Bond Strength Evaluation of Three Self-adhesive Luting Systems Used for Cementing Composite and Porcelain

Although all self-adhesive systems give improved handling and ease of use compared to traditional multi-step adhesive cements, clinicians should still consider self-adhesive cements as a heterogeneous category of luting agents that need to be better classified in terms of bond strength and chemical/mechanical properties.

Clodronate combined with a surfactant (Tween 20) does not improve osseointegration: a rabbit immunohistomorphometric study

Biphosphonates are compounds that inhibit bone reabsorption mediated by osteoclasts or the progression of periodontal disease independent on the host response to pathogenic bacteria that colonize the tooth surface. The use of biphosphonates in oral implantology is still in the experimental stage. The aim of this study is to evaluate the efficacy of a non-aminobiphosphonate combined with a surfactant to increase the ability of the drug to link to the implant and bone surfaces in the development of osseointegration in rabbits. Smooth titanium implants were devised to be used on rabbit femurs. A topical administration of clodronate combined with the surfactant (Tween 20) at different concentrations was made on the implant surface and in the implant site to increase the bone and implant adhesiveness. Placebo was given to the control group. New Zealand rabbits were used and sacrificed by CO2 after 8 weeks from the implantations. A histologic and histomorphometric analysis was carried out. Results did not show significant difference between the tests and the placebo groups. Our data are different from other similar studies obtaining statistically significant differences. These differences could depend on the efficacy of the drug used and on the procedure of application of the drug on the implant. This study demonstrates poor efficacy of clodronate applied topically to the implant and implant site during surgery to increase the percentage of osseointegration in the implant. Further studies using different fixation techniques of the drug may be necessary to confirm the present data.

Bevacizumab-Related Osteneocrosis of the Jaw

We describe a case of jaw bone necrosis after a lung adenocarcinoma bone metastasis, treated the first time in 2004 by means of pneumonectomy and lymph node ablation. One week after a dental extraction, the patient experienced pain in the mandibular region, in conjunction with alveolar bone exposure. Treatment with amoxicillin and clavulanate every 12 hours for 15 days and 0.2% chlorhexidine rinses was administered and there was a remission of infective complications, but not the closure of the exposed alveolar bone. Only at this time did the patient refer that he was treated with bevacizumab therapy immediately after the extraction. A preventive dental assessment of patients scheduled for bevacizumab therapy should be useful as for the zoledronic acid therapy. Dental surgery procedures for patients during bevacizumab therapy should be carefully evaluated and considered as the last choice, to reduce all possible risks and prevent complications.

Microbiological and Biochemical Effectiveness of an Antiseptic Gel on the Bacterial Contamination of the Inner Space of Dental Implants: A 3-Month Human Longitudinal Study

Microbial penetration inside the implant's internal cavity produces a bacterial reservoir that is associated with an area of inflamed connective tissue facing the fixture-abutment junction. The aim of this clinical trial is to evaluate the effectiveness of a 1% chlorhexidine gel on the internal bacterial contamination of implants with screw-retained abutments and on the level of AST secreted in peri-implant crevicular fluid. Twenty-five patients (aged 29 to 58 years) each received one implant. Three months after the end of the restorative treatment, and immediately after a clinical and radiographic examination and the abutment removal, microbiological samples were obtained from the internal part of each fixture and biochemical samples were collected by peri-implant sulci. The patients were then divided into two groups: the control (CG; n=10) and test (TG; n=15) groups. The CG had the abutment screwed into place and the crown cemented without any further intervention. In contrast, before the abutment placement and screw tightening, the TG had the internal part of the fixture filled with a 1% chlorhexidine gel. Three months later, the same clinical, microbiological and biochemical procedures were repeated in both groups. Total bacterial count, specific pathogens and AST activity were detected. The clinical parameters remained stable throughout the study. From baseline to the 3-month examination, the total bacterial counts underwent a significant reduction only in the TG. In contrast, the AST activity showed a significant increase in the CG. The administration of a 1% chlorhexidine gel appears to be an effective method for the reduction of bacterial colonization of the implant cavity and for safeguarding the health status of peri-implant tissue over a 3-month administration period.

Sinus augmentation procedure of the jaw sinus in patients with mucocele

The sinus augmentation procedure of the jaw sinus (SAP) is a surgical technique which permits the prosthetic rehabilitation of the edentulous saddles by the insertion of dental implants where unfavourable conditions exist for their application. Nevertheless, apart from malignant tumors, benign pathologies exist, such as mucocele or radicular cysts, which can complicate the SAP, causing sinusal disturbances. In this study we describe our experience of SAP in patients with mucocele of the jaw sinus, and describe our surgical technique without the preventive emptying of the mucocele. Based on our experience, the SAP operation can be carried out without complications if the distance between the top of the mucocele with SAP and the osteomeatal complex (OMC) is 22 mm, or for mucocele no larger than 18 mm. In fact, these parameters guarantee that, because of the lifting of the sinusal membrane, the antral drainage (AD) duct does not alter or become obstructed.

Biological considerations on the use of zirconia for dental devices

Zirconium oxide, known as zirconia, is a ceramic material with optimal esthetical and mechanical properties. Zirconia stabilized with yttrium oxide has the best properties for medical uses. A stress on ZrO2 surface creates a crystalline modification that opposes to propagation of cracks. Zirconia core for fixed partial dentures (FPD) on anterior and posterior teeth and on implants are now available. Clinical evaluations after 3 years report good percentage of success for zirconia fixed partial denture. Zirconia biocompatibility was studied in vivo and in vitro by orthopedic research; no adverse responses were reported on insertion of ZrO2 samples in bone or muscle. In vitro experimentation showed absence of mutation and a good viability of cells cultured on this material.

Effect of a subgingival chlorhexidine chip on the clinical parameters and the levels of alkaline phosphatase activity in gingival crevicular fluid during the non-surgical treatment of periodontitis

The main therapeutic approaches for inflammatory periodontal diseases include the mechanical treatment of root surfaces. Multi-center clinical trials have demonstrated that the adjunctive use of a chlorhexidine (CHX) chip is effective in improving clinical results compared to scaling and root planing (SRP) alone. However, some recent studies failed to confirm these clinical results, nor have any data been reported regarding the capability of the CHX chip in affecting the activity of alkaline phosphatase (ALP) in the gingival crevicular fluid (GCF). This enzyme has been related to a condition of destructive activity of periodontitis. The aim of this study is to provide further data on the clinical and biochemical effects of CHX chips when used as an adjunct to SRP. Eighty-two systemically healthy patients, aged 31-63, with moderate and advanced periodontitis were recruited from the departments of Periodontology of the University of Chieti. In each patient 2 experimental sites, located in two symmetric quadrants, were chosen with a probing depth of > or = 5 mm and bleeding on probing. The 2 sites were selected randomly at the split-mouth level; control sites received SRP alone, and test sites SRP plus 1 CHX chip. Clinical indices, including probing depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), and the ALP activity in GCF were evaluated at baseline and after 6 months. Alkaline phosphatase activity was assayed spectrophotometrically. The PPD and CAL were significantly lower at 6 months as compared to the baseline scores in both treatments (p less than 0.01). The PPD reduction was 2.7 mm in the CHX+SRP group and 1.9 mm in the SRP alone group. The CHX+SRP group showed a significantly greater gain of clinical attachment (mean: 1.4 mm) in comparison with the SRP group (mean: 0.9; p less than 0.05). No differences were observed in the decrease of the percent of BOP-positive sites between the experimental groups. Conversely, the CHX+SRP group underwent a significantly greater decrease (p less than 0.01) of the GCF-ALP activity 6 months after treatment in comparison with the SRP alone group. The adjunctive use of the CHX chip resulted in a significant improvement of pocket reduction and clinical attachment gain as compared with SRP alone. These results were concomitant with a significantly greater reduction of the GCF-ALP activity levels.

