Quintessence International, 05/2012

After an inferior alveolar nerve (IAN) injury, the onset of altered sensation usually begins immediately after surgery. However, it sometimes begins after several days, which is referred to as delayed paresthesia. The authors considered three different etiologies that likely produce inflammation along the nerve trunk and cause delayed paresthesia: compression of the clot, fibrous reorganization of the clot, and nerve trauma caused by bone fragments during clot organization. The aim of this article was to evaluate the etiology of IAN delayed paresthesia, analyze the literature, present a case series related to three different causes of this pathology, and compare delayed paresthesia with the classic immediate symptomatic paresthesia. Keywords: delayed paresthesia, IAN, inferior alveolar nerve, nerve exposure, third molar, wisdom tooth

Objective: To compare the degree of root resorption in endodontically treated primary molars with that of homologous teeth without root canal treatment. Method and Materials: A retrospective study was carried out comprising 105 records of children who had received root canal treatment in a primary molar. Mean age at the time of treatment was 7.0 ± 1.4 years. Inclusion criteria included one endodontically treated primary molar and a homologous primary molar with no root canal treatment on the other side of the mouth. All teeth were treated by the same operator in the same way using the same iodoformcontaining root canal filling material. The degree of root resorption was compared by radiographic evaluation 12 or more months posttreatment. Results: The degree of root resorption on the final follow-up radiograph in the endodontically treated primary molars was significantly higher (P < .05) than the degree of root resorption in the homologous teeth. The degree of root resorption was higher in boys than in girls. No statistical significance was found between the degree of root resorption and the age at the time of treatment in either the root canal-treated teeth or the homologous teeth. Follow-up radiographs demonstrated a higher degree of root resorption in the root canal-treated teeth than in the homologous teeth, regardless of the type of treatment performed on the homologous side. Conclusion: Root canal treatment performed with iodoform-containing root canal filling material accelerates root resorption in root canal-treated primary molars compared with homologous teeth without endodontic treatment. Clinicians should be aware that endodontically treated teeth will probably shed before homologous ones that are not root canal treated. Keywords: Endoflas, primary molars, pulpectomy, root canal treatment

Objective: To review all the literature investigating the implications of increasing the vertical dimension of occlusion (VDO). Method and Materials: A comprehensive electronic search was conducted through PubMed with the aid of Boolean operators to combine the following key words: "occlusal vertical dimension," "increasing vertical dimension," "bite raising," "occlusal space," "resting vertical dimension," "rest position," "altered vertical dimension," "mandibular posture," "temporomandibular joint," and "masticatory muscles." The search was limited to peer-reviewed articles written in English and published through August 2011. Further, the literature search was endorsed by manual searching through peer-reviewed journals and reference lists of the selected articles. Results: A total of 902 studies were initially retrieved, but only 9 met the specified inclusion criteria for the review. From the selected studies, four variables were identified to be relevant to the topic of VDO increase: magnitude of VDO increase, method of increasing VDO, occlusion scheme, and the adaptation period. Conclusion: Considering the limitations of this review, it could be concluded that whenever indicated, permanent increase of the VDO is a safe and predictable procedure. Intervention with a fixed restoration is more predictable and results in a higher adaptation level. Negative signs and symptoms were identified, but they were self-limiting. Due to the lack of a welldesigned study, further controlled and randomized studies are needed to confirm the outcome of this review. Keywords: muscle relaxation, occlusal splint, occlusal vertical dimension, occlusion, patient adaptation

Ossifying fibromas are rare benign bone-related lesions of the jaw. Early diagnosis based on clinical, radiologic, and pathohistologic findings is essential, since undetected lesions may expand and cause considerable functional and cosmetic problems. The treatment of choice is purely surgical. Periodic clinical and radiologic follow-up should be scheduled, since recurrence is possible. The present article describes the diagnostic procedures, surgical management, and follow-up of an asymptomatic ossifying fibroma in the mandible of a 21-year-old man. Keywords: bone-related lesion, cone-beam computed tomography, enucleation, ossifying fibroma

Objective: Laser-assisted gingivectomies are performed in proximity to teeth, existing restorations, and implants. In case of accidental exposures, a detrimental surface defect may cause failure. Surface interactions should be evaluated for safety margin determination of certain laser-material combinations. The purpose of this in vitro study was to assess the microscopic and visible effects of CO2, Nd:YAG, and 810-nm diode laser irradiations on various dental materials and tooth tissue. Method and Materials: Study samples were fabricated (10 × 7.5 mm irradiation surface area, 1 mm thickness) from eight material groups (amalgam, base metal, gold, palladium-silver, composite, ceramic, titanium, and extracted tooth slices). Laser irradiations were performed with CO2, Nd:YAG, and 810- nm diode lasers using the manufacturer's recommended settings for gingivectomy at a 45-degree angle for 30 seconds. Irradiated surfaces were evaluated under SEM at 200× and 1,000× magnifications. Standardized photographs were obtained using a camera mount system (10× high-definition macro lens). The SEM images and photographs were correlated to determine surface interactions. Results: Nd:YAG detrimentally affected all metallic materials and tooth structures. CO2 altered amalgam, gold, and palladium-silver slightly, whereas composite, ceramic, and tooth surfaces were detrimentally altered. The 810-nm diode altered amalgam, gold, titanium, palladium-silver, and composite but only gold and palladium-silver surfaces were barely traceable. Conclusion: Within the limitations of this in vitro study, surface effects were all instant; therefore, even a short accidental exposure may be destructive in some laser-material combinations. During gingivectomies, CO2 near tooth-colored restorations and Nd:YAG near metallic restorations and implants should be used carefully. The 810-nm diode was found to be safer due to its reversible alterations in only some materials. Further in vivo studies are necessary to clinically apply the outcomes of this study. Keywords: dental materials, gingivectomy, soft tissue layers, surface

