An overview of periodontal surgical procedures

Molecular profiling of gingival crevicular fluid fails to distinguish between infrabony and suprabony periodontal defects

AIM

To assess the differential molecular profiling of gingival crevicular fluid (GCF) from infrabony and suprabony periodontal defects compared with healthy sites.

MATERIALS AND METHODS

Seventy-five samples from 25 patients with untreated periodontitis stage III-IV were included. Clinical and radiological parameters as well as GCF samples were collected from an infrabony defect, a suprabony defect and a periodontally healthy site per patient. A multiplex bead immunoassay was performed to assess the level of 18 biomarkers associated with inflammation, connective tissue degradation and regeneration/repair.

RESULTS

GCF volume was higher in periodontal sites compared with healthy sites, with no significant difference between infrabony and suprabony defects. Fourteen biomarkers were elevated in infrabony and suprabony sites compared with healthy sites (p < .05). Only interleukin-1α levels were increased in infrabony compared with suprabony sites, whereas there was no difference in probing pocket depth.

CONCLUSIONS

Although the GCF molecular profile clearly differentiates periodontally affected sites from healthy sites, the different architecture between infrabony and suprabony defects is not reflected in GCF biomarker changes.

Single-flap versus double-flap approach for periodontal pocket reduction in supraosseous defects: a comparative study

Purpose

The single-flap approach (SFA) is a minimally invasive technique with limited mucoperiosteal flap elevation to gain access to the buccal/palatal aspects, thus limiting post-surgical complications. The purpose of the present study was to gain insights into the impact of the SFA over the double-flap approach (DFA) on periodontal flap treatment outcomes and patient compliance in terms of discomfort and time taken for surgical procedures.

Methods

Twenty patients with persistent probing pocket depths of ≥5 mm were scheduled for the SFA (test site) and for the DFA (control site). All the clinical periodontal parameters were recorded at baseline, 3 months, and 6 months. Radiographic bone level (cone-beam computed tomography) was evaluated at baseline and 6 months. Patients' postoperative pain perception and wound healing were also assessed.

Results

The SFA showed a significant reduction in periodontal pocket depth, gain in clinical attachment level (CAL), and gain in bone level when compared with the DFA. The SFA substantially improved wound healing and induced less postoperative pain than the DFA.

Conclusions

The SFA resulted in substantial improvement in the composite outcome measures, as shown by a reduction in pocket depth with minimal gingival recession, gain in CAL, early wound healing, less postoperative discomfort, and better patient-centered outcomes.

Trial Registration

Clinical Trials Registry-India Identifier: CTRI/2018/05/013562

The efficacy of pocket elimination/reduction compared to access flap surgery: A systematic review and meta-analysis

AIM

To assess the efficacy and adverse effects of resective surgery compared to access flap in patients with periodontitis.

METHODS

Randomized controlled trials with a follow-up ≥6 months were identified in ten databases. Screening, data extraction, and quality assessment were conducted by two reviewers. The primary outcome was probing pocket depth, and the main secondary outcome was clinical attachment level. Data on adverse events were collected. Meta-analysis was used to synthesize the findings of trials.

RESULTS

A total of 880 publications were identified. Fourteen publications from nine clinical trials met the inclusion criteria and were included for analysis. Meta-analysis was carried out using all available results. The results indicated superior pocket depth reduction following resective surgery compared to access flap after 6-12 months of follow-up (weighted mean difference 0.47 mm; confidence interval 0.7-0.24; p = .010). After 36-60 months of follow-up, no differences were found between the two treatments in pocket depth and attachment level. The prevalence of adverse effects was not different between the groups. Post-operative recession tended to be more severe for the resective approaches.

CONCLUSION

Resective surgical approach was superior to access flap in reducing pocket depth 6-12 months post-surgery, while no differences between the two modalities were found at 36-60 months of follow-up.

