Association of clinical risk factors with treatment outcomes

Baseline probing depth and interproximal sites predict treatment outcomes of non-surgical periodontal therapy

BACKGROUND/PURPOSE

The efficacy of non-surgical periodontal therapy (NSPT) has been well discussed. The aim of this study was to investigate whether the baseline clinical periodontal parameters, radiographic defect angle, and interproximal site predict the treatment outcome of NSPT.

MATERIALS AND METHODS

A total of 39 patients who were diagnosed with generalized chronic periodontitis and met the inclusion criteria were enrolled in this study. All patients received full-mouth periodontal examination by two well-trained periodontists. Clinical periodontal parameters, including probing depth (PD), recession (Rec), and clinical attachment level (CAL), were recorded, and vertical bitewing radiographs were taken as baseline data. Revaluation was performed after 4 weeks of non-surgical periodontal treatment. Pearson's correlation coefficient and multivariate logistic regression were performed to examine the association between favorable treatment outcome (PD reduction ≥ 3 mm) and various clinical parameters.

RESULTS

A significant improvement was observed in PD reduction and CAL gain after NSPT. The radiographic defect angle was strongly correlated with baseline Rec, baseline CAL, and interproximal sites in teeth with a deeper PD. Baseline PD and interproximal sites emerged as significant prediction factors for favorable treatment outcome with a PD reduction of ≥3 mm.

CONCLUSION

Our study is the first to report that distal sites show wider radiographic angles with shallow infrabony defects and that pocket reduction is more obvious at distal sites than at mesial sites. These data provide evidence that baseline PD and interproximal sites may predict the treatment outcome of NSPT.

Using prognostic factors from case series and cohort studies to identify individuals with poor long-term outcomes during periodontal maintenance

BACKGROUND

The accuracy of applying prognostic factors to individual patients is uncertain.

AIM/METHOD

The aim was to apply prognostic factors from several outcome studies (case series and cohort) to identify: (1) patients who lost a tooth/teeth during periodontal maintenance; (2) patients who were non-responding to treatment; (3) patients needing re-treatment during periodontal maintenance. In addition, tooth loss was related to initial prognosis and it was determined which of the prognostic factors were also risk factors. Chi squared analysis was carried out for the outcomes of patients with-, and without prognostic factors. Significance level was set at p ≤ 0.05. Sensitivity and specificity was calculated for patients with and without prognostic factors.

RESULTS

The prognostic factors only identified a small proportion of patients who lost teeth (34-38%). Combining the prognostic factors resulted in a lower accuracy. A higher proportion of patients with no prognostic factors lost teeth (53.8-96.2%). The chance of identifying a non-responding patient based on family history was 5.9%, for stress 32.4%, and for heavy smoking 8.7%. Significantly more patients (29/40 , χ² = 16.2 p < 0.05) with initial uncertain/poor prognosis and significantly fewer patients (11/40, χ² = 16.2, p < 0.05) with erratic/no compliance needing re-treatment were identified. 21 of 40 patients (52.5%) (p = 0.655) with family history needing retreatment were identified. Combining the prognostic factors identified 5-22% out of a total of 40% of patients needing re-treatment. six out of nine (67%) teeth with an initial hopeless prognosis were lost, 10/109 (9%) teeth with a poor prognosis were lost, 11/346 (3%) teeth with a moderate prognosis were lost and 9/1972 (0.46%) of teeth with a good prognosis were lost. None of the prognostic factors was found also to be a risk factor for developing periodontal diseases.

CONCLUSION

Applying prognostic factors to identify individual patients with poor long-term outcomes is associated with low accuracy.

Commentary: prognosis revisited: a system for assigning periodontal prognosis

Prognosis is an integral part of the periodontal practice because it directly influences treatment planning. However, there is limited direct evidence in the literature regarding the assignment of periodontal prognosis. There are several important concepts to consider in developing a system of periodontal prognosis. Traditional systems are based on tooth loss and may have limited use for patient management. On the other hand, prognosis can be based on stability of the periodontal supporting apparatus, which is influenced by more evidence-based factors and may be more useful for patient management. Other important concepts include the timing of the projection (short and long term) and the consideration of individual teeth versus the overall dentition. Historically, several authors have formulated and investigated their own prognostication systems. Results were variable, but they generally showed that systems based on tooth loss were unpredictable over the long term. Therefore, the purpose of this report is to review relevant literature and propose a new periodontal prognostication system.