SEM analysis of oral lichen planus before and after treatment with 13 cis-retinoic acid

Cancer of the oral cavity is a frequent worldwide neoplasia, averaging 4% in men and 2% in women. Cancer of the oral cavity is often preceded by particular epithelial lesions, called precancerous lesions. The aim of this study is to evaluate, by SEM microscope analysis, before and after treatment with 0.1% 13-cis-retinoic, the morphostructural variation of the surface of the oral mucous affected by lichen planus in respect to healthy oral mucous. Following topical therapy with 0.1% 13-cis-retinoic acid for 8 weeks, a restoration of the physiological morphostructure was observed by SEM, demonstrating the efficaciousness of the treatment and the SEM analysis for identifying the lesions of oral epithelium.

Immediate implantation in fresh extraction sockets. A controlled clinical and histological study in man

BACKGROUND

Early implantation may preserve the alveolar anatomy, and the placement of a fixture in a fresh extraction socket helps to maintain the bony crest. Although a number of clinical studies exist, no histological reports show the outcome of implantation in fresh extraction sockets without the use of membranes in humans compared to implants placed in mature bone.

METHODS

Forty-eight healthy patients, receiving at least 4 fixtures in each of 2 symmetrical quadrants, underwent placement of 1 experimental fixture placed in a fresh extraction socket (TI) and 1 contralateral fixture in mature bone (CI). TI were placed after atraumatical tooth extraction, with a surgical site at the apex of the socket and a tight contact between the fixture and the socket's walls, but without the use of filling materials or membranes. The flap was coronally repositioned to obtain primary wound closure. Immediately after surgical intervention, a standardized periapical radiograph was taken. Second-stage surgery was done after 6 months. Six months after the second surgery, a second standardized periapical radiograph was taken and clinical parameters (bleeding and plaque index) recorded. Marginal bone loss (MBL) from the time of implant placement to the time of fixture removal was calculated by comparing periapical radiographs. TI and CI were then removed by a hollow drill to obtain histological specimens. Non-demineralized sections were stained by acid fuchsin and toluidine blue, and by von Kossa to evaluate the degree of bone mineralization. The percentage of direct implant-bone contact (DBC) was calculated by a computerized microscopic digitizer.

RESULTS

No significant differences in the clinical and radiographic parameters were observed between the 2 experimental categories. There was no statistically significant difference between TI and CI for DBC either in the maxilla or in the mandible. No connective or fibrous tissues were present around TI or CI. Bone resorption was not present in any of the histological sections.

CONCLUSIONS

The present study shows that when a screw-type dental implant is placed without the use of barrier membranes or other regenerative materials into a fresh extraction socket with a bone-to-implant gap of 2 mm or less, the clinical outcome and degree of osteointegration does not differ from implants placed in healed, mature bone.

Periodontal healing in humans using anorganic bovine bone and bovine peritoneum-derived collagen membrane: a clinical and histologic case report

The authors report the clinical and histologic data on the healing of a severe periodontal lesion obtained in a one-walled intrabony defect using anorganic bovine bone under a bovine peritoneum-derived collagen membrane. Eight months after surgery, a bone-like tissue replaced the lost tissues. A biopsy of this tissue was carried out. In the part of the specimen closer to the residual bony wall of the original defect, anorganic bone particles (ABP) appeared to be surrounded by a layer of newly formed bone; its osteocyte lacunae were colonized by osteocytes from the host, and actively secreting osteoblasts were observed in many microscopic fields. No resorption phenomena were observed in the ABP Newly formed cementum with actively secreting cementoblasts was present on the tooth surface, and well-oriented fibers inserting in both newly formed cementum and bone were observed. In an area far from residual bone, all ABP did not appear to be surrounded by newly formed bone. Osteocytic lacunae appeared not to be colonized by cells, and ABP was surrounded by dense connective tissue without osteoblasts near the grafted particles. A very limited amount of newly formed bone, without relations with ABP, was observed close to the root surface. From a clinical point of view, anorganic bone in association with a collagen membrane can be effective in the treatment of bony defects characterized by an unfavorable architecture. From a histologic point of view, the clinical appearance of bone regeneration is not always confirmed in the part of the defect far from the bony walls.

Fluids and microbial penetration in the internal part of cement-retained versus screw-retained implant-abutment connections

BACKGROUND

It has been recently observed that in implants with screw-retained abutments, in in vitro as well as in vivo conditions, bacteria can penetrate inside the internal cavity of the implant as a consequence of leakage at the implant-abutment interface. An alternative to screw-retained abutments is represented by implants that can receive cemented abutments. In this case, the abutment goes through a transmucosal friction implant extension (collar) and is cemented inside the internal hexagonal portion of the implant. The aim of the present research was to compare fluids and bacterial penetration in 2 different implant systems, one with cement-retained abutments (CRA) and the other with screw-retained abutments (SRA).

METHODS

Twelve CRA dental implants and 12 SRA implants were used in this study. The research was done in 3 steps: scanning electron microscopic (SEM) analysis, fluid penetration analysis, and bacterial penetration analysis.

RESULTS

1) Under SEM it was possible to observe in the SRA implants a mean 2 to 7 micron gap between implant and abutment, while in the CRA implants, the gap was 7 micron. In the latter group, however, the gap was always completely filled by the fixation cement. All the spaces between abutment and implant were filled by the cement. 2) With SRA implants, it was possible to observe the presence of toluidine blue at the level of the fixture-abutment interface and the internal threads; the absorbent paper was stained in all cases. With CRA implants, the absorbent paper inside the hollow portion of the implants was never stained by toluidine blue. No penetration of toluidine blue was observed at the implant-abutment interface and inside the hollow portion of the implants. 3) In all the SRA implant assemblies, bacterial penetration was observed at the implant-abutment interface. No bacteria were detected in the hollow portion of the CRA implants.

CONCLUSION

On the basis of the results obtained in the present study using 2 different implant systems, we conclude that CRA implants offer better results relating to fluid and bacterial permeability compared to SRA implants.

Prevalence of Actinobacillus actinomycetemcomitans and clinical conditions in children and adolescents from rural and urban areas of central Italy

BACKGROUND

The aim of this study was to report on the prevalence of Actinobacillus actinomycetemcomitans (Aa) and the periodontal clinical conditions in children and adolescents from a rural area of central Italy compared with the ones from an urban area of the same region.

METHOD

The study population consisted of 780 systemically healthy children, aged 6-14 years inhabiting the county of Chieti. 505 children attended 3 primary and 2 secondary schools from a rural area whereas 275 individuals attended 1 primary and 1 secondary school from the city of Chieti. The 2 provincial areas present a great difference in socioeconomic level and cultural background. Clinical examination consisted of recording the % of gingival sites positive for the presence of plaque (P1+), bleeding on probing (BOP+), mean probing depth (PD) from each primary or permanent tooth fully erupted in the oral cavity. Loss of periodontal attachment (AL+) was evaluated only in interproximal sites. AL+ subjects were distinguished in juvenile periodontitis (JP) prepubertal periodontis and early periodontitis (EP) patients. 8 gingival sites were microbiologically sampled in each subject and cultured, after pooling, for the presence of Aa.

