Is There a Positive Effect of Smoking Cessation on Periodontal Health? A Systematic Review

Background: Although the detrimental effects of tobacco on the periodontal tissues have been reported extensively, little is known about the potential beneficial effect of smoking cessation on periodontal health. The aim of this systematic review is to evaluate the effect of smoking cessation on periodontitis progression and response to periodontal therapy. Methods: Two independent reviewers completed the review process through title (n = 118), abstract (n = 24), and whole‐paper selection (n = 5). Sources include Medline and EMBASE databases (up to December 2012) and a reference list of selected studies. Prospective studies comparing progression rates of periodontitis between smokers and quitters and clinical trials evaluating the effect of smoking‐cessation programs, alone or in combination with periodontal treatment, were included. At least 1 year of follow‐up was required for inclusion. Results: Of 331 potentially relevant publications, five studies fulfilled the inclusion criteria. Because of heterogeneity of the studies, a meta‐analysis could not be performed. One study reported that the progression of clinical attachment loss (AL) ≥3 mm during a 6‐year period was approximately three times higher among smokers than quitters (P <0.001). Two studies (10 and 20 years of follow‐up) observed a decrease in radiographic bone loss of ≈30% among quitters when compared with smokers. Among individuals receiving non‐surgical periodontal treatment, quitters were more likely to have periodontal probing depth reductions (P <0.05) than non‐quitters/oscillators. No differences in AL were observed. Conclusion: Based on the limited available evidence, smoking cessation seems to have a positive influence on periodontitis occurrence and periodontal healing.     

Smoking cessation advice for patients with chronic periodontitis

BACKGROUND: There are limited data on the utility of dental professionals in providing smoking cessation counselling in the UK. OBJECTIVES: The purpose of this study was to determine quit rates for smokers with chronic periodontitis who were referred to a dental hospital for treatment. MATERIALS AND METHODS: Forty-nine subjects with chronic periodontitis who smoked cigarettes were recruited. All subjects received periodontal treatment and smoking cessation advice as part of an individual, patient-based programme provided by dental hygienists trained in smoking cessation counselling. Smoking cessation interventions included counselling (all patients), and some patients also received nicotine replacement therapy (NRT) and/or Zyban medication. Smoking cessation advice was given at each visit at which periodontal treatment was undertaken (typically four to six visits) over a period of 10-12 weeks. Smoking cessation advice was also given monthly during the programme of supportive periodontal care over the following nine months. Smoking status was recorded at three, six and 12 months and was confirmed with carbon monoxide (CO) monitors and salivary cotinine assays. RESULTS: Forty-one per cent, 33%, 29% and 25% of patients had stopped smoking at week four, months three, six and 12, respectively. Gender, age, the presence of another smoker in the household, and baseline smoking status (determined using subject-reported pack years of smoking) were not significant predictors of quit success (P < 0.05). Baseline CO levels were significantly associated with quit success, however, and were significantly higher in those subjects who continued to smoke compared to those subjects who were quitters at week four, month three and month six (P < 0.05). CONCLUSION: Success rates in quitting smoking following smoking cessation advice given as part of a periodontal treatment compared very favourably to national quit rates achieved in specialist smoking cessation clinics. The dental profession has a crucial role to play in smoking cessation counselling, particularly for patients with chronic periodontitis.     

The effect of smoking on periodontal treatment response: a review of clinical evidence

BACKGROUND: Smoking has been identified as a significant risk factor for periodontal diseases and is regarded as being responsible for incomplete or delayed healing in patients following treatment. AIM AND METHOD: The aim of this conventional review was to review, collate and tabulate the relative effectiveness of treatments of chronic periodontitis in smokers, non-smokers and ex-smokers. OBSERVATIONS: The majority of clinical trials show significantly greater reductions in probing depths and bleeding on probing, and significantly greater gain of clinical attachment following non-surgical and surgical treatments in non-smokers compared with smokers. This benefit is also seen at class I and II furcation sites and in patients prescribed systemic or local antimicrobial treatments. CONCLUSIONS: Data from epidemiological, cross-sectional and case-control studies strongly suggest that quitting smoking is beneficial to patients following periodontal treatments. The periodontal status of ex-smokers following treatment suggests that quitting the habit is beneficial although there are only limited data from long-term longitudinal clinical trials to demonstrate unequivocally the periodontal benefit of quitting smoking.     

