Healing responses of human intraosseous lesions following the use of debridement, grafting and citric acid root treatment. I. Clinical and histologic observations six months postsurgery

Preclinical evaluation of a new synthetic carbonate apatite bone substitute on periodontal regeneration in intrabony defects

OBJECTIVE

To evaluate the potential of a novel synthetic carbonate apatite bone substitute (CO3 Ap-BS) on periodontal regeneration.

BACKGROUND

The use of various synthetic bone substitutes as a monotherapy for periodontal regeneration mainly results in a reparative healing pattern. Since xenografts or allografts are not always accepted by patients for various reasons, a synthetic alternative would be desirable.

METHODS

Acute-type 3-wall intrabony defects were surgically created in 4 female beagle dogs. Defects were randomly allocated and filled with CO3 Ap-BS (test) and deproteinized bovine bone mineral (DBBM) or left empty (control). After 8 weeks, the retrieved specimens were scanned by micro-CT, and the percentages of new bone, bone substitute, and soft tissues were evaluated. Thereafter, the tissues were histologically and histometrically analyzed.

RESULTS

Healing was uneventful in all animals, and defects were present without any signs of adverse events. Formation of periodontal ligament and cementum occurred to varying extent in all groups without statistically significant differences between the groups. Residues of both bone substitutes were still present and showed integration into new bone. Histometry and micro-CT revealed that the total mineralized area or volume was higher with the use of CO3 Ap-BS compared to control (66.06 ± 9.34%, 36.11 ± 6.40%; p = .014, or 69.74 ± 2.95%, 42.68 ± 8.68%; p = .014). The percentage of bone substitute surface covered by new bone was higher for CO3 Ap-BS (47.22 ± 3.96%) than for DBBM (16.69 ± 5.66, p = .114).

CONCLUSIONS

CO3 Ap-BS and DBBM demonstrated similar effects on periodontal regeneration. However, away from the root surface, more new bone, total mineralized area/volume, and higher osteoconductivity were observed for the CO3 Ap-BS group compared to the DBBM group. These findings point to the potential of CO3 Ap-BS for periodontal and bone regeneration.

Regenerative potential of biphasic calcium phosphate and enamel matrix derivatives in the treatment of isolated interproximal intrabony defects: a randomized controlled trial

Background

The combined use of biomaterials for regeneration may have great biological relevance. This study aimed to compare the regenerative potential of biphasic calcium phosphate (BCP) alone and with growth factor enamel matrix derivatives (EMDs) for the regeneration of intrabony defects at 1 year.

Methods

This randomized controlled trial included 40 sites in 29 patients with stage II/III periodontitis and 2/3 wall intrabony defects that were treated with BCP alone (control group) or a combination of BCP and EMD (test group). BCP alloplastic bone grafts provide better bio-absorbability and accelerate bone formation. EMDs are commercially available amelogenins. Mean values and standard deviations were calculated for the following parameters: plaque index (PI), papillary bleeding index (PBI), vertical probing pocket depth (V-PPD), vertical clinical attachment level (V-CAL), and radiographic defect depth (RDD). Student paired and unpaired t-tests were used to compare the data from baseline to 12 months for each group and between the groups, respectively. The results were considered statistically significant at p<0.05.

Results

At 12 months, the PI and PBI scores of the control and test groups were not significantly different (p>0.05). The mean V-PPD difference, V-CAL gain, and RDD difference were statistically significant in both groups at 12 months (p<0.001 for all parameters). Intergroup comparisons showed that the mean V-PPD reduction (2.13±1.35 mm), V-CAL gain (2.53±1.2 mm), and RDD fill (1.33±1.0 mm) were statistically significant between the groups at 12 months (p<0.001 for all parameters).

Conclusion

BCP and EMDs combination is a promising modality for the regeneration of intrabony defects.

Experimental and clinical studies on regenerative periodontal therapy

The recognition of a periodontal therapy as a regenerative procedure requires the demonstration of new cementum, periodontal ligament, and bone coronal to the base of the defect. A diversity of regenerative strategies has been evaluated, including root surface conditioning, bone grafts and bone substitute materials, guided tissue regeneration, enamel matrix proteins, growth/differentiation factors, combined therapies and, more recently, tissue-engineering approaches. The aim of this chapter of Periodontology 2000 is to review the research carried out in Latin America in the field of periodontal regeneration, focusing mainly on studies using preclinical models (animal models) and randomized controlled clinical trials. This review may help clinicians and researchers to evaluate the current status of the therapies available and to discuss the challenges that must be faced in order to achieve predictable periodontal regeneration in clinical practice.

Comparative Evaluation of Bioactive Synthetic NovaBone Putty and Calcified Algae-derived Porous Hydroxyapatite Bone Grafts for the Treatment of Intrabony Defects

Introduction

To compare and evaluate clinically and radio-graphically the bone regeneration and the amount of bone fill in intrabony component of periodontal osseous defects through the osteoconductive and osteostimulative effect of bioactive synthetic NovaBone Putty - CMF and osteoconductive effect of calcified algae-derived porous hydroxyapatite Frios^® Algi-pore^® bone grafts.

Materials and methods

Twenty-two sites in 11 patients, within the age range of 25 to 60 years, showing intrabony defects were selected according to split mouth design and divided into group I (Frios^® Algipore^®) and group II (NovaBone Putty - CMF). All the selected sites were assessed with the clinical and radiographic parameters like plaque index, gingival index (full mouth and site specific), sulcus bleeding index, probing pocket depth, clinical attachment level, gingival recession, and radiographic bone fill. All the clinical and radiographic parameter values obtained at different intervals (baseline, 3, and 6 months) were subjected to statistical analysis.

