guided tissue regeneration (GTR) in patients with G-AgP. Fifteen patients, with two intrabony defects ≥3 mm deep, were selected. Patients were randomly allocated to be treated with ABM/P-15 or GTR. At baseline and at 3 and 6 months after surgery, clinical and radiographic parameters and IL-1β and IL-6 gingival fluid concentrations were recorded. There was a significant probing pocket depth reduction (p<0.001) for both groups (2.27 ± 0.96 mm for ABM/P-15 group and 2.57 ± 1.06 mm for GTR group). Clinical attachment level gain (1.87 ± 0.94 mm for ABM/P-15 group and 2.09 ± 0.88 mm for GTR group) was also observed. There were no statistically significant differences in clinical parameters between the groups. The radiographic bone fill was more expressive in ABM/P-15 group (2.49 mm) than in GTR group (0.73 mm). In subtraction radiographs, the areas representing gain in density were 93.16% of the baseline defect for ABM/P-15 group versus 62.03% in GRT group. There were no statistically significant differences in inter-group and intra-group comparisons with regards to IL-1β and IL-6 quantification. Treatment of intrabony periodontal defects in patients with G-AgP with ABM/P-15 and GTR improved significantly the clinical outcomes. The use of ABM/P-15 promoted a better radiographic bone fill.

A primer on network meta-analysis for dental research

In the last decade, a new statistical methodology, namely, network meta-analysis, has been developed to address limitations in traditional pairwise meta-analysis. Network meta-analysis incorporates all available evidence into a general statistical framework for comparisons of all available treatments. A further development in the network meta-analysis is to use a Bayesian statistical approach, which provides a more flexible modelling framework to take into account heterogeneity in the evidence and complexity in the data structure. The aim of this paper is therefore to provide a nontechnical introduction to network meta-analysis for dental research community and raise the awareness of it. An example was used to demonstrate how to conduct a network meta-analysis and the differences between it and traditional meta-analysis. The statistical theory behind network meta-analysis is nevertheless complex, so we strongly encourage close collaboration between dental researchers and experienced statisticians when planning and conducting a network meta-analysis. The use of more sophisticated statistical approaches such as network meta-analysis will improve the efficiency in comparing the effectiveness between multiple treatments across a set of trials.

Are there predictors of outcome following rectovaginal fistula repair?

BACKGROUND

Rectovaginal fistula is a distressing condition for patients and for physicians who are continuously challenged in providing durable treatment options. The aim of this study is to assess the results of rectovaginal fistula repair and identify predictive factors for poor outcome.

METHODS

Retrospective analysis of patients who underwent rectovaginal fistula repair from 1988 to 2008 was performed. chi tests and logistical regression analysis were used to study treatment outcomes according to the following fistula characteristics: etiology, size, location, and number of prior attempts at fistula repair. In addition, patient factors such as age, body mass index, smoking history, comorbid condition of diabetes, use of steroid and immunosuppressive medications, number of prior vaginal deliveries, and presence of a diverting stoma were analyzed.

RESULTS

A total of 184 procedures were performed in 125 patients. Inflammatory bowel disease was the most common indication for surgery (45.6%), followed by obstetric injury (24%) and surgical trauma (16%). The mean duration of fistula presence was 31.2 months. The procedures performed included endorectal advancement flap (35.3%), gracilis muscle interposition (13.6%), seton placement (13.6%), and transperineal (8.7%) and transvaginal repair (8.1%). The overall success rate per procedure was 60%, with no difference in recurrence rates based on the type of repair. Patients with Crohn's disease had more recurrent fistulas (44.2% success per procedure; P < .01), although 78% eventually healed after an average of 1.8 procedures. Patients with obstetric injuries had an 89% success rate after an average of 1.3 procedures per patient, which is similar to the success rate for traumatic fistulas. Pouch vaginal fistulas had a 91% success rate after an average of 1.6 procedures per patient. The overall success rate per patient was 88% after multiple procedures with a mean follow-up of 16.3 months. Age, body mass index, diabetes, use of steroids and immunosuppressive agents, size and location of the fistula, number of vaginal deliveries, time interval between a recurrent episode and subsequent repair, and the presence of fecal diversion did not affect outcomes. The presence of Crohn's disease and a smoking history are strongly associated with rectovaginal fistula recurrence (P = .02).

CONCLUSIONS

Despite a relatively low initial success rate (60%), most rectovaginal fistulas can be successfully repaired with subsequent operations. Crohn's disease and smoking are associated with adverse outcomes.

Regeneration of periodontal tissues: guided tissue regeneration

The concept that only fibroblasts from the periodontal ligament or undifferentiated mesenchymal cells have the potential to re-create the original periodontal attachment has been long recognized. Based on this concept, guided tissue regeneration has been applied with variable success to regenerate periodontal defects. Quantitative analysis of clinical outcomes after guided tissue regeneration suggests that this therapy is a successful and predictable procedure to treat narrow intrabony defects and class II mandibular furcations, but offers limited benefits in the treatment of other types of periodontal defects.

Partial least squares path modelling for relations between baseline factors and treatment outcomes in periodontal regeneration

BACKGROUND

Some clinical outcome variables in periodontal research are mathematically coupled, and it is not feasible to include all the mathematically coupled variables in an ordinary least squares (OLS) regression analysis. The simplest solution to this problem is to drop at least one of the mathematically coupled variables. However, this solution is not satisfactory when the mathematically coupled variables have distinctive clinical implications.

