Effect of anesthetics containing lidocaine and epinephrine on cardiovascular changes during dental implant surgery

The purpose of this study was to evaluate cardiovascular changes during dental implant surgery using 2% lidocaine with 1:80 000 epinephrine. Eleven normotensive subjects, ranging from 18 to 56 years, were selected to undergo dental implant surgery in the jaw. They were monitored in the pre-, intra-, and postsurgical periods by continuous noninvasive automatic arterial pressure and cardiac frequency measurements taken every 2 minutes. Parameter scores were obtained for the following phases: P1, 15 minutes during preparation of the patient (control period); P2, before anesthesia; P3, immediately after anesthesia; P4, 2 minutes into anesthesia; P5, during incision and detachment; P6, during perforation; P7, during implant placement; P8, during suturing; P9, on completion; and P10, 10 minutes after termination. Individualized statistical analysis for each group during the pre-, intra-, and postoperative periods were performed by analysis of variance. The greatest variations in systolic pressure were increases of 2.29% during phase P2 and 2.59% in phase P5. Diastolic pressure decreased during phase P6 (-2.58%) and increased in P10 (3.27%). The greatest changes in heart rate occurred in phase P10 (-3.24%). There were no statistically significant changes among the evaluated phases (P > .05). In conclusion, there were no changes in the analyzed cardiocirculatory parameters during dental implant surgery (systolic, diastolic, and mean arterial blood pressures and heart rate) in normotensive subjects anesthetized with 2% lidocaine with epinephrine 1:80000.     

Resistance to maxillary premolar fractures after restoration of class II preparations with resin composite or ceromer.

OBJECTIVE: The aim of this study was to evaluate the resistance to fracture of intact and restored human maxillary premolars. METHOD AND MATERIALS: Thirty noncarious human maxillary premolars, divided into three groups of 10, were submitted to mechanical tests to evaluate their resistance to fracture. Group 1 consisted of intact teeth. Teeth in group 2 received mesio-occlusodistal cavity preparations and were restored with direct resin composite restorations. Teeth in group 3 received mesio-occlusodistal cavity preparations and were restored with ceromer inlays placed with the indirect technique. After restoration, teeth were stored at 37 degrees C for 24 hours and then thermocycled for 500 cycles at temperatures of 5 degrees C and 55 degrees C. RESULTS: Statistical analysis revealed that group 3 (178.765 kgf) had a significantly greater maximum rupture load than did group 1 (120.040 kgf). There was no statistically significant difference between groups 1 and 2 or between groups 2 and 3. CONCLUSION: Class II cavity preparations restored with indirect ceromer inlays offered greater resistance to fracture than did intact teeth. The fracture resistance of teeth restored with resin composite was not significantly different from that of either the ceromer or intact teeth.     

Transcervical submandibular sialoadenectomy

The submandibular glands are subject to several pathologies that require excision. The most common problem that affects these salivary glands is sialadenitis combined with sialolithiasis. This problem occurs in the submandibular gland 10 times more frequently than it does in the parotid gland. Other illnesses frequently involving the submandibular glands are represented by sialadenosis and benign, malign, and intermediate neoplasms.Diagnosis of any disturbance in the submandibular gland involves both a clinical and instrumental (echography, traditional radiography [ortopantomography] and eventually computed tomography (CT) or magnetic resonance imaging) assessment. Surgery is the usual method of treatment of both chronic sialadenitis and neoplasms in the submandibular gland. A submandibular gland surgical approach can be cervical, intraoral, or endoscopic.The authors present their clinical experience with a total of 40 patients with illnesses involving the submandibular gland treated with submandibular gland excision by a transcervical approach. Their experience suggests that this approach entails a relatively simple procedure, involves low risks for the nerve structure around the gland, permits wide resection margins for neoplasms, and incurs little aesthetic damage.     