It is rare for surgeons in the United States to perform primary repair of a cleft lip on an adult. However, in developing nations with limited specialized health care, late presentation for primary cheiloplasty occurs due to limitations in access to care, lack of awareness of treatment availability, and inability to afford treatment. Oral and maxillofacial surgeons who participate in humanitarian surgical mission trips to the developing world may encounter this subpopulation of cleft patients. The following case report describes the repair of an incomplete bilateral cleft lip in a 68-year-old man performed during a mission trip to rural Bangladesh. Based on an extensive literature search, this is the oldest patient to have undergone primary cheiloplasty reported in the English-language surgical literature. Keywords: adult, Bangladesh, cleft lip, cheiloplasty

Objective: The present study was carried out as a multicenter, randomized controlled, split-mouth clinical trial to evaluate the efficacy of locally delivered lycopene on periodontal health and gingival crevicular fluid (GCF) levels of 8-hydroxydeoxyguanosine (8-OHdG) in smokers and nonsmokers compared with periodontally healthy control subjects. Method and Materials: One hundred ten subjects including 50 smokers, 50 nonsmokers, and 10 controls participated in this study. Subjects in the smoker and nonsmoker groups had contralateral sites treated with lycopene gel and a placebo. Clinical parameters included recording site-specific measures of plaque, gingivitis, probing depth, and clinical attachment level. GCF 8-OHdG values were analyzed using a commercially available ELISA kit. Results: Compared with the placebo, lycopene-treated sites in smokers and nonsmokers showed significant reductions in probing depths and gain in the clinical attachment levels. However, there was no statistically significant difference in the clinical parameters when lycopene-treated sites in smokers and nonsmokers were compared, except for the reduction in the 8-OHdG levels. The 8-OHdG levels at 1 week and 3 months in sites treated with lycopene in the smoker and nonsmoker group were comparable with those in the periodontally healthy control group. Conclusion: The gel formulation was effective in increasing clinical attachment and reducing gingival inflammation, probing depth, and oxidative injury compared with the placebo in smoking and nonsmoking subjects. Keywords: antioxidants, lycopene, periodontitis, smoking

Objectives: Nowadays, the extended ecological plaque hypothesis equates dental health with the occurrence of acidogenic generalists in the plaque flora and explains disease-the irreversible demineralization of the dental hard tissue-by an ecologic shift in plaque composition, favoring acidogenic and aciduric specialists, following repeated conditions of high sugar. In the present study, aspects of the extended ecological plaque hypothesis were examined in retrospect. Method and Materials: Serving as a basis were data on (1) the caries incidence of children, classified according to their DMFT as having low or high caries risk; (2) the qualitative plaque composition of the children with the prevalence of mutans streptococci and actinomyces; (3) the amounts of acid and acid tolerance, determined by pH state titration (glucose), of representatively isolated strains of mutans streptococci and actinomyces; (4) the extrapolation of the acid amount to the occurrence of mutans streptococci and actinomyces in the plaque of children; and (5) the relationship between the extrapolated acid amount in plaque and caries incidence and the respective classification of the children into low and high caries risk. Results: The synoptic consideration of the numbers of A naeslundii and S mutans in plaque of children, with their capacity for acid production in vitro, reflected the caries risk classification. Conclusion: The analysis of the clinical, microbiologic, and in vitro findings concerning the virulence of the plaque isolates supports the extended ecological plaque hypothesis. Children with low caries risk had developed one new decayed surface within 4 years; children with high caries risk developed four within the same time period. Keywords: acidogenic generalists, aciduric specialists, actinomyces, caries, mutans streptococci, plaque hypothesis