MATERIAL AND METHODS

Partial least squares (PLS) methods were used to analyse data from a study on guided tissue regeneration. Relationships between characteristics of baseline lesions and treatment outcomes after 1 year were analysed using PLS, and the results were compared with those from OLS regression.

RESULTS

PLS analysis suggested that there were multiple dimensions in the characteristics of baseline lesion: vertical dimension was positively associated with probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain, whilst horizontal dimension was negatively associated with the outcome. Baseline gingival recession had a negative association with PPD reduction but a small positive one with CAL gain.

CONCLUSION

PLS analysis provides new insights into the relationships between baseline characteristics of infrabony defects and periodontal treatment outcomes. The hypothesis of multiple dimensions in baseline lesions needs to be validated by further analysis of different datasets.

Predictability of clinical outcomes following regenerative therapy in intrabony defects

BACKGROUND

Demineralized bone matrix (DBM) and guided tissue regeneration (GTR) support substantial gains in clinical attachment level (CAL), reductions in probing depth (PD), and gains in defect fill compared to open flap debridement (OFD) in intrabony defects. Although these regenerative therapies support improvements in mean clinical parameters, it is unclear whether the procedures improve the predictability of clinical outcome. The purpose of this study was to examine the relative variability in clinical outcome measures, independent of the magnitude of gains, in regenerative studies comparing DBM or GTR to OFD therapy for the management of intrabony defects. For comparative purposes, a similar analysis was performed evaluating the consistency of clinical outcomes with other (non-DBM) bone replacement graft (BRG) materials relative to OFD alone.

METHODS

Fifty-five randomized controlled clinical trials comparing regenerative therapy (seven DBM, 22 BRG, and 26 GTR) to OFD and meeting inclusion criteria provided mean change scores (pretreatment to post-treatment) and variance estimates for CAL, PD, and bone fill, allowing for calculation of a coefficient of variability (CV) for each measure within studies. The mean CV for each measure was submitted to an analysis of variance or covariance with repeated measures (P < or =0.05) to compare relative variation in treatment outcomes.

RESULTS

DBM was associated with a significantly lower relative variability (mean +/- SE) in CAL gain (96.3 +/- 38.6 versus 137.7 +/- 30.9) and defect fill (69.1 +/- 11.2 versus 133.1 +/- 15.3) compared to OFD alone. As a group, other BRGs were found to support significant reductions in variation in CAL and defect fill. GTR therapy was associated with significantly lower CV for CAL compared to OFD (50.6 +/- 5.0 versus 68.7 +/- 8.2, respectively). Variability in defect fill was similar for GTR and OFD.

CONCLUSIONS

DBM and GTR therapy support more consistent improvements in clinical parameters; however, with the exception of defect fill following bone grafting, the reduction in variability in clinical outcomes was relatively modest compared to OFD alone. Overall, the treatment of intrabony defects is associated with a relatively high degree of variability in clinical outcome, regardless of therapeutic approach.

Surgical treatment of peri-implantitis using a bone substitute with or without a resorbable membrane: a prospective cohort study

OBJECTIVES

The aim of this prospective cohort study was to compare two regenerative surgical treatment modalities for peri-implantitis.

MATERIAL AND METHODS

Thirty-six patients having a minimum of one osseointegrated implant, with a progressive loss of bone amounting to > or =3 threads (1.8 mm) following the first year of healing, combined with bleeding and/or pus on probing, were involved in this study. The patients were assigned to two different treatment strategies. After surgical exposure of the defect, granulomatous tissue was removed and the infected implant surface was treated using 3% hydrogen peroxide. The bone defects were filled with a bone substitute (Algipore). In 17 patients (Group 1), a resorbable membrane (Osseoquest) was placed over the grafted defect before suturing. In 19 patients (Group 2), the graft was used alone.

RESULTS

One-year follow-up demonstrated clinical and radiographic improvements. Probing depths were reduced by 2.9 mm in Group 1 and by 3.4 mm in Group 2. Defect fill amounted to 1.5 and 1.4 mm, respectively. There was no significant difference between the groups.

CONCLUSION

It is possible to treat peri-implant defects with a bone substitute, with or without a resorbable membrane.

Levels of gingival tissue platelet activating factor after conventional and regenerative periodontal surgery

The hypothesis, a relationship between gingival tissue platelet activating factor (PAF) levels and healing after periodontal surgery, was tested by measuring PAF levels in gingival tissues collected from sites that had undergone flap surgery and guided tissue regeneration (GTR) or flap surgery alone. Using a split-mouth design, 20 intrabony defects were randomly assigned to treatment with flap surgery and GTR (group 1) or with flap surgery alone (group 2). Gingival tissue samples were obtained at surgery (baseline) and at 6-month follow-up evaluation visit. One half of each sample was used for analysis of PAF levels by high-performance liquid chromatography, and the other half of the sample was used for histomorphometric analysis that included measurements of number and diameter of blood vessels. PAF levels and diameter of blood vessels were significantly decreased (p < 0.01), and the number of blood vessels was significantly increased (p < 0.05) in both groups after 6 months compared to the baseline values. Postoperative number of blood vessels were significantly higher in group 1 (p < 0.05), whereas there was no significant difference in postoperative PAF levels between the two groups (p > 0.05). Based on the reported results, it is suggested that a decrease in gingival PAF levels might be found after conventional and regenerative periodontal surgery.

