The effect of smoking on inflammatory and bone remodeling markers in gingival crevicular fluid and subgingival microbiota following periodontal therapy

BACKGROUND AND OBJECTIVE

Periodontal health is mediated by suppressing microorganisms inducing a local inflammatory host response. Smoking may impair this process. This study compares gingival crevicular fluid levels of inflammatory and bone remodeling markers in heavy smokers and non-smokers following active and supportive periodontal therapy in patients with chronic periodontitis.

MATERIAL AND METHODS

Gingival crevicular fluid and subgingival plaque were collected from the deepest periodontal pocket in 50 patients, 25 smokers and 25 non-smokers, at baseline (T0), following active (T1) and 12 mo of supportive periodontal therapy (T2). Smoking status was validated measuring serum cotinine levels. Gingival crevicular fluid levels of 27 inflammatory and two bone remodeling markers were analyzed using multiplex and singleplex micro-bed immunoassays, and subgingival plaque samples using checkerboard DNA-DNA hybridization. Amounts of markers in smokers and non-smokers were compared calculating the effect size.

RESULTS

Expression of inflammatory and bone-remodeling markers in smokers demonstrated an overall reduced effect size at T0 and T2 (p < 0.001). In particular, proinflammatory markers (p < 0.001), chemokines (p = 0.007) and growth factors (p = 0.003) at T0, osteoprotegerin (p = 0.003) at T1, proinflammatory markers (p = 0.019) and chemokines (p = 0.005) at T2. At T2, interleukin-8 was detected in significantly higher levels in smokers. Ten different markers in non-smokers and none in smokers responded to periodontal therapy (p < 0.05). An overall negative association was revealed between smoking and subgroups of markers at sites presenting ≥ 10⁵ red complex periodontal microbial species.

CONCLUSION

Except for an upregulation of interleukin-8, smokers exhibited reduced gingival crevicular fluid levels of several inflammatory markers at baseline and following active and supportive periodontal therapy. Only inflammatory responses in non-smokers adapted to periodontal therapy. Apparently, there seems to be an immunosuppressant effect of smoking regulating the local inflammatory response and bone remodeling markers captured in gingival crevicular fluid following periodontal therapy.

Coronally positioned flap procedures with or without a bioabsorbable membrane in the treatment of human gingival recession

BACKGROUND

A variety of surgical techniques have been used to cover recession type defects. New data have indicated that the outcome of coronally positioned flap procedures may be augmented by supporting the flap with a membrane.

METHODS

The present study aimed at comparing the clinical outcome following treatment of localized gingival recessions by a coronally positioned flap procedure alone, or combined with a bioabsorbable membrane. Twenty patients with buccal bilateral Miller Class I or Class II gingival recessions in cuspids or premolars participated in the study. The split-mouth design, randomized selection of site treatment, and blind evaluation provided 20 sites in a membrane group and 20 sites in a non-membrane group for examination at baseline, and at 3 months and 6 months postoperatively. Clinical variables included the apical extent of the gingival recession, the width of the recession defect measured at the cemento-enamel junction (CEJ), and the width of keratinized tissue at the recession site as well as probing depth and attachment level.

RESULTS

Both treatments resulted in a significant gain (P <0.0001) of root coverage, amounting to an average of 2.3 mm in the membrane group and 2.5 mm in the non-membrane group at the 6-month evaluation. There was no significant difference between the treatments. Similarly, a significant gain of clinical attachment level was seen in the membrane (1.3 mm; P <0.001) as well as in the non-membrane (1.5 mm; P <0.0001) group, but without a significant difference between the groups. The reduction of the recession width from baseline to 6 months was significantly greater (P <0.01) for the non-membrane (2.3 mm) than for the membrane (1.4 mm) group. Probing depth changes were small and not significant for either of the treatments. When patients were grouped as smokers (8) and non-smokers (12), no significant differences were revealed for any of the response variables. Overall, among the 20 membrane sites, one showed no change while the remaining 19 gained root coverage at the 6-month examination. Five sites obtained coverage to the CEJ. Among the non-membrane sites, all gained root coverage at 6 months and 10 sites showed complete coverage to the CEJ.

