Abrasiveness of an air-powder polishing system on root surfaces in vitro.

OBJECTIVE: The purpose of this study was to evaluate the abrasiveness of a new air polisher on root surfaces. METHOD AND MATERIALS: Fifty extracted human teeth were air polished for 5 seconds. RESULTS: All root surfaces showed a circular defect visible with the naked eye. Scanning electron microscope examination showed smooth crater walls and a few open dentin tubules, but most seemed to be obliterated. Laser profilometry of the exposed areas revealed defects with an average depth of 484 microns, whereas the unexposed root surfaces showed irregularities with an average depth of 323 microns. The depths of the abraded areas were evaluated in relation to the values for the unexposed surfaces, and an average depth of 161 microns was found. The difference between the exposed and unexposed surfaces was statistically significant. CONCLUSION: The present study indicates that the air polisher has a strong abrading effect on exposed root surfaces and should therefore be used with caution on patients with gingival retractions.     

The effect of an air-powder abrasive system on in vitro root surfaces

An air-powder abrasive system, the Prophy-Jet model C-100, is now available for use by the dental community. However, its use has been restricted to cleaning enamel surfaces of stain and dental plaque. The purpose of this investigation was to ascertain the effects of this air-powder abrasive system on root surfaces of extracted human teeth. Thus, root surfaces of 20 teeth were covered with a template consisting of a metal band with a centrally located 2-mm diameter hole. The banded root surfaces, under controlled conditions, were exposed to the air-powder abrasive for 30 seconds. The resulting defects were measured by using a light microscope equipped with a graduated focus knob. Three teeth were randomly selected for examination by scanning electron microscopy and one was selected for histologic evaluation by light microscopy. Untreated extracted teeth were used as controls. In addition, one untreated tooth root was exposed to the air-powder abrasive without use of the template. In this instance, a brush stroke was used for approximately 1 minute, as might be done in a clinical situation. This tooth root was also examined by scanning electron microscopy. The Prophy-Jet air-powder abrasive system removed an average of 636.6 micrometers of root structure in 30 seconds of exposure time. The resulting surface was smooth, free of connective tissue fibers and debris, and all cementum was removed. Few open dentin tubules were observed since most appeared to have been obliterated. The powder crystals, as viewed by scanning electron microscopy, were sharp-pointed, somewhat elongated and of varying lengths. The Prophy-Jet air-powder abrasive system appears to have considerable potential for treatment of periodontally diseased root surfaces. However, its use should be tempered by the results of this and future research and sound clinical judgment.     

Er:YAG laser in defocused mode for scaling of periodontally involved root surfaces: an in vitro pilot study

BACKGROUND: The Er:YAG laser may be used on periodontally involved teeth in combination with conventional periodontal therapy in order to improve the efficacy of root instrumentation. The aim of this study was to compare the effect of hand instrumentation on root surfaces of periodontally involved teeth with Er:YAG laser application. METHODS: Thirty freshly extracted, non-carious, single-rooted, periodontally diseased human teeth from adult humans with advanced periodontal disease were used in this study. The teeth were divided into three groups of 10 specimens each. Group A was treated with scaling and root planing (SRP) with curets only (control). In group B, the root surfaces were scaled with curets and then lased with an Er:YAG laser (wavelength 2.94 microm). A handpiece with a water spray was used in non-contact mode (defocused) at a distance of 1 cm from root surface. Laser parameters were set at energy of 100 to 200 mJ/pulse, with 10 Hz of frequency. In group C, the root surfaces were lased only with power settings 250 to 300 mJ/pulse and 10 Hz frequency. An epon-araldite plastic embedding technique was used for light microscopic investigation. RESULTS: Histologic findings showed significant differences between the test and control sites. In control sites, after hand instrumentation, the surface was smooth, without a cementum layer, and the dentin layer presented opened tubules. Defects on the dentin layer were also present along root surfaces. In the test sites (B, C) root surfaces revealed no thermal damage; no cracking or tissue carbonization were observed. The superficial layers of lased surfaces appeared smooth and melted without alterations. CONCLUSION: Based on these findings, it appears that it may be feasible to use the Er:YAG laser for root instrumentation without prior root planing if the proper parameters are followed.     