Surgical Treatment of Infrabony Defects With Autologous Platelet Concentrate or Bioabsorbable Barrier Membrane: A Prospective Case Series

BACKGROUND

Autologous platelet concentrate (APC) contains concentrated platelet-derived growth factors that promote wound healing and tissue regeneration. The purpose of this prospective case series was to compare the treatment effects of an intralesional graft of APC to guided periodontal regeneration (GPR) using a bioabsorbable barrier membrane (MEM) over a 52-week period.

METHODS

Five patients were recruited for the study from two private periodontal practices. There were four females and one male having a mean age of 33 +/- 10.23 years. The five selected contralateral teeth had similar, but not identical, combinations of 1-, 2-, and 3-wall infrabony defects not involving furcations. Probing depths (PDs) of the defects were > or = 6 mm and had radiographic angular infrabony defects > or = 4 mm in depth. The patients had no local or systemic contraindications to minor oral surgical procedures and had not taken systemic antibiotics for > or = 6 months before the commencement of the study. All patients had completed cause-related periodontal therapy up to 6 months previously and had achieved a satisfactory level of oral hygiene. The selected teeth did not have purulent discharge from the pockets and responded normally to pulp sensibility testing. Patients were excluded if they smoked, were pregnant or lactating, or were allergic to any of the materials to be used in the treatment. At baseline and 8, 26, and 52 weeks after surgery, PDs, recession (REC), presence of plaque, and bleeding on probing were recorded, and standardized periapical radiographs were taken. At the time of surgery, the vertical distance to the deepest point of the infrabony defect was measured from the cemento-enamel junction (CEJ) to the buccal and lingual bone crests. The vertical distance to the base of the defect from the CEJ and defect angles were obtained from radiographs. The paired contralateral infrabony defects were treated with a graft APC or MEM after debridement and EDTA root surface conditioning. Surgical flaps were prepared and closed according to the papilla preservation method. Post-surgical care was provided at 1, 2, 8, 26, and 52 weeks after surgery. A mouthwash of 0.2% chlorhexidine gluconate was used twice daily for the first 3 weeks after surgery. Mean PD, REC, clinical attachment level (CAL), radiographic bone loss, and defect angle were computed and compared for each data collection point.

RESULTS

From baseline to 52 weeks, a mean PD reduction of 3 +/- 1.41 mm (APC) and 3.6 +/- 1.67 mm (MEM), mean REC increase of 0.8 +/- 1.01 mm (APC) and 0.6 +/- 1.14 mm (MEM), mean CAL gain of 2.2 +/- 1.79 mm (APC) and 3 +/- 1 mm (MEM), mean radiographic bone fill of 3.24 +/- 2.85 mm (APC) and 2.7 +/- 1.9 mm (MEM), and mean defect-angle increase of 15.25 degrees +/- 18.21 degrees (APC) and 22.4 degrees +/- 27.3 degrees (MEM) were calculated. CAL gain was not related clearly to defect angle at baseline, although radiographic bone fill was slightly greater for defect angles <39.4 degrees +/- 7.88 degrees.

CONCLUSIONS

This case series of five similar, but not identical, bilateral paired infrabony defects suggests that an APC graft achieves a similar CAL gain and PD reduction to GPR using an MEM over a 52-week period. A larger, controlled clinical trial is needed to evaluate further the efficacy of autologous platelet-rich plasma for the treatment of infrabony defects.

Levels of platelet activating factor in gingival crevice fluid following periodontal surgical therapy

BACKGROUND AND OBJECTIVE

Elevated levels of platelet activating factor (PAF), a potent inflammatory phospholipid mediator, have been previously detected in gingival tissues and gingival crevice fluid (GCF) in periodontal disease. However, the role of this mediator during wound healing after periodontal surgery remains unclear. The hypothesis, a relationship between PAF levels and periodontal healing, was tested by measuring PAF levels in GCF samples collected from sites that had undergone guided tissue regeneration (GTR) or flap surgery.

MATERIAL AND METHODS

Using a split-mouth design, 30 intrabony defects were randomly assigned to treatment with GTR (group 1) or to flap surgery (group 2). GCF was sampled pre-operatively and at 6-, 12- and 24-wk follow-up evaluation visits. PAF levels in GCF were analyzed by high-performance liquid chromatography (HPLC).

RESULTS

Both treatment modalities significantly reduced the probing pocket depth and improved the clinical attachment level (p < 0.01). Compared with pre-operative values, the GCF volume and PAF levels were significantly decreased at postoperative weeks 6, 12 and 24 in both groups (p < 0.01). There were also significant differences in GCF volume and PAF levels at all time points up to 24 wks in both groups (p < 0.01). No statistically significant differences were observed in any of the parameters investigated between the two groups (p > 0.05).

CONCLUSION

PAF is detectable in GCF by HPLC and showed a continuous decrease at all the time points monitored following periodontal surgical therapy. This suggests that changes in the levels of this mediator in GCF might be useful for monitoring the progress of periodontal repair and regeneration.

Reconstructive periodontal surgery: A challenge for modern periodontology

The overall rationale for the proposed clinical approach in this paper comes from consideration of different regenerative approaches reported in the literature. The protocol proposed is based mainly on evidence and partly on the clinical experience of the author and co-workers, who have found that patient associated factors such as plaque control, residual periodontal infection, and smoking habits are those of particular relevance. Among the technical/surgical associated factors, lack of primary closure of the interdental space and consequent bacterial contamination of the regenerating wound represent the most significant factors leading to compromised outcomes. Modified flap designs and a microsurgical approach have been shown to improve the outcomes. There is now sufficient evidence to suggest that clinicians can incorporate periodontal regeneration in their surgical armamentarium. Periodontal regeneration can be predictably used to treat deep pockets associated with deep intrabony defects in young and old people, aimed at pocket/defect resolution with aesthetic preservation, gain of clinical attachment and bone.

