Lucía García-Caballero

Membrane perforation in sinus floor elevation - piezoelectric device versus conventional rotary instruments for osteotomy: an experimental study.

PURPOSE Sinus membrane perforation is the most common intraoperative complication of maxillary sinus floor elevation (MSFE) procedures and frequently causes postoperative problems. Piezoelectric devices have been claimed to reduce the frequency of membrane perforations although no clear evidence supports this view. MATERIALS AND METHODS Ten surgeons with different expertise levels performed 80 MSFEs in selected lamb heads, with rotary and piezoelectric instruments following standard protocols. After the procedures, specimens were coded and perforations or tears determined through a microscope. RESULTS No significant differences in terms of thickness either of the sinus lateral wall (xi -xj  = 73.2; 95% confidence interval [CI] = 45.3-191.8) or the membrane (xi -xj  = 24.2; 95% CI = -29.4 to 77.9) were identified between the specimens allocated to each group. Nine membrane perforations (11.2%) occurred during the study, all within the lower expertise group. Membrane elevation by hand instruments caused five perforations (40%) in the rotary instrument group and one in the piezoelectric group. Expert surgeons produced no membrane perforations, the size of the antrostomy that was smaller in the piezoelectric group being the only significant difference between the rotary and piezoelectric groups. CONCLUSIONS The use of piezoelectric material for MSFE reduces the frequency of membrane perforation among surgeons with a limited experience.

In Situ Chlorhexidine Substantivity on Saliva and Plaque-Like Biofilm: Influence of Circadian Rhythm

BACKGROUND The aim of the present study is to assess in situ substantivity of a single mouthrinse with 0.2% chlorhexidine (CHX) on saliva and on undisturbed de novo plaque-like biofilm (PL-biofilm), differentiating between two times of application: 1) CHX mouthrinse in the morning; and 2) CHX mouthrinse at night. METHODS The study participants were 10 healthy volunteers who wore an individualized splint with glass disks for 48 hours to boost the growth of PL-biofilm. Saliva samples were collected, and two disks were removed from each volunteers splint at 8, 10, and 12 hours after performing a mouthrinse with 0.2% CHX at 7:00 am (M-0.2% CHX-diurnal) and 1:00 am (M-0.2% CHX-nocturnal). The saliva and plaque samples were analyzed by epifluorescence and confocal laser scanning microscopy, respectively, using a green fluorescent nucleic acid stain/propidium iodide staining. RESULTS With M-0.2% CHX-diurnal, the frequency of vital bacteria in saliva was significantly higher than in the PL-biofilm at 8, 10, and 12 hours after mouthrinse. After M-0.2% CHX-nocturnal, the frequency of vital bacteria in saliva was significantly lower than in the PL-biofilm at 8 hours and higher than in the PL-biofilm at 12 hours after mouthrinse. CONCLUSION These results support the more active physiologic dynamics of the salivary flora and the possible reservoir function associated with the structure of undisturbed de novo PL-biofilm.

Lamb ex vivo model for training in maxillary sinus floor elevation surgery: a comparative study with human standards.

BACKGROUND Many models have been suggested for surgical training in sinus floor elevation (SFE), but information on key features that provide feedback to the trainee is scarce. The aim of this study is to compare the thickness of the lateral wall of the maxillary sinus (TLWMS) and the thickness of the Schneiderian membrane (TSM) between an animal model and the human standard. METHODS The observational study used 20 fresh lamb heads. Cone-beam computed tomography (CT) was performed for recording the following: TLWMS, sinus lateral floor width, distance from the lateral border of the anteroposterior bone crest to the sinus wall, and height of lateral maxillary sinus. Thirty human radiologic exploration cone-beam CTs were used for comparisons. The sinus membrane thickness was measured at three points per section and compared to those of 10 formalin-preserved human membranes. RESULTS TLWMS in the animal model scored 2.25 ± 0.3 mm and was thicker than that of humans with subsinusal edentulism (Xi - Xj = 0.3; 95% confidence interval = 0.1 to 0.4), although this difference was not considered clinically relevant. The average thickness of the sinus membrane was 485.5 ± 137.1 μm with no significant differences between sides (P = 0.12) or between the thickness of human and lamb Schneiderian membranes. CONCLUSIONS The model based on lambs is potentially useful for training in SFE techniques because of the similarities in the TLWMS and particularly the TSM. Additional studies are needed to validate this model within a teaching environment.

Er,CR:YSGG lasers induce fewer dysplastic-like epithelial artefacts than CO2 lasers: an in vivo experimental study on oral mucosa

Our aim was to assess wounds made by lasers (CO(2) and Er,Cr:YSGG) for their epithelial architectural changes and width of damage. We allocated 60 Sprague-Dawley(®) rats into groups: glossectomy by CO(2) laser at 3 different wattages (n=10 in each); glossectomy by Er,Cr:YSGG laser at two different emissions (n=10 in each), and a control group (n=10). Histological examination assessed both prevalence and site of thermal artefacts for each group. Both lasers (CO(2) and Er,Cr:YSGG) caused the same type of cytological artefacts. The 3W Er,Cr:YSGG laser produced the fewest cytological artefacts/specimen, and was significantly different from the other experimental groups: 3W CO(2) laser (95% CI=0.8 to 1.0); the 6W CO(2) laser (95% CI=0.1 to 2.0) and the 10W CO(2) laser (95% CI=1.1 to 3.0). CO(2) lasers (3-10W) generate epithelial damage that can simulate dysplastic changes with cytological atypia that affects mainly the basal and suprabasal layers. Irradiation with Er,CR:YSGG laser (2-4W) produces significantly fewer cellular artefacts and less epithelial damage, which may be potentially useful for biopsy of oral mucosa.

