Control Teeth Research Articles

A Randomized Pilot Clinical and Microbiological Study Comparing Laser Microtextured Implants with and without Platform Switching

Minimising marginal bone loss around dental implants is of paramount importance. The success of methods such as platform switching (PS) and laser-micro-texturing (LM) are well documented. Whether or not a combination of these designs will further improve outcomes has not been studied previously. Hence, this prospective, randomized controlled single-centre pilot study compared the clinical and microbiological outcomes of implants with both PS and LM (test) to implants with only LM (control). A test and control implant were placed in thirteen patients totalling 26 implants. The primary investigated outcome was marginal bone level (MBL); secondary outcomes were peri-implant probing depths (PPD), bleeding on probing (BOP) and marginal tissue height (MTH). Additionally, the presence of five putative periodontal pathogens were assessed using real-time polymerized chain reaction. At 12 months the overall implant survival rate was 95.8%. MBL change was not found to be different between test and control at any time points, but a significant change was detected within the test implants at 6 months compared to baseline (p = 0.006). No differences were found in the secondary outcomes. Average PPD at 12 months was 2.68 ± 0.73 mm and 2.30 ± 0.46 mm and average change in MTH was 0.05 ± 0.72 mm and −0.24 ± 0.59 mm at tests and controls. No differences were reported in BOP frequency. Total periodontal pathogens count revealed no significant difference among control, test implants and adjacent tooth sites. Within the limitations of this study, it can be concluded that the addition of PS to LM implants does not significantly alter either short-term clinical outcomes or the vulnerability to pathogenic microflora colonization.

Randomized clinical trial of zirconia and polyetheretherketone implant abutments for single-tooth implant restorations: A 5-year evaluation

Statement of problemTitanium-supported polyetheretherketone (PEEK) abutments provide an economic alternative to zirconia abutments in esthetically important areas. Research comparing the performance regarding esthetics, longevity, and biologic parameters of PEEK abutments is lacking. PurposeThe purpose of this clinical study was to determine whether PEEK implant abutments provide similar esthetic and biologic parameters and survival rates as zirconia implant abutments. Material and methodsForty participants (age 20 to 50 years) receiving maxillary anterior and premolar implants were enrolled in the study and randomly assigned into 1 of 2 groups: Group PEEK (20 titanium-supported PEEK abutments) and group ZIR (20 zirconia abutments). Both groups were restored with pressed lithium disilicate ceramic crowns. Technical, biologic, and esthetic evaluation was performed at baseline and at 1, 3, and 5 years. The probing pocket depth, plaque control record, and bleeding on probing were recorded at the abutments (test) and compared with those at the corresponding contralateral teeth (control) and also between the 2 test groups. Standardized digital radiographs of the implants were made, and the bone level was recorded with the implant shoulder as the reference on the mesial and distal sides. The color difference between the peri-implant mucosa and control teeth gingiva and the discoloration of the implant crowns were determined with a spectrophotometer. The Student unpaired t test and repeated-measure ANOVA were used to statistically analyze the data (α=.05). ResultsFrom the 5-year evaluation, both PEEK and zirconia abutments with ceramic crowns showed 100% survival rate without any fracture or restoration loss. Differences in the biologic parameters of zirconia and PEEK abutments were statistically similar: mean probing pocket depth (group ZIR: 2.32 ±0.50 mm, group PEEK: 2.13 ±0.60 mm); mean plaque control record (group ZIR: 0.19 ±0.19, group PEEK: 0.15 ±0.17); and mean bleeding on probing (group ZIR: 0.12 ±0.11, group PEEK: 0.08 ±0.12). The mean marginal bone loss at 5 years was similar for implants supporting zirconia and PEEK abutments: mean mesial bone level (group ZIR: 1.8 ±0.5 mm; group PEEK: 1.9 ±0.6 mm), and mean distal bone level (group ZIR: 1.7 ±0.6 mm, group PEEK: 1.8 ±0.3 mm). The initial color difference (ΔE) between the peri-implant mucosa and gingiva of the analogous contralateral teeth diminished over time. No discoloration of the definitive restoration supported by PEEK or zirconia was detected over 5 years. ConclusionsAt the 5-year evaluation, zirconia and PEEK abutments exhibited the same survival rate with similar biologic and esthetic outcomes.

