[Complete removable denture retained by symphyseal implant]. / Prothèse amovible complète retenue par un implant symphysaire médian.

INTRODUCTION: Edentulous patients often hope for stable and retentive prostheses. In very unfavorable anatomophysiological circumstances, the implant-retained removable full denture is a simple and reliable option that considerably optimizes the prosthetic balance. We present the case of one of those patients taken in charge in our department. OBSERVATION: A full edentulous 82 years old male patient was referred for a prosthetic rehabilitation. He presented with a negative mandibular crest and a very tonic peri-prosthetic musculature in the anterior region. He refused a bone augmentation surgery; we performed a piezographic mandibular prosthesis retained by a single symphyseal implant in a lingual position. The denture was stable and retentive. Comfort and masticatory efficiency were satisfactory and the psychological integration of the prosthesis was improved. DISCUSSION: Several studies focusing on octogenarian patients concluded that a complete removable denture retained by a single symphyseal implant is a simple, efficient and cost-effective option. Studies including more patients are needed.

[Atraumatic bone expansion: Interest of piezo-surgery, conicals expanders and immediate implantation combination]. / L'expansion osseuse atraumatique : intérêts de la combinaison pièzo-chirurgie, expanseurs coniques et implantation immédiate.

The durability of dental implants depends on the presence of a 1mm coating bone sheath all around the fixture. Therefore, bone resorption represents a challenge for the practitioner. Bone expansion is a surgical technique that allows the management of horizontal bone atrophy. Cortical bone splitting allows for an enlargement of the residual crest by displacement of the vestibular bone flap. The immediate placement of implants secures the widening and allows for a 97% survival rate. However, bone expansion is hard to undertake in sites with high bone density. Furthermore, the use of traditional instruments increases patient's stress and the risk for an interruptive fracture during bone displacement. Non-traumatic bone expansion is one solution to this problem. The combination of piezo-surgery and conical expanders allows for a secured displacement of the selected bone flap as well as an immediate implant placement, avoiding the risk of slipping, overheating, or fracture, all within an undeniable operative comfort. Non-traumatic bone expansion is a reliable, reproducible, conservative, and economical in time and cost procedure. We describe our atraumatic bone expension and immediate implant placement technique in high bone density sites and illustrate it by a clinical case.

Amoxicillin prophylaxis in oral surgery.

INTRODUCTION: Postoperative infection is the most common postsurgical oral complication but no double-blind, randomized, placebo-controlled trial has been made yet to assess amoxicillin prophylaxis for oral surgery. The aim of this pilot study was to assess the effectiveness of prophylactic amoxicillin 3g per os versus placebo in the prevention of postoperative oral infections. METHODS AND MATERIALS: A 5-year, multicentric, randomized, double-blind clinical trial was made on healthy patients undergoing complex oral surgery. Final analysis was by intention to treat. RESULTS: The 286 patients were randomly assigned to the amoxicillin or placebo group. After a mean follow-up of two weeks, 11 patients in the control group and three patients in the amoxicillin prophylaxis group developed a postoperative infection (P=0.001 in unilateral test). The hazard ratio was 0.27 [95% CI: 0.07-0.94]. CONCLUSION: Amoxicillin prophylaxis seems to be effective in preventing postoperative infection in complex oral surgery, especially when mandibular third molars and multiple avulsions are involved.

Carpegen real-time polymerase chain reaction vs. anaerobic culture for periodontal pathogen identification.

BACKGROUND/AIMS: The aim of this study was to compare two methods of microbiological diagnosis, anaerobic bacterial culture and real-time polymerase chain reaction (PCR), for the detection of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, and Treponema denticola. METHODS: Seventy-two samples were collected from 18 patients who were suffering from aggressive periodontitis. The data obtained were compared for the two methods. RESULTS: The results obtained with real-time PCR were different from those obtained with bacterial culture. The detection differences were 3% for A. actinomycetemcomitans, 8.33% for P. intermedia, and 12.5% for F. nucleatum. However, the differences for P. gingivalis and T. forsythia were 51.39% and 36.11%, respectively. No comparison was possible for T. denticola because it cannot be identified in culture. The variations found were the result of the better detection level (10(2) pathogens) of the PCR probe. Unlike bacterial culture, PCR allows the detection of T. denticola, which does not forming colonies and is oxygen sensitive. For F. nucleatum, T. forsythia and P. gingivalis, the real-time PCR technique was more sensitive than culture. CONCLUSION: Good results were obtained with the real-time PCR technique for the six periopathogens targeted. This method seems to be indicated for its simplicity, rapidity and reproducibility but it cannot analyze data for an antibiotic susceptibility test. The periodontist must therefore choose one of these two methods according to his specific clinical objective: to obtain rapid, specific detection even with weak initial concentrations (but for targeted periopathogens only) or to be non-specific and analyze the pathological activity with an antibiogram.