CONCLUSIONS

The coronally positioned flap operation offers a predictable, simple, and convenient approach as a root coverage procedure in Miller Class I and Class II recession defects. Combining this technique with the placement of a bioabsorbable membrane does not seem to improve the results following surgical treatment of such defects.

Oral tissue reactions to suture materials

Tissue reactions to natural and synthetic braided and monofilament suture materials in gingiva and oral mucosa were studied. A total of 138 sutures made of four commonly used materials were placed in the edentulous ridges and vestibular mucosa of eight beagle dogs. Biopsy specimens including the suture loop and surrounding tissues were obtained after 3, 7, and 14 days and processed for histologic analysis. The inflammatory reaction was more rapid and intense than the reaction that has been reported after suture placement in skin. Bacterial invasion of the suture track was a common sequela regardless of the material used, but it was particularly prominent for silk. The formation of a perisutural epithelial sleeve was well under way at 3 days and in some instances included the entire suture track within 7 days. Connective tissue reactions consisted of several well-defined, concentric perisutural zones. At 14 days, these zones were partly replaced by granulation tissue surrounded by a fibrous capsule. The synthetic monofilament suture elicited a mild inflammatory tissue response. The results showed that sutures placed in gingiva and oral mucosa produce a prolonged tissue response that is most likely a result of the continual influx of microbial contamination along the suture channel, which may be a lesser problem when sutures are placed in other surgical compartments. The results indicate that chromic gut sutures are rapidly and unpredictably absorbed when used in an environment characterized by moisture and infectious potential.

Recurrence of mandibular molar furcation defects following citric acid root treatment and coronally advanced flap procedures

This report concerns long-term (4 to 5 years) clinical evaluation of 22 resolved (complete bone closure) mandibular Class 2 furcation defects following coronally advanced flap procedures and citric acid root treatment with or without adjunctive implantation of freeze-dried, demineralized allogeneic bone. Sixteen buccal furcation sites in 12 patients were available for the follow-up evaluation. The furcation involvement was independently evaluated by a panel of three examiners, each using three furcation index systems. Oral hygiene standards, gingival health, probing depth, clinical attachment level, gingival recession, tooth vitality, and detectable caries or root resorption were also recorded. Mean attachment level at the furcation sites was 5.8 +/- 2.9 mm, compared to 4.5 +/- 2.2 mm and 3.5 +/- 1.3 mm over the prominence of the mesial and distal roots, respectively. The clinical examination further revealed that 12 out of 16 sites exhibited recurrent Class 2 furcation involvement. Of the 16 teeth examined, one had received endodontic treatment, while the remaining 15 responded within the normal range to pulp testing. One tooth had developed caries in the furcation region. No teeth demonstrated periradicular pathology. The results of this study question the long-term stability of furcation bone regeneration following coronally advanced flap procedures.

The influence of anatomic and iatrogenic root surface characteristics on bacterial colonization and periodontal destruction: a review

PERIODONTITIS IS A MULTIFACTORIAL infectious disease affecting primarily a subset of subjects and a subset of sites. Recent microbiological data have acknowledged that before disease progression can occur, a susceptible host and site are required, in addition to the presence of pathogenic bacteria. This review discusses factors affecting periodontal disease progression and focuses in particular on the influence of anatomic and iatrogenic root surface characteristics. Retrospective studies clearly suggest a strong association between anatomic aberrations and periodontal attachment loss. Cemental tear seems to have the potential to initiate an aseptic, rapid, site-specific periodontal breakdown in a non-infected environment, illustrating the complexity of the attachment loss process. Recent experimental findings, furthermore, demonstrate a significant influence of root surface instrumentation roughness upon subgingival plaque formation and gingival tissue reactions, as well as a significant and positive relationship between subgingival plaque accumulation and inflammatory cell mobilization. These results indicate that subgingivally located irregularities may form stagnant sites or ecological niches which favor both retention and growth of organisms. Such events in addition to the progressive inflammatory changes may critically influence the subgingival environment by turning a stable site into an unstable or active periodontitis site. Thus, local anatomic and iatrogenic root surface characteristics may have a more profound effect on gingival health than previously assumed, particularly on a site level.