Results

A statistically significant reduction in pocket depth of 2.55 ± 0.52 mm (group I), 2.64 ± 0.67 mm (group II) and gain in clinical attachment level of 7.55 ± 1.44 mm (group I), 7.55 ± 2.38 mm (group II) were recorded at the end of the study. A slight increase in gingival recession was observed. The mean percentage change in amount of radiographic bone fill of group II (71.34%) was more than group I (61.93%).

Conclusion

Both NovaBone Putty - CMF and Frios^® Algipore^® improve healing outcomes and lead to a reduction of probing depth, a resolution of osseous defects, and a gain in clinical attachment, but radiographic observation found better results with NovaBone Putty.

How to cite this article

Bembi NN, Bembi S, Mago J, Baweja GK, Baweja PS. Comparative Evaluation of Bioactive Synthetic NovaBone Putty and Calcified Algae-derived Porous Hydroxyapatite Bone Grafts for the Treatment of Intrabony Defects. Int J Clin Pediatr Dent 2016;9(4):285-290.

Mandibular tori as bone grafts: an alternative treatment for periodontal osseous defects - clinical, radiographic and histologic morphology evaluation

OBJECTIVES

The present study was designed to evaluate the clinical, radiographic and histochemical significance of using the mandibular tori as autogenous bone graft for treatment of intraosseous defects in patients with chronic periodontitis.

MATERIALS AND METHODS

Twenty-eight sites from 14 patients with chronic periodontitis were included in this study. Each patient was treated with split mouth design; one site received torus mandibularis bone graft and the other site received a full-thickness fap alone. Histopathologic assessment was evaluated on removal of torus mandibularis to evaluate its histologic structure and by the end of the study 9 month later. Clinical and radiographic parameters were re-evaluated at 3 months interval for 1 year.

RESULTS

The results of the present study revealed significant gain in the clinical attachment level (CAL) (88.4%, 4.53 ± 0.06 mm) for torus mandibularis sites compared to (39.7%, 2.01 ± 0.04 mm) for full-thickness fap. Moreover, there was a reduction in the probing pocket depth (PPD) of (75.4%, 5.75 ± 0.12 mm) for torus mandibularis sites and (49.6%, 3.73 ± 0.14 mm) for sites treated with a full-thickness fap only; CAL and PPD differences were significant at p-value ≤0.01. Concomitantly, significant radiographic increase in the bone height and density were recorded in the test group.

CONCLUSION

The use of mandibular tori as autogenous bone graft could provide benefits as a periodontal therapeutic modality and enhance regenerative potential of periodontal intraosseous defects.

Clinical evaluation of a biphasic calcium phosphate grafting material in the treatment of human periodontal intrabony defects

Purpose

The aim of this study was to compare the clinical outcome of open flap debridement (OFD) with a biphasic calcium phosphate (BCP) graft to that of OFD without BCP graft for the treatment of intrabony periodontal defects (IBDs).

Methods

The study included 25 subjects that had at least one intrabony defect of 2- or 3-wall morphology and an intrabony component≥4 mm as detected radiographically. Subjects were randomly assigned to treatment with (BCP group, n=14) or without BCP (OFD group, n=11). Clinical parameters were recorded at baseline and 6 months after surgery and included the plaque index, gingival index, probing depth (PD), clinical attachment level (CAL), and gingival recession (REC). A stringent plaque control regimen was enforced for all of the patients during the 6-month observation period.

Results

In all of the treatment groups, significant PD reductions and CAL gains occurred during the study period (P<0.01). At 6 months, patients in the BCP group exhibited a mean PD reduction of 3.7±1.2 mm and a mean CAL gain of 3.0±1.1 mm compared to the baseline. Corresponding values for the patients treated with OFD were 2.5±0.8 mm and 1.4±1.0 mm, respectively. Compared to OFD group, the additional CAL gain was significantly greater in the patients in BCP group (P=0.028). The additional PD reduction was significant for the BCP group (P=0.048). The REC showed a significant increase in both groups, and the amount of recession was significantly smaller in the BCP group than OFD group (P=0.023). In radiographic evaluation, the height of the bone fill in the BCP group was significantly greater than OFD group.

Conclusions

The clinical benefits of BCP found in this study indicate that BCP may be an appropriate alternative to conventional graft materials.

Effect of Autogenous Cortical Bone Particulate in Conjunction With Enamel Matrix Derivative in the Treatment of Periodontal Intraosseous Defects

BACKGROUND

The aim of the present study was to assess the additional clinical benefit of autogenous cortical bone particulate (ACBP) when added to enamel matrix derivative (EMD), compared to EMD alone, in the treatment of deep periodontal intraosseous defects.

METHODS

A total of 28 intraosseous lesions in 27 patients with advanced periodontitis were included in this controlled clinical trial and randomly assigned to the EMD group (14 defects) or to the EMD + ACBP group (14 defects). Immediately before surgery (baseline) and after 6 and 12 months, probing depth (PD), clinical attachment level (CAL), and gingival recession (REC) were recorded. Radiographic depth of the defect (DEPTH) was also measured at baseline and 12 months post-surgery.

RESULTS

At 6 and 12 months, PD and CAL significantly improved from baseline in both groups (P <0.000). No significant differences in terms of CAL gain and PD reduction were detected between groups. However, defect distribution according to CAL gain was significantly different between groups (P <0.05). DEPTH significantly decreased from baseline to 12 months in both groups (P <0.000); between-group differences were not significant. At 12 months, a significantly greater REC increase in the EMD group (1.1 +/- 0.7 mm) compared to the EMD + ACBP group (0.3 +/- 0.8 mm) was observed (P <0.05).