Analysis of Posterior Zirconia Crowns with Vertical Margin Preparations.

The interest in vertical crown preparation is growing and several variations are presented in the dental literature but limited clinical outcome data exists for teeth prepared for a vertical finish line. To audit clinical outcomes for 73 teeth after vertical preparation for knife-edge zirconia crowns. Seventy-three teeth had knife-edge zirconia crowns placed after vertical finish line preparation. The outcomes for these teeth were analysed from a retrospective audit of clinical records. The mean follow-up time was 21 months (SD: 10 months; range: 6-40). One tooth had to be extracted due to fracture at cervical level. One crown had to be re-made after margin fracture during try-in. No subsequent endodontic treatment was needed for any of the prepared teeth. No change in alveolar bone height was noted on radiographic follow-up. The mean bleeding score for the crowned teeth was higher than the mean bleeding score for a control tooth, but this was not statistically significant. This retrospective evaluation has shown favourable outcomes for 72 teeth after vertical preparation for knife-edge crowns. Longer follow-up is needed but the present results show that the technique is a viable procedure with potential advantages.

Conformational and constitutional analysis of dental caries following radiotherapy for head and neck cancer.

BackgroundThis study aimed to investigate the morphology and chemical composition of dental caries related to ionizing radiation (DCIR), an aggressive and progressive disease that affects dental hard tissues.Materials and methodsEight human teeth with DCIR were paired with sixteen control teeth (8 teeth with conventional caries and 8 without caries) and included in this study. An analysis of the morphology of the lesions was performed using the following techniques: periapical radiography, cone beam computed tomography, computed microtomography, and scanning electron microscopy. The chemical composition was assessed using X-ray dispersive spectroscopy.ResultsThere was more demineralization in DCIR lesions when compared to conventional dental caries, even though there was no cavitation in the cervical region of the teeth. The superficial roughness and topography of DCIR lesions were similar to those of healthy teeth. On the other hand, lesions of conventional dental caries showed greater surface and topographic irregularity when compared to DCIR and healthy teeth (p = 0.001). Calcium (Ca) and phosphorus (P) levels were lower in DCIR lesions when compared to controls. However, higher levels of carbon (C) have been observed in DCIR lesions. There was a greater loss of the mineral matrix in DCIR followed by conventional caries. The reduction in the mineral matrix (Ca and P) was compatible with the imaging patterns observed in teeth with DCIR and conventional caries.ConclusionDespite their rapid evolution, DCIR presents an irregular, apparently intact surface with significant changes in the amount of Ca, P, and C.

A Cross-Sectional Cohort Study of the Effects of FGF23 Deficiency and Hyperphosphatemia on Dental Structures in Hyperphosphatemic Familial Tumoral Calcinosis.

ABSTRACTHyperphosphatemic familial tumoral calcinosis (HFTC) is a rare autosomal recessive disorder caused by mutations in FGF23, GALNT3, KLOTHO, or FGF23 autoantibodies. Prominent features include high blood phosphate and calcific masses, usually adjacent to large joints. Dental defects have been reported, but not systematically described. Seventeen patients with HFTC followed at the National Institutes of Health underwent detailed clinical, biochemical, molecular, and dental analyses. Studies of teeth included intraoral photos and radiographs, high‐resolution μCT, histology, and scanning electron microscopy (SEM). A scoring system was developed to assess the severity of tooth phenotype. Pulp calcification was found in 13 of 14 evaluable patients. Short roots and midroot bulges with apical thinning were present in 12 of 13 patients. Premolars were most severely affected. μCT analyses of five HFTC teeth revealed that pulp density increased sevenfold, whereas the pulp volume decreased sevenfold in permanent HFTC teeth compared with age‐ and tooth‐matched control teeth. Histology revealed loss of the polarized odontoblast cell layer and an obliterated pulp cavity that was filled with calcified material. The SEM showed altered pulp and cementum structures, without differences in enamel or dentin structures, when compared with control teeth. This study defines the spectrum and confirms the high penetrance of dental features in HFTC. The phenotypes appear to be independent of genetic/molecular etiology, suggesting hyperphosphatemia or FGF23 deficiency may be the pathomechanistic driver, with prominent effects on root and pulp structures, consistent with a role of phosphate and/or FGF23 in tooth development. Given the early appearance and high penetrance, cognizance of HFTC‐related features may allow for earlier diagnosis and treatment. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Occlusion variation of posterior implant-supported single crown: a prospective 4-year follow-up study