Validation and improvement of a predictive model for treatment outcome in patients with temporomandibular disorders

OBJECTIVE

To examine whether it was possible to improve individual prediction of treatment outcome in patients with temporomandibular disorders (TMD) through continuous quality improvement registrations and implementation of changes in clinical routines.

MATERIAL AND METHODS

All 5777 patients referred to a specialist clinic for stomatognathic physiology; 2187 TMD patients started treatment. The patients were divided into Muscle or Mainly TMJ symptom groups. Actual treatment outcome was predicted as Good or Dubious based on patient history and clinical findings. The degree of improvement of initial symptoms was graded using a numeric rating scale 0-100. Improvement in initial complaints of 50% or more was judged as a clinically important difference (CID); 989 patients (76%) completed treatment 1992-1998 (Sample 1) and 769 (86%) treatment 1999-2004 (Sample 2).

RESULTS

For patients with Muscle symptoms in Sample 1, CID was reached by 90% of those predicted Good and by 56% of those predicted Dubious. In Sample 2, the figures were Good 93% and Dubious 57%. In subgroup Mainly TMJ symptoms, CID was reached by 94% of those predicted Good and by 88% if predicted Dubious in Sample 1. In Sample 2, the figures were the same for those predicted Good, i.e. 94%, and Dubious, 73%.

CONCLUSION

Continuous quality improvement registrations and implementation of changes in clinical routines improved the ability to predict individually the actual treatment outcome between patients predicted Good or Dubious, respectively. Rheumatic disease turned out not to be a negative predictor for treatment outcome.

Oral findings and periodontal status in children, adolescents and young adults suffering from renal failure

AIM

Describe the oral condition of chronic renal failure and healthy subjects, and the relationship between oral variables, chronic renal failure (CRF) conditions, and their treatment.

MATERIALS AND METHODS

Four renal failure groups: chronic renal disease (n=22); undergoing dialysis (n=22); after dialysis and transplant (n=21); and after transplant (n=32), and a healthy control (n=38) were examined. Caries, enamel hypoplasia, pulp obliteration, plaque index, gingival bleeding, recession, overgrowth and index, probing depths, attachment loss, renal treatments and their relations with the oral variables were analysed.

RESULTS

The renal failure groups had higher gingival index (GI) and bleeding, probing depths, attachment loss, hypoplasia and obliteration and less caries, than the control. Plaque was higher in the dialysis and pre-dialysis (PD) groups. Overgrowth was evident after transplant. The PD group showed lower GI than other renal groups. Dialysis duration and end-stage renal failure significantly correlated with gingivitis, probing depth, attachment loss and enamel hypoplasia. Immuran correlated positively with probing depth, gingival recession and attachment loss. Normiten and Nifedipine had positive correlations with gingival overgrowth.

CONCLUSIONS

CRF patients are characterized by pulp obliteration, gingival and periodontal diseases. Duration of end stage renal failure and type of systemic treatment have a significant influence on the oral condition.

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.

Locally delivered minocycline microspheres for the treatment of periodontitis in smokers

AIM

The aim of the present analysis of a larger phase 3 clinical trial was to evaluate the efficacy of 1 mg minocycline hydrochloride microencapsulated in 3 mg of resorbable polymer, subgingivally administered as an adjunct to scaling and root planing (SRP) in smokers with chronic periodontitis.

MATERIAL AND METHODS

Two hundred and seventy-one patients who smoked were randomized to one of three treatment groups: (1) SRP alone, (2) SRP plus vehicle (polymer without minocycline) or (3) SRP plus minocycline microspheres. Full mouth SRP was performed for all groups at baseline, and vehicle or minocycline microspheres were administered to the appropriate patients at all periodontal pockets > or =5 mm at baseline, 3 and 6 months. Efficacy was evaluated over 9 months.

RESULTS

Significantly greater pocket depth reductions with SRP plus adjunctive minocycline microsphere treatment were observed at 1, 6 and 9 months (p<0.05) versus control treatments. At 9 months, smokers treated with SRP plus minocycline microspheres exhibited a pocket depth reduction of 1.19 mm from baseline, as compared to 0.90 mm for smokers treated with SRP alone. The efficacy of adjunctive minocycline microspheres was consistent among all tested smoking subcohorts, including those based on gender, age and smoking exposures.

CONCLUSION

These data indicate that treatment with SRP plus locally delivered minocycline microspheres is more effective than SRP alone in reducing pocket depths in smokers with periodontitis.