Guided tissue regeneration for periodontal infra-bony defects

BACKGROUND

Conventional treatment of destructive periodontal (gum) disease arrests the disease but does not usually regain the bone support or connective tissue lost in the disease process. Guided tissue regeneration (GTR) is a surgical procedure that specifically aims to regenerate the periodontal tissues when the disease is advanced and could overcome some of the limitations of conventional therapy.

OBJECTIVES

To assess the efficacy of GTR in the treatment of periodontal infra-bony defects measured against conventional surgery (open flap debridement (OFD)) and factors affecting outcomes.

SEARCH STRATEGY

We conducted an electronic search of the Cochrane Oral Health Group Trials Register, MEDLINE and EMBASE up to April 2004. Handsearching included Journal of Periodontology, Journal of Clinical Periodontology, Journal of Periodontal Research and bibliographies of all relevant papers and review articles up to April 2004. In addition, we contacted experts/groups/companies involved in surgical research to find other trials or unpublished material or to clarify ambiguous or missing data and posted requests for data on two periodontal electronic discussion groups.

SELECTION CRITERIA

Randomised, controlled trials (RCTs) of at least 12 months duration comparing guided tissue regeneration (with or without graft materials) with open flap debridement for the treatment of periodontal infra-bony defects. Furcation involvements and studies specifically treating aggressive periodontitis were excluded.

DATA COLLECTION AND ANALYSIS

Screening of possible studies and data extraction was conducted independently. The methodological quality of studies was assessed in duplicate using individual components and agreement determined by Kappa scores. Methodological quality was used in sensitivity analyses to test the robustness of the conclusions. The Cochrane Oral Health Group statistical guidelines were followed and the results expressed as mean differences (MD and 95% CI) for continuous outcomes and risk ratios (RR and 95% CI) for dichotomous outcomes calculated using random-effects models. Any heterogeneity was investigated. The primary outcome measure was change in clinical attachment.

MAIN RESULTS

The search produced 626 titles, of these 596 were clearly not relevant to the review. The full text of 32 studies of possible relevance was obtained and 15 studies were excluded. Therefore 17 RCTs were included in this review, 16 studies testing GTR alone and two testing GTR+bone substitutes (one study had both test treatment arms).No tooth loss was reported in any study although these data are incomplete where patient follow up was not complete. For attachment level change, the mean difference between GTR and OFD was 1.22 mm (95% CI Random Effects: 0.80 to 1.64, chi squared for heterogeneity 69.1 (df = 15), P < 0.001, I(2) = 78%) and for GTR + bone substitutes was 1.25 mm (95% CI 0.89 to 1.61, chi squared for heterogeneity 0.01 (df = 1), P = 0.91). GTR showed a significant benefit when comparing the numbers of sites failing to gain 2 mm attachment with risk ratio 0.54 (95% CI Random Effects: 0.31 to 0.96, chi squared for heterogeneity 8.9 (df = 5), P = 0.11). The number needed to treat (NNT) for GTR to achieve one extra site gaining 2 mm or more attachment over open flap debridement was therefore 8 (95% CI 5 to 33), based on an incidence of 28% of sites in the control group failing to gain 2 mm or more of attachment. For baseline incidences in the range of the control groups of 3% and 55% the NNTs are 71 and 4. Probing depth reduction was greater for GTR than OFD: 1.21 mm (95% CI 0.53 to 1.88, chi squared for heterogeneity 62.9 (df = 10), P < 0.001, I(2) = 84%) or GTR + bone substitutes, weighted mean difference 1.24 mm (95% CI 0.89 to 1.59, chi squared for heterogeneity 0.03 (df = 1), P = 0.85). For gingival recession, a statistically significant difference between GTR and open flap debridement controls was evident (mean difference 0.26 mm (95% CI Random Effects: 0.08, 0.43, chi squared for heterogeneity 2.7 (df = 8), P = 0.95), with a greater change in recession from baseline for the control group. Regarding hard tissue probing at surgical re-entry, a statistically significant greater gain was found for GTR compared with open flap debridement. This amounted to a weighted mean difference of 1.39 mm (95% CI 1.08 to 1.71, chi squared for heterogeneity 0.85 (df = 2), P = 0.65). For GTR + bone substitutes the difference was greater, with mean difference 3.37 mm (95% CI 3.14 to 3.61). Adverse effects were generally minor although with an increased treatment time for GTR. Exposure of the barrier membrane was frequently reported with a lack of evidence of an effect on healing.

AUTHORS' CONCLUSIONS

GTR has a greater effect on probing measures of periodontal treatment than open flap debridement, including improved attachment gain, reduced pocket depth, less increase in gingival recession and more gain in hard tissue probing at re-entry surgery. However there is marked variability between studies and the clinical relevance of these changes is unknown. As a result, it is difficult to draw general conclusions about the clinical benefit of GTR. Whilst there is evidence that GTR can demonstrate a significant improvement over conventional open flap surgery, the factors affecting outcomes are unclear from the literature and these might include study conduct issues such as bias. Therefore, patients and health professionals need to consider the predictability of the technique compared with other methods of treatment before making final decisions on use. Since trial reports were often incomplete, we recommend that future trials should follow the CONSORT statement both in their conduct and reporting. There is therefore little value in future research repeating simple, small efficacy studies. The priority should be to identify factors associated with improved outcomes as well as investigating outcomes relevant to patients. Types of research might include large observational studies to generate hypotheses for testing in clinical trials, qualitative studies on patient-centred outcomes and trials exploring innovative analytic methods such as multilevel modelling. Open flap surgery should remain the control comparison in these studies.