In vitro polishing effectiveness of interdental aids on root surfaces

The purpose of this study was: to determine whether polishing standardized proximal root surfaces with dental floss, Superfloss, wood and plastic interdental cleaners, using a polishing paste, produces any significant change on root surface roughness; and to determine the effectiveness of different number of strokes in polishing. 80 tooth specimens were prepared, 10 in each of 8 sample groups. Each proximal root surface was standardized with 600A grit silicone carbide paper and polished with either waxed dental floss, Superfloss, wood or plastic interdental cleaners, using alkali aluminum silicate polishing paste. All specimens were mounted on a flossing machine and polished with 10 or 20 strokes. Before and after polishing, measurements were recorded with the Surfanalyzer 150 System to produce profile and average roughness tracings. Average maximum peak heights, mean number of peaks, and mean average roughness values were calculated from the tracings. The data were analyzed statistically by paired t-test and Student t-test. No significant mean differences were found between the number of strokes used. No significant differences were found for waxed dental floss in relation to the values analyzed. Significant differences were found for maximum peak heights for Superfloss following 20 strokes of polishing. However, no significant differences were found for Superfloss for mean number of peaks and average roughness. Significant differences were found for average roughness values, maximum peak heights, and mean number of peaks for the wood and plastic interdental cleaners. It was concluded that root surface roughness increased significantly with the use of wood and plastic interdental cleaners but not with waxed dental floss or Superfloss.     

Local chemotherapeutics as an adjunct to scaling and root planing

Gingival diseases are the most widely held diseases in America. In some patients, periodontal disease appears in a generalized form, but more often it appears in localized areas. Furthermore, after treatment with scaling and root planing (SRP) in generalized cases, the disease is often reduced to a few local areas in the patient's mouth. Since periodontitis is a bacterial infection with known pathogenic microorganisms, the local delivery of antimicrobials has been considered to be a possible solution for treating and controlling localized forms of periodontal disease. Three current local chemotherapeutic agents are reviewed in this paper: doxycycline gel, chlorhexidine chip and minocycline microspheres. With the advancement of local drug delivery systems, clinicians and their patients have new alternatives for treatment of periodontal disease.     

Effect of cigarette smoking on human PDL fibroblasts attachment to periodontally involved root surfaces in vitro

BACKGROUND/AIM: Cigarette smoking is one of the most significant risk factors in the development and further advancement of inflammatory periodontal disease. However, no study has been performed to investigate the effect of smoking on the attachment of human periodontal ligament fibroblasts to either periodontally diseased or healthy roots. The present study was conducted to evaluate the attachment of fibroblasts derived from healthy human periodontal ligament (PDL) to periodontally diseased root surfaces of smokers. METHOD: The subjects included 14 smokers and seven nonsmokers with at least a single periodontally involved anterior tooth planned for extraction. In addition, seven impacted third molars, which had been removed from nonsmoking adolescents, were used as a healthy control. The smoking status of each patient was determined by classifying the volunteers into four groups according to their level of cigarette consumption at the initial examination (seven patients each). Nonsmoking subjects who had never smoked cigarettes and had healthy periodontium were called healthy control (G1). In subjects with periodontal diseases, nonsmoking subjects who had never regularly smoked cigarettes (< 2 cigarettes/week) were called positive control (G2), smokers consuming or=20 cigarettes/day were located in group G4. To exclude the effects of all local irritants except for the adsorbed tobacco products, all teeth were subjected to thorough scaling and root planing 1 week before extraction. After 1 week of meticulous home care and continued smoking experience, teeth were extracted and the periodontally involved test areas were prepared for PDL culturing. PDL cells were cultured on root segments for 24 h. Samples were prepared for SEM viewing, photographing and counting at x750 in a standard area. RESULTS: The results of this study indicated that smokers' data (G3, G4) revealed a significant reduction of attached PDL cells when compared to that of nonsmokers' healthy and positive controls (G1, G2). No significant difference in the mean number of attached cells was found between data derived from smokers' groups (G3 vs. G4). The attached cells in all groups varied in shape; they were flatter in the control groups, while they were round in smokers' groups, with no dose-dependent effect. CONCLUSION: The present results suggest that cigarette smoking compromises PDL cell adhesion to root planed surfaces, which might affect periodontal regeneration following therapy.     