The relationship between life-events and periodontitis A case-control study

Abstract This case-control study (n=100 dental patients, matched for age and sex) investigated the rôle of life-events in periodontitis. Data collected included life events, tobacco use, oral health behaviours and socio-demographics. The results of conditional simple logistic regression analysis showed that periodontitis was associated with the negative impact of life-events (p<0.01), the number of negative life-events (p<0.05), high levels of dental plaque (p<0.01), tobacco smoking (p<0.01) and being unemployed (p<0.05). These associations remained statistically significant after adjusting for oral health behaviour and socio-demo-graphic variables, but not tobacco smoking (p>0.05). Marital status became statistically significant after adjusting for the other variables (p<0.05). A model is suggested to explain the pathways through which life events may affect periodontal health. It was concluded that psychosocial factors and oral health risk behaviours cluster together as important determinants of periodontitis.     

A mandibular advancement device reduces sleep disordered breathing in patients with congestive heart failure

Sleep disordered breathing (SDB) including obstructive and central sleep apnoea/hypopnoea as well as periodic breathing (PB) is common and is believed to increase risk for mortality in patients with congestive heart failure (CHF). Mandibular advancement device (MAD) has widely been recommended for treatment of obstructive sleep apnoea but the method has never been investigated for treatment of SDB in the patients with CHF. The aim with the present study was to examine the effect of MAD intervention on SDB in patients with CHF. The study included 17 male patients, aged 68.4+/-5.7 (mean+/-SD) with stable, mild to moderate CHF due to left ventricular systolic dysfunction and with SDB, expressed as apnoea/hypopnoea index (AHI) > or = 10. The SDB was examined during a single night using an unattended, portable polysomnographic device in the patients home, prior to and following intervention with a individually adjusted MAD. The SDB was evaluated by calculating AHI, PB expressed as the percentage of the total registration time, oxygen desaturation index (ODI) and snoring time. The AHI was reduced by MAD intervention from 25.1+/-9.4 to 14.7+/-9.7 (p=0.003). ODI reduced from 21.1+/-9.0 to 10.5+/-7.8 (p=0.007) and snoring time decreased from 53+/-111 to 18+/-47 seconds (p=0.02). PB was reduced from 55.7+/-25.6 to 40.4+/-26.4 per cent without statistical significance. In conclusion, the MAD intervention may be a feasible method for reducing SDB in patients with stable, mild to moderate CHF and left ventricular systolic dysfunction.     

The genetics of amelogenesis imperfecta: a review of the literature

A melogenesis imperfecta (AI) is a group of inherited defects of dental enamel formation that show both clinical and genetic heterogeneity. Enamel findings in AI are highly variable, ranging from deficient enamel formation to defects in the mineral and protein content. Enamel formation requires the expression of multiple genes that transcribes matrix proteins and proteinases needed to control the complex process of crystal growth and mineralization. The AI phenotypes depend on the specific gene involved, the location and type of mutation, and the corresponding putative change at the protein level. Different inheritance patterns such as X-linked, autosomal dominant and autosomal recessive types have been reported. Mutations in the amelogenin, enamelin, and kallikrein-4 genes have been demonstrated to result in different types of AI and a number of other genes critical to enamel formation have been identified and proposed as candidates for AI. The aim of this article was to present an evaluation of the literature regarding role of proteins and proteinases important to enamel formation and mutation associated with AI.     

Effects of adhesive temperature on the early and 6-month dentin bonding

Objectives

The aim of this study was to test the effect of adhesive temperature on the bond strength to dentin (μTBS) and silver nitrate uptake (SNU) of an ethanol/water (Adper Single Bond 2 [SB]) and an acetone-based (Prime&;Bond 2.1 [PB]) etch-and-rinse adhesive system.

Methods

The bottles of each adhesive were kept in various temperatures (5 °C, 20 °C, 37 °C and 50 °C) for 1 h previously to its application in the occlusal demineralized dentin of 40 molars. Bonded sticks (0.8 mm²) were tested in tension (0.5 mm/min) immediately (IM) or after 6 months (6 M) of water storage. Two bonded sticks from each hemi-tooth were immersed in silver nitrate and analyzed by SEM. Data were analyzed by two-way repeated measures ANOVA and Tukey's test (α = 0.05).