Objective: To analyze the longitudinal variation of occlusal force distribution and occlusal contact time in posterior implant-supported single crown with the computerized occlusal analysis system. Methods: Partially edentulous patients who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology between December 2012 and December 2013, and had received implant-supported single crown in the posterior region were enrolled. The participants underwent occlusal examinations with the computerized occlusal analysis system at 2 weeks, 3 and 6 months, 1, 2, 3, and 4 years after implant prosthesis delivery. The relative occlusal force (ROF) of implant prostheses, mesial adjacent teeth, and control teeth (corresponding teeth on the contralateral side) were recorded, and implant prosthesis occlusion time ratios (implant prosthesis occlusion time/occlusion time) were calculated. The interproximal contact between implant prostheses and adjacent teeth was evaluated using metal contact gauge and dental floss. Mechanical complications of implant prostheses were recorded. The paired t test or Wilcoxon signed-rank test was used to compare the implant prosthesis occlusion time ratios and ROF of implant prostheses at 2 different times as a self-control. The differences in ROF between implant prostheses and control teeth in the same participant at the same time were also analyzed using paired t test. Using a complementary log-log model, the correlation between the occurrence of veneering material fracture and ROF of implant prosthesis was analyzed with gender, age and follow-up time as the control variables. Results: Thirty-seven posterior fixed implant-supported single crowns in 33 participants, including 16 men and 17 women aged (42.8±12.9) years (23.9 to 70.0 years) were followed up for 2 weeks to 4 years [(38.3±15.2) months]. The ROF of implant prostheses increased significantly (P<0.01) from 2 weeks [(7.0±4.2)%] to 3 months [(9.9±6.8)%], whereas those of control natural teeth decreased significantly (P<0.05) from (13.1±6.1)% to (11.4±5.5)%. The ROF of implant prostheses continued to increase from 6 months to 1 year, from 1 year to 2 years and from 2 years to 3 years, with significant differences (P<0.05). Implant prosthesis occlusion time ratios also increased significantly between 2 weeks and 3 months and between 3 months and 6 months (P<0.05). No significant differences were found between other time points (P>0.05). For comparison between implant prosthesis and control teeth at the same time point, the ROF of the implant prostheses [(7.5±4.2)%] were significantly lower than those of the control teeth [(13.8±6.0)%] at 2 weeks (P<0.01). While at 4 years, ROF of implant prostheses [16.7% (8.6%, 32.4%)] became significantly higher than those of control teeth [9.5% (4.9%, 18.0%)] (P<0.05). ROF of the implant prostheses did not differ significantly with those of the control teeth in other follow-up time points (P>0.05). The 4-year cumulative incidence of proximal contact loss rate was 32% (22/68). The incidences of veneering material fracture and prostheses loosening were 16% (6/37) and 8% (3/37), respectively. Logistic regression showed a significant correlation between veneering material fracture and ROF of implant prostheses (r=0.26, P<0.05). Conclusions: The occlusal force and occlusal contact time of posterior implant-supported single crown change over time in 4-year follow-up period, which is mainly reflected in the increasing occlusal force and occlusal contact time. The occlusion of posterior implant prostheses should be carefully monitored during follow-up examinations, and occlusal adjustment should be considered when necessary.

Pulp Response to Periodontal Disease: Novel Observations Help Clarify the Processes of Tissue Breakdown and Infection