CONCLUSIONS

Both EMD and EMD + ACBP treatments led to a significant improvement in clinical and radiographic parameters at follow-up with respect to presurgery condition. The combined approach resulted in reduced post-surgery recession and increased proportion of defects with substantial CAL gain (> or = 6 mm).

Histomorphometric Analysis of Bone Density in the Maxillary Tuberosity of Cadavers: A Pilot Study

BACKGROUND

Maxillary tuberosities have been widely used as a source of autogenous bone for a variety of oral surgical procedures. However, no previous studies have actually demonstrated the histologic and histomorphometric characteristics of this anatomical region in detail. The aim of this study was to evaluate maxillary tuberosities in cadavers histologically and histomorphometrically.

METHODS

A block section, including the overlying alveolar mucosa, was obtained from a randomly assigned maxillary tuberosity of 20 cadavers (nine females and 11 males). All cadavers were edentulous distal to the second bicuspid teeth, and 14 out of 20 were edentulous distal to the cuspids. A minimum of 35 serial sections were obtained from each cadaver. Description analysis was performed for the presence of either a fibrotic or fatty infiltration of the marrow spaces and thickness and continuity of alveolar bone. Computer-based histomorphometric image analysis of the percentage surface area of bone was also carried out in three sections of each cadaver. Statistical analysis was performed to establish possible differences between genders. The analysis did not control for nutritional status and/or possible systemic or skeletal diseases.

RESULTS

Little variation existed between specimens, regardless of gender, with respect to thickness of oral mucosa overlying the tuberosity. Descriptive bone analysis revealed thin cortical bone and sparse cancellous bone patterns. In addition, the block specimens exhibited no evidence of osteoid or active bone formation, but large marrow spaces infiltrated with loosely organized fibrous connective tissue and/or lipid cells. Histomorphometric analysis demonstrated a mean percentage of vital bone of 24.23% +/- 5.2%. Stratification of the data revealed statistically significant differences in mean percentage of vital bone between genders (27.15% +/- 4.7% for males versus 20.66% +/- 3.4% for females; P = 0.003).

CONCLUSIONS

Within the limitations of this study, maxillary tuberosities seem to mainly consist of marrow spaces, adipose tissue, and a low vital bone profile. Females demonstrated a statistically significant lower amount of vital bone than males. The results suggest that this specific area may not be an ideal source of autogenous bone for grafting purposes in older individuals. However, it is imperative to note that this investigation did not control for nutritional imbalances and skeletal disorders. Further studies are necessary to control all confounding factors.

Autogenous bone graft in conjunction with enamel matrix derivative in the treatment of deep periodontal intra-osseous defects: a report of 13 consecutively treated patients

AIM

The purpose of the present study was to investigate the effectiveness of a regenerative procedure based on supra-crestal soft tissue preservation in association with combined autogenous bone (AB) graft/enamel matrix derivative (EMD) application in the treatment of deep periodontal intra-osseous defects.

METHODS

Thirteen consecutively treated patients, seven females and six males, aged 30-65 years, three smokers, were included. A total of 15 deep, one- to two-wall intra-osseous defects were selected. Immediately before surgery and 6 months after surgery, pocket probing depth (PPD), clinical attachment level (CAL), and gingival recession (REC) were recorded.

RESULTS

PPD amounted to 9.4+/-1.8 mm before surgery, and decreased to 4.7+/-1.2 mm post-surgery (p<0.0000). CAL varied from 10.5+/-2.0 mm pre-surgery to 6.2+/-1.7 mm post-surgery (p<0.0000), with CAL gain averaging 4.3+/-1.4 mm. Fourteen (93.3%) defects presented CAL gain >/=3 mm. REC change was 0.4+/-0.7 mm.

CONCLUSIONS

Results from the present study indicated that a regenerative procedure based on supra-crestal soft tissue preservation and combined AB/EMD treatment leads to a clinically and statistically significant improvement of soft tissue conditions of deep periodontal intra-osseous defects.

Formation of human cementum following different modalities of regenerative therapy

The aim of the present study was to compare newly formed cementum following different types of regenerative therapy in humans. Eighteen patients, each displaying one advanced intrabony defect around teeth scheduled for extraction, were included in this study. The defects were treated with either guided tissue regeneration (GTR), enamel matrix protein derivative (EMD), EMD plus bioactive glass, bovine-derived xenograft (BDX), BDX plus GTR, or BDX plus EMD. After healing, the teeth were removed together with their surrounding soft and hard tissues. Cellular content, presence of artifactual splits between the new cementum and the old one or the dentin surface, and thickness of the new cementum were evaluated. Irrespective of treatment, the new cementum was of a reparative, cellular, extrinsic and intrinsic fiber type. There were no differences in cementum thickness among treatments. These findings indicate that in humans, (a) the new cementum formed after different types of regenerative therapy was, irrespective of the treatment, of a reparative, cellular, extrinsic and intrinsic fiber type, and (b) the regenerative modality does not seem to influence the type of newly formed cementum.

Efficacy of Chemical Root Surface Modifiers in the Treatment of Periodontal Disease. A Systematic Review

BACKGROUND

Periodontal regeneration has been a relentless goal of the periodontist. Perhaps the oldest and most frequently attempted type of regeneration has involved chemical modification of the root surface. Varying results from histological and clinical studies have created controversy about the clinical effectiveness of root surface decalcification.

RATIONALE

This systematic review assesses the efficacy of root surface biomodification through the use of citric acid, tetracycline, or ethylenediaminetetraacetic acid (EDTA) in patients with chronic periodontitis.

FOCUSED QUESTION

Does the use of chemical root declacification result in effective periodontal regeneration and improved clinical outcomes in patients with chronic periodontitis?