A correlation study of inflammatory cell mobilization in response to subgingival microbial colonization

This study evaluated site-by-site the relations between subgingival microbial colonization and gingival tissue reactions. Experimental, deep periodontal defects were established at buccal surfaces of mandibular and maxillary canine teeth in 5 beagle dogs. The root surfaces were instrumented by a flame-shaped, fine-grained, rotating diamond point, or by a sharp curet. Following a 10-day postsurgical healing period, the dogs were fed a plaque-inducing diet for 70 days. The animals were then sacrificed and tissue blocks of the experimental sites including teeth and periodontal tissues were secured. The buccal gingiva was removed and processed for histomorphometric analysis while the teeth were prepared for scanning electron microscopic evaluation of the extent of subgingival microbial colonization. The results revealed that inflammatory cell density in the junctional epithelium and in the connective tissue were positively correlated to subgingival microbial colonization (P < 0.01). Furthermore, the degree of significance decreased with increasing distance from the plaque. The present study demonstrates that a close relation may exist between the extent of subgingival microbial colonization and inflammatory gingival tissue reactions.

Cemental tear: a risk factor in periodontal attachment loss

The objective of this retrospective study was to evaluate the influence of cemental tear as a risk factor in periodontal attachment loss. Seventeen extracted, single-rooted teeth showing loss of attachment and having one cemental tear surface and one opposite intact surface were examined. The teeth were stained in 0.1% toluidine blue to visualize attached periodontal ligament remnants and examined in a light microscope under incident light. On each tooth, loss of attachment was measured along the long axis of the root from the cemento-enamel junction to the most coronal level of the periodontal ligament on intact as well as on defect surfaces. Cemental tear surfaces demonstrated a significantly greater loss of attachment than opposite intact surfaces (P < 0.0001). In one specimen, the cemental tear fragment was partially attached to the root after the extraction procedure. This specimen was processed for light microscopy to determine the location of the cemental tear fracture. Histological examination clearly revealed that the split between the root and the fragment had occurred along the cemento-dentinal border. The results indicate that cemental tear should be considered as a possible etiologic entity in localized rapid periodontal breakdown.

Influence of tooth instrumentation roughness on gingival tissue reactions

Histological studies have demonstrated a relationship between the amount of subgingival plaque and the magnitude and extension of gingival tissue reactions. The objective of the present study was to evaluate inflammatory reactions in the gingival tissues facing plaque accumulation at a diamond and curet-instrumented root surfaces. Experimental, deep periodontal defects were established at buccal surfaces of mandibular and maxillary canine teeth in 5 beagle dogs. The root surfaces were instrumented by a flame-shaped, fine-grained. rotating diamond point, or by a sharp curet. Next, the dogs were fed a plaque-inducing diet for 70 days. The animals were then sacrificed, and tissue blocks of the experimental sites including teeth, alveolar bone, and gingival tissues were secured. The gingival soft tissue was processed for histomorphometric analyses at 3 levels. Epithelium and connective tissue area measurements showed no differences between the two instrumentations. Junctional epithelium (JE) cell point counts exhibited a higher proportion of inflammatory cells (IC)in specimens facing diamond compared to curet-instrumented defects. A higher proportion of IC was present within the coronal compared to the apical aspect of the JE for both instrumentations (P < 0.05). A significant difference in IC density between instrumentations was detected for non-infiltrated (P < 0.05), as well as for infiltrated (P < 0.01) connective tissue. The infiltrated connective tissue (ICT) inflammatory cell density was significantly (P < 0.01) and positively correlated to the JE inflammatory cell density (r = 0.75), and to area measurements of ICT (r = 0.55). The overall results demonstrate that the character of subgingival root instrumentations significantly affects gingival inflammatory reactions, most likely by influencing subgingival plaque formation.