Reliability of clinical parameters for predicting the outcome of oral malodor treatment

We conducted the present study to determine which clinical parameters for diagnosing halitosis are most reliable in the development of an accurate prognosis for oral malodor treatment. Clinical evaluation included a questionnaire, oral examination and volatile sulfur compounds (VSC) measurement, and organoleptic test (OLT) at baseline. Ninety-two patients classified with oral pathologic halitosis were treated in a similar manner. Improved treatment outcome was defined as < 0.25 ppm of total VSC, < or = 2 OLT score, and < 30 on the "sad feeling" scale as subjective stress level by oral malodor 6 months after baseline. Thirty-four patients demonstrated improvement due to the treatment. In a multiple logistic model, pocket depth, OLT score, intra-oral discomfort, and self-perception of oral malodor at baseline displayed significant association with "not improved outcome". These results suggest that malodor- and periodontal-disease-related parameters and self-estimation of malodor at baseline are effective for prediction of outcome.

Clinical response to experimental forces and non-surgical therapy of teeth with various alveolar bone loss

Firm lateral force is necessary for the thorough removal of calculus during scaling and root planning (SRP) with hand instruments. However, this firm lateral force should be applied to root surfaces without considering the tooth's loss of supporting tissues. The purpose of the present study was two-fold: firstly, to evaluate the initial pain response of periodontally diseased non-molar teeth with two different levels of alveolar bone loss (ABL) to experimental lateral and vertical pull forces; and secondly, to examine the clinical response of these teeth to non-surgical therapy. Twenty patients with chronic periodontitis were specifically selected in two groups according to the level of ABL at non-molar teeth. Group I consisted of 10 patients who have 141 non-molar teeth with a radiographic evidence of 40-65% ABL. Group II consisted of 10 patients who have 132 non-molar teeth with a radiographic evidence of > or =70% ABL. All patients were systemically healthy, free of pain, and reported no current medication usage. Starting from 0 and gradually increasing an experimental lateral force with digital force gauge, and also an experimental vertical pull force with mechanical force gauge were applied to each tooth and measured. As a result of a single experimental force applied to each non-molar tooth, the initial pain response emerged in the patients was determined by means of electronic bell system used by patients themselves. Each patient was treated with SRP using specific hand instruments under local anesthesia. Plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL) and periotest values (PV scores) were compared in both groups at initial and at month 3. A mean experimental lateral force of 24.6 N and a mean experimental vertical pull force of 48.3 N caused initial pain response in group I. Initial pain response occurred with a mean experimental lateral force of 5.3 N and a mean experimental vertical pull force of 19.4 N in group II. Only group I showed statistically significant decrease in PI, GI, PD and a significant attachment gain at month 3 (P < 0.05). There was a decrease of 6 PV in group I at month 3 (P < 0.05), whereas an increase of 4 PV was observed in group II (P > 0.05). This study showed that lateral and vertical forces required for effective SRP do not cause any problem in the group with 40-65% ABL. However, they may cause trauma in the group with approximately 70% ABL. Thus, the results suggest that the degree of healing would be different in the group with > or =70% ABL and in the group with 40-65% ABL.

Changes in subgingival microflora and humoral immune response following periodontal therapy

OBJECTIVES

To investigate the effect of scaling and root planing (SRP) on the microflora and humoral immune response in adult periodontitis.

MATERIALS & METHODS

Clinical measurements, subgingival plaque samples, gingival crevicular fluid and sera were taken from 4 sites in 28 adult periodontitis patients before and after SRP. Polymerase chain reaction was used to determine the presence of A. actinomycetemcomitans, P. gingivalis, B. forsythus, P. intermedia, and T. denticola. ELISA was used to investigate the systemic and local antibody titres to these organisms, and thiocyanate dissociation for the determination of serum antibody avidity.

RESULTS

SRP produced a good clinical improvement. On a subject basis there was little significant change in the microflora. However, on a site basis, there were significant reductions in P. intermedia, B. forsythus and T. denticola. There was little change in systemic and local antibody titres following SRP, although there was a significant reduction in antibody avidity to P. gingivalis and P. intermedia

CONCLUSION

Post-therapy clinical improvement was associated with a reduction in bacterial prevalence, but statistical significance was only reached at a site level and this microbial reduction was not significant for all organisms. No significant post-therapy effects on the humoral immune response were noted other than a reduced antibody avidity to P. gingivalis and P. intermedia. The lack of a clear pattern in the humoral immune response may reflect a failure of the host response to produce adequate levels of biologically functional antibodies, and complex interactions between the subgingival flora and the host response.