Perioprosthetic and Implant-Supported Rehabilitation of Complex Cases: Clinical Management and Timing Strategy

Treatment of complex perioprosthetic cases is one of the clinical challenges of everyday practice. Only a complete and thorough diagnostic setup may allow the clinician to formulate a realistic prognosis to select the abutments to support prosthetic rehabilitation. Clinical, radiographic, or laboratory parameters used separately are useless to correctly assign a reliable prognosis to single teeth except in the case of a clearly hopeless tooth. Therefore, it is crucial to gather the greatest quantity of data to determine the role that every single element can play in the prosthetic rehabilitation of the case. The following report deals with the management of a multidisciplinary periodontally compromised case in which a treatment strategy and chronology were designed to reach clinical predictability while reducing the duration of the therapy.

The histopathological comparison on the destruction of the periodontal tissue between normal junctional epithelium and long junctional epithelium

BACKGROUND AND OBJECTIVE

The barrier function of long junctional epithelium is thought to be important after periodontal initial therapy and periodontal surgery. Although the difference between long junctional epithelium and normal junctional epithelium regarding their resistance to destruction of periodontal tissue has been investigated, the mechanism still remains unclear. Using our rat experimental periodontitis model in which loss of attachment and resorption of alveolar bone is induced by the formation of immune complexes, we investigated the resistance of periodontal tissue containing long junctional epithelium and normal junctional epithelium to destruction.

MATERIAL AND METHODS

Rats were divided into four groups. In the immunized long junctional epithelium (I-LJE) group, rats were immunized with lipopolysaccharide (LPS), and curettage and root planing procedures were performed on the palatal gingiva of the maxillary first molars to obtain reattachment by long junctional epithelium. In the immunized normal junctional epithelium (I-JE) group, rats were immunized without curettage and root planing procedures. In the nonimmunized long junctional epithelium (nI-LJE) group, rats were not immunized but curettage and root-planing procedures were performed. In the control group, neither immunization nor curettage and root-planing was performed. In all rats, periodontal inflammation was induced by topical application of LPS into the palatal gingival sulcus of maxillary first molars. The rats were killed at baseline and after the third and fifth applications of LPS. Attachment loss and the number of inflammatory cells and osteoclasts in the four groups were compared histopathologically and histometrically.

RESULTS

After the third application of LPS in the I-LJE group, attachment loss showed a greater increase than in control and nI-LJE groups, and inflammatory cell infiltration and osteoclasts were increased more than in the other groups. After the fifth application of LPS, attachment loss was greater and there was a higher degree of inflammatory cell infiltration in nI-LJE and I-LJE groups than in control and I-JE groups.

CONCLUSION

Our findings suggest that the destruction of periodontal tissue is increased in tissue containing long junctional epithelium compared with normal junctional epithelium and that the immunized condition accelerates the destruction by forming immune complexes.

Comparative evaluation of the efficacy of synthetic nanocrystalline hydroxyapatite bone graft (Ostim®) and synthetic microcrystalline hydroxyapatite bone graft (Osteogen®) in the treatment of human periodontal intrabony defects: A clinical and denta scan study

Background:

To evaluate the relative efficacy of synthetic nanocrystalline hydroxyapatite (HA) (Ostim^®) and microcrystalline HA (Osteogen^®) bone grafts in the treatment of human periodontal intrabony defects clinically and radiographically through denta scan.

Materials and Methods:

Ten chronic periodontitis patients with bilateral intrabony periodontal defects of ≥2 mm radiographic defect depth below 55 years of age were selected randomly and treated with synthetic nanocrystalline HA (Ostim^®) or synthetic microcrystalline HA (Osteogen^®) bone graft. Clinical parameters including probing depth (PD) and clinical attachment level (CAL) were measured preoperatively and postoperatively at 3 and 6 months for each of the defects using an occlusal acrylic stent. Radiographic parameters were measured with the help of denta scan preoperatively and postoperatively at 6 months.