RESULTS

30.3% of rural subjects, were positive for the presence of Aa, the difference from urban children (16%) being statistically significant (p=0.01) irrespective of gender and age. Aa showed a significantly (p=0.006) higher mean proportion in subgingival plaque samples from rural children (0.13% versus 0.02%). Loss of periodontal attachment in at least one site was found in 18 rural children (3.56%) (3 JP; 15 EP) and 2 urban girls (0.72%)(1 JP; 1 EP). No significant differences for AL were observed within the rural group according to the gender and age differentiation. In the urban group, both AL+ subjects were Aa+, while among children from rural areas all 3 JP and 13 EP subjects were Aa+. Rural subjects evidenced significantly worse clinical parameters with respect to urban children (% PI+ sites: p=0.000; % BOP+ sites: p=0.010; mean PD: p=0.000.) The relative risk for AL+ sites was significantly greater (2.42) in rural subjects harboring Aa in subgingival plaque. Similarly, the presence of Aa in subgingival plaque was related to a greater risk of more than 50% of BOP+ gingival sites in both rural and urban subjects (1.45 and 8.40, respectively).

CONCLUSIONS

Results of this study suggest that Aa colonization in children and adolescents from central Italy is affected by socioeconomic and cultural factors; these factors also affect the periodontal condition of the subjects.

Aspartate aminotransferase activity in crevicular fluid from dental implants

BACKGROUND

Aspartate aminotransferase (AST) is an enzyme normally confined to the cytoplasm of cells, but released to the extracellular environment upon cell death. Its levels are associated with the severity of experimental gingivitis and the loss of periodontal attachment. The aim of the present study was to investigate the presence and activity levels of AST in peri-implant crevicular fluid (PCF) from healthy and diseased endosseous implants in order to assess if AST in PCF can be further studied as a possible objective diagnostic aid in oral implantology.

METHODS

Eighty-one fixtures from 81 systemically healthy subjects were divided into 3 groups, 27 healthy implants (HI), 27 implants with mucositis (MI) and 27 implants affected by peri-implantitis (PI) according to well-defined clinical and radiographic criteria. PCF was collected by the insertion of a #40 standardized endodontic paper point to the base of the crevice or pocket for 30 seconds. AST activity was determined spectrophotometrically at 25 degrees C. The results were expressed as AST Units/ml in PCF.

RESULTS

An AST activity was detected in each sample from HI, MI and PI. The mean AST activity in HI was 0.26 +/- 0.16 U/ml; in MI, 0.38 +/- 0.27 U/ml; in PI, 0.62 +/- 0.29 U/ml. ANOVA showed that the difference among HI, MI, and PI was statistically significant at P <0.01 level. Post-hoc tests demonstrated that a significant difference in AST activity existed between HI/PI (t = 5.14; P<0.01) and MI/PI (t = 3.09; P<0.01). No statistically significant difference was found between HI/MI (t = 1.07; P >0.1) AST activity was significantly (P <0.01) associated with probing depth (r = 0.55), the amount of bone loss (r = 0.60) and bleeding on probing (r = 0.67). When the threshold for a positive AST test was set > or =0.4 U/ml, a sensitivity = 0.81 and a specificity = 0.74 were found in the detection of peri-implantitis; the positive predictive value was 61% and the negative predictive value was 88%.

CONCLUSIONS

Within the limits of this study, our results may suggest that PCF analysis could be further investigated in longitudinal studies as a suitable diagnostic strategy in the evaluation of dental implants.

[A comparative evaluation of the efficacy of the excisional new attachment procedure (ENAP) relative to root planing in the etiological phase of periodontal therapy]

BACKGROUND

In the present study, the effectiveness of root planing has been compared to the excisional new attachment procedure (ENAP) during the etiological phase of periodontal therapy, after the supragingival scaling, in order to establish if a technique offering an easy access to the subgingival areas could reduce the need for a surgical phase in the periodontal treatment.

METHODS

Twenty-seven patients, affected by moderate periodontitis, participated in this study; in each of them root planing was performed in a half of the oral cavity (control site) and the ENAP in the other half (test site). The main clinical parameters of periodontal health (probing depth--PD-, attachment loss--AL-, plaque index--PlI- and gingival index--GI-) were evaluated before and 1, 2 and 6 months after the periodontal treatment.

RESULTS

The results of the study showed that the parameters related with the amount of plaque and with the conditions of the marginal gingival tissue were not influenced by the different treatments used. Better improvements were found in PD and AL values in teeth treated by ENAP compared to those treated by root planing; this result is explained by a better access to the roots offered by the ENAP.

CONCLUSIONS

We can conclude that, within the limits of the present study, the ENAP can reduce the need for a further surgical treatment of the periodontal patient.

Bacteriological and clinical follow-up of periodontal pockets during a topically applied 1% metronidazole-gel therapy in patients with adult periodontitis

The aim of this study was to evaluate the clinical and bacteriological effects of the intrasulcular application of a 1% metronidazole-gel (repeated administrations outdistanced of 7 days weeks long) currently employed in dermatological practice, to observe if a lower concentration of the chemotherapic agent could be equally effective as the 25% formulation in improving the periodontal condition of nine patients with adult periodontitis. The results showed that this regimen can modify, at a statistically significant level, the clinical (Pocket Probing Depth, Gingival Bleeding Index and Plaque Index) and bacteriological (Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Veillonella parvula) parameters associated with adult periodontitis. The results are similar to those obtainable with a 25% Metronidazole-gel administered two times outdistanced by 7 days.

Microbiological and clinical effects of a 1% chlorhexidine-gel in untreated periodontal pockets from adult periodontitis patients

The aim of this study was to report the microbiological and clinical effects of repeated subgingival administration of a 1% Chlorhexidine-gel in periodontal pockets from 10 patients with adult periodontitis. Results showed that the experimental treatment significantly improved clinical parameters (Plaque Index, Gingival Bleeding Index, and Pocket Probing Depth). Direct subgingival administration of Chlorhexidine-gel also produced a remarkable modification in the proportions of putative periodontopathic microorganisms, such as Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Veillonella parvula, Fusobacterium nucleatum, and Peptostreptococcus micros, in subgingival bacterial plaque from periodontitis patients.