Microbial colonization patterns predict the outcomes of surgical treatment of intrabony defects

AIM

To explore the impact of bacterial load and microbial colonization patterns on the clinical outcomes of periodontal surgery at deep intrabony defects.

MATERIALS AND METHODS

One hundred and twenty-two patients with advanced chronic periodontitis and at least one intrabony defect of >3 mm were recruited in 10 centres. Before recruitment, the infection control phase of periodontal therapy was completed. After surgical access and debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CAL), pocket probing depths (PPD), recession (REC), full-mouth plaque scores and full-mouth bleeding scores were assessed. Microbial colonization of the defect-associated pocket was assessed using a DNA-DNA checkerboard analysis.

RESULTS

Total bacterial load and counts of red complex bacteria were negatively associated with CAL gains 1 year following treatment. The probability of achieving above median CAL gains (>3 mm) was significantly decreased by higher total bacterial counts, higher red complex and T. forsythensis counts immediately before surgery.

CONCLUSIONS

Presence of high bacterial load and specific periodontal pathogen complexes in deep periodontal pockets associated with intrabony defects had a significant negative impact on the 1 year outcome of surgical/regenerative treatment.

The problem of analysing the relationship between change and initial value in oral health research

The relationship between initial disease status and subsequent change following treatment has attracted great interest in dental research. However, medical statisticians have repeatedly warned against correlating/regressing change with baseline because of two methodological concerns known as mathematical coupling and regression to the mean. In general, mathematical coupling occurs when one variable directly or indirectly contains the whole or part of another, and the two variables are then analyzed by using correlation or regression. Consequently, the statistical procedure of testing the null hypothesis - that the coefficient of correlation or the slope of regression is zero - may become inappropriate. Regression to the mean occurs with any variable that fluctuates within an individual or a population, either owing to measurement error and/or to physiological variation. The aim of this article was to clarify the conceptual confusion around mathematical coupling and regression to the mean within the statistical literature, and to correct a popular misconception about the correct analysis of the relationship between change and initial value. As examples that use inappropriate methods to analyze the relationship between change and baseline are still found in leading dental journals, this article seeks to help oral health researchers understand these problems and explain how to overcome them.

The relationship between baseline value and its change: problems in categorization and the proposal of a new method

Oral health researchers have shown great interest in the relationship between the initial status of diseases and subsequent changes following treatment. Two main approaches have been adopted to provide evidence of a positive association between baseline values and their changes following treatment. One approach is to use correlation or regression to test the relationship between baseline measurements and subsequent change (correlation/regression approach). The second approach is to categorize the lesions into subgroups, according to threshold values, and subsequently compare the treatment effects across the two (or more) subgroups (categorization approach). However, the correlation/regression approach suffers a methodological weakness known as mathematical coupling. Consequently, the statistical procedure of testing the null hypothesis becomes inappropriate. Categorization seems to avoid the problem of mathematical coupling, although it still suffers regression to the mean. We show, first, how the appropriate null hypothesis may be established to analyze the relationship between baseline values and change in the correlation approach and, second, we use computer simulations to investigate the impact of regression to the mean on the significance testing of the differences in the average treatment effects (or average baseline values) in the categorization approach. Data available from previous literature are reanalyzed by testing the appropriate null hypotheses and the results are compared to those from testing the usual (incorrect) null hypothesis. The results indicate that both the correlation and categorization approaches can give rise to misleading conclusions and that more appropriate methods, such as Oldham's method and our new approach of deriving the correct null hypothesis, should be adopted.

The combined use of enamel matrix proteins and a tetracycline-coated expanded polytetrafluoroethylene barrier membrane in the treatment of intra-osseous defects

OBJECTIVES

The purpose of this split-mouth study was to evaluate the clinical response of enamel matrix proteins (EMPs, Emdogain Gel in intra-osseous defects with or without a combined application of a tetracycline-coated expanded polytetrafluoroethylene barrier membrane (e-PTFE, Gore-Tex).

METHODS

Twelve pairs of intra-osseous periodontal defects in 11 patients received the application of EMPs on the exposed root surface (EMP). One of the two defects received randomly, as an adjunct to EMP treatment, a tetracycline-coated e-PTFE membrane (MEMP). At baseline, 6- and 12-month probing pocket depth (PPD), clinical attachment level (CAL) and probing bone level (PBL) were measured.

RESULTS

After 12 months, the EMP defects showed a significant mean PPD reduction of 2.86+/-0.75 mm, a mean gain in CAL of 1.28+/-2.04 mm, a mean PBL gain of 1.63+/-1.21 mm and a mean increase of recession (REC) of 1.56+/-2.30 mm. The MEMP defects showed a significant mean PPD reduction of 3.02+/-1.55 mm, a mean gain in CAL of 1.65+/-1.29 mm, a mean PBL gain of 1.58+/-1.92 mm and a mean increase of REC of 1.38+/-1.63 mm. Except for significantly more post-operative discomfort at the MEMP sites, no significant differences were found between EMP and MEMP defects.

CONCLUSION

Within the limits of this study, it is concluded that in the treatment of intra-osseous defects with EMP, the adjunctive use of a tetracycline-coated e-PTFE membrane failed to show more gain of CAL and PBL.