Results:

At 6 months following therapy, the Osteogen^® group showed a reduction in mean PD from 11.10 ± 1.663 to 8.50 ± 0.850 mm and a change in mean CAL from 6.30 ± 1.160 to 3.40 ± 0.516 mm, whereas in the Ostim^® group, the mean PD decreased from 11.20 ± 0.919 to 8.30 ± 0.823 mm and mean CAL decreased from 6.10 ± 0.738 to 3.30 ± 0.483 mm. At 6 months following therapy, denta scan showed a reduction in mean intrabony defect depth in the Osteogen^® group from 2.54 ± 0.786 to 1.01 ± 0.448 mm, whereas in the Ostim^® group, it was 2.71 ± 0.650 mm to 1.12 ± 0.563 mm.

Conclusion:

It was concluded that both the HA bone grafts produced statistically significant reduction in pocket depth, in the depth of osseous lesion, and a statistically significant gain in attachment level, irrespective of their physico-chemical properties.

Regeneration therapy for oral disease

The aim of this paper is to provide a review of the current understanding of the mechanisms, cell and factors required for regeneration and restoration of periodontal tissue around natural teeth. Periodontal regeneration is a complex multifactorial process involving cell populations: periodontal ligament cells, bone cells, gingival fibroblasts and epithelial cells. This paper describes bone graft, guided tissue regeneration and enamel matrix derivative with the application of growth factors.

Attachment of human epithelial cells and periodontal ligament fibroblasts to tooth dentin

A goal of treatment in periodontal therapy is to regenerate a new fibroblastic attachment rather than to repair lost attachment with a long junctional epithelium. To date, there is no evidence that fibroblastic attachment formed during regeneration is stronger or less susceptible to periodontal breakdown than a long junctional epithelial attachment. We measured the rate and strength of attachment of epithelial cells (NHEK) and periodontal ligament fibroblasts (PDLF) cultured individually and cocultured to dentin surfaces to determine which cell type has a faster attachment rate and greater adhesive strength to human dentin, and whether the cell types attach independently. Longitudinal dentin slices were seeded with either PDLF or NHEK for 2 or 24 h. The specimens were placed into a parallel plate flow chamber and defined laminar shear stresses were applied. Shear stress was created by step increases in fluid flow rate. Effluent fluid was collected and cell numbers (detached) were counted using a hemocytometer. Cocultures of PDLF and NHEK at three seeding ratios (10:1, 1:1, 1:10) were also tested. Each cell type attached equally well to polystyrene or dentin. PDLF showed a stronger attachment to polystyrene and dentin at 24 versus 2 h. NHEK attached to polystyrene or dentin equally well at 2 and 24 h. NHEK were more strongly attached after 2 h when compared to PDLF. PDLF were more strongly attached after 24 h versus NHEK. When NHEK and PDLF were seeded together on dentin at a 1:1 ratio, PDLF appeared to be more strongly attached than NHEK at 2 but not 24 h. At a ratio of 10 PDLF:1 NHEK, PDLF appeared to be more strongly attached at 2 and 24 h. At a ratio of 1 PDLF:10 NHEK, NHEK appeared to be more strongly attached at 2 h, but PDLF showed a trend of stronger attachment at 24 h. We conclude that epithelial cells attach more quickly to dentin surfaces than PDLF, but do not demonstrate increased attachment strength over time (PDLF do show increased attachment strength overtime). The purported advantages of periodontal regeneration over periodontal repair are supported by our results. Furthermore, our results support the concept of guided tissue regeneration. On the basis of on cellular competition experiments, epithelial cells and PDLF do not act independently, because epithelial cells enhanced the attachment rate of PDLF.

Oral Health Impacts on Daily Living Related to Four Different Treatment Protocols for Chronic Periodontitis

BACKGROUND

The aims of this study were to evaluate the oral health impacts perceived by patients submitted to different treatments of chronic periodontitis and their association with clinical parameters.