Absence of Helicobacter pylori in the oral cavity of 10 non-dyspeptic subjects demonstrated by real-time polymerase chain reaction.

Helicobacter pylori plays a significant role in gastric disease. However, the presence of this bacterium in the oral cavity remains controversial. The aim of the present study was to detect and quantify H. pylori in 29 different sites of the oral cavity in non-dyspeptic subjects by means of real-time polymerase chain reactions (PCR). Ten subjects without gastric symptoms were studied. Samples from unstimulated saliva, three sites of the tongue, oral mucosa, and 12 sites of both supragingival and subgingival plaque were collected from each subject. DNA was extracted from the oral samples and analysed for the presence of H. pylori by real-time PCR (LightCycler) using JW23/22 primers which targeted the 16S rRNA gene. DNA from H. pylori DSM 4867 was used as a positive control. Amplification efficiency for the LightCycler 2.0 runs ranged from 1.8 to 2.4. Melting curve analysis identified all the positive control capillaries, which contained H. pylori reference DNA, as a single and narrow peak at a melting temperature between 84.5 and 84.9 degrees C. All the negative control capillaries with no template control and the 29 oral samples from each subject showed either no melting peaks or broad melting peaks below 80 degrees C, which were considered as primer dimers. Therefore, H. pylori was not detected from any of the 290 oral samples. As a conclusion, H. pylori seems not to be permanently present in the oral cavity of a non-dyspeptic population.

[Bacterial DNA alteration by plasma generated atomic nitrogen. Real-time PCR detection contribution]. / Dégradation de l'ADN bactérien par de l'azote atomique produit par plasma. Apport de la détection par PCR en temps réel.

AIMS: Bacterial sterilization by the technology of plasma in post-discharge shows a growing interest. The main appeal of this new process resides in its action at dry and low temperature (60 degrees C). This technology would be therefore useful for the complex medical equipment, sensitive to the oxidization, humidity and/or requiring a temperature lower than 60 degrees C. The objective of this survey is to demonstrate the activity of an atomic flux emanating a plasma of pure molecular nitrogen on the bacterial DNA: does the plasma of nitrogen damage the genetic material? MATERIALS AND METHODS: The bacteria tested (Bacillus stearothermophilus, Staphylococcus aureus MRSA and Helicobacter pylori) are cultivated on suitable agar, and the bacterial DNA is extracted from every CFU by the technique of the columns (High Pure PCR Template, Roche). Every quantity of DNA extracted is diluted in 1 ml pure water. Then, 50 microl of each of these solutions of DNA are laid down in sterile Nunclon's plates holes, which undergo an advanced emptiness cycle during 60 minutes. The DNA residues will be then introduced during 40 minutes in a plasma sterilization surrounding wall (Plasmalyse), Satelec) where the debit of nitrogen, the pressure and the temperature are adjusted respectively to 1 L x min(-1), 5 Torrs and 60 degrees C. The DNA so ''plasmalysé'', is recovered then by aspiration in 500 mul pure water and processed to undergo an amplification/detection by Real-Time PCR (LightCycler2.0, Roche). The DNA ''plasmalysé'' will be compared to the intact DNA control(1), to the DNA control control(2) having undergone the cycle of emptiness solely, as well as to the DNA control(3) solely heated to 60 degrees C during 40 min. RESULTS: The amplification curves demonstrated that the only advanced emptiness and the only heat don't have any activity on the bacterial DNA. On the other hand, the DNA ''plasmalysé'' shows a deterioration of the amplified sequences. CONCLUSION: The genomic bacterial DNA, once extracted, is damaged by the gaseous flux of nitrogen plasma. A new sterilization process of the medical material will presumably impose itself in medium-term.