Results

No significant difference in μTBS was detected for both adhesives at 5 °C and 20 °C. The highest bond strength for PB was observed in the 37 °C group while for SB it was in the 50 °C. Significant reductions of bond strengths were observed for PB at 37 °C and SB at 50 °C after 6 M of water storage. Silver nitrate deposition was seen in all hybrid layers, irrespective of the group. Lower silver nitrate deposition (water trees) in the adhesive layer was seen for PB and SB at higher temperatures.

Conclusions

The heating or refrigeration of the adhesives did not improve their resin–dentin bond resistance to water degradation over time.     

Chlorhexidine induces DNA damage in rat peripheral leukocytes and oral mucosal cells

OBJECTIVE: Chlorhexidine digluconate is widely used in dental practice for decreasing plaque control, controlling gingivitis and disinfecting root canals. However, the undesirable effects of chlorhexidine digluconate regarding its genotoxicity are conflicting in the literature. Thus, the aim of this study was to investigate the genotoxicity of chlorhexidine digluconate in rat peripheral blood and oral mucosal cells by the single cell gel (comet) assay and micronucleus assay. METHODS: Thirty male Wistar rats were distributed into three groups: negative control; experimental group orally treated with 0.5 ml of 0.12% chlorhexidine digluconate, twice daily, during 8 days; and positive control, which received 4-nitroquinoline 1-oxide at 0.5 g/l by drinking water. RESULTS: A statistically significant increase of DNA damage was observed in leukocytes and oral mucosal cells of the chlorhexidine digluconate treated group, as assessed by the comet assay. However, no increase of micronucleated cells was detected in reticulocytes from peripheral blood cells. CONCLUSIONS: Taken together, the data indicate that chlorhexidine digluconate is able to induce primary DNA damage in leukocytes and in oral mucosal cells, but no chromosome breakage or loss in erythrocytes.     

Influence of the use of Er:YAG laser for cavity preparation and surface treatment in microleakage of resin-modified glass ionomer restorations

This study quantitatively assessed the amount of microleakage on Class V cavities prepared by Er:YAG laser and high-speed handpiece, varying the surface treatment and restoring with a resin-modified glass ionomer cement. Fifty cavities were prepared using either an Er:YAG laser device or a carbide bur at high speed. The surface treatment was performed as follows: Er:YAG laser irradiation (G1); 40% polyacrylic acid (G2); laser + acid (G3); finishing with low speed + laser + acid (G4); conventional bur preparation + acid (G5-control). The samples were restored with Fuji II LC, thermocycled, isolated and immersed in a 50% AgNO3 solution. The restorations were serially sectioned and the extent of dye penetration was measured in milimeters using specific computer software. Data were analyzed by two-way ANOVA and Tukey test. The lowest degree of microleakage was observed for G5, which was statistically similar (p>0.05) to G4 but different (p<0.05) from all the other experiental groups. Lesser microleakage was observed at the occlusal margins than at the cervical margins (p<0.05). It may be concluded that the use of Er:YAG laser for cavity preparation and surface treatment negatively affected the marginal sealing of resin-modified glass ionomer restorations.     

Tissue destruction in periodontitis: bacteria or cytokines fault?

The pathogenesis of periodontal disease involves the sequential activation of a great variety of components of the host immune response, primarily acting to defend periodontal tissues against bacterial aggression, but also functioning as mediators of tissue destruction. The expression of the disease results from the interaction of host, microbiological agents, and environmental factors. Leukocytes play a critical role in the pathogenesis of the disease, producing different cytokines, chemokines, and other mediators, thus generating a host defense response, as well as inducing tissue inflammation and bone destruction. The aim of this review is to address the role of some inflammatory mediators in response to bacterial aggression in periodontitis.