Intra - and inter-examiner reproducibility in constant force probing

This study evaluated intra- and inter-examiner reproducibility for a conventional manual probe versus a computer-interfaced force-controlled periodontal probe. 2 examiners recorded probing depths (PD) and relative attachment levels (AL) at 1128 sites in 15 periodontal maintenance patients. Each site was evaluated 2x, 7 to 10 days apart by both examiners. Probing force for the electronic probe was 15 g. PD intra-examiner reproducibility (within +/- 1.0 mm) for shallow sites (PD < or = 3 mm) was 98.6% versus 91.5% for the conventional versus the electronic probe for examiner 1 and 98.5% versus 88.7% for examiner 2. Corresponding values for deeper sites (PD > 3 mm) were 96.4% versus 85.9% for examiner 1 and 95.1% versus 77.0% for examiner 2. Generally, AL intra-examiner reproducibility was 1 to 3% lower than for PD. PD inter-examiner reproducibility (within +/- 1.0 mm) was 99.2% versus 90.7% for the conventional versus the electronic probe, respectively, for shallow sites and 95.4% versus 76.9% for deeper sites. AL inter-examiner reproducibility (within +/- 1.0 mm) was 1 to 5% lower than for PD. Both intra- and inter-examiner reproducibility was higher for anterior than for posterior sites. Mean PD and AL were similar for both examiners. However, the electronic probe consistently recorded 0.1 to 0.2 mm higher values than the conventional probe. Standard deviations indicated a greater variability for electronic than for manual probing. The results suggest that intra- and inter-examiner reproducibility may not necessarily be higher with an electronic, force-controlled periodontal probe than with a conventional manual probe.

Reproducibility of periodontal probing using a conventional manual and an automated force-controlled electronic probe

A total of 1,128 sites in 15 periodontal maintenance patients were examined twice, 7 to 10 days apart, to evaluate reproducibility of periodontal probing by a conventional manual and an automated force-controlled electronic probe. Probing depths (PD) and relative attachment levels (AL) were recorded to the nearest 0.5 mm with both instruments. At each visit, all sites were probed first with the conventional and then with the electronic probe. Reproducibility of PD at shallow sites (PD < or = 3 mm) by the manual probe was 59.1% for exact agreement and 98.6% within +/- 1.0 mm variation. For the electronic probe, corresponding values were 41.3% and 91.5%, respectively. Reproducibility of PD measurements at deeper sites (PD > 3 mm), was 33.0% for exact match and 96.4% within +/- 1.0 mm for the manual and, correspondingly, 31.7% and 85.9% for the electronic probe. Reproducibility of AL followed a similar pattern, but was consistently lower than for PD. Reproducibility was consistently higher for anterior than for posterior sites and, for some comparisons, higher in the maxilla than in the mandible. These differences were smaller for the manual than for the electronic probe. Time required to complete the probing was longer for the conventional probe than for the electronic instrument. Under the prevailing study conditions, the automated force-controlled electronic probe failed to offer significant advantages over the conventional manual probe.

Root grooves: a risk factor in periodontal attachment loss

Periodontal health reflects a balance between harmful and protective elements in the gingival margin area. The total plaque mass, specific periodontopathogens, and local environmental factors may challenge this balance. The aim of this retrospective study was to evaluate the effect of proximal root grooves as a risk factor in periodontal attachment loss. One-hundred and three (103) extracted, formalin-stored, single-rooted teeth showing loss of attachment and having one non-grooved and one grooved proximal root surface were selected for the study. Following staining in 0.1% toluidine blue to visualize attached periodontal ligament remnants, the teeth were examined in a light microscope under incident light. On each tooth, loss of attachment was measured along the long axis of the root from the cemento-enamel junction to the most coronal level of the stained periodontal ligament remnants on mesial as well as on distal surfaces. Incisors and premolars were grouped separately. For both groups, a statistically significant greater loss of attachment was present on grooved than on non-grooved surfaces (P < 0.0001). Generally, there was a direct relationship between groove location and maximum loss of attachment. The results indicate that proximal root grooves should be considered in periodontal diagnosis, prognosis, and treatment planning.