Smoking cessation and response to periodontal treatment

Smoking has detrimental oral effects. The aim of this study was to review the literature related to the impact of smoking cessation on periodontal health, periodontal disease and periodontal treatment outcome as well as to review the smoking cessation strategies and the dentist's role in the smoking cessation effort. Smoking cessation seems to have a positive effect on the periodontium, to decrease the risk for incidence and progression of periodontitis and to lead to a non‐significant trend for greater mean probing depth reductions after non‐surgical treatment over a 12‐month period. Smoking cessation effect on the periodontium should be further investigated. Dentists should inform their patients on the harmful effect of smoking and the beneficial effect of smoking cessation on oral health. They should advise, motivate and support their patients to quit smoking. Smoking‐control strategies should be incorporated in dental practise. The dentist's role in the smoking cessation effort is important. Guidelines on smoking‐control strategies applied in the dental office are required.     

Prognostic factors in the treatment of generalized aggressive periodontitis: II. Effects of smoking on initial outcome

AIMS: The aim of this study was to investigate the effects of smoking on the response to non-surgical treatment for aggressive periodontitis. METHODS: Seventy-nine patients with generalized aggressive periodontitis were included in the study; 20 were smokers. All patients received a course of non-surgical periodontal therapy and outcomes assessed 10 weeks post-operatively. Non-responding patients were designated if they had 30% or more non-responding deep sites. RESULTS: At baseline, bleeding scores were lower in smokers. There was no difference in baseline plaque, pocket depth (PD), recession or clinical attachment levels (CALs); when sites were selected by equal levels of CAL, increased recession was seen in smokers. Outcomes were poorer in smokers (mean PD change 1.75+/-0.56 versus 2.23+/-0.87 mm). The odds ratio for 30% of sites not responding in smokers was 2.9; for 40% non-responding it was 5.9. Smoking altered the distribution of site-specific responses to increase specifically the number of non-responding sites. There was no significant difference in responses between ex-smokers and never-smokers. CONCLUSIONS: The results demonstrate that smoking is a major risk factor for poor response to initial treatment and emphasize the importance of smoking cessation in periodontal therapy.     

Periodontal healing and periopathogenic microflora in smokers and non-smokers

Abstract The aim of the present study was to monitor the clinical and microbiological effects of non-surgical therapy in smokers and non-smokers. The subject material included 32 patients (age range 32–61 years), 11 men and 21 women with moderate to severe periodontitis. 17 patients were smokers ( l5 cigarettes/day) and 15 non-smokers. All patients were subjected to non-surgical periodontal therapy performed by a dental hygienist. Periodontal variables (plaque index, gingival index and probing depth) were registered and bacterial samples were collected before and 2 months alter treatment. The treatment resulted in significant reductions towards very low plaque and gingival indices in smokers and non-smokers alike (p<0.05). Although probing depth was reduced in both smokers and non-smokers, the probing pocket depth reduction was significantly smaller in smokers than non-smokers (p<0.05). Microbiologically, the same therapeutical efficacy was attained in both smoking groups, indicating an almost total eradication of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. Concerning Prevotella intermedia, out of 14 smokers and 10 non-smokers positive at baseline, 9 and 5, respectively, remained positive after treatment. The results suggest a less favourable clinical outcome of non-surgical therapy in smokers than non-smokers in spite of the fact that the therapy was equally effective with regard to reducing the alleged periopathogens A. actinomycetemcomitans, P. gingivalis and P. intermedia.     

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.     