METHODS

Sixty patients were assigned to one of the following therapeutic groups: control, treated with full-mouth scaling and root planing (SRP); test 1, treated with SRP and 400 mg systemically administered metronidazole (MET) three times per day for 10 days; test 2, treated with SRP and professional supragingival plaque removal (PP) every week for 3 months; and test 3, treated with SRP and MET plus PP. Clinical periodontal measurements and data regarding patients' oral health impacts (perceived impacts on bleeding gums, gingival recession, sensitivity to cold, packing foods, aesthetics, bad breath, and tooth mobility) were collected at baseline and 3 months after therapy.

RESULTS

All groups presented significant improvement in oral health perceived impacts. There was no statistically significant difference in the improvement of oral health impacts among groups subjected to different treatments. The clinical data of percentage of deep probing depth, deep clinical attachment level, and bleeding on probing were found to be correlated significantly with oral health impacts.

CONCLUSIONS

Periodontal treatment leads to a significant reduction of self-perceived impacts regardless of the non-surgical treatment protocol employed. Most of the clinical data were associated with oral health impacts.

Clinical and microbiological effects of subgingival administration of two active gels on persistent pockets of chronic periodontitis patients

OBJECTIVES

The present controlled, single-blind study was performed to assess and compare the clinical healing and the microbiological findings following repeated intrasulcular applications of 1% metronidazole or 1% chlorhexidine gels in persistent periodontal pockets previously treated by scaling and root planing (SRP).

MATERIAL AND METHODS

Sixty-three systemically healthy subjects, 25 males and 38 females (mean age 48.4+/-7.2 years), diagnosed for chronic periodontitis were enrolled in this study. They underwent SRP and received oral hygiene instructions (OHI). Three months later, at baseline, a single persistent pocket with a probing depth (PD) of 5-9 mm was chosen as the experimental site in each patient; the subjects were stratified into three matched experimental groups on the basis of the treatment to be performed, which consisted of the subgingival administration of 1% metronidazole gel (MG, n=19), 1% chlorhexidine gel (CG, n=20) or placebo gel (PG, n=24). The treatments consisted of four repeated administrations of subgingival gels, each separated by 7 days, starting at the baseline. Clinical assessment was performed at the baseline and at the 180-day follow-up, after the end of treatment. For microbiological evaluations, subgingival plaque was sampled from the experimental sites at baseline, prior to the first subgingival gel administration, and at 7, 15, 30 and 90 days after the end of the treatment (days 28, 36, 51 and 111 from baseline).

RESULTS

Plaque accumulation did not change significantly in all three groups. Bleeding on probing and clinical attachment levels reduced in the MGs and CGs only. PD was significantly reduced by the same amount in all experimental groups. In the MGs and CGs a remarkable reduction in the frequencies of detection of several periodontopathic micoorganisms was recorded after the treatment. The same was not seen for the PGs.

CONCLUSIONS

Subgingival administration of MG or CG, both at 1%, may have a role in the management of persistent pockets during chronic periodontitis.

A 15-month evaluation of the effects of repeated subgingival minocycline in chronic adult periodontitis

BACKGROUND

A double-blind, randomized, parallel, comparative study was designed to evaluate the long-term safety and efficacy of subgingivally administered minocycline ointment versus a vehicle control.

METHODS

One hundred four patients (104) with moderate to severe adult periodontitis (34 to 64 years of age; mean 46 years) were enrolled in the study. Following scaling and root planing, patients were randomized to receive either 2% minocycline ointment or a matched vehicle control. Study medication was administered directly into the periodontal pocket with a specially designed, graduated, disposable applicator at baseline; week 2; and at months 1, 3, 6, 9, and 12. Scaling and root planing was repeated at months 6 and 12. Standard clinical variables (including probing depth and attachment level) were evaluated at baseline and at months 1, 3, 6, 9, 12, and 15. Microbiological sampling using DNA probes was done at baseline; at week 2; and at months 1, 3, 6, 9, 12, and 15.