Objective: According to the ISO, the radiopacity of luting cements should be equal to or greater than that of aluminum. The aim of this in vitro study was to determine the radiopacity of 13 commercially available dental luting cements and compare them with human enamel and dentin. Method and Materials: Five classes of luting cements were evaluated: zinc phosphate (Cegal N and Harvard Zinc Phosphate), zinc polycarboxylate (Harvard Polycarboxylate and Hoffmann's Carboxylate), glass ionomers (Ketac Cem Easymix, Ketac Cem Radiopaque, and Fuji I), resin-modified glass ionomer (Rely X Luting), and resin cements (Multilink Automix, Variolink II, Speed CEM, Rely X Unicem Automix, and three shades of Variolink Veneer). Tooth slices served as controls. Five specimens of each material measuring 8 mm in diameter and 1 mm thick were prepared and radiographed alongside tooth slices and an aluminum stepwedge using a Trophy RVG sensor. The radiopacity values were expressed in mm Al and analyzed by the ANOVA and Tukey tests (P < .05). Results: All the cements examined except Variolink Veneer had significantly higher radiopacities than that of dentin. Rely X Unicem Automix, glass ionomer, and resin-modified glass-ionomer cements demonstrated radiopacities that were not significantly different with respect to enamel. Zinc phosphate, zinc polycarboxylate, and three of the resin cements presented radiopacity values that were significantly greater than that of enamel. Conclusion: Almost all the investigated materials presented an acceptable radiopacity. Radiopacity of dental cements seems to depend more on the presence of elements with high atomic numbers than on the type of the material. Keywords: dental hard tissue, digital radiography, luting cement, radiopacity

Objective: Hand washing is the most important way to prevent the spread of infection. However, studies have shown that there is a lack of knowledge among physicians about proper hand hygiene. The purpose of this study was to determine the knowledge of general dentists and dental specialists regarding the correct agents to use and the appropriate times to wash hands. Method and Materials: A questionnaire asking for demographic information and the answers to questions about proper hand hygiene practices and agents was sent via email to a list of general dentists and dental specialists. A total of 480 completed surveys were received (approximately 15% response). Results: None of the respondents answered all the questions correctly. Six percent answered 4 questions correctly, 23% answered 3 questions correctly, and 47% answered only 2 questions correctly. There was no correlation between the number of correct answers and whether the respondent was a general dentist or a specialist. Conclusion: There is a lack of knowledge among dentists regarding proper hand hygiene. For the benefit of both the patient and the doctor, this situation must be remedied. Keywords: hand hygiene, hand washing, hand washing agents

Objective: To evaluate the healing events in degree III furcation defects in dogs following the application of the combination of an enamel matrix derivative with a biphasic calcium phosphate (Emdogain Plus). Method and Materials: Seventeen degree III furcation defects, 5 mm high and 4 mm wide, were created in 9 dogs. In both groups, the defects were conditioned with EDTA. One defect was treated with Emdogain Plus (n = 9), while the contralateral defect serving as control remained empty (n = 8). The defects in both groups were fully covered by coronally repositioned flaps. After 5 months of healing, histologic and histometric analysis was preformed. Results: A significant amount of new attachment and bone formation was observed in both control and test specimens. However, in a number of control specimens, ankylosis was also observed. In the control and test groups, respectively, the mean new cementum length was 10.8 ± 2.1 mm and 8.6 ± 3.2 mm; the mean periodontal ligament length was 7.6 ± 3.8 mm and 8.1 ± 4.0 mm. The mean new bone height was 4.4 ± 1.3 mm and 4.3 ± 1.6 mm in the control and test groups, respectively. No statistical differences were found between the two groups in terms of amount of cementum, periodontal ligament, and alveolar bone regeneration. Conclusion: The present study failed to show higher amounts of newly formed cementum and bone following treatment of acute degree III mandibular furcation defects following use of Emdogain Plus compared with a coronally advanced flap. Emdogain Plus seems to have a protective role against ankylosis in this type of defect. Keywords: enamel proteins, furcation, periodontal regeneration

Objectives: To examine the initial shear bond strength of orthodontic brackets bonded to bleached teeth with a self-etching adhesive system, as well as the effect of the length of time after bleaching on the initial bond strength. Method and Materials: Ninety premolars were collected and divided equally among a control group (CG) of unbleached teeth with brackets bonded, an immediate group (IG) with teeth bonded soon after bleaching, and a delayed group (DG) consisting of teeth bleached and then immersed in artificial saliva for 7 days before bracket bonding. Subsequently, the teeth of each group were equally assigned to two different primer adhesive systems: the acid-etch-and-rinse adhesive system (35% phosphoric acid gel and Transbond XT primer) and the self-etching adhesive system (Transbond Plus self-etching primer). Initial bond strength was measured 24 hours after bracket bonding. Results: IG registered the lowest mean initial bond strength when the self-etching adhesive system was in use, followed by DG and CG (in that order). As for the acid-etch-and-rinse adhesive system, the mean initial bond strength was significantly lower in IG than in CG and DG. Significant differences in mean initial bond strength were noted between the two adhesive systems in IG and DG. Conclusion: In trials using a self-etching adhesive system, the mean initial bond strength that declined immediately after bleaching returned to a clinically acceptable level of 6 MPa after the specimens were immersed in artificial saliva for 7 days but fell short of the level of unbleached teeth. Keywords: bleaching, hydrogen peroxide, orthodontic bracket, self-etching primer, shear bond strength