Topical metronidazole application as an adjunct to scaling and root planing

AIM: This study was carried out to investigate the effect of 2 applications of a metronidazole 25% dental gel as adjunctive therapy to subgingival scaling with root planing. METHOD: 59 of the original collective of 64 patients with adult periodontitis were observed for a 9-month period. This randomised single-blind study was carried out in split-mouth design. Each patient had to have at least 2 pockets with a probing depth of > or =5 mm in each quadrant. The clinical parameters, pocket probing depth (PPD), attachment level (AL) and bleeding on probing (BOP), were recorded at all teeth on days 0, 91, 175 and 259; in addition, subgingival plaque samples taken from 45 patients were analysed by means of dark-field microscopy. Therapy comprised subgingival scaling and root planing (SRP) of all quadrants and additional application of metronidazole 25%, dental gel in 2 randomly selected quadrants (SRP+Metro). Treatment was confined to teeth with a baseline PPD of > or =5 mm. Average PPD and AL and the incidence of BOP were computed for all pockets with a baseline PPD of > or =5 mm, and the 2 methods compared. The main efficacy variable for evaluation of the 2 treatments was the difference in PPD on day 259. RESULTS: Comparison of the 2 treatments revealed a statistically significant improvement in the clinical parameters for both treatment methods over the study period. Between baseline and day 259, significant differences in PPD (SRP+Metro: from 6.00 to 4.63 mm, SRP: from 6.02 to 4.83 mm) and BOP (SRP+Metro: from 67 to 31%, SRP: from 64 to 36%) were observed between the 2 treatment groups. Evaluation according to different patient groups demonstrated significant advantages of the combined therapy in previously-untreated patients, especially in female probands. Dark-field microscopy revealed a shift in the bacterial flora towards "healthy conditions". CONCLUSIONS: The results show that only minor advantages are to be gained from the application of a metronidazole 25% dental gel as adjunctive therapy to subgingival scaling. The distinctly better results of combined therapy in previously-untreated patients calls for more thorough investigation.     

Subgingival triclosan-polydimethylsiloxane gel as an adjunct to scaling and root planing

PURPOSE: To evaluate the influence of a triclosan-polydimethylsiloxane-containing gel when used as an adjunct to scaling and root planing on the treatment of chronic periodontal disease. METHODS: A 3-month, double-blind, randomized parallel design clinical trial was performed in 20 subjects with chronic periodontitis. The subjects, presenting at least three anterior sites with probing depth (PD) +/- 5 mm and bleeding on probing (BoP), were randomly assigned to two experimental groups: Group SRP-T: scaling/root planing plus test gel application (triclosan 1% + polydimethylsiloxane 13%) or Group SRP: scaling/root planing plus control gel application (polydimethylsiloxane 13%). Immediately following mechanical therapy, each assigned gel was applied to the selected sites and once a week during the following 3 weeks. Re-examinations were carried out on days 45 and 90 after the last irrigation. RESULTS: Significant reductions in PD and clinical attachment level (CAL) were observed for both groups in both periods (P < 0.05). However, SRP-T showed lower means of PD than SRP at Day 45 (3.60 +/- 0.87 versus 4.77 +/- 1.38, respectively, P = 0.035) and CAL at both 45 days (4.63 +/- 1.17 versus 6.07 +/- 1.43, P = 0.023) and 90 days (4.45 +/- 1.19 versus 5.91 +/- 1.37, P = 0.021). No differences were found for bleeding on probing, plaque index and gingival recession (P > 0.05) between groups.     