Smoking affects the subgingival microflora in periodontitis

BACKGROUND

Tobacco smoking has been identified as one major risk factor for destructive periodontal disease. Scaling and root planing have been shown to be less effective in smokers with periodontitis. The aim of the present study was to compare the subgingival microbial flora of treated and untreated smokers and non-smokers.

METHODS

Four independent adult patient groups with periodontitis were included in this investigation: 88 untreated smokers (U-S); 90 untreated non-smokers (U-NS); 119 treated non-smokers (T-NS); and 171 treated smokers (T-S). Clinical variables included cumulative plaque index (CPI), probing depth (PD), clinical attachment level (CAL), cumulative bleeding index (CBI), and cumulative suppuration index (CSI). Paper point samples from the deepest bleeding pocket in each quadrant of the dentition were analyzed for the presence and levels of 6 periodontal bacterial pathogens using anaerobic culture techniques.

RESULTS

U-S showed a higher mean cumulative plaque index than U-NS (3.5 versus 2.7). Mean PD and mean CAL were higher in the T-S in comparison to the T-NS group (7.0 versus 6.6 mm and 5.6 versus 4.7 mm, respectively). Microbiological characteristics of U-S were a higher prevalence of Prevotella intermedia/nigrescens and higher mean levels of Peptostreptococcus micros (Pm) and Fusobacterium nucleatum (Fn). T-S patients were characterized by higher prevalence of Bacteroides forsythus (Bf), Pm, and Campylobacter rectus (Cr) and higher mean levels of Pm and Fn. The mean percentage of B. forsythus tended to be higher in the T-S group than in the T-NS group (6.9% versus 5.6%). The relative risk to be infected with Bf, Pm, and Cr was statistically higher in smokers (odds ratios: 1.9, 1.9, and 1.6, respectively). The chance to find > or =10% of Bf, Pm, and/or Fn was 3.3 higher in smokers when A. actinomycetemcomitans and P gingivalis were absent. Detection of > or =20% Pm/Fn in treated patients was strongly associated with smoking (odds ratio 13.8, P= 0.002).

CONCLUSIONS

Smoking is a determining factor for the composition of the subgingival microflora in adult patients with periodontitis and may select for a specific cluster of periodontal pathogens, notably Bf, Pm, Fn, and Cr. On the basis of these observations, smoking, among other criteria, may be one parameter to use in deciding to treat refractory periodontitis in smokers with a systemic antibiotic therapy directed against smoking-associated periodontal bacteria.

Human gingival crevicular fluid contains MRP8 (S100A8) and MRP14 (S100A9), two calcium-binding proteins of the S100 family

Human gingival crevicular fluid contains unidentified proteins which might play a role as markers in periodontal diseases. Therefore, low-molecular-weight proteins found in human gingival crevicular fluid (GCF), but absent from serum, were identified in the present study by means of two-dimensional electrophoresis (2-D PAGE) analysis. GCF, serum, and whole saliva were collected from periodontitis and healthy subjects, as well as from edentulous and newborn subjects. Protein samples were separated by two-dimensional polyacrylamide gel electrophoresis, stained with silver, and compared with reference protein maps in the SWISS-2D PAGE database. In GCF and saliva from periodontitis patients and healthy subjects, four dominant low-molecular-mass (from 8 to 14 kDa) acidic spots were observed. They were not found in serum and were less visible in saliva from edentulous and newborn subjects. From N-terminal amino acid sequencing, the two 2-D protein spots of 8 kDa and isoelectric points between 6.5 and 7.0 were both identified as protein MRP8 (SI00A8), a member of the S100 family of calcium-binding proteins. Using peptide mass fingerprinting and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS), we identified the other two protein spots, with mass of 14 kDa and isoelectric points between 5.5 and 6.0, as protein MRP14 (S100A9), also belonging to the S100 family. The presence of MRP8 and MRP14 in GCF was confirmed by Western blot, with monoclonal antibodies. The two polypeptides, MRP8 and MRP14, identified in GCF represent the major difference between the 2-D PAGE patterns of serum and GCF, and we hypothesize that they may play an important role in the gingival sulcus and could represent possible markers for periodontal diseases.