IntroductionThis study evaluated the pulp response to periodontal disease of increasing severity. MethodsThe material comprised human teeth affected by moderate (n = 16) to severe (n = 48) periodontal disease and no clinically identified caries lesions. Specimens were obtained by extraction and were processed for histopathologic and histobacteriologic methods. ResultsIn 13 of 16 teeth with moderate periodontal disease and vital pulp, no frank accumulations of inflammatory cells were observed. In 22 of 32 teeth with severe periodontal disease and vital pulps, no distinct inflammatory cell accumulations were observed in any portion of the pulp when there was an intact or minimally damaged cementum layer in the corresponding areas. Intravascular bacterial aggregations were detected in pulp blood vessels in 6 teeth with symptomatic pulpitis and severe periodontal disease, which had not reached the root apex in 4 of them. Focal areas of infection and varying accumulations of acute and chronic inflammatory cells were observed throughout the pulp tissue and surrounding these infected blood vessels. When the periodontal pocket reached the apex of single-rooted teeth, the entire canal space was necrotic and colonized by bacteria, often forming biofilms. In multirooted teeth, the pulp response varied according to the root(s) affected. Intrapulpal calcifications were observed in 91% of the teeth. The pulp and cementum of the control teeth showed no pathologic changes or bacteria. ConclusionsThe pulp showed a significantly detectable response when the cementum coverage was lost or when the periodontal pocket reached the root apex. In the former condition, the pulp response was usually discrete, whereas in the latter, severe reactions usually developed. In some teeth, vessels with a compromised blood flow may serve as avenues for bacteria to invade the pulp via apical or lateral foramina. This indicates that in some teeth the pulp may undergo severe inflammation and necrosis even before the periodontal disease reaches the apical root segment.

Dental microfracture detection using wavelet features and machine learning.

Microfractures (cracks) are the third most common cause of tooth loss in industrialized countries. If they are not detected early, they continue to progress until the tooth is lost. Cone beam computed tomography (CBCT) has been used to detect microfractures, but has had very limited success. We propose an algorithm to detect cracked teeth that pairs high resolution (hr) CBCT scans with advanced image analysis and machine learning. First, microfractures were simulated in extracted human teeth (n=22). hr-CBCT and microCT scans of the fractured and control teeth (n=14) were obtained. Wavelet pyramid construction was used to generate a phase image of the Fourier transformed scan which were fed to a U-Net deep learning architecture that localizes the orientation and extent of the crack which yields slice-wise probability maps that indicate the presence of microfractures. We then examine the ratio of high-probability voxels to total tooth volume to determine the likelihood of cracks per tooth. In microCT and hr-CBCT scans, fractured teeth have higher numbers of such voxels compared to control teeth. The proposed analytical framework provides a novel way to quantify the structural breakdown of teeth, that was not possible before. Future work will expand our machine learning framework to 3D volumes, improve our feature extraction in hr-CBCT and clinically validate this model. Early detection of microfractures will lead to more appropriate treatment and longer tooth retention.

Effects of mineral trioxide aggregate and platelet-rich fibrin on histological results of direct pulp capping in dogs

Aim: This study aimed to compare the effects of mineral trioxide aggregate (MTA) and platelet-rich fibrin (PRF) on histological results of direct pulp capping (DPC) in dogs. Methodology: In this animal study, 36 class V cavities were prepared in the incisors of adult healthy mixed-breed dogs. The teeth were then randomly divided into three groups. No material was placed in the control teeth. MTA and PRF were placed on the exposure site in groups 2 and 3, respectively. After 2 months, the teeth were extracted under general anesthesia and were histological analyzed regarding inflammation, calcified bridge formation and necrosis. Data were analyzed using non-parametric Kruskal-Wallis test. Pairwise comparisons were made using the Mann-Whitney U test. Results: There are no statistically significant differences in terms of pulp inflammation, dentinal bridge formation and necrosis among the treatment groups capping with MTA and PRF. (P Value >0.05), however, PRF and MTA were the same in all parameters, these groups were both significantly superior to the control group. Conclusion: Within the limitations of this study, PRF can be used for DPC as an alternative to MTA.

EFFECT OF LOCAL ADMINISTRATION OF HYALURONIC ACID ON ORTHODONTIC TOOTH MOVEMENT IN A RABBIT MODEL

Introduction: Using a biocompatible material to control tooth movement and enhance anchorage may be a useful method to help the orthodontist to give better treatment results. Objectives: To evaluate the effect of hyaluronic acid (HA) local injection on orthodontic tooth movement. Materials and Methods: The sample size was 15 male New Zealand rabbits. Randomized prospective split mouth trial was conducted on each rabbit. A mesializing force was applied in both sides for 21 days. Group A (control): Saline was injected on day 0. Group B: HA 1% was injected. Tooth movements were measured on 3D models. Histological analysis of alveolar bone modeling was done at the end of the experiment. Results: The quadrant receiving HA showed less amount of tooth movement than that in the control quadrant. Local administration of HA yielded 10% less tooth movement. Histological analysis revealed less resorptive activity in the quadrant receiving HA. Conclusion: There was statistically significant reduction in orthodontic tooth movement magnitude after local HA administration as well as reduction in bone resorptive activity.