Periodontal maintenance in a specialist periodontal clinic and in general dental practice

OBJECTIVES: To monitor the efficacy of periodontal maintenance whether conducted in a specialist periodontology clinic or in the practice of the referring general dentist. MATERIALS AND METHODS: Thirty-five subjects with a diagnosis of moderate-severe chronic periodontitis who were referred to the specialist clinic received periodontal non-surgical therapy. Following a 6-month healing phase, subjects were randomly allocated to one of two groups: A (n=18, periodontal maintenance provided within the specialist clinic) or B (n=17, periodontal maintenance provided by the referring general dentist in accordance with written instructions provided by the specialist). All subjects were examined at months 0 (corresponding to 6 months post-completion of non-surgical therapy), 6 and 12. Full-mouth plaque index (PI), % bleeding on probing (%BOP) and probing depth (PD) measurements were recorded. PDs were also recorded at eight test sites which, prior to non-surgical therapy, exhibited PD 5-8 mm, BOP and radiographic alveolar bone loss. Standardized radiographs were exposed at test sites at months 0 and 12, and bone changes assessed using digital subtraction radiography (DSR). RESULTS: As a result of the non-surgical therapy, statistically significant improvements in all clinical parameters were recorded. In the maintenance period, mean PI increased significantly from months 0 to 12 (p<0.05), but this increase did not differ significantly between groups A and B (p>0.05). No other clinical parameters changed significantly in the maintenance phase of the study. Reductions in %BOP, mouth mean PD and mean test sites PD achieved by the non-surgical therapy were maintained and did not differ significantly whether subjects were allocated to group A or group B (p>0.05). Current smokers had significantly deeper PD than non-smokers and former smokers at all time points (p<0.05), although otherwise, smoking status did not affect the outcomes of the study. DSR analysis identified statistically non-significant, slight, alveolar bone loss in both groups between months 0 and 12. CONCLUSION: In the short term, periodontal maintenance can be provided in general dental practice with the same expected outcomes compared with maintenance that is provided in a specialist clinic, providing that general dentists are given specific instructions regarding the maintenance regimen. A strong emphasis on effective plaque control is necessary.     

Effect of cigarette smoking on periodontal healing following surgical therapy

The influence of cigarette smoking on the outcome of surgical therapy was investigated in 54 patients, 24 of whom were smokers. The patients had moderate to severe periodontitis with persisting diseased pockets after non-surgical therapy. The surgical modality used was the modified Widman flap operation and the pockets under scrutiny were those with an initial probing depth of 4-6 mm. Re-examination was made 12 months following the completion of surgery. The probing depth reduction at the 12-month follow-up was 0.76 +/- 0.36 mm (mean +/- SD) in smokers as compared to 1.27 +/- 0.43 mm in non-smokers. The difference was statistically significant (P less than 0.001) and persisted after accounting for plaque. The results suggest that smoking may impair the outcome of surgical therapy.     

Regenerative treatment with platelet-rich plasma combined with a bovine-derived xenograft in smokers and non-smokers: 12-month clinical and radiographic results

Aim: The purpose of this study was to assess the healing response of intrabony defects following regenerative treatment with platelet-rich plasma (PRP) combined with a bovine-derived xenograft (BDX) in smokers and non-smokers.
Materials and Methods: A total of 24 advanced chronic periodontitis patients, 12 smokers and 12 non-smokers, with 113 intrabony defects with an intrabony component of 3 mm were included in this study. Defects were surgically treated with PRP/BDX. At baseline and 12 months after surgery, the following parameters were recorded: plaque and sulcus bleeding indices, probing depth (PD), relative attachment level, marginal recession, probing and radiographic bone levels.
Results: Considering the soft tissue measurements, smokers and non-smokers presented a mean PD reduction of 3.97 ± 0.76 and 4.63 ± 0.52 mm, recession of 0.76 ± 0.44 and 0.50 ± 0.12 mm and attachment gain of 3.26 ± 0.42 and 4.06 ± 0.40 mm, respectively. Evaluation of the hard tissue findings revealed that the mean clinical and radiographic bone gains in smokers and non-smokers were 2.83 ± 0.47 and 3.63 ± 0.38 mm, 2.98 ± 0.38 and 3.67 ± 0.48 mm, respectively. Inter-group differences for PD reduction ( p <0.05), attachment ( p <0.001), clinical ( p <0.001) and radiographic bone gains ( p <0.001) were found to be significant between smokers and non-smokers.
Conclusions: Within the limits of this study, the results indicate that treatment outcome following PRP/BDX application in intrabony defects is impaired with smoking.     