Gingival crevicular fluid inflammatory mediators and bacteriology of gingivitis in nonhuman primates related to susceptibility to periodontitis

The hypothesis to be tested was that the microbiota and resulting local host inflammatory response characteristics in oral conditions of high levels of chronic gingival inflammation increases susceptibility to progressing periodontitis. This study used cynomolgus monkeys, Macaca fascicularis (nonhuman primates), with high and low levels of long-standing gingival inflammation to define the profiles of gingival crevicular fluid mediators, cytokines and immunoglobulins; describe the subgingival microbiota; and evaluate their susceptibility to ligature-induced periodontitis. Sixteen nonhuman primates were stratified into two groups (HI, LO) based upon Bleeding Index as a measure of the natural level of inflammation (HI = 1.26 +/- 0.45; LO = 0.22 +/- 0.16). The host mediator levels, subgingival microbiota, and clinical characteristics of the LO and HI groups were compared after 30 days of oral hygiene, during a 30 day experimental gingivitis (7, 14, and 30 days), and during periodontitis (30, 60, and 90 days). The results demonstrated that nonhuman primates with high levels of long-standing gingival inflammation when compared to those nonhuman primates with low inflammation show: 1) different inflammatory mediator profiles in gingival crevicular fluid (particularly for immunoglobulin A (IgA) and IgG levels), 2) a different quantitative and qualitative subgingival microbiota; and 3) a similar progression of periodontitis. Thus, while variations in host inflammatory responses to local factors exist in the nonhuman primates, an extensive subgingival challenge (such as ligation) may negate these individual differences.

Position paper: tobacco use and the periodontal patient. Research, Science and Therapy Committee of the American Academy of Periodontology

This paper was prepared by the Research, Science and Therapy Committee of The American Academy of Periodontology and is intended for the information of the dental profession. The purpose of the paper is to provide the reader with a general overview of the relationship of tobacco use and periodontal diseases. This paper will review the epidemiological and clinical findings that have led to our understanding of the role of tobacco use in relation to periodontal diseases and their treatment. In addition, this paper will review the possible underlying mechanisms for these effects from tobacco use. The practitioner can use this information in treatment decisions and in giving advice to the patients who use tobacco products.

The effect of smoking and periodontal treatment on salivary composition in patients with established periodontitis

BACKGROUND

The purpose of this study was to evaluate the effect of smoking on the periodontal status and the salivary composition in subjects with established periodontitis before and after periodontal therapy.

METHODS

Our study group included 26 healthy subjects, 12 smokers and 14 non-smokers with established periodontitis. Clinical measurements and non-stimulated whole saliva were obtained and analyzed at baseline and after scaling and root planing. Smokers presented at baseline with significantly greater probing depth (4.16+/-0.26) compared to non-smokers (3.52+/-0.32) which was statistically significant (P = 0.0268); likewise, baseline clinical attachment level was greater in smokers (4.49+/-0.31 compared to non-smokers 3.87+/-0.13; P = 0.0620). Mean plaque index was also greater in smokers compared to non-smokers (0.86 and 0.65, respectively; P = 0.0834). Baseline pretreatment sodium values were significantly greater in non-smokers (14.36 mEq/l compared to 9.31 mEq/l in smokers; P = 0.0662); likewise non-smokers exhibited 50% greater salivary calcium levels (6.04 mg/100 ml compared to 4.32 mg/100 ml in smokers; P = 0.0133).

RESULTS

Post-treatment probing depth and clinical attachment level were not different between smokers and non-smokers; this in spite of significant difference in plaque index in smokers (0.35 compared to 0.13 in non-smokers; P = 0.0135). Post-treatment, smokers had reduced calcium concentration (3.58 mg/100 ml compared to 5.11 mg/100 ml in non-smokers; P = 0.0438). Treatment affected albumin level in smokers only, consequently non-smokers had significantly greater salivary albumin concentration (1.1 mg/100 ml compared to 0.38 mg/100 ml in smokers; P = 0.0274).

CONCLUSIONS

Subjects with established periodontitis exhibited elevated concentrations of salivary electrolytes and proteins. Within this study group, smokers exhibited greater disease level but reduced sodium, calcium, and magnesium concentrations. Smokers responded favorably to treatment. The clinical improvement eliminated the differences in salivary composition.

Improved clinical decision-making using the evidence-based approach

This article summarizes the evidence-based approach, a comprehensive and rigorous method for evaluating information, improving decision-making and implementing clinical treatment. The participants in The American Academy of Periodontology World Workshop assessed the evidentiary status of periodontal and implant treatment using the evidence-based approach. The major goal of the Workshop was to improve treatment decisions by increasing the strength of the inference that practitioners can derive from the base of knowledge contained within the literature.