Site-specific subgingival colonization by Actinobacillus actinomycetemcomitans in orthodontic patients

A high prevalence of Actinobacillus actinomycetemcomitans (Aa) in subgingival plaque in patients for orthodontia already has been observed. The present study had the following aims: 1) to ascertain a direct relationship between the orthodontic appliance placement and the subgingival colonization by Aa, and 2) to determine whether the Aa growth specifically occurred on teeth with braces attached or whether the presence of orthodontic appliances could also cause the isolation of Aa in teeth free from therapeutic appliances. Twenty-four young systemically and periodontally healthy subjects with malaligned and crowded teeth in the anterior sextants of both dental arches participated in this study. After 1 session of ultrasonic scaling with oral hygiene instructions during the first experimental session, the mesiobuccal sites of the first molars and the distobuccal sites of the lateral incisors in both dental arches in each participant were subjected to clinical and microbiologic examination for the recovery of Aa. Clinical examination consisted of recording the presence of plaque and the examination of gingival bleeding on probing and probing depth. Microbiologic sampling was obtained with the insertion of 3 sterile paper points at the deepest part of each gingival sulcus. Altogether, 192 periodontal sites were examined. After the examinations, the patients received fixed orthodontic appliances in only 1 dental arch (test sites) and the other one was left free from appliances (control sites). Clinical examination and microbiologic sampling were repeated in the same experimental test and control sites after 4, 8, and 12 weeks. At the 12-week session, the orthodontic appliance was removed from the test arch, and, 4 weeks later, a further clinical and microbiologic examination was performed. The results showed that, during the period with orthodontic appliances, the presence of plaque scores and the gingival bleeding on probing scores were increased significantly and that Aa, initially absent from all but 1 subject, was isolated in 19 and 20 subjects after 4 and 8 weeks, respectively. Furthermore, no gingival sites from the control teeth (free from Aa colonization at baseline) showed positive results for the sought-after bacterium throughout the entire length of the study. It was concluded that the placement of orthodontic appliances promotes the subgingival growth of Aa; this specific microbial change is specifically restricted to subgingival plaque from orthodontic appliance-bearing teeth. The presence of orthodontic bands and brackets therefore cannot affect the microbiologic condition of the whole mouth.

Expanded polytetrafluoroethylene and dental rubber dam barrier membranes in the treatment of periodontal intrabony defects. A comparative clinical trial

As observed in previous case reports, dental rubber dam (DRD) can be utilized as a barrier membrane in the guided tissue regeneration (GTR) technique for the treatment of periodontal intrabony defects. The purpose of the present study was (1) to confirm the validity of DRD as a suitable material in regenerative procedures and (2) to compare, in a split-mouth clinical trial, the effectiveness of DRD-made membranes in the treatment of periodontal intrabony defects versus that of expanded polytetrafluoroethylene (e-PTFE) barriers. 22 systemically healthy non-smoker adult periodontitis patients (7 male, 15 female) aged between 35 to 58 years were selected for the study. In each patient, a couple of 2-3 wall intrabony defects, located in different quadrants, were treated by a GTR technique using DRD (test sites) and e-PTFE (control sites), respectively. Performing a strict control of the oral hygiene level and of the marginal gingival health during the whole period of study, clinical (pocket probing depth, PPD; probing attachment level, PAL; gingival recession, GR) and intrasurgical (depth of the defect's intraosseous component, IOC; level of the alveolar crest, ACL) parameters were recorded at baseline and at the 1-year re-entry procedure in each experimental site. Furthermore, the coronal level of the newly formed tissue from the base of the defect (NFTL) and the vertical bone gain (VBG) were calculated at the time of membrane removal and after the re-entry procedure respectively. Membranes were removed from both test and control sites after 5 weeks; however, exposure of the membrane always occurred in test sites whereas it was observed in only 6 out of 22 control sites, this fact leading to an incomplete coverage of the regenerated tissue by the gingival flap in 18 out of 22 test sites. In both test and control sites, a statistically significant improvement of clinical and intrasurgical parameters occurred at the end of the study period; however, a significantly greater improvement was observed in control sites for PAL (+4.0 mm versus +3.0 mm; p<0.05) and VBG (3.9 mm versus 2.9 mm; p<0.05) although at the time of membrane removal, NFTL was similar between the experimental sites (test: 5.8; control: 5.6; p>0.05). Conversely, test sites exhibited a statistically significant greater increase in gingival recession (+1.9 versus +1.2; p<0.05) and alveolar crest resorption (-1.1 versus -0.3, p<0.01) in comparison to controls. It was concluded that (1) DRD is a suitable material to be used as a barrier membrane in GTR procedures although (2) e-PTFE membranes can provide a greater improvement in PAL and VBG, probably because of the difficulty in completely covering the regenerated tissue due to the fact that the gingival tissues have undergone a consistent recession in DRD-treated sites. Further studies are needed to demonstrate if an adequate coverage of the regenerated tissue in DRD-treated sites can eliminate these differences.

Histologic and histomorphometric analysis of the bone response to machined and sandblasted titanium implants: an experimental study in rabbits

The aim of this study was to make a comparative analysis between the bone response to machined and sandblasted implants. The sandblasting was done with 150-microns aluminum oxide particles. Under scanning electron microscopic examination, the machined implants presented typical machining grooves, while a very rough, highly irregular surface with depressions and indentations was present on the sandblasted implants. Light microscopy showed a different bone growth pattern on machined (implantopetal growth) and sandblasted (implantofugal growth) implants. No negative effects on the rate of bone growth were observed in spite of the presence of aluminum ions. The histomorphometric analysis showed that sandblasted implants presented, from the third week onwards, a significantly higher contact percentage (P < .0001). These values could point to higher osteoconductivity as a result of the higher surface roughness of sandblasted surfaces.

Molar root furcation: morphometric and morphologic analysis

The objective of the present study was a morphometric and morphologic analysis of maxillary and mandibular first and second molars using three different techniques. Measurements of 207 maxillary molars (105 first and 102 second molars) and 207 mandibular molars (110 first and 97 second molars) were measured; root length, radicular trunk length (RTL), mesiodistal and buccolingual diameters (BLD) at the cementoenamel junction, inter-radicular angle (IRA) width, and furcal roof area (FRA) were recorded. No significant statistical correlations were found for most of these measurements, the only exception being the relationship between IRA/FRA, IRA/BLD in maxillary molars, and IRA/RTL in the maxillary first molar. Morphologic examination was carried out by stereo microscopy, light microscopy of undecalcified sections, and scanning electron microscopy. All of these techniques showed the complexity of the furcation area with a large number of anatomic irregularities and plaque-retentive structures that could hamper adequate cleaning during periodontal treatment.

Laboratory and clinical comparison of preservation media and transport conditions for survival of Actinobacillus actinomycetemcomitans

The capacity of clinical isolates and type strains of Actinobacillus actinomycetemcomitans to survive in a new transport medium (AaTM), phosphate-buffered saline (PBS) and Ringer's solution (RS) was evaluated. The effects of exposure to air, transportation time and temperature on viability were also studied. In addition, the culture of A. actinomycetemcomitans from subgingival plaque of patients with different forms of periodontitis was quantified. The results following storage in AaTM, PBS and RS showed that A. actinomycetemcomitans survived better in AaTM than in PBS or RS when transportation times exceeded 20-22 h, and that survival was enhanced by storage at below 12 degrees C. Serotype b strains of A. actinomycetemcomitans were able to survive better than either serotype a or c. In the clinical study the optimal transportation conditions for subgingival plaque containing A. actinomycetemcomitans were AaTM at a temperature of 8 degrees C for 24 h under anaerobic conditions. These conditions resulted in a high survival and isolation rate for A. actinomycetemcomitans without inhibition of the other periodontopathic bacteria isolated from deep periodontal pockets. These findings have practical implications for future multicentre clinical trials in which the transportation of oral specimens over relatively long distances and at different ambient temperatures during various periods of the year are required.

[Periodontal guided tissue regeneration with a rubber dam: short term clinical study]

BACKGROUND

The guided regeneration of periodontal tissues demonstrated to represent a therapeutical technique with predictable results. It has been observed that different materials, used as regenerative membranes, offer very similar results. Unconventional materials too, like the rubber dam, seem to be useful in the guided tissues regeneration technique. The object of the present study has been to comparatively evaluate the effectiveness of Gore-Tex and rubber dam-made membranes in the therapy of intra-osseous periodontal defects.