伴糖尿病的慢性牙周炎患者牙周基础治疗效果研究

目的研究牙周基础治疗对伴有糖尿病的慢性牙周炎患者的治疗效果。方法选择伴Ⅱ型糖尿病的老年慢性牙周炎患者(糖尿病组)与不伴糖尿病的老年慢性牙周炎患者(非糖尿病组)各20例行牙周基础治疗,记录并比较两组患者在基线和术后3、6、12个月的菌斑指数、牙龈指数、探诊出血、探诊深度、附着丧失等指标。结果牙周基础治疗对两组患者均有较好的治疗效果,各项指标均明显改善,与基线水平比较差异有统计学意义(P<0.01),而两组间各项牙周指数的改善在术后3、6、12个月差异均无统计学意义(P>0.05)。结论牙周基础治疗对伴有糖尿病的老年慢性牙周炎患者在短期内(12个月)有良好的治疗效果。     

The effect of smoking on the response to periodontal therapy

Abstract This study evaluated the effect of smoking on the clinical response to non-surgical and surgical periodontal therapy. 74 adult subjects with moderate to advanced periodontitis were treated according to a split-mouth design involving the following treatment modalities: coronal scaling, root planing, modified Widman surgery, and flap with osseous resectional surgery. Clinical parameters assessed included probing depth, probing attachment level, horizontal attachment level in furcation sites, recession, presence of supragingival plaque and bleeding on probing. Data were collected: initially, 4 weeks following phase-I therapy, 10 weeks following phase-II therapy and on a yearly basis during 6 years of maintenance care. Data analysis demonstrated that smokers exhibited significantly less reduction of probing depth and less gain of probing attachment level when compared to non-smokers immediately following active therapy and during each of the 6 years of maintenance (p< 0.05). A greater loss of horizontal attachment level was evident in smokers at each yearly exam during maintenance therapy (p < 0.05). There were no differences between groups in recession changes. In general, these findings were true for the outcomes following all 4 modalities of therapy and were most pronounced in the deepest probing depth category (≥ 7 mm). Statistical analysis showed a tendency for smokers to have slightly more supragingival plaque and bleeding on probing. In summary, smokers responded less favorably than non-smokers to periodontal therapy which included 3-month maintenance follow-up.     

Clinical response of azithromycin as an adjunct to non-surgical periodontal therapy in smokers

BACKGROUND: Antibiotic therapy can be used in very specific periodontal treatment situations such as in refractory cases of periodontal disease found to be more prevalent in smokers. This study was designed to determine the efficacy of azithromycin (AZM) when combined with scaling and root planing (SRP) for the treatment of moderate to severe chronic periodontitis in smokers. METHODS: Thirty-one subjects were enrolled into a 6-month randomized, single-masked trial to evaluate clinical, microbial (using benzoyl- DL-arginine naphthylamine [BANA] assay), and gingival crevicular fluid (GCF) pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) levels in response to SRP alone or SRP + AZM. At baseline, patients who smoked > or =1 pack per day of cigarettes who presented with at least five sites with probing depths (PD) of > or =5 mm with bleeding on probing (BOP) were randomized into the test or control groups. At baseline and 3 and 6 months, clinical measurements (probing depth [PD], clinical attachment loss [CAL], and bleeding on probing [BOP]) were performed. GCF bone marker assessment (Ctelopeptide [ICTP] as well as BANA test analyses) were performed at baseline, 14 days, and 3 and 6 months. RESULTS: The results demonstrated that both groups displayed clinical improvements in PD and CAL that were sustained for 6 months. Using a subject-based analysis, patients treated with SRP + AZM showed enhanced reductions in PD and gains in CAL at moderate (4 to 6 mm) and deep sites (>6 mm) (P <0.05). Furthermore, SRP + AZM resulted in greater reductions in BANA levels compared to SRP alone (P <0.05) while rebounds in BANA levels were noted in control group at the 6-month evaluation. No statistically significant differences between groups on mean BOP and ICTP levels during the course of the study were noted. CONCLUSIONS: The utilization of AZM in combination with SRP improves the efficacy of non-surgical periodontal therapy in reducing probing depth and improving attachment levels in smokers with moderate to advanced attachment loss.     