RESULTS

Both treatment groups showed significant and clinically relevant reductions in the numbers of each of the 7 microorganisms measured during the entire 15-month study period. When differences were detected, sites treated with minocycline ointment always produced statistically significantly greater reductions than sites which received the vehicle control. For initial pockets > or =5 mm, a mean reduction in probing depth of 1.9 mm was seen in the test sites, versus 1.2 mm in the control sites. Sites with a baseline probing depth > or =7 mm and bleeding index >2 showed an average of 2.5 mm reduction with minocycline versus 1.5 mm with the vehicle. Gains in attachment (0.9 mm and 1.1 mm) were observed in minocycline-treated sites, with baseline probing depth > or =5 mm and > or =7 mm, respectively, compared with 0.5 mm and 0.7 mm gain at control sites. Subgingival administration of minocycline ointment was well tolerated.

CONCLUSIONS

Overall, the results demonstrate that repeated subgingival administration of minocycline ointment in the treatment of adult periodontitis is safe and leads to significant adjunctive improvement after subgingival instrumentation in both clinical and microbiologic variables over a 15-month period.

The use of locally delivered minocycline in the treatment of chronic periodontitis. A review of the literature

Tetracyclines are frequently used in the treatment of periodontitis; however, emergence of resistant bacterial strains has decreased the utility of these drugs. At present, there are a lot of data in the literature from which one can draw conclusions regarding the use of local drug delivery. This paper reviews the utility and different systems of local delivery of minocycline, a semisynthetic tetracycline, in the treatment of periodontitis.

Factors affecting the healing response of intrabony defects following guided tissue regeneration and access flap surgery

Identification and control of significant factors determining clinical outcomes is of paramount importance to improve expected results of a variety of therapeutic procedures. The aim of this investigation was to identify, with a multivariate approach, factors associated with healing outcomes of 3 periodontal surgical procedures in deep intrabony defects. 45 patients with evidence of deep intrabony defects were randomly assigned to 3 treatment groups: access flap (group C), conventional guided tissue regeneration (GTR) with non-resorbable expanded polytetrafluoroethilene (ePTFE) membranes (group B), and GTR with self supporting membranes combined with the modified papilla preservation technique (group A). In both GTR procedures, membranes were positioned coronal to the interproxymal alveolar crest. Primary outcome variables (i.e., probing attachment level gains at 1 year and the amount of newly formed tissue present at membrane removal) were explained in terms of a series of patient, defect morphology and surgical factors, using a multivariate approach. Highly significant treatment effects were observed, indicating that the 3 tested therapeutic modalities resulted in significant differences in primary outcome variables. Detailed analysis assessing the significance of the tested factors in determining the healing outcomes following each procedure was performed with a stepwise elimination approach of non-significant factors. The results indicated that: (i) the need to create and maintain space should be a key objective of regenerative approaches based upon the principles of guided tissue regeneration; (ii) control of patient's oral hygiene and residual periodontal infection in the oral cavity are strongly associated with clinical outcomes of both regenerative and conventional surgical procedures and should receive proper attention.

Growth factor modulation of fibroblasts in simulated wound healing

Growth factors are potent bioactive molecules responsible for the co-ordination of many cells functions and interactions. Of these agents PDGF and IGF have shown particular promise as agents which may be used to stimulate periodontal regeneration. In order to further understand the mechanisms by which growth factors may work, a simple model of in vitro wound healing has been utilized to assess the effects of PDGF on human periodontal ligament fibroblasts and its potential to stimulate wound healing. Human periodontal ligament fibroblasts were plated into 24-well plates and upon reaching confluence were wounded by creating uniform discoid lesions stripped of cells. The influence of various concentrations of PDGF on cell proliferation, cell migration and extracellular matrix synthesis was monitored. The results of this study indicated that in the presence of 10 ng/ml PDGF on 0.2% fetal calf serum, both cell proliferation and cell migration were significantly stimulated. In the wounded cultures, PDGF appeared to cause a moderate stimulation of proteoglycan synthesis compared to unwounded cultures. In conclusion, the model system tested appears to be useful for studying fundamental cellular and biochemical events associated with wound healing. The effects of PDGF in this system confirm that it is capable of modulating fibroblasts in a manner compatible with the events associated with wound repair.