Smoking affects the outcome of guided tissue regeneration with bioresorbable membranes: a retrospective analysis of intrabony defects

OBJECTIVES

To disclose factors that may influence the results of guided tissue regeneration (GTR) treatment in intrabony defects with bioresorbable membranes.

METHODS

Forty-seven intrabony defects in 32 patients were treated by means of polylactic acid/citric acid ester copolymer bioresorbable membranes. At baseline and after 1 year, the following parameters were recorded: (1) probing pocket depth (PPD), (2) gingival recession (REC), (3) probing attachment level (PAL)=PPD+REC, (4) presence/absence of plaque (PI), (5) presence/absence of bleeding on probing (BOP) and (6) intrabony component (IC) configuration (i.e. primarily presence of one, two, or three bone walls). Occurrence of membrane exposure and smoking habits were also recorded. Significance of differences between categorical variables was evaluated with McNemar's test, and between numerical variables with the t-test for paired observations. Generalized linear models were constructed to evaluate the influence of various factors on PAL gain and PPD after 1 year, including in the analysis only one defect per patient (i.e. 32 defects) chosen at random. Odds ratios were calculated using the Mantel-Haenszel method. Differences between smokers and non-smokers were evaluated by means of Pearson's chi2 and Student's t-test for non-paired observations.

RESULTS

At baseline, a mean PPD of 8.6+/-1.1 mm and a mean PAL of 9.8+/-1.6 mm was recorded. Statistically significant clinical improvements were observed 1 year after GTR treatment. An average residual PPD of 3.7+/-1.1 mm and a mean PAL gain of 3.8+/-1.5 mm were recorded. IC configuration and exposure of the membrane did not seem to influence the results, while a negative effect of smoking on the clinical parameters was observed. Smokers gained approximately 1 mm less in PAL than non-smokers (3.2+/-1.4 versus 4.3+/-1.3, respectively; p=0.03) and had approximately seven times less chances to gain 4 mm in PAL as compared with patients who did not smoke (odds ratio: 0.15). PPD reduction was less pronounced in smokers than in non-smokers (4.5+/-0.7 versus 5.5+/-0.7, respectively; p<0.01), resulting in somewhat deeper residual PPD in smokers than in non-smokers (3.6+/-1.0 versus 3.4+/-1.1; p>0.05).

CONCLUSION

Smoking impairs the healing outcome of GTR treatment of intrabony defects with bioresorbable membranes.

The efficacy of bone replacement grafts in the treatment of periodontal osseous defects. A systematic review

BACKGROUND

Bone replacement grafts (BRG) are widely used in the treatment of periodontal osseous defects; however, the clinical benefits of this therapeutic practice require further clarification through a systematic review of randomized controlled studies.

RATIONALE

The purpose of this systematic review is to access the efficacy of bone replacement grafts in proving demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone.

FOCUSED QUESTION

What is the effect of bone replacement grafts compared to other interventions on clinical, radiographic, adverse, and patient-centered outcomes in patients with periodontal osseous defects?

SEARCH PROTOCOL

The computerized bibliographical databases MEDLINE and EMBASE were searched from 1966 and 1974, respectively, to October 2002 for randomized controlled studies in which bone replacement grafts were compared to other surgical interventions in the treatment of periodontal osseous defects. The search strategy included screening of review articles and reference lists of retrieved articles as well as hand searches of selected journals.

INCLUSION CRITERIA

All searches were limited to human studies in English language publications.

EXCLUSION CRITERIA

Non-randomized observational studies (e.g., case reports, case series), publications providing summary statistics without variance estimates or data to permit computation, and studies without BRG intervention alone were excluded.

DATA COLLECTION AND ANALYSIS

The therapeutic endpoints examined included changes in bone level, clinical attachment level, probing depth, gingival recession, and crestal resorption. For purposes of meta-analysis, change in bone level (bone fill) was used as the primary outcome measure, measured upon surgical re-entry or transgingival probing (sounding).

MAIN RESULTS

1. Forty-nine controlled studies met eligibility criteria and provided clinical outcome data on intrabony defects following grafting procedures. 2. Seventeen studies provided clinical outcome data on BRG materials for the treatment of furcation defects.

REVIEWERS' CONCLUSIONS

1. With respect to the treatment of intrabony defects, the results of meta-analysis supported the following conclusions: 1) bone grafts increase bone level, reduce crestal bone loss, increase clinical attachment level, and reduce probing depth compared to open flap debridement (OFD) procedures; 2) No differences in clinical outcome measures emerge between particulate bone allograft and calcium phosphate (hydroxyapatite) ceramic grafts; and 3) bone grafts in combination with barrier membranes increase clinical attachment level and reduce probing depth compared to graft alone. 2. With respect to the treatment of furcation defects, 15 controlled studies provided data on clinical outcomes. Insufficient studies of comparable design were available to submit data to meta-analysis. Nonetheless, outcome data from these studies generally indicated positive clinical benefits with the use of grafts in the treatment of Class II furcations. 3. With respect to histological outcome parameters, 2 randomized controlled studies provide evidence that demineralized freeze-dried bone allograft (DFDBA) supports the formation of a new attachment apparatus in intrabony defects, whereas OFD results in periodontal repair characterized primarily by the formation of a long junctional epithelial attachment. Multiple observational studies provide consistent histological evidence that autogenous and demineralized allogeneic bone grafts support the formation of new attachment. Limited data also suggest that xenogenic bone grafts can support the formation of a new attachment apparatus. In contrast, essentially all available data indicate that alloplastic grafts support periodontal repair rather than regeneration. 4. The results of this systematic review indicate that bone replacement grafts provide demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone.