Phenotypic features of dentinogenesis imperfecta associated with osteogenesis imperfecta and COL1A2 mutations

Dentinogenesis imperfecta (DI) requires dental treatment. This study investigated the characteristics of DI teeth associated with osteogenesis imperfecta (OI) and COL1A2 mutations. Whole exome and Sanger sequencing were performed. Three primary teeth (called "OIDI teeth") obtained from 3 unrelated COL1A2 patients were investigated and compared with 9 control teeth from age-matched healthy individuals using colorimetry, micro-computed tomography, Knoop microhardness, energy dispersive X-ray spectroscopy, scanning electron microscopy, and histology. All patients were identified with heterozygous glycine substitutions in COL1A2. The COL1A2 mutations, c.1531G>T and c.2027G>T, were de novo, whereas c.3106G>C was inherited. OIDI1, 2, and 3 teeth had a substantial decrease in dentin microhardness and lightness. OIDI2 enamel microhardness was significantly reduced, whereas OIDI1 and 3 had enamel microhardness comparable to that of control individuals. The OIDI1 pulp cavity was large; OIDI2 was narrow; and OIDI3 was obliterated. OIDI1 and 3 had significantly higher carbon levels than those in control individuals. Numerous ectopic calcified masses, sparse and obstructed dentinal tubules, dentin holes, and collagen disorientation were observed. OIDI teeth had reduced lightness and variable pulp morphology. Weak dentin, mineral disproportion, and abnormal ultrastructure could contribute to the brittleness of OIDI teeth and adhesive restoration failure. Here, we expand the phenotypic spectrum of COL1A2 mutations and raise awareness among dentists seeing patients with OI.

Correlation analysis of pre-operative glucose control targets and tooth extraction prognosis in elderly diabetic patients

Objective: To evaluate the prognosis of tooth extraction in elderly mellitus patients with fasting plasma glucose (FPG)>8.88 mmol/L and ≤10.00 mmol/L. Methods: This study was a prospective cohort study. One hundred elderly mellitus patients, 53 males and 47 females, aged 65-95 years old (75.8±8.0), were recruited for tooth extraction at the ECG monitoring out-patient clinic in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from Oct 2018 to Oct 2019. Fifty cases were selected into the observation group with FPG>8.88 mmol/L and ≤10.00 mmol/L before tooth extraction, while the rest 50 cases were in the control group with FPG≤8.88 mmol/L. The levels of glycosylated hemoglobin (HbA1c) of patients were required to be≤8.5% before tooth extraction in both groups. Post-operative pain, swelling, pus discharge, fistula at local sockets and systemic fever were observed 24 h and 1 week after the extraction. The healing of tissues around the extraction socket was observed 1 month after operation. The correlation between blood glucose control target and the effects of socket healing before and after tooth extraction was analyzed statistically using SPSS 25.0 software. Results: The pre-operative FPG levels of observation group and control group were (6.92±0.99) and (9.88± 0.68) mmol/L, and HbAlc levels were (6.76±0.83)% and (7.69±0.75)%, respectively. There were no significant differences in age, gender, diabetes history, extraction position, gingival index and tooth looseness between the two groups (P>0.05). Ninety-four percent (47/50 in each group) of patients in the two groups healed well within 24 h after the extraction. There were 6 patients, 3 in each of the two groups, complained tolerable post-operative pain in tooth extraction sockets. However, no redness, swelling and pus in the surrounding tissues were observed. There was no statistical difference of socket healing after the extractions between two groups (P>0.05). Conclusions: The pre-operative levels of FPG≤10.00 mmol/L and HbA1c≤8.5% are reasonable creteria for evaluating tooth extraction risk for the elderly diabetic patients.

Chemical cleansing as an adjunct to subgingival instrumentation with ultrasonic and hand devices in deep periodontal pockets: a randomized controlled study.