SEARCH PROTOCOL

The Cochrane Database of Systematic Reviews; Database of Abstracts of Reviews of Effectiveness; Cochrane Central Register of Controlled Trials; American College of Physicians Journal Club, evidence-based MEDLINE journals; and National Center for Biotechnology Information PubMed Journals, as well as Dogpile, Google, and Copernic search engines were screened. Hand searches were performed on the Journal of Clinical Periodontology, Journal of Periodontology, Journal of Periodontal Research, and Periodontology 2000. Searches were performed for relevant clinical trials published through September 25, 2002.

SELECTION CRITERIA

INCLUSION CRITERIA

Histological and clinical studies evaluating the effects of citric acid, tetracycline, or EDTA on root surfaces of patients with chronic periodontitis were considered for inclusion.

EXCLUSION CRITERIA

Studies evaluating extracellular matrix proteins (e.g., fibronectin), enamel matrix proteins (e.g., amelogenins), or other proteins or growth factors applied to the root surface were not included.

DATA COLLECTION AND ANALYSIS

Primary outcome measures included changes in connective tissue attachment, cementogenesis, clinical attachment levels, probing depths, and gingival recession. Secondary outcome measures included changes in bone level, gingival inflammation, and plaque levels. Results for continuous outcome measures for primary variables (clinical attachment levels, probing depths, and recession) were expressed as mean differences or standardized mean differences. Clinical attachment levels and reduction in probing depth were evaluated using meta-analysis. All papers were rated according to methodological strength of evidence.

MAIN RESULTS

1. Thirty-four studies incorporating a total patient population of 575 were analyzed: 26 for citric acid, 5 for tetracycline, and 3 for EDTA treatment. 2. Four of 8 human histological studies reported regeneration with the use of citric acid. Only 1 of 18 clinical studies reported attachment gain. 3. Of the 5 studies examined using tetracycline, 1 histological study and 1 clinical study reported attachment gain. 4. No regeneration was reported in the 3 studies evaluating the use of EDTA. 5. Meta-analysis performed on 28 clinical trials did not show any significant effects of acid root treatment on attachment level gains or probing depth.

REVIEWER'S CONCLUSIONS

1. Evidence to date suggests that the use of citric acid, tetracycline, or EDTA to modify the root surface provides no benefit of clinical significance to regeneration in patients with chronic periodontitis. 2. The best method for ascertaining the clinical efficacy of acid-treated root regeneration would be to conduct a randomized clinical trial with sufficient statistical power that is supported by quantitative histological evaluation. 3. The majority of the studies that evaluated the regenerative potential of root surface modifiers were observational in nature; therefore, the value of conclusions reached in this manuscript must be carefully considered.

Treatment of plaque-induced gingivitis, chronic periodontitis, and other clinical conditions

The inflammatory components of plaque induced gingivitis and chronic periodontitis can be managed effectively for the majority of patients with a plaque control program and non-surgical and/or surgical root debridement coupled with continued periodontal maintenance procedures. Some patients may need additional therapeutic procedures. All of the therapeutic modalities reviewed in this position paper may be utilized by the clinician at various times over the long-term management of the patient's periodontal condition.

Bone and bone substitutes

Bone replacement grafts will play a continuing role in periodontal and other regenerative therapy. Several choices are available to the clinician including autogenous, allogeneic, xenogeneic and a variety of alloplastic materials. Except for fresh autogenous bone, bone replacement graft(s) do not provide the cellular elements necessary for osteogenesis nor can they reliably be considered truly osteoinductive, but instead are mostly osteoconductive, providing a scaffold for bone deposition. Currently, significant decrease in clinical probing depth and gain of clinical attachment have been reported following use of bone replacement grafts when compared to flap debridement surgery alone for periodontal osseous defects. Reported differences among bone replacement grafts (autogenous, allogeneic, xenogeneic, and alloplastic) occur with respect to histological outcomes. Overall, probing depth reduction, attachment level gain and degree of defect fill are similar for all bone replacement grafts.

Comparative SEM study on the effect of different demineralization methods with tetracycline HCl on healthy root surfaces

Periodontal regeneration through the use of root demineralization received a lot of interest in periodontology. Topical application of acid to dentin surfaces produced a zone of demineralization, exposing dentin collagen fibrils and opening dentin tubules. In this study, the in vitro effects of different tetracycline HCl application techniques were investigated. According to the results of this SEM study, it may be desirable to apply tetracycline HCl using burnishing technique to expose maximum intertubular fibrils and for the tubular openings. However, this technique should be studied when placed in an in vivo system.

Periodontal regeneration around natural teeth

1. Evidence is conclusive (Table 2) that periodontal regeneration in humans is possible following the use of bone grafts, guided tissue regeneration procedures, both without and in combination with bone grafts, and root demineralization procedures. 2. Clinically guided tissue regeneration procedures have demonstrated significant positive clinical change beyond that achieved with debridement alone in treating mandibular and maxillary (buccal only) Class II furcations. Similar data exist for intraosseous defects. Evidence suggests that the use of bone grafts or GTR procedures produce equal clinical benefit in treating intraosseous defects. Further research is necessary to evaluate GTR procedures compared to, or combined with, bone grafts in treating intraosseous defects. 3. Although there are some data suggesting hopeful results in Class II furcations, the clinical advantage of procedures combining present regenerative techniques remains to be demonstrated. Additional randomized controlled trials with sufficient power are needed to demonstrate the potential usefulness of these techniques. 4. Outcomes following regenerative attempts remain somewhat variable with differences in results between studies and individual subjects. Some of this variability is likely patient related in terms of compliance with plaque control and maintenance procedures, as well as personal habits; e.g., smoking. Variations in the defects selected for study may also affect predictability of outcomes along with other factors. 5. There is evidence to suggest that present regenerative techniques lead to significant amounts of regeneration at localized sites on specific teeth. However, if complete regeneration is to become a reality, additional stimuli to enhance the regenerative process are likely needed. Perhaps this will be accomplished in the future, with combined procedures that include appropriate polypeptide growth factors or tissue factors to provide additional stimulus.