Influence of tooth instrumentation roughness on subgingival microbial colonization

This study evaluated microbial colonization of periodontal pockets subjected to root instrumentation with a curet or a rotating diamond. Ten maxillary and 10 mandibular subgingival pockets were established in the canines of 5 beagle dogs. The subgingival root surface areas were debrided by a sharp curet or a flame-shaped, fine-grained, rotating diamond point. The dogs were fed a plaque-inducing diet for 70 days. Specimens from both instrumentation groups were then harvested and prepared for stereomicroscopic and scanning electron microscopic evaluation. Grading of the extent of subgingival colonization was performed in coded specimens directly on the fluorescent screen of the scanning electron microscope in a grid-counting system. Error of the method was assessed by duplicate counts. The subgingival root surface areas were divided into 3 zones: cervical, middle, and apical, and statistical differences between these zones as well as between the 2 instrumentation groups were calculated. The results revealed that curet-treated surfaces were smoother and promoted less subgingival colonization than diamond-treated surfaces. The difference in amount of bacterial colonization between the 2 groups was statistically significant (P < 0.05) in all zones. Bacterial colonization decreased in apical direction in both instrumentation groups. For the diamond-treated specimens, this decrease was significant (P < 0.05) between each of the 3 zones. In the curet-treated specimens, the decrease was significant only between the cervical and the apical zone (P < 0.05). The present study has demonstrated that subgingival instrumentation roughness significantly influences the subgingival microbial colonization.

Ultrastructure of plaque associated with polytetrafluoroethylene (PTFE) membranes used for guided tissue regeneration

The purpose of the study was to examine the ultrastructure of plaque contaminating polytetrafluoroethylene (PTFE) membranes used for guided periodontal tissue regeneration. 8 patients treated with Gore-Tex membranes received daily antibiotics (650 mg x 2 Femepen) and rinsed with 10 ml 0.2% chlorhexidine during a healing period of 30 days. Following retrieval, the membranes were processed for electron microscopy. External aspects of 12 portions from 4 partially exposed membranes were selected for detailed ultrastructural examination. The plaque-membrane interface was characterized by the presence of fibrin or discontinuous accumulation of intermicrobial matrix. Adjacent plaque-free areas of membrane surface exhibited no detectable electron-dense material. 3 structurally different groups of bacterial aggregations were observed on the strips: (i) dense layers of gram-positive cocci and rods dominated the external aspect of the open microstructure portion; (ii) cocci, rods and filamentous microorganisms embedded in fibrin filled the spaces of the open microstructure; (iii) a loosely arranged mixed microbiota consisting of gram-positive cocci and rods as well as of gram-negative microorganisms and spirochetes were present on the occlusive portion. Areas with morphologically intact bacteria alternated with areas with empty bacterial cell walls. One specimen also displayed degenerated Candida-like blastospores. This study shows that oral micro-organisms may colonize and extensively invade the open microstructure of PTFE material and that adhesion of plaque to the membrane surface is mediated either by fibrin or a discontinuous layer of intermicrobial matrix.

Comparative in vitro studies of sonic, ultrasonic and reciprocating scaling instruments

Flat root surface areas of formalin-stored mandibular incisors with plaque and calculus were scaled by sonic (PHATELUS SONIC SCALER, SONIC FLEX 2000, TITAN-S SONIC SCALER) or ultrasonic instruments (HYGIENIST ULTRASONIC SCALER, CAVITRON) or by a new reciprocating scaling insert for the EVA/PROFIN system. The test areas were photographed by SEM and coded micrographs were independently graded by three examiners using the RCI (Remaining Calculus Index) and the RLTSI (Roughness Loss of Tooth Substance Index). The findings revealed that the sonic scalers as a group removed calculus more completely but also left significantly more roughness and loss of tooth substance than the other instruments tested. No difference was seen between the two ultrasonic scalers. The reciprocating insert gave results similar to those of the ultrasonic except for the scaling time which was significantly longer for the new "cleansing principle".