In vitro abrasion using an air-powder polishing device and its quantification by radiotracer measurement.

OBJECTIVES: This study was conducted to examine the assessment of abrasion of two different materials after neutron activation. METHODS: A fissure sealant material (Fissurit F/VOCO with a compressive strength of 235 MPa) and a glass ionomer cement (Aqua Ionofil/VOCO with a compressive strength of 170 MPa) were activated by irradiation with neutrons. Subsequent measurements of the full-energy-peak (FEP) (1368.55 keV of 24Na) were made of the sample materials before and after abrasion via exposure to the air-powder polishing to accurately describe substance loss. RESULTS: Abrasion varied more than three-fold between the two materials. SIGNIFICANCE: Neutron activation and radiotracer measurement allows the quantification of abrasion effects in different materials. In comparison with other current methods its use may allow a superior measurement accuracy and precision in determining the abraded mass.     

Anti-bacterial effect of citric acid treatment of periodontally diseased root surfaces In vitro

Abstract This investigation examined whether citric acid may exert an anti-bacterial effect against plaque deposits present on root surfaces in vitro. Aerobic and anaerobic blood-agar plate cultures were prepared from plaque samples obtained from the proximal root surfaces of 20 periodontally diseased human teeth following extraction. Ten teeth were exposed to saturated citric acid (pH 1) for 3 min, followed by rinsing in sterile 0.85% saline and plaque samples were then obtained immediately adjacent to those sites sampled initially. Controls consisted of using sterile water instead of citric acid on a further five teeth. The numbers of colonies present on pre- and post-treatment culture plates were counted al 24 h. The results indicated that citric acid application reduced, in all instances, the numbers of colonies grown from post-exposure plaque samples as compared to pre-exposure samples. No colonies were detected in 55% of aerobic and 30% of anaerobic cultures of acid-treated root surface samples. For aerobic cultures, citric acid exposure reduced the number of colonies grown from >10⁴ to <100 in 95% of the root surfaces sampled, while for anaerobic cultures, reduction from >10⁴ to <100 was found in 80% of surfaces sampled. The findings indicate that citric acid exerts anti-bacterial activity against microbial plaque deposits present on periodontally diseased root surfaces in vitro.     

Effect of a carbon dioxide laser on periodontally involved root surfaces.

BACKGROUND: The purpose of this in vitro study was to evaluate the effect of CO2 laser on the periodontally involved root surface, and to compare its efficacy with citric acid, EDTA and hydrogen peroxide in removal of root surface smear layer after root planing. METHODS: The study was conducted on 50 periodontally involved single rooted human teeth with poor prognosis. Immediately after extraction the teeth were scaled and root planed with Gracey curets; 50 specimens were obtained from the proximal side of each tooth which were assigned randomly to 1 of the 4 groups. Group A (35 specimens) was divided into 7 subgroups of 5 specimens each and irradiated with CO2 laser using a defocused mode at 3-watt power for 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, or 1.4 seconds, respectively. Groups B, C, and D (5 specimens each) were treated with 6% hydrogen peroxide, EDTA solution (pH 7.4), or saturated citric acid solution (pH 1), respectively for 3 minutes. The specimens were then fixed and scanned using SEM. RESULTS: It was observed that surface smear layer was present on root surfaces of teeth that were root planed; the CO2 laser was not able to remove the smear layer on the sites that were irradiated for 0.2, 0.4 or 0.6 seconds at 3W power. Irradiation time of 0.8 seconds at 3W power was able to remove the smear layer, but the dentinal tubules were partially exposed. The surface irradiated for 1 second showed a flat appearance with many clear orifice of dentinal tubules. No change in diameter of exposed dentinal tubules was observed and their diameter was nearly equal that of normal dentinal tubules. Irradiation time of 1.2 and 1.4 seconds produced surface charring and carbonization and was totally ineffective in exposing the dentinal tubules; 6% hydrogen peroxide did not remove the smear layer completely and the exposed dentinal tubules orifice was not clear. EDTA (pH 7.4) and citric acid (pH 1) were found to be effective in removing the smear layer and exposing the dentinal tubules, which showed funnel shaped widening. CONCLUSIONS: Surface smear layer was present on root surfaces of teeth that were root planed. Laser irradiation of 1 second at 3W completely removed the smear layer with minimal change in the diameter of the dentinal tubules. EDTA and citric acid were also effective in removing smear layer, but the exposed dentinal tubules showed funnel-shaped widening.     