Human histologic evaluation of HTR polymer and freeze-dried bone allograft. A case report

This case report compares the results of placement of HTR (Hard Tissue Replacement Synthetic Bone) and freeze-dried bone allograft (FDBA) in the same patient. 2 notches were made in each of 6 teeth, 1 at the gingival margin and the other at the most apical level of calculus. Soft tissue responses with both materials included probing depth reduction, gingival shrinkage and gain in clinical attachment. Histological sections of block extraction sites 30 months after placement of either material showed no signs of new attachment. Little or no inflammation was present with both materials. There was also an absence of all FDBA particles which assumes complete resorption of this material prior to 30 months. Gingival shrinkage resulted in the exposure of the gingival and calculus notch in all FDBA treated sites. Gingival epithelium was found adjacent to the gingival notch in all HTR treated sites. The calculus notch in HTR treated sites was lined by junctional epithelium with connective tissue and bone opposing the adhesion. HTR particles were present and surrounded by connective tissue or bone. HTR appears to serve as a scaffold for new bone formation when in close contact with alveolar bone.

Implications of cellular and molecular biology advances in periodontal regeneration

BACKGROUND

The mechanisms by which new periodontium is established on root surfaces previously exposed to periodontal disease has been an area of active research interest for the past decade.

METHODS

Recently, histological examination of periodontal regeneration has revealed a complex process orchestrated by temporo-spatial specific cell-matrix interactions.

RESULTS

Advances in cell and molecular biology techniques have provided invaluable tools to begin investigating the cascade of events occurring periodontal regeneration.

CONCLUSION

This report summarizes current understanding of the cellular and molecular aspects of periodontal regeneration and determines the clinical relevance of these findings.

Bone allografts in periodontal therapy

Bone allografts as used in dentistry have a 20-year history of safety and efficacy. Case reports and controlled clinical trials have shown the potential of both mineralized and decalcified cortical freeze-dried bone allograft to reconstruct the bone defects caused by periodontitis. Histomorphometric analysis of human biopsies following grafts of decalcified freeze-dried bone allograft have shown the ability of decalcified freeze-dried bone allograft to promote regeneration of new bone, cementum, and periodontal ligament on a tooth root surface previously exposed to bacterial plaque. The addition of mineralized freeze-dried bone allograft and decalcified freeze-dried bone allograft to the guided tissue and guided bone regeneration procedures have significantly enhanced results, especially in large osseous lesions.

Citric acid demineralization of cementum and dentin: the effect of application pressure

Previous work has shown that a 25-30% citric acid solution was the most effective concentration with which to demineralize dentin. The purpose of this investigation was to study the topography, using a scanning electron microscope, of root surfaces treated with a 30% citric acid solution using various application pressures. 20 freshly extracted human teeth were collected and stored in physiologic saline at room temperature. 3 root specimens, approximately 3x5x5 mm in size, were prepared from the coronal periodontally healthy area of each tooth. 30 specimens were root planed to expose dentin (dentin group) while the remaining 30 specimens were lightly scaled to remove periodontal soft tissue (cementum group). A freshly made 30% citric acid (CA) solution, (pH = 1.60), was applied to each of the experimental areas. Cotton pellets soaked in the citric acid solution were either placed (CAP), lightly rubbed (CAR) or heavily burnished (CAB) on the prepared root surface for 3 min. Pellets were resoaked every 30 s. The root sections were rinsed, fixed in glutaraldehyde, dehydrated in graded ethanol, critically point dried in liquid CO2 and sputter coated in gold. The treated surfaces were assessed for fibril tufting using scanning electron microscopy. Assessment was made of: (i) the % of surface area tufted; (ii) tufting depth (0-3); (iii) tufting density (1-3). Results of the study showed significantly more tufted surface area and greater tufting depth on both dentin and cementum for CAR and CAB compared to CAP. CAP produced a flat/mat fibril surface with no evidence of tufting.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of the carbon dioxide laser in retarding epithelial migration: a pilot histological human study utilizing case reports

Predictable regeneration of tooth-supporting tissues lost to periodontal disease is the aim of periodontal therapy. Often the result of conventional treatment is healing with a long junctional epithelium along the root surface and little regeneration of the complete attachment apparatus. The purpose of this pilot study was to evaluate whether de-epithelialization with a CO2 laser at the time of flap surgery and at 10-day intervals over the first 30 days of healing has the potential to enhance the formation of a connective tissue attachment. Six mandibular incisors in two patients were selected for the study. Each patient received oral hygiene instruction and initial therapy prior to surgery. The teeth were splinted together, open flap debridement was performed on all teeth, a notch was placed on the roots at the height of the crest of the alveolar bone, and the flaps were sutured in place. The test side received controlled de-epithelialization of the outer (oral) gingiva with the carbon dioxide laser, and the inner gingival flap. The de-epithelialization was repeated on the test side at 10, 20, and 30 days postsurgically. Controls received open debridement only. Block sections were taken at 90 days and processed for histologic analysis. The results showed that for both patients, junctional epithelium (JE) was formed on both test and control teeth. In all control teeth, the JE extended the entire length of the root to the base of the reference notch.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of periodontal furcation defects. Coronally positioned flap with or without citric acid root conditioning in class II defects

A total of 27 mandibular, buccal class II furcation defects were treated in 16 subjects using a coronally positioned flap procedure, with or without citric acid conditioning of the root surfaces. The effect of the therapies was evaluated from a series of soft and hard tissue measurements. Mean improvements were slightly greater for acid treated than for non-acid treated defects. However, none of the mean differences reached statistical significance, indicating that citric acid conditioning may not be a necessary part of the regenerative, coronally positioned flap procedure in mandibular furcations.