MATERIALS AND METHODS

Six patients with two similar intra-osseous defects, participated in the study; one defect has been treated using, during the surgical intervention, a Gore-Tex membrane, while the other has received, a fragment of sterile rubber dam membranes. The principal clinical parameters of the periodontal health (probing depth -PD- and attachment loss -AL-) has been evaluated in both the defects before and 6 months after the periodontal surgery.

RESULTS AND CONCLUSIONS

The results have showed that there are not statistically significant differences (p > 0.05) in the healing of the intra-osseous defects treated by rubber dam or Gore-Tex. The conclusion is drawn that the rubber dam can represent a valid and cheap alternative to the materials traditionally used in the regenerative surgery of the periodontal tissues.

Immediate loading of titanium plasma-sprayed implants: an histologic analysis in monkeys

Aim of this study was to evaluate peri-implant tissue reactions to immediately loaded titanium plasma-sprayed implants in Macaca fascicularis monkeys. A total of 48 titanium plasma-sprayed implants were inserted (24 in the posterior maxilla and 24 in the posterior mandible). A metal superstructure was cemented 3 days after implant insertion on 24 implants (12 in the maxilla and 12 in the mandible) (test implants). The remaining 24 implants (12 in the maxilla and 12 in the mandible) were left unloaded (control implants). Nine months after implant placement a block section was carried out, the defect filled with non-resorbable hydroxyapatite, and all 48 implants retrieved. The implants were treated to obtain thin ground sections. Three slides were cut for each implant and examined under normal and polarized light and a morphometrical analysis done. All implants were covered by bone under light microscopy. The histomorphometrical analysis demonstrated that in test implants, the bone-implant contact percentage was 67.3% (+/-7.6%) in the maxilla, and 73.2% (+/-5.9%) in the mandible; in control implants the percentages were, respectively, 54.5% (+/-3.3%) and 55.8% (+/-6.5%). In the test implants the bone around the implants tended to have a more compact appearance. In conclusion, our study demonstrated that in test implants the bone-implant contact percentage was significantly greater than in the controls (P < 0.01) and no fibrous connective tissue was present at the interface.

Clinical and histologic features of a nonaxial load on the osseointegration of a posterior mandibular implant: report of a case

The authors report on the clinical and histologic features of a single implant replacing a mandibular molar, which fractured after a 1-year loading period. Because of anatomic factors, the implant had been placed in an angulated position. The histologic examination showed a very high percentage of bone-implant contact. The bone located at the interface with the implant was mature, compact, and had few marrow spaces. No resorption areas were present, and no connective tissue was seen at the interface. Most likely, the lateral nonaxial forces exerted on the implant created very high bending moments. These forces produced a fracture of the implant, although no loss of osseointegration was observed at the interface.

In vitro antimicrobial susceptibility of periodontopathic Actinobacillus actinomycetemcomitans to roxithromycin and erythromycin

The in vitro minimal inhibitory concentrations (MIC) and minimal bactericidal concentration (MBC) of roxithromycin and erythromycin against Actinobacillus actinomycetemcomitans were evaluated. Sixty-seven different A. actinomycetemcomitans isolated from periodontal pockets of 101 subjects with different forms of early-onset and adult periodontitis and three reference strains of A. actinomycetemcomitans (ATCC 29522, ATCC 29523, and NCTC 9710) were included in this study. Erythromycin showed poor in vitro activity against A. actinomycetemcomitans; roxithromycin, on the contrary, exhibited good in vitro activity. Moreover, roxithromycin showed the best in vitro antimicrobial activity against 17 serotype a and 12 serotype c subpopulations of A. actinomycetemcomitans; against 38 serotype b subpopulation of A. actinomycetemcomitans, roxithromycin was consistently active. Roxithromycin exhibited MBC values usually equal to, or one-fold higher than MIC values. All the MBC values of erythromycin were three- to four-fold higher than the respective MIC result. Since roxithromycin is characterized by high concentrations in serum and good penetration and diffusion into gingival tissue, it could be expected to pass into the gingival crevicular fluid at levels sufficiently high to inhibit A. actinomycetemcomitans in vivo. These data indicate that roxithromycin might be a potential candidate for therapeutic trials in patients with A. actinomycetemcomitans-associated periodontitis.

Clinical significance of Actinobacillus actinomycetemcomitans in young individuals during orthodontic treatment. A 3-year longitudinal study

The aim of the present study was: (1) to assess longitudinally the occurrence of Actinobacillus actinomycetemcomitans (Aa) in young subjects wearing fixed orthodontic appliances compared to matched appliance-free controls; (2) to determine whether the presence of the micro-organism at baseline could influence the periodontal status assessed 3 years later. 70 subjects, 27 male and 43 female, aged between 12 and 20 years participated in the study: 35 subjects under orthodontic treatment with fixed appliances for at least 6 months, and 35 appliance-free individuals matched for age and gender. All subjects were free of clinically demonstrable loss of attachment. They all received oral hygiene instructions 2x during the 2 months preceding the first clinical and microbiological examination. No subgingival instrumentation was performed between baseline and the 3-year examination. Clinical parameters included gingival bleeding index (GBI), pocket probing depth (PPD) and measurements of attachment level (AL). Statistically significant differences were reported regarding frequency of detection of Aa between both groups at each examination. The %s of orthodontic subjects infected with Aa at the baseline and at the 3-year examination were 86% and 80%, respectively, while the corresponding figures for control subjects were 16.6% and 26.6%. The frequency distribution of %s of Aa in the total anaerobic subgingival flora among control subjects remained fairly stable, whereas the proportion of orthodontic subjects yielding Aa at a concentration > or = 1.0% dropped significantly from 32% at baseline to 19% at the 3-year visit. Calculations of the relative risk for increasing GBI and PPD in both groups when Aa was present at baseline, revealed that the orthodontic subjects positive for Aa had a negligible relative risk of experiencing worse periodontal conditions compared to orthodontic patients where Aa was not detected at baseline. In contrast, control subjects initially infected with Aa presented with a risk for increased GBI 6.6x higher than that for subjects without Aa. In conclusion, the present study confirmed previous cross-sectional findings reporting that young individual with an integer periodontium wearing fixed orthodontic appliances harbor Aa with a statistically significant greater frequency than appliance-free matched controls. However, although orthodontic patients exhibited more inflammation, their deteriorated clinical conditions could not be accounted for by the sole presence of Aa in their sulci. In contrast, appliance-free young subjects initially infected with Aa had a higher risk of experiencing more gingival inflammation than subjects without the bacterium during a 3-year observation period.

Immediate loading of titanium plasma-sprayed screw-shaped implants in man: a clinical and histological report of two cases

THIS STUDY REPORTS ON THE histological findings of two immediately loaded titanium plasma-sprayed (TPS) implants, retrieved for a fracture of the abutment and for psychological reasons, after 8 and 9 months of loading, respectively. The microscopical analysis showed that mature, compact, cortical bone was present around both implants, with the bone implant contact percentage about 60 to 70%. No fibrous tissue or gaps were present at the interface. No resorption was present in the peri-implant bone. On both implants a few osteoblasts were found positive at the interface for alkaline phosphatase (ALP); while no cells positive for acid phosphatase (ACP) were present. Immediate loading can, perhaps, be used in very selected cases of good bone quality, with implants that have certain macro- (screw shape) and micro-interlocks (titanium plasma-sprayed surface) characteristics. Good results have been reported also for non-TPS surface (e.g., machined surface). More data about different designs (e.g., cylinders) or coatings (e.g., hydroxyapatite) are needed before any firm conclusions about immediate loading can be reached.