Effects of an air-powder abrasive system on plasma-sprayed titanium implant surfaces: an in vitro evaluation

The purpose of this study was to conduct an in vitro evaluation of the effects of an air-powder abrasive system, commonly used in clinical dentistry for periodontal maintenance, on the surfaces of plasma-sprayed titanium dental implants. Twenty-eight plasma-coated titanium implant specimens were divided into a sterile water-treated control group and an air-powder-abrasive-treated test group. All specimens were subjected to three different in vitro testing conditions and post-treatment evaluations by scanning electron microscopy (SEM): (1) Topographical features of implant surfaces were studied before and after direct exposure to the abrasive; (2) biocompatibility of treated implant surfaces was evaluated and compared with those of control specimens via in vitro fibroblast attachment studies; and (3) the attachment of a common oral microbe to the implant surface and its subsequent removal by exposure to the air-powder abrasive were also evaluated. Results indicate that exposure of implant specimens to the air-powder abrasive for various periods resulted in only slight changes in surface topography, i.e., rounding of angles and edges of the plasma-spray coating and occasional surface pitting. Examination by SEM and a statistical comparison of the difference between the mean numbers of attached fibroblasts between control and test groups revealed no statistical significance. In both specimen groups, fibroblasts exhibited uniform attachment over the entire implant surface. A comparison of test and control groups demonstrated 100% removal of bacteria from the surfaces of test specimens exposed to the air-powder abrasive and approximately a 75% removal from control specimens exposed to sterile water.     

Effect of an air-powder abrasive system on root surfaces in periodontal surgery

The purpose of this study was to compare the effectiveness of an air-powder abrasive technique to conventional root planing during periodontal surgery. 7 patients scheduled for multiple extractions of periodontally-involved teeth were selected. Full thickness mucoperiosteal flaps were reflected, and proximal surfaces of 32 teeth were either ultrasonically scaled and exposed to the air-powder abrasive, or ultrasonically scaled and then manually root planed. Following extraction, teeth were stained for residual plaque and photographed, or prepared for scanning electron microscopy. The air-powder abrasive technique used for surgical root preparation was found to produce a root surface favorably comparable to manual root planing with regard to removal of plaque, calculus, and exposed cementum. A mean of 80 micron of cementum was abraded away after 40 s of exposure to the air-powder spray. The air-powder abrasive spray demonstrated an advantageous ability to remove plaque and cementum from areas of difficult access, such as furcations and root flutings.     

Effect of subantimicrobial dose doxycycline as an effective adjunct to scaling and root planing