Dentin demineralization. The effects of citric acid concentration and application time

Preliminary work has shown that the rate of dentin demineralization increases with increasing concentrations of citric acid. This rate subsequently diminishes at much higher concentrations. The purpose of this study was to more precisely identify the citric acid concentration which produces peak dentin demineralization and to determine if this demineralization process is time dependent. Flat dentin surfaces were prepared on the buccal and lingual sides of 15 bovine molars. 8 depressions were made in each dentin surface using a #8 round bur in a high-speed handpiece with air-water coolant. Various concentrations of citric acid solutions (weight per cent) were prepared, e.g., 0%, 10%, 20%, 25%, 30%, 35%, 40%, 65% and their respective pH's recorded. 3 microliters of each citric acid solution were placed in individual depressions on the dentin surfaces and left undisturbed for 1, 2 or 3 min. Cotton pellets were used to soak up the citric acid solution, along with any dissolved calcium, and were subsequently placed in 10 ml of 18 Me omega water. The parts per million calcium found in each water sample were determined using atomic absorption spectrophotometry. Peak dentin demineralization for 1-, 2- and 3-min application times occurred at 30% (pH = 1.55), 25% (pH = 1.62) and 25% (pH = 1.62) citric acid concentrations/(pH), respectively. Dentin demineralization was found to be time-dependent for all citric acid solution concentrations. The clinical significance of these findings is discussed.

In vitro effects of citric acid application techniques on dentin surfaces

The present study evaluated the in vitro effects of different application techniques of citric acid on dentin root surfaces. Ten freshly extracted, periodontally involved teeth were obtained and 4 dentin slabs, approximately 4 x 6 x 2 mm, were obtained from the roots of each tooth, for a total of 40 slabs. These slabs were identified by tooth and preserved in 1:1 anhydrous glycerol/absolute alcohol solution. Citric acid pH 1 was applied to 32 of the slabs for 5 minutes with one of 4 different techniques: 1) immersion; 2) placed with a saturated cotton pellet with no rubbing; 3) placed and burnished with a saturated cotton pellet; or 4) applied with a camel hair brush. The remaining 8 dentin slabs were used as negative control specimens, root-planed and non-acid treated. Following the various treatments, the slabs were fixed, dehydrated, critical point dried, and coated for scanning electron microscopic (SEM) evaluation. Scanning photomicrographs were obtained at 2,000, 6,000, and 40,000 magnifications. The surface characteristics of the treated dentin slabs were evaluated descriptively regarding the degree of fiber exposure; the number of exposed tubules and the surface area occupied by tubule orifices were also measured. Friedman's 2-way analysis for block designs was employed. Results demonstrated that root-planed, non-acid treated specimens had an amorphous, irregular surface which corresponded to a smear layer.(ABSTRACT TRUNCATED AT 250 WORDS)

Autogenous and allogeneic bone grafts in periodontal therapy

This article is limited to a review of bone autografts and allografts, as used in periodontal therapy. The various graft materials are discussed with respect to case reports, controlled clinical trials, and human histology. Other reviewed areas are wound healing with periodontal bone grafts, tissue banking and freeze-dried bone allografts, and the use of bone grafts in guided tissue regeneration.

Regenerating bone in clinical periodontics

Bone autografts and allografts, various alloplastic materials, and guided tissue regeneration are used to reconstruct lost periodontal tissues. This paper focuses on controversies related to these therapeutic modalities as well as their role in periodontal regeneration.

Comparison of freeze-dried bone allograft and porous hydroxylapatite in human periodontal defects

This study was conducted to clinically compare the efficacy of freeze-dried bone allograft (FDBA) and porous hydroxylapatite granules. Nineteen pairs of intraosseous defects were grafted in seven patients. One defect of each pair was implanted with FDBA, the other with granular porous hydroxylapatite. Matching defects were treated similarly in all other aspects. Evaluations were based on both preoperative and postoperative measurements from a fixed reference point, standardized radiographs, surgical osseous measurements, and histology of degranulated tissues. Grafted sites were reentered 6 to 11 months postsurgery. Results showed a mean osseous fill of 2.1 mm for FDBA versus 1.3 mm for granular porous hydroxylapatite (P = .07). A mean clinical attachment gain of 2.2 mm for FDBA versus 1.3 mm for granular porous hydroxylapatite (P less than .05), and a mean decrease in probing depths of 3.0 mm for FDBA versus 1.4 mm for granular porous hydroxylapatite (P less than 0.5) was found. FDBA was clinically indistinguishable from host bone, whereas porous hydroxylapatite appeared to be separated from host bone by soft tissue. The data and clinical findings suggested that FDBA may have some enhanced reparative potential when compared to granular porous hydroxylapatite in the treatment of periodontal defects in humans.