PurposeThe aim of this randomized clinical trial was to assess whether chemical cleansing using a sulfonic/sulfuric acid gel solution (HBX) as an adjunct to scaling and root planing (SRP) resulted in a decrease in residual plaque and calculus in deep periodontal pockets compared to SRP alone.MethodsFifty-six patients with 56 hopeless posterior teeth, scheduled for extraction due to severe periodontitis, were enrolled in this study. Each tooth was randomly assigned to 1 of the 2 experimental procedures. The test teeth were subjected to the irrigation of the subgingival area with HBX for 2 minutes, followed by SRP with hand and ultrasonic instruments for 14 minutes, and then extracted. The control teeth received only mechanical instrumentation before extraction. Residual biofilm was evaluated on photographs and measured as total area and percentage of root surface covered by remaining plaque (RP) or calculus (RC) after treatment.ResultsThe initial pocket depth (PD) and total subgingival root surface area were similar between the 2 treatment groups. After treatment, the total subgingival root area covered by RP and RC was statistically significantly larger (P<0.001) in the control group than in the test group. The test teeth showed a lower percentage of RP, but a higher percentage of RC than the control teeth (both P<0.001). Complete calculus removal was achieved in 42% of the control teeth surfaces and in 25% of the test teeth surfaces for a PD of 4 mm.ConclusionsThe additional chemical cleansing with HBX resulted in a statistically significant improvement in bacterial plaque removal during SRP of deep pockets, but it was not effective in reducing calculus deposits.

Efficacy of PerioTabs, a NitrAdine-based gingiva brushing solution, on periodontally affected patients treated with fixed partial dentures: a randomized controlled study.

Objectives: Recent data show that teeth prepared with horizontal finishing lines supporting crowns and fixed partial dentures present more periodontal disorders than untreated control teeth. Several studies have shown that NitrAdine (bonyf) induces a significant reduction of dental biofilm. The aim of this study was to demonstrate that 10-day use of PerioTabs (bonyf), a NitrAdine-based gingiva brushing solution, is effective in treating gingival inflammation of prosthodontic patients. Method and materials: Forty-nine subjects were instructed to brush their teeth, gingivae, and prostheses with the PerioTabs solution for 10 days (treatment group) and 49 with any toothpaste (control group). The initial and 11-day Plaque Index and Bleeding Index were recorded. A five-point Likert scale was used to evaluate the level of patient satisfaction. The Shapiro-Wilk statistical test was used to compare the results for the two groups. Results: Highly significant differences between the treatment and control group (P < .001) for the Plaque Index and Bleeding Index resulted. The treatment group patients' satisfaction was high: 31 (63.3%) reported the highest level, 5, on the Likert scale, and 18 (36.7%) declared they were satisfied (level 4). Conclusions: The use of a NitrAdine-based gingiva brushing solution (PerioTabs) was effective in reducing the gingival inflammation in periodontally affected patients treated with fixed partial dentures. Clinical relevance: The NitrAdine-based gingiva brushing solution (PerioTabs) was highly accepted by the patients and seems to be a promising alternative to the solutions widely used.

Success of resin infiltration treatment on interproximal tooth surfaces in young adults-A practice-based follow-up study.

ObjectivesArresting active initial caries lesions is part of the modern caries controlling system. Resin infiltration (RI) system has been found a promising method in arresting interproximal initial lesions. The aim was to investigate whether RI arrests progression of active caries lesions.Materials and methodsParticipants (n = 20) of the retrospective study were patients in the Dental Teaching Unit, City of Oulu, Finland, mean age 26 years (SD5.2). Indication for RI was radiographically diagnosed progressing (ICDAS 1–3) interproximal lesions (n = 54). RI treatments were performed in 2015–2017. Controls were initial lesions in the same bitewing radiographs without RI or other treatment (n = 24). For analyzes teeth were categorized as lower and upper premolars and molars. The change in lesions during the follow‐up period was recorded surface wise as follows: deterioration / improvement from ICDAS score 3/improvement from ICDAS score 2/improvement per se/at follow‐up, lesion was less diffuse/no change. The changes in each tooth surface were analyzed between RI intervention and control teeth by using Chi‐square test. Proportions of successful and failed surfaces were given.ResultsThe mean length of follow‐up period was 17.4 m (SD7.2). Arresting of caries lesions (ICDAS scores 2 and 3) was distinctly better in RI group (63.0%) compared with the controls (29.1%). The situation progressed among 29.2% of the controls whereas the respective proportion among the intervention group was 14.8%. Progression of lesions was more distinct in all tooth groups in the control group. Outcome was successful despite the lesion depth.ConclusionsResin infiltration seems effective in arresting progression of initial caries lesions with monitoring period of 1.5 years.