Subpedicle connective tissue graft versus free gingival graft in the coverage of exposed root surfaces. A 5-year clinical study

The authors compared the clinical results obtained in gingival recession correction treatment using free gingival and bilaminar connective subpedicle grafts. 35 patients were treated with free gingival grafts (Group A) and 35 with subpedicle grafts (Group B). Class I and II Miller gingival recessions were chosen for treatment by the 2 procedures. The degree of gingival recession (GR), keratinized tissue (KT) and the exposed root surface area (ERSA) were measured preoperatively and again 5 years post-surgery. Bilaminar connective grafting showed better results in reducing the amount of GR while both techniques significantly increased the width of KT (p > 0.05). The mean % of root coverage obtained in patients in group A was 53.19% +/- 21.48, whereas for the group B, 85.23% +/- 17.86 of exposed root surface was covered post surgical intervention (p < 0.001). In group A, only 3 patients (8.75%) showed a complete resolution of gingival recession after treatment, whereas in group B, 17 subjects (48.57%) presented with complete coverage. On the basis of these results, the authors conclude that the subpedicle graft promises better results in the coverage of exposed root surfaces when compared with the free gingival graft.

Occurrence of Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola in periodontally healthy and diseased subjects as determined by an ELISA technique

The aim of this study was to assess by means of an ELISA technique, the occurrence of 3 putative periodontopathogens, Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola, in 3 clinically-defined adult periodontal conditions. Thirty systemically-healthy subjects were selected and grouped into 3 categories according to their periodontal health: 1) 10 periodontitis subjects (PS), having moderate adult chronic periodontitis; 2) 10 untreated gingivitis subjects (UGS), exhibiting no signs of periodontal destruction but presenting with clinical signs of mild gingivitis; and, 3) 10 treated gingivitis subjects (TGS), having the same clinical status as UGS, but who received a thorough prophylaxis treatment within the past 7 to 14 days prior to the baseline examination. A total of 60 samples were collected subgingivally from the six Ramfjord teeth per subject in each group and ELISA analysis was carried out to give a semiquantitative estimate of P. gingivalis. B. forsythus, and T. denticola. The immunologic detection method suggested the presence of antigens of P. gingivalis, B. forsythus, and T. denticola in subjects from each of the 3 groups. When a global analysis for the 3 disease groups was performed at one time, statistically significant differences were found among the ELISA scores of the 3 bacterial species. For example, comparisons of the ELISA scores showed that the concentrations of P. gingivalis differed significantly when comparing TGS to UGS and PS, but not when examining UGS/PS. The ELISA scores for B. forsythus were significantly different between TGS and PS. Mean concentrations of T. denticola were significantly different when comparing PS to TGS or UGS, whereas no difference was found between the latter categories. Within the limited scope of this study, the concentration of antigens detectable from putative periodontopathogens like P. gingivalis, B. forsythus, and T. denticola differed among the 3 diseased groups, with periodontitis subjects often showing the greatest level of antigens. Thus, it is reasonable to expect that, when using sensitive immunological detection methods, antigens of suspected periodontal pathogens can be found irrespective of the individual's clinical status. However, while detectable in the periodontal sites, the concentrations of these microorganisms are most likely to be above the threshold necessary to induce clinically-significant disease. Studies with larger sample size and standardized antigens are necessary to determine if the groups we found not to differ, were, in fact, different.

Frequency of detection of Actinobacillus actinomycetemcomitans in young patients during fixed orthodontic therapy

The aim of the present study was to assess the occurrence of Aa in subgingival plaques from young subjects undergoing orthodontic treatment with fixed appliances; moreover we sought a possible relationship between the presence of Aa and the clinical conditions, also taking into consideration the different types of appliances, i.e., orthodontic bands or brackets.

Bone formation inside the material interstices of e-PTFE membranes: a light microscopical and histochemical study in man

Membranes used in guided bone regeneration (GBR) should possibly achieve a good degree of tissue integration with neighbouring connective tissues in order to obtain a mechanically stable environment necessary for successful bone and soft tissue healing. The authors observed, in a histological study of e-PTFE membranes used for GBR and retrieved from 10 patients, inside the material interstices of the membranes, in many cases the presence of connective tissue cells and collagen fibres, and in two cases the presence of bone. The presence, inside the membrane, of connective tissue and bone could help toward a tight integration between the membrane and neighbouring tissues, with the production of a biological seal.

Occurrence of Actinobacillus actinomycetemcomitans in patients wearing orthodontic appliances. A cross-sectional study

The aim of the present study was to assess: (1) the occurrence of Actinobacillus actinomycetemcomitans (Aa) in subgingival plaque from young patients undergoing orthodontic treatment with fixed appliances; (2) a possible relationship between the presence of Aa and the clinical conditions; (3) a relation between the duration of orthodontic treatment and the microbiological and clinical parameters; (4) whether differences exist when taking into consideration the different type of appliances, i.e., bands or brackets. 34 subjects aged between 12 and 20 years participated in the study. Of these, 20 subjects had worn orthodontic appliances (test group), while the remaining 14 subjects served as matched control (control group). 4 to 8 sites in each patient were available for clinical and microbiological examination. Clinical parameters consisted of presence/absence of plaque and gingival bleeding index (GBI). Microbiological sampling was performed in the same sites as in the clinical examination. A statistically significant difference was present when comparing %s of GBI positive scores between teeth from the test group (57.5%) and teeth from the control group (25%). Plaque was present in 53% of test sites and 37% of control sites, but this difference was not statistically significant. Aa was detected from at least one site in 85% of test subjects and in 15% of the control subjects (p < 0.001). Among the subjects, 41% harboured Aa at a concentration between 0.1% and 1.0%, whereas another 40% yielded Aa at a concentration greater than 1.0%. Finally, a positive correlation was noted between the % of sites positive for Aa and the % of sites displaying a positive GBI score (r = 0.41; p < 0.005). No relation was found between the duration of orthodontic treatment and the microbiological or clinical parameters; neither were statistically significant differences found when we compared results from sites wearing bands or brackets. In conclusion, the present study showed that young subjects wearing orthodontic appliances harbour Aa with a remarkable frequency of detection, although plaque levels do not significantly differ from those of a matched control group.

Compound odontoma associated with a primary molar

The authors describe a case of a compound odontoma located between the roots of a primary molar. It is a very unusual location. The primary tooth and the odontoma were extracted and a slide was obtained with the cutting grinding system.

Flow cytometric approach to human polymorphonuclear leukocyte activation induced by gingival crevicular fluid in periodontal disease

In gingival pockets of patients with periodontal disease, polymorphonuclear leukocytes (PMN) are in contact with a peculiar exudate, the gingival crevicular fluid (GCF). Because of the pivotal role played by PMN in periodontal disease, we evaluated the ability of GCF in modulating normal human PMN. GCF was obtained from two gingival sites with severe periodontitis (SP) and two gingival sites with only mild periodontitis (MP) in 12 patients. Purified PMN were exposed to GCF from SP and MP sites and, as a control, to sterile culture medium. GCF activity was evaluated by monitoring the modulation of membrane molecules relevant to cell function. Compared to control medium, GCF from SP and MP sites was able to induce an activation status in PMN evidenced by an increased CD11b (62 +/- 9% and 28 +/- 7%, respectively) and f-Met-Leu-Phe (56 +/- 5% and 31 +/- 7%, respectively) receptor expression, with a concomitant reduction of CD62L expression (56 +/- 8% and 23 +/- 7%, respectively). Thus, reflecting the clinical status, GCF from SP sites was significantly more efficient in affecting PMN than GCF from MP sites. Cell size modifications, evaluated as an additional indicator of PMN activation, were consistent with membrane molecule modulation. The difference in PMN-activating capacity between SP and MP was abrogated by the successful completion of an appropriate periodontal therapy that dramatically improved clinical status. This is the first direct demonstration that GCF from periodontitis has the capacity to activate normal resting PMN and that this capacity reflects the magnitude of the inflammatory process that takes place in the gingiva.