Long-term stability of clinical attachment following guided tissue regeneration and conventional therapy

44 patients (34% smokers) presenting with severe periodontitis were treated with full mouth root planing (RPL). In each patient, 1 intrabony defect was treated with guided tissue regeneration (GTR). After 1 year of monthly prophylaxis, full mouth plaque (FMPS) and bleeding (FMBS) scores were 8.3 +/- 4.1% and 5.6 +/- 3.8%. At 1 year, the GTR treated sites were matched, in each patient, with 1 RPL site, in terms of probing attachment level (PAL 6.8 +/- 2.4 mm GTR, and 6.5 +/- 2.3 mm RPL). At this point, 24 patients took part in a supportive periodontal care program. 20 patients did not participate, and received only sporadic care by general dentists. At 5 years, all patients were reexamined. FMPS was 10.5 +/- 6.8% and FMBS 7.7 +/- 6.4%. A significant PAL loss was observed in both sites (1.2 +/- 1.4 mm GTR, 1.3 +/- 1.3 mm RPL, p < 0.0001) between 1 and 5 years. Differences in PAL loss between GTR and RPL sites were not statistically significant. Only a minority of sites (34%), however, lost PAL, while 66% remained stable. 75% of the matched sites (GTR and RPL) within the same patients were concordant in terms of PAL stability. The 23 patients in which both sites remained stable, had good oral hygiene, complied with the recall system, and did not smoke. The 10 patients in which both sites lost PAL showed deteriorating oral hygiene, did not comply with the recall system, and smoked. PAL loss in the GTR and/or RPL sites was consistently observed in patients (losers) showing PAL loss in other teeth. Losers had, in general, negative subjects characteristics, and showed a higher prevalence of tooth loss.

IN CONCLUSION

(i) GTR and RPL sites showed comparable susceptibility to periodontal breakdown; (ii) stability of outcomes was consistently associated with good oral hygiene, compliance with a supportive periodontal care program, and no cigarette smoking.

A survey of endpoint characteristics in periodontal clinical trials published 1988-1992, and implications for future studies

Endpoints are conditions or events that are associated with individual study subjects and that are used to assess treatment efficacy. 2 types of endpoints can be distinguished: "true" endpoints (reflect unequivocal evidence of tangible benefit to the patient) and "surrogate" endpoints (usually a measure of disease process). The purpose of this study was to survey four aspects of endpoint usage in randomized controlled trials (RCT's) on the treatment of periodontitis: (1) the typical number of endpoints per RCT, (2) the proportion of RCTs using the same endpoint, (3) the proportion of RCTs using true endpoints, and (4) whether treatment choice influenced endpoint choice. 92 publications (1988-1992) reporting on 82 RCT's were identified. The typical number of endpoints per RCT was 6 (range: 1-28). The 3 most frequently used endpoints were mean probing depth (78% of the trials), mean probing attachment level (66%), and the plaque index (37%). In total, 153 distinct surrogate endpoints were defined. Most of these were used infrequently; over 80% of the 153 endpoints were used in fewer than 5 of the 82 trials. No trials used tooth loss as a true endpoint. In the design of an RCT, treatment choice influenced surrogate endpoint choice. Surrogate endpoints based on re-entry surgery were exclusively used for regenerative procedures and microbiological surrogate endpoints were mostly used for RCT's on anti-microbials. The conclusion is that the typical RCT used multiple surrogate endpoints, some of which were used infrequently by other trials. Such endpoint usage characteristics are suitable for exploratory RCTs (designed to identify active treatments or to elucidate treatment mechanisms). The question is raised as to whether periodontal research has reached the point of needing properly designed definitive studies, whose purpose it would be to provide unequivocal evidence of tangible benefits to the patient by the various treatments. If a need for definitive randomized controlled trials is perceived, then the use of (multiple) surrogate endpoints as primary outcomes should be questioned. Surrogate endpoint usage has led to both false positive and false negative conclusions in other chronic disease studies. Endpoint selection and validation in RCTs may be an important element in resolving controversies about periodontal treatments.