Cigarette Smoking and the Periodontal Patient

Evidence from cross-sectional and case-control studies in various populations demonstrates that adult smokers are approximately three times as likely as non-smokers to have periodontitis. The association between smoking and attachment loss is even stronger when the definition of periodontitis is restricted to the most severely affected subjects. Smokers have a diminished response to periodontal therapy and show approximately half as much improvement in probing depths and clinical attachment levels following non-surgical and various surgical modalities of therapy. Implant failures in smokers are twice those of non-smokers, with a higher failure rate in the maxillary arch accounting for the majority of the difference. Tobacco-induced alterations in microbial and host factors contribute to these deleterious effects of smoking on the periodontium. In longitudinal studies, the rate of periodontal disease progression is increased in smokers, but decreases to that of a non-smoker following tobacco cessation. Likewise, recent non-smokers respond to periodontal therapy in a manner similar to patients who have never smoked. Data regarding the impact of smoking on periodontal status included in this review will be helpful to dental health professionals as they counsel their patients regarding tobacco use. The role of dental health professionals in tobacco cessation is discussed, including the use of the five A's: ask--identify tobacco users; advise--advise them to quit; assess--evaluate the patient's readiness to quit; assist--offer assistance in cessation; and arrange--follow up on the patient's cessation efforts. The addition of pharmacotherapy to behavioral therapy, including nicotine replacement therapy and bupropion, can increase cessation rates. The most popular form of nicotine replacement therapy is the patch, and its use has been shown to double cessation rates compared to behavioral therapy alone. Use of bupropion in combination with nicotine replacement therapy may be particularly helpful for heavy smokers or smokers who have experienced multiple failed attempts at cessation. The American Academy of Periodontology Parameters of Care include tobacco cessation as a part of periodontal therapy, and the 2000 Surgeon General's Report on Oral Health in America encourages dental professionals to become more active in tobacco cessation counseling. Doing so will have far-reaching positive effects on our patients' oral and general health.

Factors Influencing the Outcome of Regenerative Therapy in Mandibular Class II Furcations: Part I

BACKGROUND

Factors influencing the outcome of regenerative therapy of Class II furcations are incompletely and poorly understood. The purpose of this 24-month prospective study was to examine the relationship of patient-, site-, and treatment-related factors to the clinical closure of randomly selected mandibular Class II furcations. Results of therapy were evaluated at 1 and 2 years postoperatively. One-year outcome data are presented in this report.

METHODS

A total of 43 otherwise healthy individuals with chronic periodontitis (26 male, 17 female), 36 to 70 years of age, completed the 12-month evaluation of the study. Entry criteria included clinical and radiographic evidence of two or more mandibular facial Class II furcation defects (> or = 3 mm horizontal probing depth). Surgical therapy was completed by four periodontists (two each) in either a university clinic or private practice. Each patient contributed two furcation defects that were treated by combination therapy using an expanded polytetrafluoroethylene (ePTFE) membrane and demineralized freeze-dried bone allograft (DFDBA). Clinical measurements included a gingival index, plaque index, mobility, and, referencing an occlusal stent, probing depth (PD), probing attachment level-vertical (PAL-V), and probing attachment level-horizontal (PAL-H). Multiple linear measurements were recorded for each site clinically and after surgical debridement to characterize defect morphology, root configuration, and barrier placement. Defect volume was computed mathematically. Postsurgical maintenance care was provided at 1 to 2, 4, 6, and 8 weeks, and then biweekly until 3 months, with subsequent supportive periodontal maintenance visits at 3-month intervals. The clinical status of the furcation (open or closed), measured by a non-treating periodontist at 1 and 2 years, was the primary outcome measure. The association of patient-related factors (e.g., smoking), site-related factors (e.g., root configuration and defect morphology), and treatment-related factors (e.g., membrane exposure) to clinical status of furcations was assessed using random effects hierarchical logistic regression analysis, controlling for design and demographic variables. Non-parametric analysis was used for specific group comparisons.

RESULTS

Complete clinical closure was achieved in 74% of all sites. Of the residual furcation defects, 68% were reduced to Class I. No defects progressed to Class III. Significant improvements in mean PD and PAL-V were obtained following surgical therapy. Although the proportion of sites demonstrating complete furcation closure was comparable for smokers and non-smokers, the proportion of Class II residual defects was significantly higher among smokers than non-smokers (62.5% versus 14.3%, respectively). Increases in presurgical PAL-H were associated with monotonic decreases in the percentage of sites demonstrating complete clinical closure, with only 53% of lesions > or = 5 mm responding with complete closure. Similarly, significant reductions in the frequency of clinical closure were associated with increases in the distance between the roof of furcation and crest of bone, roof of furcation and base of defect, depth of horizontal defect, and divergence of roots at the crest of bone.

CONCLUSIONS

The successful clinical closure of Class II furcations was achievable at 1 year following combination therapy with an ePTFE membrane and DFDBA. The highest frequency of clinical furcation closure was observed in early Class II defects. Furcations with vertical or horizontal bone loss of 5 mm or greater responded with the lowest frequency of complete clinical closure. Nevertheless, complete furcation closure was achievable in 50% of molars with extensive bone loss. Also, 15 out of 22 (68%) of all residual defects were reduced to Class I and only seven (8%) failed to improve, demonstrating that successful clinical resolution of advanced defects remains an attainable goal.