Eosinophilic granuloma of the mandible involving the periodontal tissues. A case report

This case reports on a 14-year-old boy with multiple radiolucent lesions widely distributed in the mandible, particularly in the right side (body-angle-ascending ramus). The lesion was first diagnosed as early-onset periodontitis and treated accordingly. It continued to grow very quickly, however, over a 6-month period, resulting in involvement of the entire mandible, with complete destruction of the lingual cortical bone, erosion of the external cortex with expansion in the neighboring soft tissues, and with a periosteal reaction in some areas. This case may serve to illustrate the rapid progress of eosinophilic granuloma, the importance and the difficulties of an early diagnosis, and the consequences of late diagnosis and treatment.

Influence of gingival crevicular washing on the expression of polymorphonuclear leukocyte membrane receptors before and after periodontal therapy

Extensive data demonstrate that polymorphonuclear leukocytes (PMN) are the predominant cell type involved in periodontal disease and that gingival crevicular fluid constituents are influenced by the inflamed gingiva. The aim of the present study was to evaluate the ability of gingival crevicular washing (GCW) (a dilution of gingival crevicular fluid) from periodontal sites in different clinical conditions of modulating the PMN membrane receptors involved in motility, adhesion and phagocytosis before and after periodontal treatment. 10 patients affected by adult periodontitis (AP) were selected. From each patient, 2 test sites (TS) were chosen on the basis of a probing depth > 5 mm and attachment loss, and 2 control sites (CS) with probing depth < 3 mm without. Modifications of membrane receptor density of PMN from healthy donors incubated with GCW harvested from TS and CS was evaluated using fluorescent probes and flow cytometry. Compared to CS-GCW, TS-GCW before therapy increased the expression of the beta 2 integrin CD11b and the chemotactic receptor for the oligopeptide N-formyl methionyl leucyl phenylalanine (FMLP-R) while it reduced the expression of L-selectin. GCW collected from the same TS after the successful completion of periodontal treatment did not influence PMN receptors, indicating that the clinical improvement paralleled the disappearance of the PMN modulating capability contained in TS-GCW before therapy. In conclusion, the present data illustrate the relevant modifications occurring at PMN membrane in chronic adult periodontitis exerted by GCW obtained by a simple fluid collection technique. Thus, monitoring gingival crevicular fluid PMN activating capability may help disclose the presence of chronic periodontitis and may be useful in assessing successful treatment.

[The effect of subgingival irrigation with acetylsalicylate on the polymorphonuclear leukocyte count in periodontal pockets of medium depth]

Considering the role played by arachidonic acid metabolites in the pathogenesis of periodontal disease and the possible beneficial effects exerted by non steroidal anti inflammatory drugs on periodontal damage, the aim of the present study was to assess the capability of a 1% acetylsalicylate solution, delivered by subgingival irrigation, in reducing the number of polymorphonuclear leukocytes (PMN) in periodontal pockets of patients affected by periodontitis. Ten patients systemically healthy, in the age between 36 and 64, participated in the study. After supragingival scaling in each patient test and two control sites were chosen among those exhibiting a pocket depth between 5 and 7 mm. The number of periodontal pocket PMN was evaluated after subgingival washing by the technique of Skapski & Lenher and Gingival Bleeding Index (GBI) score was recorded in each experimental site. Test sites then received subgingival subgingival washing by 0.5 ml of a 1% acetylsalicylate solution three times a week whereas control sites were irrigated by physiologic solution. After treatment the number of PMN and GBI scores from each test and control site was re-evaluated. Results showed that test sites exhibited a decrease in the number of pocket-PMN respect to control sites although not statistically significant (p > 0.5). At contrary GBI score did not modify through the study. In conclusion subgingival irrigation by acetylsalicylate demonstrated to be able to reduce subclinical inflammation in periodontal pockets evaluated by the number of PMN in gingival fluid.

[The prognostic significance of the presence of Actinobacillus actinomycetemcomitans in the subgingival plaque of young orthodontic patients]

The aim of present study was to evaluate the prognostic significance of the presence of Actinobacillus actinomycetemcomitans in subgingival plaque from young patients wearing fixed orthodontic appliances. Fifteen orthodontic patients, 3 males and 12 females, aged 10 to 27, systemically healthy, participated in the study. First examination took place in the spring of 1992 (T1) and consisted in the collection of clinical (pocket depth, PD; Gingival Index, GI; Plaque Index, P1I; Gingival Bleeding Index, GBI) and microbiological (Actinobacillus actinomycetemcomitans presence) parameters in 4-8 periodontal sites in each patient. The same clinical and microbiological parameters were collected again in the spring of 1994 (T2). Results showed that the presence of Actinobacillus actinomycetemcomitans in the examined periodontal sites underwent fluctuation, 25% of sites being positive for the sought after bacterium in T2 whereas the percentage of Actinobacillus actinomycetemcomitans positivity in T1 was 47.5% with a statistically significant difference (p < 0.005). On the contrary clinical parameters did not show significant modifications through the study period T1-T2. Differential analysis of clinical parameter modifications in relation to Actinobacillus actinomycetemcomitans positivity in T1 or Actinobacillus actinomycetemcomitans-positivity fluctuations in T1-T2 period did not evidence any significant difference among various microbiological conditions. The authors conclude that the mere presence of Actinobacillus actinomycetemcomitans in subgingival plaque from specific periodontal sites in young orthodontic patients does not seem sufficient to consider those sites at risk for periodontal destruction in the medium-short term.

[The presence of Actinobacillus actinomycetemcomitans in subgingival bacterial plaque in relation to the amount of supragingival plaque]

Actinobacillus actinomycetemcomitans (Aa) is currently considered the principal bacterium involved in juvenile forms of periodontitis. Considering that supragingival and subgingival plaque are closely correlated, the aim of the present research has been to assess if a correlation can be recognized between the amount of supragingival plaque and the presence of Aa in subgingival plaque in young subjects. Thirty-three individuals participated in the study. In each subject's dentition two periodontal sites were chosen: one (test site) was randomly selected among those sites which displayed a Plaque Index (P1I) = 0; another site was similarly chosen among those which presented the highest P1I score (2 or 3). In each test and control site Gingival Bleeding Index (GBI) was recorded and a microbiological sampling of subgingival plaque was performed. After anaerobic culture of plaque samples, the occurrence of Aa in each test and control site and the proportional representation of the bacterium in total cultivable anaerobic flora were assessed. Results showed a statistically significant difference in the occurrence of Aa between test and control sites in the same oral cavity and a correlation between GBI positivity and Aa presence. In conclusion, according to other authors, Aa seems to be more frequently founded in subgingival plaque coming from periodontal sites where supragingival plaque in more abundant.