Epithelial adherence to polytetrafluoroethylene (PTFE) material

The aim of this study was to examine adherence/attachment of gingival cellular elements to polytetrafluoroethylene (PTFE) material with special reference to epithelial cells. Six Gore-Tex membranes used for guided tissue regeneration in patients with severe periodontal disease were studied by transmission electron microscopy. Upon retrieval, after 30 days of healing, the membranes were immediately immersed in formaldehyde-glutaraldehyde, divided in segments (2 x 4 mm) and embedded in Epon. The majority of segments were devoid of any adhering tissue other than erythrocytes and polymorphonuclear cells. Epithelial cell adherence was mediated by a 2-microns-thick acellular layer containing membraneous profiles with diameter 370 nm or less. Adhering epithelial cells exhibited characteristics of cellular degeneration as evidenced by tonofilamentous and cytoplasmic condensation, vacuolization and loss of structural details. An uneven basement lamina with hemidesmosomal contacts was present at the epithelium-connective tissue interface. It is concluded that epithelial cells adhere to PTFE material without formation of attachment complexes.

Cemental tear related to rapid periodontal breakdown: a case report

Cemental tears have been described both in exposed and unexposed cementum. The phenomenon is believed to be elicited by overloading or acute trauma from occlusion. In this case report a patient, with a history of periodontal health, presented with an acute periodontal lesion on the distal aspect of a bridge abutment tooth. Periapical radiographs demonstrated an extensive vertical intrabony defect adjacent to the vital abutment tooth containing a radiopaque "foreign body." Histological examination of the surgically removed "foreign body" revealed a piece of dental cementum with some attached soft tissue. The lesion responded well to a surgical approach. Healing was uneventful and periodontal health was restored. This case illustrates that cemental tear should be considered as a differential diagnostic entity in isolated sites with rapid periodontal breakdown.

The effect of hygiene instruments on dentin surfaces: scanning electron microscopic observations

The present study consists of two separate parts. The first section is an in vitro evaluation of the relative abrasiveness of some hygiene instrumentations commonly used during maintenance therapy. In the second section, one of the instruments, a recently developed plastic tip for use on a sonic scaler, was examined for its ability to remove dental plaque from root surface specimens instead for 5 weeks in the oral cavities of dogs. The in vitro study was performed on recently obtained dentin specimens where a ridge had been machined parallel to the long axis of the tooth. The sonic scaler fitted with the plastic tip gave considerably less removal of dentin and a smoother dentin surface than the curet, the rubber cup with polishing paste, or the sonic scaler with an ordinary metal tip. These findings further demonstrated that the plastic tip was able to efficiently remove 5-week old dental plaque from experimental root surface areas within a time frame of 5 seconds. The new plastic tip may be valuable in maintenance therapy giving less risks for iatrogenic effects on the root surfaces than other debridement methods.

Influence of polishing procedures on sonic scaling root surface roughness

The present in vitro study aimed to evaluate the efficacy of various polishing procedures in reducing root roughness caused by sonic scaling. Proximal root surface areas of extracted, formalin-stored teeth were scaled in a bucco-lingual direction by a sonic scaler. The resulting roughness was measured along the direction of scaling and perpendicular to that direction by a profilometer. The specimens were then split into two groups. Group 1 was polished by an air-powder polishing instrument followed by a rotating rubber cup and chalk; Group 2 was polished by pumice followed by chalk. Root roughness (Ra) was recorded for each step in the procedures. The measurements revealed lower Ra values when the stylus of the profilometer was running perpendicular to the scaling direction, and a weak negative correlation was found when scaling time and Ra values were compared. In both groups Ra values were significantly reduced at each step of the polishing procedures and the terminal result was similar for the groups. Pumice and air-powder polishing gave a similar reduction of the sonic scaling roughness.

Evaluation of the effect on root surfaces of air turbine scalers and ultrasonic instrumentation

Three air turbine scalers were compared to each other and to an ultrasonic instrument (CAVITRON) on medium and maximum power setting. The amount of remaining calculus, roughness and loss of tooth substance were estimated by means of well-defined index systems (RCI and RLTSI). The time required to clean the test surfaces--marked on proximal root surfaces of mandibular incisors--was also noted. Standardized scanning electron microscope (SEM) micrographs were independently "blind-scored" by three examiners, and total mean scores were calculated. The results revealed significant differences (P less than 0.001) between the instruments with respect to the amount of remaining calculus. There were also significant differences (P less than 0.05) between roughness and loss of tooth substance produced by CAVITRON at maximum power setting and that produced by the other instruments. No differences were found with regard to the time required to clean the test surface (until visually clean).