Cigarette smoking and periodontal diseases: etiology and management of disease

Cigarette smoking has long been suspected to be associated with a variety of oral conditions including periodontal diseases. Experimental evidence accumulated over the last 2 decades has indicated that cigarette smoking is probably a true risk factor for periodontitis. This environmental exposure has been associated with 2- to 3-fold increases in the odds of developing clinically detectable periodontitis. Smokers have both increased prevalence and more severe extent of periodontal disease, as well as higher prevalence of tooth loss and edentulism, compared to non-smokers. The greater severity of periodontal destruction may be partly accounted for by the reported increases in the rate of periodontal disease progression. The noxious effect of smoking has been shown to be dose dependent and to be particularly marked in younger individuals; in these subjects, up to 51% of the observed risk of periodontitis was associated with smoking. Much of the literature has also indicated that smokers affected with periodontitis respond less favorably to both non-surgical, surgical, and regenerative periodontal treatments. The success rate of dental implants has also been shown to be compromised in smokers. Furthermore, longterm studies have pointed out that smoking was associated with recurrence of periodontitis during periodontal maintenance; the effect appeared to be dose dependent, with heavy smokers (> 10 cigarettes/day) presenting with higher levels of disease progression. The indication that previous smokers have lower levels of risk for periodontitis compared to current smokers is considered to be the strongest available evidence that smoking cessation will result in improved periodontal health and that smoking cessation counseling should be an integral part of periodontal therapy and prevention. So far, however, no randomized controlled clinical trial establishing the effect of smoking cessation and/or reduction on the periodontal outcomes has been reported. Given the present state of uncertainty about the periodontal benefits, but in light of the established general health gains for the patient that could be derived from a smoking cessation program, practitioners are incorporating smoking cessation counseling as an integral part of periodontal therapy. Furthermore, smoking status represents a key parameter to assess the periodontal risk of an individual subject and therefore to make evidence-based clinical decisions.

The effect of smoking on mechanical and antimicrobial periodontal therapy

The aim of this investigation was to evaluate the effect of smoking on the outcome of periodontal therapy. The study consisted of 54 patients who participated in a 4-group parallel-arm clinical trial on the efficacy of three locally delivered antimicrobial systems as adjuncts to scaling and root planing in the treatment of sites with persistent pocketing after a course of scaling and root planing. These groups included scaling and root planing either alone (S) (n = 3), or in conjunction with the application of 25% tetracycline fibers (S&T) (n = 13), 2% minocycline gel (S&Mi) (n = 14), or 25% metronidazole gel (S&Me) (n = 14). In each patient four pockets > 5 mm with bleeding on probing (BOP) and/or suppuration were studied. The number of subjects who smoked was: 8 (61.5%) in the S&T group, 8 (57.1%) in the S&Mi group, 6 (42.9%) in the S&Me group, and 6 (46.2%) in the S group. The probing depth, attachment level and other clinical parameters were assessed at baseline and 6 weeks after treatments. The clinical results of this comparative study have been previously reported. Regardless of the type of treatment, the change in the probing depth (delta PD) and attachment gain (delta AL) were greater in non-smoker subjects than smoker subjects. delta PD was 1.14 mm versus 0.76 mm (P = 0.019), and delta AL was 0.52 mm versus 0.50 mm at (P = 0.845) for non-smokers and smokers respectively. The analysis of variance using the general linear model (GLM) was used for delta PD and delta AL and took into account the variations in the treatments, number of smoker subjects per group, and baseline probing depth. There was a significant interaction between the "smoking" and the "baseline PD." Further analysis using linear regression indicated that, while there was a significant relationship between the baseline PD and the delta PD or delta AL among the non-smokers, weak and insignificant relationship existed among the smoker subjects. Thus, smoking may have an important role in determining the prognosis of periodontal treatment, particularly in persistent and deep pockets.