Fate of pocket epithelium in an apically positioned flap

The fate of periodontal pocket epithelium when sulcular incisions are used in apically positioned flap surgery was investigated by serial histology. Human subjects received apically positioned flap segments on the facial aspect of anterior teeth timed to give 1, 3, 5, 7, 21 and 35 days of healing on the day of extraction. Companion surgeries for comparison consisted of similar flaps, but utilized an inverse bevel primary incision. Assessment of the sulcular incision specimens revealed that epithelial degeneration and dissolution occurred within 7 days and resulted in a collagen-to-collagen attachment of the periodontal flap to the alveolar bone. The inverse bevel incision was consistently effective in removing the pocket epithelium and resulted in healing by a connective tissue union of the flap to the alveolar bone. By 21 days of healing, the 2 surgical methods were indistinguishable histologically. On the basis of this investigation, it is suggested that the inverse bevel primary incision traditionally advocated for apically positioned flap surgeries may be replaced by the more rapid and simple sulcular incision as the preferred technique.

The angular bony defect in the maintenance of the periodontal patient

The present retrospective study was performed to evaluate some long-term alterations of the alveolar bone level at periodontal sites with angular and even ("horizontal") patterns of bone loss. The investigation included 48 patients who, following treatment for advanced periodontal disease, were placed in a maintenance care program which included recall appointments every 3-6 months for a period of 5 to 16 years. The material of the study comprised all teeth at which angular osseous defects (test sites) could be detected in a full-mouth series of radiographs obtained at the end of the active treatment phase. Alterations in the position of the marginal alveolar bone crest and the base of the osseous defect which took place during the maintenance period were assessed by comparing the post-treatment radiographs with a 2nd set of radiographs obtained at the final examination. In the same patients, an equal number of contralateral or neighboring teeth at which bone loss in the radiographs had an even or "horizontal" character were included as controls. The results from the assessments demonstrated that periodontal sites which, following active therapy displayed either angular or "horizontal" patterns of alveolar bone loss underwent, during a 5-16 year period of maintenance, only minor bone level alterations. Additional loss of supporting bone occurred equally frequently at sites with "horizontal" and angular patterns of bone loss. Thus, the findings reported failed to show up sites with angular bony defects as being particularly susceptible to recurrent destructive periodontitis.

Maintenance care for treated periodontitis patients

This paper is a review of current literature combined with clinical observations. Well-controlled maintenance care is a key consideration in the long-term prognosis of treated periodontitis patients. Periodic professional tooth cleaning every 3 to 4 months often is recommended. Furthermore, recent studies indicate a potential need for selected retreatment in problem areas, since minute residual accretions may be left behind during active therapy--even with "open" surgery. While efficient plaque control is essential for optimal results during the healing phase of periodontal therapy, periodic prophylaxis may prevent loss of clinical attachment over long periods of time even for patients with less than perfect oral hygiene.

The relationship of the position of crown margins to gingival health

A survey was conducted of 423 crown margins that were divided into 355 subgingival margins and 68 supragingival margins. The plaque index, gingival bleeding, and recession surrounding the artificial crown were recorded and compared to the unprepared contralateral tooth. Gingival tissues tended to bleed 2.42 times more frequently with subgingival margins and have a 2.65 times higher chance of gingival recession. Crowns with supragingival margins did not differ significantly compared with the contralateral tooth, but crowns with subgingival margins had greater bleeding and recession compared with the contralateral tooth. It is recommended that supragingival margins become standard clinical procedures when feasible. A further analysis will be instituted to determine whether different crown materials affect the gingivae.