BACKGROUND: This study evaluated the efficacy and safety of a subantimicrobial dose of doxycycline (SDD) in conjunction with scaling and root planing (SRP). METHODS: The study was a 9-month, double masked, randomized, placebo-controlled, parallel-group trial. A total of 41 patients with moderate chronic periodontitis who received SRP were randomly allocated to receive either a doxycycline hyclate or a placebo 2 weeks after SRP. Clinical attachment level (CAL), the probing depth (PD), gingival crevicular fluid (GCF) levels, and matrix metalloproteinase (MMP)-8 and -13 levels were measured throughout the study. The effect of SDD in conjunction with SRP on the dynamics of the periodontal microflora was also assessed using dark-field microscopic and culture analysis. Information on adverse events was collected throughout the study. RESULTS: During the treatment period, per-patient reductions in PD and CAL were demonstrated for both treatment groups, with a significantly greater reduction for the SDD group. The mean value of per-patient change in the GCF was much greater for the SDD group. Microbial analysis showed there were a general tendency for cocci, non-motile rods, and aerobes to increase with increasing treatment duration and a general decreasing tendency for spirochetes, motile rods, and anaerobes and black pigmented bacteria in both treatment groups, but no significant difference between the groups. The MMP-8 and -13 levels of the SDD group gradually reduced with time, and the mean perpatient average was significantly higher than in the placebo group. The adverse events in the SDD group were similar to those in the placebo group. CONCLUSION: This study suggests that a submicrobial dose of doxycycline as an adjunct therapy with SRP might be safe and effective in the long-term management of chronic periodontitis.     

Topography of periodontally involved human root surfaces after different chemical treatment modalities: an in vitro scanning electron microscopic study

The significance of chemical and conservative treatments of cemental tissue proximal to periodontal pockets has been pointed out in recent years. This in vitro scanning electron microscopy (SEM) study aimed to investigate the surface effects of topical applications of 0.1% cetylpyridinium chloride (CPC) and 2% sodium lauryl sulfate (SLS) and polishing on the periodontally involved root surfaces of human teeth. Ten single-rooted teeth from 8 patients with advanced adult periodontitis were included. Following extraction, any calculus was removed with extreme care to preserve as much cementum as possible. Eighty root specimens were prepared. Fresh solutions of CPC and SLS were applied for 1, 3 and 5 minutes each to 10 segments of root cementum. A total of 20 segments formed the polished (P) and control (C) groups, respectively. The results showed that the surfaces treated with CPC or SLS differed considerably from polished and control specimens. Depending on time, the surface coating was partly or wholly removed, leaving a nodular cementum structure, uncovering a fibrillar collagen substrate and the openings of dentinal tubules. Scarce debris was present on both control and polished surfaces, whereas bacteria were observed only on the control specimens. In view of these results, further definitive in vitro and in vivo research must be done to determine the advantages of chemical treatment and its effect on periodontal regeneration.     

Subantimicrobial dose doxycycline as an adjunct to scaling and root planing: post-treatment effects

BACKGROUND/OBJECTIVE: Subantimicrobial dose doxycycline (SDD 20 mg bid) plus scaling and root planing (SRP) significantly improved clinical attachment level (CAL) and reduced probing depth (PD) compared with placebo plus SRP in a double-blind, placebo-controlled, multicenter study of patients with adult periodontitis (AP). In a study conducted as a follow-up, the post-treatment effects of SDD were assessed in patients who completed the SRP study. METHODS: The SRP study was a 9-month, active-treatment study and the follow-up was a 3-month, no-treatment study. In the SRP study, tooth sites in qualifying quadrants were scaled and root planed and patients were randomized to receive twice daily SDD 20 mg or placebo. In the follow-up, patients received no study drug; investigators and patients remained blinded to the previous treatment group assignments. Efficacy measures included the change in CAL and PD from baseline values determined at the start of the SRP study in tooth sites stratified by baseline PD (i.e., 0-3 mm, 4-6 mm, > or =7 mm). Safety was evaluated using adverse event data and the results of clinical laboratory tests, oral pathology examinations, and microbiological assessments. RESULTS: Within each disease stratum, the incremental improvements in PD and CAL demonstrated in the SDD group over 9 months of active treatment were maintained through 3 additional months of no treatment. Treatment cessation did not result in an accelerated regression of periodontal health. No differences in the incidence of adverse events (including those related to infection) or laboratory or microbiological parameters were noted between the SDD group and the placebo group. CONCLUSIONS: The administration of SDD 20 mg bid for a period of up to 9 months is not associated with rebound effects or delayed or negative after-effects for a 3-month period after cessation of therapy.     