Design and implementation of clinical trials of antimicrobial drugs and devices used in periodontal disease treatment

The design and implementation of clinical trials (CTs) carried out to evaluate antimicrobial and anti-infective drugs and devices are one of the most difficult challenges in contemporary periodontal research and product development. The overwhelming amount of evidence which has established a microbial etiology for periodontitis is the basis for developing and testing antimicrobial treatments. Well-designed antimicrobial CTs start with a carefully crafted hypothesis and a protocol which explicitly integrates the requirements of the patient, the clinician, the sponsor, and regulatory authorities. Surrogate variables for effectiveness must be clinically relevant, scientifically sound, and statistically valid. Currently, clinical attachment level measurements and alveolar bone assessments are accepted as proof of effectiveness. Indication and claim support of the antimicrobial product guide the design and implementation of the CT. Adverse microbiologic consequences, such as lack of antimicrobial susceptibility, wrong spectrum, incorrect dosage, non-compliance, and drug interference, must be monitored. Successful CTs balance a large group of variables used to screen, randomize, and assign subjects to experimental and control groups to ensure that prognostic and risk factors are properly accounted for.

The effectiveness of periodontal treatment as measured by tooth loss

In a retrospective study, the authors evaluated the effectiveness of periodontal treatment in preventing tooth loss in patients with moderate to advanced periodontitis. Patients had received maintenance therapy for an average of 12.5 years. Of the 2,899 teeth present after active treatment, 152 were lost to periodontal disease and 68 were lost to other causes during maintenance therapy. The authors evaluated causes and patterns of tooth loss after surgical vs. nonsurgical treatment. Surgery did not significantly improve tooth retention in the high-risk patients. This study and other retrospective studies suggest that tooth loss may be related more to the type of periodontal disease present than to the treatment rendered.

Improved clinical decision making using the evidence-based approach

Clinical experience, technical ability, and intuition are indispensable but no longer sufficient as the sole skills necessary to provide the best outcomes from periodontal and implant treatment. This article describes the evidence-based approach, a comprehensive and rigorous literature evaluation process applied by scientists and clinicians. The methodology was used by the participants in The American Academy of Periodontology World Workshop to assess the evidentiary status of periodontal and implant treatment. The major goal of using the evidence-based approach was to improve treatment decisions by increasing the strength of the inference that practitioners can derive from the base of knowledge contained within the literature.

A longitudinal study of various crevicular fluid components as markers of periodontal disease activity

In order to examine the relationship of possible crevicular biochemical parameters to attachment loss (ALOSS), 330 sites from 8 untreated adult patients were monitored longitudinally at 3-month intervals, for up to 1 year. Attachment levels were measured with a force-sensing probe and an acrylic stent in duplicates at each study point. Crevicular samples were collected and used for the determination of the following 11 markers: number of polymorphonuclear leukocytes (PMNs), prostaglandin E2 (PGE2), osteocalcin (OC), alkaline phosphatase (ALP), collagenase (COL), beta-glucuronidase (BG), antigenic and functional elastase (AEL and FEL), alpha-1 antitrypsin (a1AT), alpha-2 macroglobulin (a2M) and aspartate aminotransferase (AST). 10 sites with ALOSS of > or = 1.5 mm per 3 months (active sites) and 43 sites with negligible changes (inactive sites) were identified. Total amounts of ALP, BG and COL were found to be significantly higher in active as compared to inactive sites, prior to significant ALOSS, without any significant differences in crevicular fluid volume and clinical indices. When biochemical parameters were expressed as ratios to the number of PMNs, PGE2/ PMNs was significantly elevated in active sites. The capacity of such individual parameters to distinguish between active and inactive sites was limited. However, linear discriminant analysis using total amounts of PGE2, COL, ALP, a2M, OC and AEL showed more significant diagnostic values (sensitivity: 80%, specificity: 91%). These findings suggest that the combination of several biochemical parameters in crevicular fluid could give more information to predict future clinical ALOSS.

Levels of cigarette consumption and response to periodontal therapy

Seventy-four patients with moderate to advanced periodontitis were classified by cigarette consumption at the initial exam: heavy smokers (HS) > or = 20 cigarettes/day (n = 31); light smokers (LS) < or = 19 cigarettes/day (n = 15); past smokers (PS) had a history of smoking but had quit by the initial exam (n = 10); and non-smokers (NS) had never smoked (n = 18). All patients were treated with four modalities of periodontal therapy followed by supportive periodontal treatment (SPT) for a period of up to 7 years. Clinical parameters including probing depth (PD), clinical attachment level (CAL), recession (REC), presence of bleeding on probing (BOP), and supragingival plaque (PL) were assessed at six sites around each tooth. Horizontal probing attachment level (HAL) was obtained at molar furcation sites. Data were collected initially, 4 weeks after non-surgical therapy, 10 weeks after surgical therapy, and yearly during SPT. HS and LS demonstrated less PD reduction and less CAL gain than PS and NS following active treatment and throughout SPT. Following active treatment, HAL changes were similar for all groups, but during 7 years of SPT, HS and LS experienced greater loss of HAL. There were no differences in BOP among the four groups. HS demonstrated a higher percentage of PL positive sites compared to the other groups. In summary, HS and LS responded less favorably to therapy than PS and NS. A past history of smoking was not deleterious to the response to therapy.