Inhibitory Potential of Mangiferin on Glucansucrase Producing Streptococcus mutans Biofilm in Dental Plaque

Glucansucrase secreted by Streptococcus mutans and composed of virulence genes alters oral microbiota, creating adherent environment for structural bacteria colony forming dental biofilm. The present investigation studied the inhibitory and binding potentials of mangiferin against S. mutans and its enzyme glucansucrase implicated in biofilm formation. Antibacterial activity against planktonic S. mutans was carried out. Using reverse transcription PCR, the expression of crucial virulence genes, gtfB, gtfC, gtfD, gbpB, and comDE were determined. The effect of mangiferin on teeth surfaces biofilm was ascertained by scanning electron microscopy (SEM). Docking analysis of S. mutans glucansucrase and mangiferin revealed the binding energy of −7.35 and ten hydrogen interactions. Antibacterial study revealed that mangiferin was not lethal to planktonic S. mutans, but a concentration-dependent inhibition of glucansucrase activity was observed. The inhibitory effect of water-insoluble glucan synthesis was apparently more marked relative to water-soluble glucan synthesis attenuation. Mangiferin significantly downregulated the expression of the virulence genes, indicating a mechanism involving glucanotranferases, specifically inhibiting colony formation by attenuating bacterial adherence. SEM images revealed that S. mutans biofilm density was scanty in mangiferin treated teeth compared to non-treated control teeth. Our data therefore suggest that mangiferin inhibited S. mutans biofilms formation by attenuating glucansucrase activities without affecting bacteria growth.

Oral Fine Motor Control of Teeth Treated with Endodontic Microsurgery: A Single-Blinded Case-control Study

IntroductionPeriodontal mechanoreceptors (PMRs) are refined neural receptors present in abundance at the root apex and have a pivotal role in oral fine motor control. This case-control study aimed to evaluate the oral fine motor control of teeth treated with endodontic microsurgery (EMS) in comparison with the control teeth using a standardized behavioral biting task. MethodsFourteen eligible participants performed 5 trials of an oral fine motor control task that involved holding and splitting half of a peanut positioned on a force transducer with their EMS treated tooth and its contralateral control incisor tooth (28 teeth in total). The outcome variables were the mean food holding force, intra- and intertrial variability of the holding force, food splitting force, splitting duration, and the frequency of the stepwise splitting phase. The data were analyzed with parametric and nonparametric tests. ResultsThe results showed no statistically significant differences in the holding force, inter- and intratrial variability of the holding force, splitting force, or splitting duration between the teeth treated with EMS and the control (P > .05). However, there was a significantly higher frequency of stepwise ramp increase during the splitting phase with EMS treated teeth compared with the control (48% and 37%, respectively; P < .05). ConclusionsEMS treated teeth showed similar force regulation and oral fine motor control as the contralateral control. The findings of this study suggest that EMS treatment does not perturb the sensory information of PMRs and maintains the force regulation and oral fine motor control of the teeth.

Dental defects in the primary dentition associated with hypophosphatasia from biallelic ALPL mutations.

ALPL encodes tissue-nonspecific alkaline phosphatase (TNAP), an enzyme expressed in bone, teeth, liver, and kidney. ALPL loss-of-function mutations cause hypophosphatasia (HPP), an inborn error-of-metabolism that produces skeletal and dental mineralization defects. Case reports describe widely varying dental phenotypes, making it unclear how HPP comparatively affects the three unique dental mineralized tissues: enamel, dentin, and cementum. We hypothesized that HPP affected all dental mineralized tissues and aimed to establish quantitative measurements of dental tissues in a subject with HPP. The female proband was diagnosed with HPP during childhood based on reduced alkaline phosphatase activity (ALP), mild rachitic skeletal effects, and premature primary tooth loss. The diagnosis was subsequently confirmed genetically by the presence of compound heterozygous ALPL mutations (exon 5: c.346G>A, p.A116T; exon 10: c.1077C>G, p.I359M). Dental defects in 8 prematurely exfoliated primary teeth were analyzed by high resolution micro-computed tomography (micro-CT) and histology. Similarities to the Alpl-/- mouse model of HPP were identified by additional analyses of murine dentoalveolar tissues. Primary teeth from the proband exhibited substantial remaining root structure compared to healthy control teeth. Enamel and dentin densities were not adversely affected in HPP vs. control teeth. However, analysis of discrete dentin regions revealed an approximate 10% reduction in the density of outer mantle dentin of HPP vs. control teeth. All 4 incisors and the molar lacked acellular cementum by micro-CT and histology, but surprisingly, 2 of 3 prematurely exfoliated canines exhibited apparently normal acellular cementum. Based on dentin findings in the proband's teeth, we examined dentoalveolar tissues in a mouse model of HPP, revealing that the delayed initiation of mineralization in the incisor mantle dentin was associated with a broader lack of circumpulpal dentin mineralization. This study describes a quantitative approach to measure effects of HPP on dental tissues. This approach has uncovered a previously unrecognized novel mantle dentin defect in HPP, as well as a surprising and variable cementum phenotype within the teeth from the same HPP subject.