Comparison of Porous and Non-Porous Teflon Membranes Plus a Xenograft in the Treatment of Vertical Osseous Defects: A Clinical Reentry Study

BACKGROUND

The primary aim of this 9-month randomized, controlled, blinded, clinical reentry study was to compare the regenerative effects of a nonporous polytetrafluoroethylene (NP) periodontal membrane to a porous expanded polytetrafluoroethylene (P) periodontal membrane in the treatment of vertical osseous defects.

METHODS

Twenty-four patients, 11 males and 13 females, age 24 to 74 (mean 50.5 +/- 13.1) provided one site with an intraosseous defect > or = 4 mm and were divided equally and randomly into two groups. Following debridement both groups were grafted with a bovine-derived xenograft coated with a synthetic cell-binding peptide; then the test group received an NP membrane and the control group received a P membrane. All defects were reentered after 9 months. Measurements were performed by a masked examiner.

RESULTS

There were no statistically significant differences (P>0.05) between NP and P groups for any open or closed probing measurement at any time. Similar open initial defect depth for the NP group and P groups (4.8 versus 5.0 mm) demonstrated identical 9-month defect fill of 2.8 mm (57%) for both groups. A difference in crestal resorption for the NP compared to the P group (0.4 versus 0.8 mm) accounted for the difference in mean percent defect resolution, which was 67% for NP compared to 72% for the P group. Overall, nine (75%) of the NP group defects and eight (67%) of the P group defects showed more than 50% defect fill.

CONCLUSION

Treatment of vertical osseous defects with nonporous or porous polytetrafluoroethylene membranes in combination with a xenograft resulted in statistically significant improvement in open and closed probing measurements, with no significant difference between treatment groups.

Deproteinized bovine bone and gentamicin as an adjunct to GTR in the treatment of intrabony defects: a randomized controlled clinical study

OBJECTIVES

To evaluate whether Bio-Oss used as an adjunct to guided tissue regeneration (GTR) improves the healing of 1- or 2-wall intrabony defects as compared with GTR alone, and to examine whether impregnation of Bio-Oss with gentamicin may have an added effect.

MATERIAL AND METHODS

Sixty patients, with at least one interproximal intrabony defect with probing pocket depth (PPD) > or =7 mm and radiographic evidence of an intrabony component (IC) > or =4 mm, were treated at random with either a resorbable membrane (GTR), a resorbable membrane in combination with Bio-Oss impregnated with saline (DBB-), a resorbable membrane in combination with Bio-Oss impregnated with gentamicin (DBB+), or with flap surgery (RBF).

RESULTS

All treatment modalities resulted in statistically significant clinical improvements after 1 year. Defects treated with GTR alone presented a probing attachment level (PAL) gain of 2.9 mm, a residual PPD (PPD12) of 4.9 mm, a radiographic bone level (RBL) gain of 3.1 mm, and a residual IC (IC12) of 2.7 mm. GTR combined with Bio-Oss did not improve the healing outcome (PAL gain: 2.5 mm; PPD12: 4.9 mm; RBL gain: 2.8 mm; IC12: 3.3 mm). Impregnation of the Bio-Oss with gentamicin 2% mg/ml resulted in clinical improvements (PAL gain: 3.8 mm; PPD12: 4.2 mm; RBL gain: 4.7 mm; IC12: 2.1 mm), superior to those of the other treatment modalities, but the difference was not statistically significant. Defects treated with only flap surgery showed the most inferior clinical response (PAL gain: 1.5 mm; PPD12: 5.1 mm; RBL gain: 1.2 mm; IC12: 4.2 mm) of all groups.

CONCLUSION

The results failed to demonstrate an added effect of Bio-Oss implantation in combination with GTR on the healing of deep interproximal 1- or 2-wall, or combined 1- and 2-wall intrabony defects compared with GTR alone. Local application of gentamicin, on the other hand, improved the treatment outcome but not to an extent that it was statistically significant.

Guided tissue regeneration using a polylactic acid barrier

OBJECTIVES

The purpose of this study was to determine the relative impact of various predictors responsible for the variability in treatment outcome after guided tissue regeneration (GTR) in intraosseous periodontal defects.

PATIENTS AND METHODS

30 patients with chronic periodontitis and at least one intraosseous periodontal lesion (> or =4 mm) were enrolled. Following full-mouth scaling, GTR using polylactic acid membranes was performed at one site in each patient. Main periodontal pathogens, defect morphology, membrane exposure and smoking habit were assessed as predictor variables. Alveolar bone level change served as the primary outcome variable in a multiple regression analysis.

RESULTS

After 12 months, the 29 patients completing the study showed alveolar bone changes ranging from 4 mm bone gain to 1 mm bone loss (mean: 1.6+/-0.4 mm gain). Active smoking (beta-weight:-0.49, P=0.003) and persistence of subgingival infection with P. gingivalis (P.g.) (beta-weight:-0.25, P=0.11) were associated with poor treatment outcome. Deep initial intraosseous defects (beta-weight: 0.32, P=0.045) were associated with favorable treatment outcome, and membrane exposure had no impact on bone gain.

CONCLUSION

Active smoking was the strongest predictor variable negatively affecting alveolar bone gain following GTR in the treatment of periodontal defects. It was followed by a positive influence of a deeper intraosseous defect and by a negative effect by persistent subgingival infection of P. gingivalis. The relative impact of these factors may be useful in assessing the prognosis of GTR in intraosseous periodontal defects.