In Vivo Antiplaque Effect of Three Edible Toothpastes

Objectives: The objective of this study was to analyse the antibacterial and antiplaque activity of three edible toothpastes with the widest worldwide distribution: KidScents™, which contains essential oils; Browning B&B™, with medicinal plants; and Wysong Probiodent™, which contains probiotics. Study Design: The study group was formed of twenty healthy volunteers (dental students) with a good oral health status. Using a balanced randomisation system, all volunteers performed toothbrushing with four products (the three edible toothpastes and water) at intervals of one week. Bacterial vitality in the saliva was analysed by epifluorescence microscopy and plaque regrowth was evaluated using the Turesky-Quigley-Hein plaque index. Results: Bacterial vitality in the saliva was significantly higher after toothbrushing with water (positive control) than with the three toothpastes (P=0.002, P=0.003 and P<0.001, respectively). The plaque index was significantly higher after using these three toothpastes than after toothbrushing with water (P=0.047, P=0.032 and P<0.001, respectively). Conclusions: The three edible toothpastes analysed have some antimicrobial activity but favour plaque regrowth. Key words:Edible toothpaste, dental plaque, oral bacteria.

Pseudoepitheliomatous hyperplasia after diode laser oral surgery. An experimental study.

Background To examine the process of epithelial reparation in a surgical wound caused by diode laser. Material and Methods An experimental study with 27 Sprage-Dawley rats was undertaken. The animals were randomly allocated to two experimental groups, whose individuals underwent glossectomy by means of a diode laser at different wattages, and a control group treated using a number 15 scalpel blade. The animals were slaughtered at the 2nd, 7th, and 14th day after glossectomy. The specimens were independently studied by two pathologists (blinded for the specimens’ group). Results At the 7th day, re-epithelisation was slightly faster for the control group (conventional scalpel) (p=0.011). At the 14th day, complete re-epithelization was observed for all groups. The experimental groups displayed a pseudoepitheliomatous hyperplasia. Conclusions It is concluded that, considering the limitations of this kind of experimental studies, early re-epithelisation occurs slightly faster when a conventional scalpel is used for incision, although re-epithelisation is completed in two weeks no matter the instrument used. In addition, pseudoepitheliomatous hyperplasia is a potential event after oral mucosa surgery with diode laser. Knowledge about this phenomenon (not previously described) may prevent diagnostic mistakes and inadequate treatment approaches, particularly when dealing with potentially malignant oral lesions. Key words:Diode laser, animal model, oral biopsy, oral cancer, oral precancer, pseudoepitheliomatous hyperplasia.

Unifocal orofacial granulomatosis in retromolar mucosa: surgical treatment with Er,Cr:YSGG laser.

Orofacial granulomatosis is defined by permanent or recurrent swelling of orofacial tissues with different multiform and multifocal clinical patterns. An 11-year old boy presented with a 2-month history of mucosa enlargement. Intraoral examination revealed an erythematous, polylobulated, exophytic lesion with a smooth surface located in retromolar mucosa, non-tender and non-infiltratated to palpation. The diagnosis was inflammatory lesion compatible with pyogenic granuloma and laser excision was decided. Haematological parameters were within normal range, as well as chest Xrays. These findings lead to a diagnosis of non-symptomatic orofacial granulomatosis, whose early diagnosis can minimize the impact of systemic-related disorders, like Chron’s disease. Key words:Laser, orofacial granulomatosis, childhood, oral lesions, diagnosis.

Effect of chewing an apple on dental plaque removal and on salivary bacterial viability

Objectives Studies on dental plaque removal by chewing an apple are scarce and dated, with conflicting findings. This study aimed to determine whether chewing an apple produced mechanical removal of dental plaque or had any effect on salivary bacterial viability. Methods The study group consisted of 20 healthy adults with good oral health status who were randomly assigned to brush their teeth or eat an apple. After 2 weeks, the experiment was repeated with the order reversed. Plaque index (PI) and the bacterial viability (BV) in a sample of whole saliva (spit) were determined before brushing or apple eating (baseline, B), immediately afterward (A) and 24 hours afterward (24). Results After chewing an apple, PI-A was significantly higher than both PI-B (P < .001) and PI-24 (P < .001). BV-A was significantly lower than BV-B (P < .001), with a return to baseline values at the BV-24 measurement. Conclusions Chewing an apple does not remove dental plaque, and may favor plaque regrowth during the first 24 hours, but it does produce an immediate reduction in salivary bacterial viability similar to that after tooth brushing.