Prognosis versus actual outcome. II. The effectiveness of clinical parameters in developing an accurate prognosis

The assignment of prognosis is one of the most important functions undertaken in clinical practice, yet there is little evidence to support the current decision-making process which is based on an outdated model of disease etiology and progression. This study evaluated 100 treated periodontal patients (2,484 teeth) under maintenance care for 5 years, with 38 of these patients followed for 8 years, to determine the relationship of assigned prognoses to the clinical criteria commonly used in the development of prognosis. The method of generalized estimating equations (GEE) for correlated data was utilized to determine the relationship of each clinical factor to the assignment of initial prognosis, improvement in prognosis at 5 years, and worsening in prognosis at 5 years. A multiple linear regression model was constructed for predicting initial prognosis based on initial clinical data. Increased probing depth, more severe furcation involvement, greater mobility, unsatisfactory crown-to-root ratio, malpositioned teeth, and teeth used as fixed abutments resulted in worse initial prognoses. The coefficients from this model were able to predict accurately the 5-year and 8-year prognoses 81% of the time. When teeth with "good" prognoses were excluded, the predictive accuracy dropped approximately 50%. Multiple logistic regression models indicated that improvement in prognoses and worsening in prognoses were both strongly associated with initial probing depth, initial furcation involvement, initial tooth malposition, and smoking when adjusted for initial prognosis. In addition, good hygiene was found to increase the probability of improvement in prognosis while initial mobility was found to decrease the likelihood of improvement in prognosis. Neither of these factors was found to be significant in worsening of prognosis. Smoking decreased the likelihood of improvement by 60% and doubled the likelihood of worsening in prognosis at 5 years. The results of this study indicate that some clinical factors used in the assignment of prognoses are clearly associated with changes in clinical condition over time. The data also demonstrated that the traditional approach for assigning prognoses is ineffective for teeth with an initial prognosis of less than good. Since most periodontally involved teeth are compromised, further work should include the development of a more effective method for assigning prognoses that is based on clear, objective clinical criteria.

Nicotine effects on PGE2 and IL-1 beta release by LPS-treated human monocytes

Cigarette smoking is a major risk factor in the development and further progression of periodontitis. However, little is known regarding the pathogenesis of smoking-related periodontal diseases. The purpose of this study was to examine the effects of nicotine, alone and in combination with lipopolysaccharide (LPS), on monocyte secretion of bone-resorbing factors, PGE2 and IL-1 beta. Peripheral blood monocytes (PBM) were isolated by counterflow centrifugal elutriation from 15 healthy, non-smoking donors. PBM were incubated for 24 h in RPMI 1640 containing nicotine (0, 50 ng/ml, 1 microgram/ml, 10 micrograms/ml and 100 micrograms/ml) with or without 10 micrograms/ml Porphyromonas gingivalis LPS or Escherichia coli LPS. Culture supernatants were assayed for PGE2 and IL-1 beta by ELISA. None of the nicotine preparations resulted in significant PBM secretion of PGE2 and IL-1 beta above that of unstimulated cultures. However, PGE2 release was potentiated 1.7-fold by the combination of P. gingivalis LPS and 10 micrograms/ml nicotine relative to P. gingivalis LPS alone (p < 0.05, one-way ANOVA). Prostaglandin E2 release also was potentiated 3.5-fold by P. gingivalis LPS and 100 micrograms/ml nicotine relative to P. gingivalis LPS alone (p < 0.00001, one-way ANOVA) and 3.1-fold by E. coli LPS and 100 micrograms/ml nicotine relative to E. coli LPS alone (p < 0.00001, one-way ANOVA). IL-1 beta secretion was lower for either LPS plus 100 micrograms/ml nicotine relative to LPS alone, although not significantly. These data demonstrate upregulation of LPS-mediated monocyte secretion of PGE2 by nicotine and suggest a potential role for nicotine in periodontal disease pathogenesis.