Nd:YAG激光照射对牙周病患牙根面的影响

目的 :研究Nd :YAG激光照射对未处理过的和用超声波或手工器械刮治过的牙周病患牙根面的影响。方法 :选择因严重牙周病而须拔除的单根牙 18颗 ,随机平均分为 6组 ,在临床麻醉下分别先后作如下治疗 :超声波刮治 +激光照射 ;激光照射 +超声波刮治 ;手工器械刮治 +激光照射 ;激光照射 +手工器械刮治 ;超声波刮治 ;手工器械刮治。然后拔除患牙作扫描电镜观察。结果 :单纯用超声波或手工器械刮治过的牙根表面均有明显的涂层 ,而用激光 (2 0pps、2 .0W、3min)照射 ,无论是在刮治前还是刮治后 ,均有助于根面涂层的去除 ,但激光对牙根表面结构有不同程度的影响。结论 :先用Nd :YAG激光照射、再行龈下刮治 ,牙根表面的涂层被清除 ,而结构改变最小。     

The distribution of bacterial lipopolysaccharide (endotoxin) in relation to periodontally involved root surfaces

The distribution of lipopolysaccharide (LPS) in periodontally involved root surface associated materials has been investigated using improved methods of identification and quantification. 39% of the LPS could be removed by gently washing in water for 1 min and 60% by brushing for 1 min with a slowly rotating bristle brush. The finding that 99% of the LPS can be removed by comparatively gentle procedures suggests that effective root surface debridement may be achieved by methods other than traditional hand instrumentation.     

The effect of Nd:YAG laser exposure on root surfaces when used as an adjunct to root planing: an in vitro study.

The purpose of this study was to evaluate the effects of Nd:YAG laser treatment on root surfaces in vitro when used alone or in combination with conventional scaling and root planing. The study population consisted of 18 unerupted third molars, each with a 3 mm diameter treatment site outlined on the root surface. Three specimens were randomly assigned to each of 6 different treatment groups: 1) untreated control; 2) root planed only; 3) laser treated only using 1.25 W of energy; 4) laser treated only using 1.50 W of energy; 5) laser treated with 1.25 W of energy followed by root planing; and 6) laser treated with 1.50 W of energy followed by root planing. Following their respective treatment, all specimens were prepared for evaluation by scanning electron microscopy. Specimens from Group 2, root planed only, exhibited a smear layer of scale-like texture with parallel instrument tracks resulting from curet use. Specimens treated by laser only, Groups 3 and 4, featured various surface changes not observed in controls such as charring and carbonization of the cementum surface, randomly distributed pitting and crater formation, and melting of the root mineral phase with subsequent resolidification as porous globules. Those specimens treated by laser followed by root planing, Groups 5 and 6, exhibited surface characteristics similar to those noted in Group 2 specimens. Further, there were areas of exposed dentinal tubules resulting from a "peeling" of the cementum layer. The results of this in vitro study suggest that laser use during root preparation, even at relatively low energy levels, will result in physical changes to the root surface.(ABSTRACT TRUNCATED AT 250 WORDS)     

Topical application of doxycycline on periodontally involved root surfaces in vitro: comparative analysis of substantivity on cementum and dentin

In this study, substantivity of topically applied doxycycline hydrochloride on root surfaces obtained from patients with periodontal disease was studied in vitro. Cementum and dentin specimens were impregnated with aqueous solutions of doxycycline for 3 minutes, and incubated in serum for 10 minutes, 7 days, and 14 days. Substantivity was determined by agar diffusion inhibition assay. Comparative analyses of cementum versus dentin groups were conducted with 2-way analysis of variance. Results indicated that there was no statistically significant differences between the binding potential of doxycycline to cementum and dentin specimens. Antibacterial effect of specimens treated with the concentration of 100 mg/ml persisted for 14 days, indicating the presence of doxycycline in biologically active form. Our findings demonstrate the long lasting substantivity of doxycycline hydrochloride on periodontally diseased root surfaces and supports the concept of using root surfaces as a substrate for the deposition and slow release for local tetracycline delivery.