[The clinical and microbiological evaluation of the efficacy of oral irrigation on the periodontal tissues of patients wearing fixed orthodontic appliances]

The aim of the present study has been the evaluation of the effectiveness of oral irrigation with or without toothbrushing and dental flossing, in individuals treated with fixed orthodontic appliances, on controlling the development of dental plaque and, hence, of gingivitis. Eight individuals with a good general and oral status have been chosen. Before the experimental period, they received instructions about oral hygiene with toothbrushing and dental flossing and then they have been monitored to verify they were doing well. At the time T0, the upper tooth have been banded, three Periodontal Indexes (Plaque Index according to Silness and Loe, Modified Gingival Index according to Lobene and Gingival Bleeding Index according to Ainamo and Bay) registered and subgingival plaque samples from the premolars' gingival sulcus collected in order to point out the total anaerobes bacterial counts, the rates of motile bacteria, spirochetes, Gram positive and Gram negative cocci and bacteria, by means of optical and dark field microscopy and of cultural methods. For their oral hygiene, the patients had to use, in the right side toothbrush and dental floss (Control 1), in the left side the oral irrigator alone (Test 1). One month later (time T1), the lower teeth have been banded, too. In the right side the patients had to use toothbrush and dental floss (Control 2), while in the left one they used the same devices as Control 2 plus the oral irrigator (Test 2). At the time T1 Periodontal Indexes and Microbiological analyses have been extended to all the four quadrants.(ABSTRACT TRUNCATED AT 250 WORDS)

[The influence of the "age factor" on periodontal conditions in the diabetic patient]

Conflicting reports exist in dental literature on the relationship of diabetes mellitus to periodontal disease. Among the controversies about this relation, the role played by the age of patient has been widely investigated. Some authors, in fact, reported an increased prevalence and severity of gingivitis and periodontitis in children and young individuals with insulin dependent diabetes mellitus (IDDM) in comparison to healthy subjects, while other researchers were not able to confirm this finding. In particular some authors postulated the hypothesis that the diabetic state could influence periodontal conditions just after the age of 30-35. The aim of the present study has been to verify this hypothesis. One hundred thirty-two subjects participated in this study; among them 66 were IDDM patients and 66 were healthy controls comparable to the diabetics for the main epidemiological features. In particular, control subjects were similar to the diabetics for oral hygiene level in order not to attribute eventually occurring differences by mistake to the diabetic state instead of to a not comparable amount of bacterial plaque present on the teeth. Among 66 IDDM patients 33 were younger than 30 (medium age = 14; extremes: 6-22) and were indicated as DG (young diabetics) group; others 33 were older than 30 (medium age = 45.1; extremes: 31-66) and were indicated as DA (adult diabetics) group. A similar differentiation was made in the control group obtaining, in this way, two subgroups (CG = young controls and CA = adult controls). In the diabetic groups males were 53% while among controls they represented 58%.(ABSTRACT TRUNCATED AT 250 WORDS)

[The periodontal condition of patients with insulin- and non-insulin-dependent diabetes]

The authors compared through the most common clinical indexes the periodontal conditions of a group of type I and type II diabetic patients with those of a group of healthy control subjects. Results showed the existence of statistically significant differences for each parameter considered (plaque index, gingival index, bleeding index, attachment loss). Also with comparable oral hygiene diabetics showed a worse periodontal condition in comparison with controls. In absolute terms type II diabetics presented worse clinical index scores compared to type I diabetics even if not at a statistically significant level.

[The comparative evaluation of the efficacy of surgical and nonsurgical periodontal therapy in relation to the oral hygiene conditions and the severity of the lesions]

A retrospective longitudinal study was carried out to evaluate the efficacy of surgical and nonsurgical periodontal therapy in reducing pocket depth values. This evaluation was made in relation to the strictness with which patients observed professional and domestic oral hygiene and in relation to pretreatment pocket depth values. Results showed that the two forms of periodontal therapy offer comparable results in terms of pockets reduction of either restricted or considerable depth, whereas the most important element in order to achieve therapeutic success was the observation of an effective professional and domestic plaque control.

General considerations in the treatment of periodontal disease: infection control, medications, and wound healing

Although it is difficult to accurately predict the results of periodontal therapy, it may be possible to improve the success of therapy if the patient is considered from an immunologic, microbiologic, social, and behavioral point of view, as a heterogenous entity. The success or failure of a particular treatment can be related to the host's personal response to a therapeutic procedure rather than to the technique used.

[Oral ulcerative lesions in young adults]

Following a general discussion of the pathological and clinical aspects of recurring oral ulcerative lesions most frequently observed in dentistry, the paper illustrates a few typical and atypical clinical cases. In conclusion, the authors make a few comments on the differential diagnosis and therapy of these diseases.

[Modifications in the clinical and microbiological parameters of the periodontal tissues after the removal of overhanging class-II amalgam fillings]

A short-term longitudinal study was carried out to assess how microbiological and clinical characteristics, measured surrounding periodontal sites with amalgam class II fillings intentionally made to overhang, vary following their replacement with a correct form of filling. The results of the study showed a significant reduction of the total bacterial count and the percentages of Gram-negative and anaerobic organisms spreading from overhanging fillings to non-overhanging fillings. The paper concludes that, as has been already demonstrated in the case of onlays, there are both qualitative and quantitative variations in the subgingival plaque in the presence of overhanging fillings which can lead to periodontal damage.

[A comparative evaluation of oral and parenteral cephalosporins in inhibiting the growth of bacteria pathogenic to the periodontium]

A study was carried out in vitro to assess the inhibitory activity on the growth of Bacteroides gingivalis and Bacteroides intermedius using two oral cephalosporins (Cephalexin and Cephradine) in comparison to two parenteral cephalosporins (Cefotaxime and Ceftriaxon) and the classic Tetracycline HCl. The results of the study show that the inhibitory activity on the growth of the two periodontopathogenic bacteria produced by the oral cephalosporins is comparable to that of other antibiotics studied, and that in comparison to parenteral cephalosporins the former have the advantage of being better accepted and more economic.

[A comparative assessment of the capacity of 2 bleeding indices to represent the concentration of thromboxane B2 in the periodontal tissues]

Comparative assessment on the capability of two bleeding indexes to measure the concentration of thromboxane B2 in periodontal tissues. The aim of the study was to compare two bleeding indexes, the Gingival Bleeding Index (GBI) and the Gingival Bleeding Time Index (BTI) in evaluating the intensity of inflammation in deep periodontal tissues measured by the level of thromboxane B2 in the tissues themselves. Results showed that both bleeding indexes were closely correlated to tissue inflammation but that of the two, BTI is more significantly correlated. On the basis of these findings, the authors hope to see the application of bleeding indexes in clinical and research studies which can offer a graduated assessment of bleeding, thus increasing the specificity of this important diagnostic sign.

[The in vitro sensitivity of Bacteroides gingivalis and Bacteroides intermedius to different classes of antibiotic chemical molecules]

A study was carried out to assess the in vitro sensitivity of Bacteroides gingivalis and Bacteroides intermedius to various classes of chemio-antibiotic molecules. The activities of two cephalosporins (cefuroxime and cefotaxime), which have never previously been used for periodontal therapy, were also evaluated. Results showed that the cephalosporins possessed an equal or greater inhibitory activity against the bacteria studied than traditional tetracyclines, and a greater inhibitory activity than other antibiotics studied (metronidazole, ampicillin, piperacillin). Further studies are required to assess in vivo efficacy of cephalosporin therapy in severe periodontal diseases.