Qualitative and quantitative assessment of the potential effect of cigarette smoking on enamel of human smokers’ teeth

ObjectiveThis study aimed to examine the potential changes in enamel surface of human smokers’ teeth. Materials and methodsForty extracted permanent, human, noncarious anterior teeth were used in this study. Half of these teeth were obtained from heavy smokers, while the other half of teeth were collected from nonsmokers (control teeth). The teeth were then subjected for scanning electron microscopic examination together with energy dispersive X ray and micro-hardness analysis to evaluate the qualitative and quantitative effect of smoking respectively. ResultsSEM of smokers’ teeth showed variable degrees of destruction from small areas of demineralization as holes and pits to destruction and deterioration of the organizational pattern of the rod substance. Moreover, areas of defective remineralization were detected. The microhardness, calcium and phosphorus weight % significantly decreased whereas the Ca/P ratio was significantly increased. ConclusionCigarette smoking adversely affected the ultrastructure and mechanical properties of enamel and even hindered the normal remineralization process thus cigarette smoking cessation should be promoted in the dental office daily practices.

Could applying gels containing chlorhexidine, epigallocatechin-3-gallate, or proanthocyanidin to control tooth wear progression improve bond strength to eroded dentin?

Statement of problemA consensus on whether or how to treat eroded dentin to bond to composite resins is lacking. The role of gels containing chlorhexidine (CHX), epigallocatechin-3-gallate (EGCG), and proanthocyanidin (PAC) in controlling erosive wear progression needs to be evaluated for bonding. PurposeThe purpose of this in vitro study was to evaluate the effect of gels containing antiproteolytic agents (CHX or EGCG) or an antiproteolytic and also collagen crosslinking agent (PAC) to control tooth wear progression on the microtensile bond strength (μTBS) of an adhesive system plus a composite resin to simulated eroded dentin. Material and methodsSuperficial occlusal dentin surfaces obtained from sectioned third molars were ground with SiC paper (600-grit; 1 minute; N-normal dentin) or subsequently submitted to an initial erosive challenge (Coca-Cola; 5 minutes). They then received one of the following treatments: application of a placebo (P), a 0.12% CHX digluconate, an EGCG at 400 μM, or a 10% PAC gel (vehicle: hydroxyethylcellulose, propylene glycol, methylparaben, imidazolidinyl urea, and deionized water; active principle: as per the experimental groups when applicable) or no treatment (C: control). Initially demineralized dentin was also submitted to pH cycling (Coca-Cola; 5 minutes, 3×/day, 5 days) to simulate eroded dentin (E). After acid etching all the specimens, adhesive Adper Single Bond 2 was applied, and composite resin (Filtek Z350 XT) was placed. After 24 hours storage in distilled water at 37 °C, the specimens were sectioned into beams, and the μTBS was tested at 0.5 mm/minute. The μTBS values obtained were evaluated considering each tooth as an experimental unit, and 2-way ANOVA and the Tukey post hoc test for multiple comparisons were applied (α=.05). ResultsImmediate μTBS values for the eroded dentin were always lower than those for the normal dentin, irrespective of whether any of the gels were applied for wear control. ConclusionsCHX, EGCG, PAC, and placebo gels, applied after the initial demineralization and before the pH cycling to simulate the eroded dentin, had a similar effect on the μTBS of the adhesive system plus the composite resin to simulated eroded dentin when compared with nonapplication (control).