The effect of non-surgical treatment on periodontal pockets in smokers and non-smokers

Abstract. Changes in probing pocket depth following non-surgical periodontal treatment were investigated in 75 patients, 40 of whom were heavy smokers. Pockets with an initial probing depth of 4–6 mm were studied. The treatment consisted of patient instruction and motivation and debridement of plaque and calculus by hand instrumentation. The treatment was completed within 5 months and probing depth was recorded prior to and 1 month following the completion of therapy. Plaque index was reduced to a minimum in both smokers (P1I = 0.2) and non-smokers (P1I = 0.1) following treatment. An average reduction in probing pocket depth of 1.1 mm in smokers and 1.2 mm in non-smokers was observed. The reduction attained was less in smokers than in non-smokers for all regions of the dentition investigated. The greatest difference between groups was observed for the maxillary anterior region.     

Local minocycline as an adjunct to surgical therapy in moderate to severe, chronic periodontitis

Objective: The aim of the study was to evaluate the effects of minocycline microspheres on periodontal probing depth reduction when used in combination with surgery in adults with moderate to severe, chronic periodontitis. Material and Methods: Sixty patients with a minimum of one non‐molar periodontal site 6 mm in two oral quadrants received either local minocycline microspheres at baseline, immediately following each of two surgical therapies (Weeks 2 and 3), and at Week 5 or surgery alone. Results: The mean probing depth reduction at Week 25 at sites 5 mm at baseline was 2.51 mm in the test group and 2.18 mm in the control group. Smokers in the test group had a significantly greater probing depth reduction (2.30 mm) than smokers in the control group (2.05 mm). The number of sites with probing depth reductions of 2 and 3 mm were significantly higher in the test group than in the control group. Conclusion: Applications of local minocycline as an adjunct to surgery in adults with moderate to severe, chronic periodontitis were associated with statistically significant greater reductions in probing depth than surgery alone.     

Non-surgical periodontal treatment with and without adjunctive metronidazole in smokers and non-smokers

AIM: To determine whether adjunctive metronidazole therapy would compensate for the poorer treatment response to scaling and root planing reported in smokers. METHOD: A single-blind, randomised clinical trial of 28 smokers and 56 non-smokers, stratified for periodontitis disease severity and randomly allocated to 3 treatment groups: (1) Scaling and root planing using an ultrasonic scaler with local anaesthesia (SRP), (2) SRP+ metronidazole tabs 200 mg tds for 7 days, (3) SRP + 2 subgingival applications of 25% metronidazole gel. Probing depths (PD) and attachment levels (AL) were recorded with a Florida probe at baseline, 2 months and 6 months post treatment by a single examiner who was unaware of the treatment modality. Results were analysed for all sites with baseline probing depths equal to or greater than Florida probe recordings of 4.6 mm using analysis of variance. RESULTS: Reductions in probing depth at 6 months were significantly less (p < 0.001) in the smokers (mean 1.23 mm, 95% confidence intervals = 1.05 to 1.40 mm) than in the non-smokers (1.92, 1.75 to 2.09 mm). Attachment level gains were approximately 0.55 mm and there was no statistically significant difference between smokers and non-smokers. There were no differences in any clinical measure in response to the three treatment regimens at 2 or 6 months for either smokers or non-smokers. A reduction in the proportion of spirochaetes was observed at 6 months which was less in smokers than in non-smokers (p = 0.034). Multiple linear regression analysis on probing depth at 6 months demonstrated that smoking was a significant explanatory factor (p < 0.001) for poor treatment outcome, whilst the presence or absence of adjunctive metronidazole was not (p = 0.620). CONCLUSION: This study confirms that smokers have a poorer treatment response to SRP, regardless of the application of either systemic or locally applied adjunctive metronidazole.     