Citric acid burnishing of dentinal root surfaces. A scanning electron microscopy report

The integrity of formalin-fixed periodontally diseased root surfaces was assessed following root planing to dentin and citric acid application. Extracted human teeth (fixed in 10% formalin), with crowns removed, were vertically sectioned in half. A horizontal groove on each proximal surface marked the extent of attachment loss. The diseased root surface was vigorously root planed to expose dentin. Cotton pellets, soaked in a saturated solution of citric acid, were either "placed" (control) or "burnished" (vigorously rubbed using root planing pressure) (experimental) on the prepared root surface for 5 min. Pellets were changed 2 times/min. The teeth were fixed and prepared for scanning electron microscope viewing and photography. A representative print was selected for each specimen. To confirm differences between test and control groups, untrained raters were asked to perform 2 sorting exercises. First, they were asked to sort the representative photographs of each specimen into 2 piles based on surface characteristics. Second, they were asked to choose from pairs of photographs, representing matched specimens, the one photograph which appeared to have the greatest collagen surface area. The surfaces of experimental specimens revealed patent dentinal tubules and an intertubular area with a very distinct "shag carpet" appearance of deeply tufted collagen fibrils. Control samples also exhibited open dentinal tubules, yet the intertubular surface displayed a "matted collagen" surface. Results of the 2 sorting exercises confirm that burnishing of formalin-fixed dentin root surfaces for 5 min with cotton pellets soaked in a saturated solution of citric acid consistently produces a distinct tufted collagen fibril surface.(ABSTRACT TRUNCATED AT 250 WORDS)

Root coverage with the free gingival graft. Factors associated with incomplete coverage

The free soft tissue autograft when used for increasing the amount of attached gingiva is a relatively simple surgical procedure. The use of the free soft tissue autograft for root coverage, however, is a much more technically demanding procedure requiring the periodontist to consider additional factors. Overlooking or failing to properly address a single one of these factors can result in incomplete coverage. The purpose of this paper is to outline those factors that must be considered when complete root coverage is attempted.

Healing following devitalization of sites within the periodontal ligament by ultralow temperatures

Healing of specific rat periodontal ligament (PDL) sites following freezing injury was monitored histologically to evaluate repair potentials of this tissue. Buccal alveolar plates supporting the first mandibular molar in 15 adult rats were surgically exposed. The coronal 3 mm of plate covering the buccal surface of the mesiobuccal root and underlying periodontal ligament and cementum were subjected to ultralow temperature using a gas expansion micro/cryoprobe, diameter 2 mm, cooled to -81 degrees C for 5 seconds. Tissues were repositioned and sutured in layers. Animals were sacrificed at 1, 24 and 72 hours and at 2, 5 and 7 weeks following surgery and mandibles removed for histologic analysis. Microscopic evaluation of 24-hour specimens showed loss of cellular vitality in the PDL, adjacent bone and cementum at experimental sites. Cellularity of the gingiva coronal to the crest, and of the PDL apical to the experimental zone, appeared to be within normal limits. Transition between experimental and nonexperimental sites was abrupt. After 72 hours cells from the PDL and gingiva appeared to migrate into and repopulate the noncellular PDL. Few capillaries surrounded by mesenchymal cells and limited polymorphonuclear neutrophil infiltration were observed within the injured PDL site. Marginal gingival inflammation was minimal. At 14 days, collagen lysis, resorption of alveolar bone and root resorption were evident. In the PDL space, nonfunctionally oriented, cellular connective tissue elements were abundant. At 5 and 7 weeks, root resorption was marked. At this time interval, osteogenesis at seams of nonvital bone, repair cementum at sites of root resorption, and at times, ankylosis, were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of effect of citric acid treatment of root surfaces on the formation of new connective tissue attachment

Previous reports have described an accelerated induction of new attachment and repair of furcations in dogs after treatment of roots surfaces with citric acid, but few controlled clinical studies have examined its usefulness in surgical treatments for periodontitis. This study compared the effects of a comprehensive surgical plaque control procedure with or without citric acid treatment for generalized and localized effects on gingival height, probing pocket depth and attachment level in 72 teeth in 3 patients who were treated surgically for moderate periodontitis and examined every 3 months for 1 year. No statistically significant differences in the effects of the 2 treatments were observed. These observations suggest that there is no clinical advantage of citric acid conditioning of the root surface during surgical treatment of periodontitis.

The impact of research on scaling and root planing

The research expanding our knowledge of the periodontally involved root surface and its treatment is reviewed. To improve communication in the clinic and classroom, definitions are suggested for the terms "scaling" and "root planing." The objective and limitations of root planing procedures are discussed.

Speculations on periodontal attachment loss

A hypothesis is presented depicting patterns of human periodontal attachment loss. The patterns described occur rapidly, are site-specific and take place in response to virulence and duration of local irritants. They appear to mirror current clinical observations regarding the nature and progress of site-specific periodontal lesions.

Healing after root reimplantation in the monkey

The aim of the present investigation was to evaluate the regenerative potential of the periodontal tissues following tooth reimplantation using a model which excluded the dentogingival epithelium from the process of healing. Maxillary and mandibular incisors, premolars and molars of 5 monkeys were used. Following root filling of all experimental teeth, the teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted following the elevation of full thickness flaps. The crowns were separated from the roots at the level of the buccal cemento-enamel junction and the roots immediately reimplanted into their sockets. The flaps were replaced and sutured to accomplish complete coverage of the roots. In a 2nd group, the teeth were subjected to the same experimental procedure, but in addition, the buccal alveolar bone was removed to about half its original height prior to root reimplantation. The teeth of the 3rd group were subjected to identical experimental procedures as for group II with the addition that the buccal root surfaces were planed to the level of the surgically created bone crest. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. The results showed that a complete fibrous re-attachment formed onto roots on which the original periodontal ligament tissue was preserved. This occurred irrespective of whether the roots were reimplanted into sockets with normal (group I) or reduced (group II) bone height. When the original periodontal ligament tissue was removed by root planing before reimplantation (group III), healing resulted in a significant amount of new connective tissue attachment. However, coronal to the newly formed fibrous attachment, the root surface frequently showed signs of resorption and particularly so in those roots which remained covered by the soft tissue during the entire course of healing. In the majority of the roots which perforated the covering soft tissue during the early phase of healing, the dentogingival epithelium had migrated apically into contact with the coronally generated fibrous attachment. In these cases, root resorption was never discernible. New bone formation occurred to a variable extent in the roots of groups II-III. No relationship was found, however, between the amount of connective tissue reattachment or new attachment and newly formed alveolar bone, which in turn indicates that bone tissue regrowth and periodontal ligament regeneration are unrelated phenomena.