Effect of periodontal therapy on patients maintained for 15 years or longer. A retrospective study

A retrospective study of tooth loss in 211 patients who were treated for periodontal disease in private practice and maintained for 15 to 34 years on 3- to 6-month recall schedules is reported. The average age of the patients was 42 years, and the average length of time in maintenance was 22 years. On the basis of response to therapy, the patients were classified as Well-Maintained (62%), Downhill (28%) and Extreme Downhill (10%). Seven hundred and seventy-one (771) teeth were lost (13.4%) due to all causes. Molar teeth are the most prone to loss and the mandibular cuspid is the most resistant. The importance of maintenance therapy is emphasized.

Comparison of surgical and nonsurgical treatment of periodontal disease. A review of current studies and additional results after 61/2 years

Many well designed clinical studies have established the effectiveness of periodontal therapy. Surgical procedures have been shown to be effective in treating periodontitis when followed by appropriate maintenance care. Scaling and root planing alone have recently been compared to scaling and root planing plus soft tissue surgery in several longitudinal trials. A review of the literature indicates several important findings including a loss of clinical attachment following flap procedures for shallow (1-3 mm) pockets and no clinically significant loss after scaling and root planing. These studies also generally report either a gain or maintenance of attachment level for both procedures in deeper pockets (greater than or equal to 4 mm). For these pockets, neither procedure has been shown to be uniformly superior with respect to attachment gain. All reports indicate that both treatment methods result in pocket reduction. However, the literature also indicates that scaling and root planing combined with a flap procedure results in greater initial pocket reduction than does scaling and root planing alone. This difference in degree of pocket reduction between procedures tends to decrease beyond 1-2 years. It has been shown that both treatment methods result in sustained decreases in gingivitis, plaque and calculus and neither procedure appears to be superior with respect to these parameters. Additional data from the study at the University of Minnesota indicate that similar results are maintained up to 61/2 years following active therapy. Pocket depth did not change for shallow (1-3 mm) pockets treated by either scaling and root planing alone or scaling and root planing followed by a modified Widman flap. For pockets 4-6 mm, both treatment procedures resulted in equally effective sustained pocket reduction. Deep pockets (greater than or equal to 7 mm) were initially reduced more by the flap procedure. After 2 years, no consistent difference between treatment methods was found in degree of pocket reduction. However, as compared to baseline, pocket reduction was sustained to 61/2 years with the flap and only 3 years with scaling and root planing alone. After 61/2 years, sustained attachment loss in shallow (1-3 mm) pockets was found after the modified Widman flap. Scaling and root planing alone in these shallow pockets did not result in sustained attachment loss. For pockets initially 4-6 mm in depth, attachment level was maintained by both procedures but scaling and root planing resulted in greater gain in attachment as compared to the flap at all time intervals.(ABSTRACT TRUNCATED AT 400 WORDS)

Progressive replacement of epithelial attachment by a connective tissue junction after experimental periodontal surgery in rats

The purpose of this study was to test the hypothesis that the long junctional epithelium formed during the early stages of periodontal wound healing can become replaced, at least in part, by a connective tissue attachment. A surgical wound was created on the mesial surface of the left maxillary first molar of 4-month-old rats and the mesial root surface curetted free of soft tissue and cementum. The contralateral molar served as an unoperated control. Groups of five to eight animals were killed at intervals of 10 days, 3 and 6 weeks, and 3, 6 and 12 months after surgery. The histometric data demonstrated a progressive apical recession of the entire gingival unit on the unoperated control side during the experimental period. On the operated side, the junctional epithelium became reestablished by migration of epithelium from the wound edge along the cut gingival surface facing the tooth, until contact was established near the apical border of the instrumented root surface. Coronal migration of the epithelium from that level accounted for most of the lengthening of the junctional epithelium observed in 3 weeks. During the balance of the experimental period the junctional epithelium did not change in length significantly. However, the entire epithelial attachment was displaced coronally, primarily at the expense of sulcus depth which decreased with time, and by replacement of the apical portion of the junctional epithelium by a connective tissue junction of increasing dimension. These findings challenge the widely held belief that, once established, the dentoepithelial junction cannot be replaced by a connective tissue attachment.