[Efficacy variation of erythromycin and spiramycin on periopathogens in aggressive periodontitis. An in vitro comparative study]. / Variabilité de l'efficacité de l'érythromycine et de la spiramycine sur les pathogènes parodontaux dans les parodontites agressives. Etude in vitro comparative.

AIMS: Erythromycin (ERY) and spiramycin (SPI) are the most frequently prescribed macrolides by dentists. However, the emergence of resistant anaerobic subgingival bacteria imposes an increased vigilance. This study aims to compare these macrolides efficacy on principal periopathogens. MATERIALS AND METHODS: Twenty adult patients with aggressive periodontitis were selected and a total of 60 samples were taken from subgingival flora. Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, Peptostreptococcus micros and Actinobacillus actinomycetemcomitans were isolated according to J. Slots's rapid identification method. The susceptibilities to ERY and SPI were studied using disk diffusion susceptibility test and minimum inhibitory concentration test (MIC test). RESULTS: The efficiency variability of ERY and SPI on the 50 isolated anaerobic periopathogens was present either interindividually (between different patients) and intra-individually (within the same patient). While 68% of the tested anaerobic bacteria were sensitive to SPI (22% resistant), only 54% were sensitive to ERY (34% resistant). Although moderate, the efficacy of SPI seemed more regular in general than ERY: it's variation coefficient (40%) is lower than the ERY one (53%). The 7 A. actinomycetemcomitans tested showed all a high resistance. CONCLUSION: In a general way, the spectre of activity of SPI is stacked in that of ERY. However, this study shows a better and regular activity of SPI on the main tested periopathogens. These results are in favour of the use of SPI in periodontology when penicillins and doxycycline are not useful because specific problems are identified (allergy, pregnancy...).

Antimicrobial susceptibility variation of 50 anaerobic periopathogens in aggressive periodontitis: an interindividual variability study.

BACKGROUND/AIMS: The frequent use of antibiotics in developed countries has led to the emergence of widespread bacterial resistance. In this study, the interindividual variability of the antibiotic susceptibility of 50 putative microorganisms in aggressive periodontitis patients has been evaluated by means of VC (variation coefficient). MATERIAL AND METHODS: A total of 60 microbial samples were collected from 20 adult patients diagnosed with aggressive periodontitis (2-4 samples by patient). Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, and Peptostreptococcus micros were isolated according to Slots' rapid identification method. The susceptibilities to 10 antibiotics were studied: penicillin G (PEN), ampicillin (AMP), amoxicillin (AMX), amoxicillin/clavulanate (AMC), tetracycline (TET), doxycycline (DOX), ciprofloxacin (CIP), erythromycin (ERY), spiramycin (SPI) and clindamycin (CLIN), using the Disk Diffusion Susceptibility test (DDS test: Kirby-Bauer's modified method for anaerobic bacteria). The broth microdilution Minimum Inhibitory Concentration test was carried out as a control test. RESULTS: Among the 50 identified bacteria, 15 were P. gingivalis, 12 P. intermedia, 8 T. forsythia, 9 F. nucleatum, and 6 P. micros. The results of the DDS test show that penicillins (especially AMC, AMP, and AMX), cyclines (especially DOX) and CLIN are highly effective against the 50 anaerobic studied bacteria. CIP and ERY have the lowest efficacy against those bacteria. CIP shows a very variable activity according to anaerobic bacteria species, being particularly inactive against P. gingivalis and very efficient against T. forsythia and P. micros. SPI is also highly efficient but not against P. micros. CONCLUSIONS: The interindividual susceptibility of principal periodontal pathogens to antibiotics is not homogeneous and seems to vary according to bacterial species and antimicrobial molecules. This variability seems to be greater with older molecules (PEN, TET, ERY) than with more recent ones, which indicates more stable results (AMC, AMX, AMP, and DOX). P. intermedia appeared to be the bacteria most resistant to penicillins and showed the highest coefficient variation. Together with scaling and root planing, the combination of two antibiotics would therefore seem to be recommended in the treatment of aggressive periodontitis, particularly in the presence of P. intermedia.