Periodontitis in smokers and non-smokers: intra-oral distribution of pockets

AIM: The purpose of the present study was to establish retrospectively whether the disease severity differs between smokers and non-smokers. METHODS: The study population consisted of 183 periodontitis patients, 79 smokers and 104 non-smokers. These subjects had been referred by general dentists to the Clinic for Periodontology, Utrecht, because of periodontal problems and were selected on the basis of the clinical diagnosis: adult periodontitis. The proportion of bleeding sites and the intra-oral distribution of probing pocket depth was evaluated. RESULTS: No statistically-significant differences between smokers (SM) and non-smokers (NSM) were found regarding the mean % of sites that bled upon probing (SM=76%, NSM=72%). Overall differences in the prevalence of probing depths > or =5 mm between smokers and non-smokers were found (SM=44%, NSM=34%). The proportion of sites with a probing pocket depth of > or =5 mm was consistently higher in smokers in the anterior, premolar and molar regions. The data also show that in the upper jaw at the anterior and premolar teeth, the largest differences are found between smokers and non-smokers. Smokers have more sites with a pocket depth > or =5 mm, especially on the lingual surfaces of these teeth. CONCLUSIONS: The present study indicates that cigarette smoking is a factor associated with deeper periodontal pockets and an intra-oral distribution that is suggestive of a local effect.     

Baseline adjustment and change revisited: effect of smoking on change in periodontal status following periodontal therapy

Smokers have frequently been reported to have more severe periodontitis, to respond less favorably to periodontal therapy, and to show elevated rate of recurrence compared with non‐smokers. The aims of this study was to compare the results of baseline‐adjusted and ‐unadjusted analyses when assessing the effect of smoking on change in periodontal status following therapy and to discuss the methodological issues involved. This is a secondary analysis of data from 180 periodontitis patients enrolled in a randomized controlled clinical intervention trial. Information on smoking habits was elicited from the participants before, and 12 months after, therapy. The clinical parameters analyzed were probing pocket depth and clinical attachment level, using both simple analysis of change (SAC) and analysis of covariance (ancova ), adjusting for age, gender, and treatment group. The current smokers presented with more severe periodontitis at baseline than did former and never smokers. Results of the SAC indicated that the current smokers benefitted more from treatment than did former or never smokers, whereas the results of the baseline‐adjusted ancova indicated no such differences. Both sets of results are likely to be biased with respect to valid conclusions regarding the ‘causal’ effect of smoking. Possible sources of bias are discussed.     

Bisphosphonate therapy improves the outcome of conventional periodontal treatment: results of a 12-month, randomized, placebo-controlled study

BACKGROUND: Bone loss in periodontitis results from inflammatory reactions that stimulate osteoclastic bone resorption. Bisphosphonates inhibit bone resorption and increase bone mass. This study evaluated the effect of bisphosphonate therapy as an adjunct to non-surgical periodontal treatment in patients with moderate to severe chronic periodontitis. METHODS: Patients were randomized (2:1) to one of two bisphosphonate therapies or placebo for 1 year. All patients received non-surgical periodontal treatment (scaling, root planing) and periodontal maintenance therapy every 3 months. Clinical assessments at baseline and 6 and 12 months included clinical attachment level (CAL), probing depth (PD), and bleeding on probing (BOP). Periodontal bone mass was assessed by dental radiographs at baseline and 12 months using fractal analysis and digital subtraction radiography (DSR). RESULTS: Seventy patients were randomized, 43 to the bisphosphonate group and 27 to the placebo group. Bisphosphonate therapy significantly improved CAL, PD, and BOP relative to the placebo group during the 6- to 12-month period (CAL, P = 0.0002; PD, P = 0.0156; BOP, P = 0.0079). There was no difference in the change in periodontal bone mass between the bisphosphonate and placebo groups as measured by fractal analysis and DSR. CONCLUSION: These data suggest that bisphosphonate treatment improves the clinical outcome of non-surgical periodontal therapy and may be an appropriate adjunctive treatment to preserve periodontal bone mass.