Fluorine concentration changes in human periodontally diseased tooth roots following several treatment times with citric acid

Citric acid conditioning of exposed cementum has become an important adjunct to the clinical management of periodontal disease, and aggressive root planing is recommended to remove hypermineralized and endotoxin-laden diseased cementum. A nuclear resonance reaction technique was used to examine fluorine concentration changes subsequent to application of citric acid (pH 1.0) to the periodontal disease-exposed cementum surfaces of human tooth roots. The technique does not require the test teeth to be sectioned, thereby permitting longitudinal assessments of changes in fluorine concentration and minimizing measurement errors due to the considerable biological variation found between individuals. Initial fluorine concentrations ranged from 0.9%-2.4%, and maxima occurred within 4-6 microns of the surface, suggesting the presence of a hypermineralized layer. Within 60 sec, the citric acid had effectively removed the hypermineralized layer and the previously observed fluctuations in fluorine concentration leveled out at 0.3%-0.5%. Although the results indicated rapid removal of the hypermineralized layer and establishment of fluorine levels normally found in healthy cementum, the experimental design did not permit appraisal of potential effects upon the organic components of periodontally-exposed cementum.

Healing following reimplantation of teeth subjected to root planing and citric acid treatment

The aim of the present study was to examine the effect of citric acid treatment on periodontal healing around teeth which were extracted, root planed and then reimplanted. Maxillary incisors and mandibular incisors, premolars and molars of 5 monkeys were used. The teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted and immediately reimplanted into their own sockets. In a 2nd group, the teeth were extracted, root planed to a level corresponding to 50-75% of the root length and then reimplanted. In the 3rd group, periodontal breakdown extending to 50-75% of the root length was first induced by placing orthodontic elastic ligatures around the teeth. They were then extracted and root planed and transplanted into the sockets of the contralateral, periodontally healthy teeth which had just been extracted. Half the number of the teeth of groups 2 and 3 were treated with citric acid before reimplantation or transplantation. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. With the exception of a limited coronal regrowth of new cementum in the apical part of the planed portion of a few roots, connective tissue attachment failed to reform on most root surfaces deprived of their periodontal ligament tissue. Healing was most frequently characterized by root resorption and ankylosis. These were the most predominant features of healing both on root surfaces which had been deprived of the ligament tissue by mechanical means or during a course of experimentally-induced periodontal disease, and occurred in citric acid as well as non-citric acid treated roots. The findings imply that the result of healing following tooth reimplantation or transplantation is determined by the type of cells that repopulate the wound area adjacent to the denuded root surface.

Treatment of localized juvenile periodontitis. Results after 5 years

The present investigation was performed to study the effect on localized juvenile periodontitis (LJP) of a treatment program which included tetracycline administration, surgical elimination of inflamed tissues, scaling and root planing, and careful plaque control during healing. Treatment of LJP lesions was carried out on 16 individuals aged 14 to 18 years (JP group). Lesions in first molars and incisors in a group of patients with adult periodontal disease (AP) were treated in an identical manner and served as controls. The presence of angular bony defects adjacent to first molars and incisors was first documented in all patients. Thereafter, a clinical examination was carried out, including assessments of oral hygiene status, gingival conditions, probing depths and attachment levels. The patients were subjected to a treatment program involving administration of tetracycline (250 mg 4 times per day for 2 weeks), removal of granulation tissue after flap elevation, and root curettage. After surgery, the patients were instructed to rinse the mouth with 0.2% chlorhexidine for 2 min twice a day during the first 2 postsurgical weeks. Professional tooth cleaning was carried out once every 3 months during a 5-year period. At 6, 12, 24 and 60 months after surgical treatment, the patients were re-examined regarding oral hygiene, gingival conditions, probing depths and attachment levels. Treatment of LJP lesions resulted in resolution of gingival inflammation, gain of clinical attachment, and refill of bone in angular bony defects. The healing of the lesions of this patient sample was similar to healing observed in patients with AP.

Healing responses of human intraosseous lesions following the use of debridement, grafting and citric acid root treatment. II. Clinical and histologic observations: one year postsurgery

This report details histologic healing responses at intrabony sites within two patients about 1 year after surgery. Treatment consisted of open flat debridement of the lesions. At specific sites, augmenting procedures such as autogenous grafts, allografts, synthetic grafts and citric acid root treatment were utilized. In addition, notches were made through calculus prior to root planing at specific root surfaces. These notches were placed at varying distances from the base of the lesion. Patients were followed postsurgically with frequent maintenance visits. Block sections were removed at the end of the experimental period. Clinical reduction in pocket depth was noted at all treated sites. This reduction consisted of limited pocket closure, marginal gingival recession and repocketing. Histologically, all specimens showed evidence of repair. The most mature repair appeared at sites treated with debridement and autogenous grafts. "Regeneration" of lost periodontal attachment was demonstrated by evidence of cementogenesis, osteogenesis and the presence of functionally oriented ligaments. However, the coronal regeneration appeared spatially limited. Allografts showed a similar, but less mature healing response. Synthetic graft material acted essentially as a "filler" within the defect. Citric acid root treatment did not demonstrate clear evidence of augmentation of the repair process. Of particular note in these human specimens was further histologic demonstration that "regeneration" potential apparently can only take place in close proximity to histologically viable periodontal ligament cells which may act as "donor sites" for coronal "regeneration" of lost periodontal attachment. This histologic response was observed regardless of treatment modalities used.